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Epilepsy

Epilepsy is a chronic brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification disorder marked by recurrent and unprovoked seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures. These seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures can be classified as focal or generalized and idiopathic Idiopathic Dermatomyositis or secondary to another condition. Clinical presentation correlates to the classification of the epileptic disorder. Diagnosis is confirmed with EEG EEG Seizures. While some epileptic disorders resolve over time, many require lifelong antiepileptic medication for management or, in some refractory cases, surgical procedures.

Last updated: Jun 23, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

Epilepsy is a chronic brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification disorder marked by recurrent and unprovoked seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures.

  • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures are episodes of neurologic dysfunction caused by abnormal excitatory activities of neurons Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. Nervous System: Histology and are characterized by sudden changes in senses, perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment, motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology activity, or behavior. 
  • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures triggered by reversible or avoidable causes do not classify as epilepsy and do not require treatment with antiepileptic medications.

Epidemiology

  • Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency: approximately 65 million people worldwide  
    • Lifetime prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency in the United States: 7.6 per 1000 individuals
    • In older adults: 2%–5% in adults > 60 years of age (3–4 times higher than for younger adults)
  • Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: bimodal distribution Bimodal distribution Measures of Central Tendency and Dispersion with peaks in the young and old (< 1 year and > 70 years) 
    • In children: 0.5%–8% per 1000 person-years
    • New-onset epilepsy in older adults: 1–3 per 1000 person-years

Classification

Several features may be used to classify epilepsy, which is useful in considering management options. 

  • Features:
    • Seizure types
    • EEG EEG Seizures findings: 
      • Generalized onset
      • Local or focal onset 
    • Age at onset
    • Course 
    • Associated clinical features
  • Underlying pathophysiology 
    • Idiopathic Idiopathic Dermatomyositis (primary):
      • Presumed to be genetic
    • Symptomatic (secondary):
      • Due to structural changes in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification
      • Described by location of the lesion (e.g., temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy epilepsy)
  • Most common epilepsy syndromes:
    • Idiopathic Idiopathic Dermatomyositis/generalized onset:
      • Childhood absence epilepsy
      • Juvenile absence epilepsy
      • Juvenile myoclonic epilepsy 
    • Idiopathic Idiopathic Dermatomyositis/focal onset: benign Benign Fibroadenoma childhood epilepsy with centrotemporal spikes (BECTS) 
    • Symptomatic/generalized onset
      • Infantile spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy (West syndrome)
      • Lennox-Gastaut syndrome epilepsy
    • Symptomatic/focal onset: temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy epilepsy

Clinical Presentation

Epilepsy syndromes relate to seizure types and are classified primarily using the clinical history; classification requires input from a family member or witness to the seizure in addition to history from the affected individual.

Focal epilepsies

  • Specific epileptogenic origin in a certain region of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification limited to 1 hemisphere
  • Most common type of epilepsy in all age groups
  • Presents with a set of symptoms related to the region of origin
  • Can become generalized secondarily
  • Can be caused by any local structural alteration (e.g., scars due to ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage, vessel malformations)
  • Types of focal epilepsies:
    • BECTS: 
      • Idiopathic Idiopathic Dermatomyositis
      • Also called rolandic epilepsy
      • Age at onset: 1–16 years ( mean Mean Mean is the sum of all measurements in a data set divided by the number of measurements in that data set. Measures of Central Tendency and Dispersion, 7–9 years)
      • 1-sided clonic seizure with strong salivation, especially at night
      • Often involves the face
      • Upper extremity motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology activity is common
      • No altered consciousness
      • Associated with language function problems
      • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures stop before adolescence.
    • Temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy epilepsy: 
      • Age at onset: 10–30 years (80% present before age 16)
      • Most common type of focal epilepsy
      • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures start with temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy aura Aura Reversible neurological phenomena that often precede or coincide with headache onset. Migraine Headache ( déjà vu Déjà Vu Neurological Examination) and progress to altered awareness with automatisms.  
      • Causes include hippocampal sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor, encephalitis Encephalitis Encephalitis is inflammation of the brain parenchyma caused by an infection, usually viral. Encephalitis may present with mild symptoms such as headache, fever, fatigue, and muscle and joint pain or with severe symptoms such as seizures, altered consciousness, and paralysis. Encephalitis, head trauma Head trauma Head trauma occurs when external forces are directed to the skull and brain structures, resulting in damage to the skull, brain, and intracranial structures. Head injuries can be classified as open (penetrating) or closed (blunt), and primary (from the initial trauma) or secondary (indirect brain injury), and range from mild to severe and life-threatening. Head Trauma, hamartomas, glial tumors, vascular and congenital Congenital Chorioretinitis malformations, and perinatal injury.
      • Most common cause of refractory focal epilepsy in adults: temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy epilepsy associated with hippocampal sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor
    • Focal seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures with impaired awareness (previously known as complex partial seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures):
      • Focal motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
      • Focal sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
      • Autonomic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
    • Focal seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures without impaired awareness

Generalized epilepsies

  • Assume a widespread pathology ( affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment the whole brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification)
  • Idiopathic Idiopathic Dermatomyositis generalized epilepsies account for the greatest number of occurrences:
    • Childhood absence epilepsy (also known as petit mal epilepsy or pyknolepsy):
      • Age at onset: 3–10 years
      • Characterized by brief staring episodes with behavioral arrest 
      • May occur tens to hundreds of times per day 
      • May be provoked by hyperventilation Hyperventilation A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide. Respiratory Alkalosis 
      • Strong family history Family History Adult Health Maintenance
      • Remission Remission A spontaneous diminution or abatement of a disease over time, without formal treatment. Cluster Headaches in 2–6 years
    • Juvenile absence epilepsy:
      • Similar to childhood absence epilepsy but with a later onset (ages 10–16)
      • About 40% of individuals are not permanently free of seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures.
      • Lifelong antiepileptic medication may be required.  
    • Juvenile myoclonic epilepsy: 
      • Age at onset: 12–20 years
      • Myoclonus Myoclonus Involuntary shock-like contractions, irregular in rhythm and amplitude, followed by relaxation, of a muscle or a group of muscles. This condition may be a feature of some central nervous system diseases; (e.g., epilepsy-myoclonic). Nocturnal myoclonus is the principal feature of the nocturnal myoclonus syndrome. Neurological Examination is always present.
      • Generalized tonic-clonic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures 
      • Absence seizures Absence seizures Brief period of unresponsiveness thats lasts about 4–30 seconds and can occur multiple times per day Seizures in Children may also be seen. 
      • May be provoked by sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep deprivation and photic stimulation
      • Requires lifelong epileptic therapy.
    • Generalized motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures (grand mal epilepsy): generalized tonic-clonic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures with great irregularity
  • Symptomatic generalized epilepsies:
    • Most often caused by early childhood brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification damage due to hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage or metabolic diseases. 
    • Infantile spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy (West syndrome): 
      • Occurs in the 1st year of life 
      • Triad of infantile spasm, hypsarrhythmia ( EEG EEG Seizures pattern), and psychomotor delay
      • Epileptic spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy occur in clusters during sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep transition. 
      • Etiologies: perinatal hypoxic injury, brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification malformations, tuberous sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor, Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21), metabolic disorders 
      • Poor prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas with likely neurodevelopmental delay
    • Lennox-Gastaut syndrome:
      • Age at onset: 2–8 years 
      • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures are generally astatic (falling), absence, and/or generalized tonic-clonic.
      • Can develop from West syndrome or late generalized brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification damage
      • Poor prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas with severe developmental delay and medically nonrefractory seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures 

Diagnosis

Diagnosis is based on history, lab results, and EEG EEG Seizures findings.

Initial evaluation

  • History and exam must determine if seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures are provoked or unprovoked.
  • Neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant indicated for initial seizure event: 
    • Noncontrast CT 
    • Brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification MRI

Lab testing

  • For a 1st seizure: 
    • Chemistries: electrolytes Electrolytes Electrolytes are mineral salts that dissolve in water and dissociate into charged particles called ions, which can be either be positively (cations) or negatively (anions) charged. Electrolytes are distributed in the extracellular and intracellular compartments in different concentrations. Electrolytes are essential for various basic life-sustaining functions. Electrolytes, glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance, calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes, magnesium Magnesium A metallic element that has the atomic symbol mg, atomic number 12, and atomic weight 24. 31. It is important for the activity of many enzymes, especially those involved in oxidative phosphorylation. Electrolytes, BUN/creatinine, liver function tests Liver function tests Liver function tests, also known as hepatic function panels, are one of the most commonly performed screening blood tests. Such tests are also used to detect, evaluate, and monitor acute and chronic liver diseases. Liver Function Tests
    • CBC
    • Urinalysis Urinalysis Examination of urine by chemical, physical, or microscopic means. Routine urinalysis usually includes performing chemical screening tests, determining specific gravity, observing any unusual color or odor, screening for bacteriuria, and examining the sediment microscopically. Urinary Tract Infections (UTIs) in Children
    • Toxicology screen
  • Pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care test in women of childbearing years, as pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care may affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment treatment decisions
  • Serum lactate:
    • If episode was not witnessed 
    • Elevated in the 1st 2 hours after a seizure
    • Differentiates seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures from syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope or psychogenic nonepileptic seizure (PNES)

Electroencephalography Electroencephalography Seizures ( EEG EEG Seizures)

EEG EEG Seizures is a test to monitor the electrical sensitivity of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification.

Types of normal electrical activity on an electroencephalogram

Types of normal electrical activity on an electroencephalogram

Image by Lecturio.
  • Gold standard for diagnosing epilepsy 
  • Indicated for those who do not return to baseline consciousness in the emergent setting
  • Included as part of the workup for new-onset seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
  • More specific in adults than in children
  • Procedure:
    • Electrodes Electrodes Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum. Electrocardiogram (ECG) are placed on the surface of the scalp and connected to a computer, which detects brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification electrical activity.
    • Provocation factors can be used to show epileptogenic potentials: photic stimulation, hyperventilation Hyperventilation A pulmonary ventilation rate faster than is metabolically necessary for the exchange of gases. It is the result of an increased frequency of breathing, an increased tidal volume, or a combination of both. It causes an excess intake of oxygen and the blowing off of carbon dioxide. Respiratory Alkalosis, or sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep deprivation
  • Video-EEG monitoring is the standard test for:
    • Classifying the type of seizure or syndrome
    • Diagnosing PNES or pseudoseizures (psychiatric-related)
Electrical activity of the brain on an eeg during a seizure

Electrical activity of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification on an EEG EEG Seizures during a seizure

Image by Lecturio.
Electrode placement of 21 electrodes of international 10-20 system for eeg

Electrode placements for standard EEG EEG Seizures

Image: “21 electrodes Electrodes Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum. Electrocardiogram (ECG) of International 10-20 system for EEG EEG Seizures” by トマトン124. License: Public Domain

Important EEG EEG Seizures findings with respective epilepsy syndromes

  • BECTS: centrotemporal spikes activated by sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep 
  • Temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy epilepsy: temporal lobe Temporal lobe Lower lateral part of the cerebral hemisphere responsible for auditory, olfactory, and semantic processing. It is located inferior to the lateral fissure and anterior to the occipital lobe. Cerebral Cortex: Anatomy spikes or sharp waves 
  • Childhood and juvenile absence epilepsy:
  • Juvenile myoclonic epilepsy (JME): 
    • 4–6 Hz generalized polyspike and wave discharges
    • Often frontal Frontal The bone that forms the frontal aspect of the skull. Its flat part forms the forehead, articulating inferiorly with the nasal bone and the cheek bone on each side of the face. Skull: Anatomy predominance
  • Infantile spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy (West syndrome): 
    • Hypsarrhythmia (interictal EEG EEG Seizures pattern of very-high-amplitude, random, slow waves and spikes in all cortical areas)
    • Chaotic, irregular, disorganized interictal pattern
  • Lennox-Gastaut syndrome: slow spike–wave complexes (< 2.5 Hz)
  • Creutzfeldt-Jakob disease Creutzfeldt-Jakob Disease A rare transmissible encephalopathy most prevalent between the ages of 50 and 70 years. Affected individuals may present with sleep disturbances, personality changes, ataxia; aphasia, visual loss, weakness, muscle atrophy, myoclonus, progressive dementia, and death within one year of disease onset. A familial form exhibiting autosomal dominant inheritance and a new variant cjd (potentially associated with bovine spongiform encephalopathy) have been described. Pathological features include prominent cerebellar and cerebral cortical spongiform degeneration and the presence of prions. Transmissible Spongiform Encephalopathies: triphasic waves

Management

The choice of antiseizure medications is based on the type of epilepsy syndrome. Starting treatment after a single unprovoked seizure remains controversial.

Antiepileptic medications

  • Determine whether epilepsy is partial or generalized. 
  • Goals of treatment:
    • Seizure-free status 
    • No adverse effects
Table: Antiepileptic drugs by mechanism of action
Name Mechanism of action Indication Side effects
Phenobarbital Phenobarbital A barbituric acid derivative that acts as a nonselective central nervous system depressant. It potentiates gamma-aminobutyric acid action on gaba-a receptors, and modulates chloride currents through receptor channels. It also inhibits glutamate induced depolarizations. First-Generation Anticonvulsant Drugs Enhances GABA-mediated inhibition of synaptic transmission Synaptic transmission The communication from a neuron to a target (neuron, muscle, or secretory cell) across a synapse. In chemical synaptic transmission, the presynaptic neuron releases a neurotransmitter that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across electrical synapses. Synapses and Neurotransmission All types of epilepsy except absence
  • Sedation
  • Induces cytochrome P450 Cytochrome P450 A superfamily of hundreds of closely related hemeproteins found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (mixed function oxygenases). In animals, these p450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (biotransformation). They are classified, according to their sequence similarities rather than functions, into cyp gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the cyp1, cyp2, and cyp3 gene families are responsible for most drug metabolism. Drug-induced Liver Injury enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes for drug interactions
Phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs Inhibits Na channel activation to inhibit neurotransmission Neurotransmission The communication from a neuron to a target (neuron, muscle, or secretory cell) across a synapse. In chemical synaptic transmission, the presynaptic neuron releases a neurotransmitter that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across electrical synapses. Synapses and Neurotransmission Focal seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures and generalized tonic-clonic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
  • Long-term use associated with osteoporosis Osteoporosis Osteoporosis refers to a decrease in bone mass and density leading to an increased number of fractures. There are 2 forms of osteoporosis: primary, which is commonly postmenopausal or senile; and secondary, which is a manifestation of immobilization, underlying medical disorders, or long-term use of certain medications. Osteoporosis, peripheral neuropathy Neuropathy Leprosy, and gingival hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation
  • Induces CYP450: drug interactions
Fosphenytoin Fosphenytoin First-Generation Anticonvulsant Drugs Same as phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs Same as phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs Less risk of hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension and cardiac dysfunction then with phenytoin Phenytoin An anticonvulsant that is used to treat a wide variety of seizures. The mechanism of therapeutic action is not clear, although several cellular actions have been described including effects on ion channels, active transport, and general membrane stabilization. Phenytoin has been proposed for several other therapeutic uses, but its use has been limited by its many adverse effects and interactions with other drugs. First-Generation Anticonvulsant Drugs
Carbamazepine Carbamazepine A dibenzazepine that acts as a sodium channel blocker. It is used as an anticonvulsant for the treatment of grand mal and psychomotor or focal seizures. It may also be used in the management of bipolar disorder, and has analgesic properties. First-Generation Anticonvulsant Drugs Works on voltage-gated Na channels Voltage-gated Na+ channels A family of membrane proteins that selectively conduct sodium ions due to changes in the transmembrane potential difference. They typically have a multimeric structure with a core alpha subunit that defines the sodium channel subtype and several beta subunits that modulate sodium channel activity. Cardiac Physiology to inhibit synaptic transmission Synaptic transmission The communication from a neuron to a target (neuron, muscle, or secretory cell) across a synapse. In chemical synaptic transmission, the presynaptic neuron releases a neurotransmitter that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across electrical synapses. Synapses and Neurotransmission Focal and secondary generalized seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
  • Hyponatremia Hyponatremia Hyponatremia is defined as a decreased serum sodium (sNa+) concentration less than 135 mmol/L. Serum sodium is the greatest contributor to plasma osmolality, which is very tightly controlled via antidiuretic hormone (ADH) release from the hypothalamus and by the thirst mechanism. Hyponatremia
  • Agranulocytosis Agranulocytosis A decrease in the number of granulocytes; (basophils; eosinophils; and neutrophils). Lincosamides
  • Induces CYP450 enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes
Lamotrigine Lamotrigine A phenyltriazine compound, sodium and calcium channel blocker that is used for the treatment of seizures and bipolar disorder. Second-Generation Anticonvulsant Drugs Blocks excitatory Na ion channels Channels The Cell: Cell Membrane Focal and generalized epilepsy; safest antiepileptic drug during pregnancy Pregnancy The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth. Pregnancy: Diagnosis, Physiology, and Care
Ethosuximide Ethosuximide An anticonvulsant especially useful in the treatment of absence seizures unaccompanied by other types of seizures. First-Generation Anticonvulsant Drugs Works on T-type Ca CA Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts) channel to decrease burst firing of thalamocortical neurons Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. Nervous System: Histology Absence seizures Absence seizures Brief period of unresponsiveness thats lasts about 4–30 seconds and can occur multiple times per day Seizures in Children
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
  • Blood dyscrasias
Gabapentin Gabapentin A cyclohexane-gamma-aminobutyric acid derivative that is used for the treatment of partial seizures; neuralgia; and restless legs syndrome. Second-Generation Anticonvulsant Drugs Acts on voltage-gated Ca CA Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding. Condylomata Acuminata (Genital Warts) channels Channels The Cell: Cell Membrane, which increase inhibitory tone Focal seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
  • Somnolence
  • Weight gain
Levetiracetam Levetiracetam A pyrrolidinone and acetamide derivative that is used primarily for the treatment of seizures and some movement disorders, and as a nootropic agent. Second-Generation Anticonvulsant Drugs Modifies synaptic protein SV2A Focal and generalized epilepsy; often used as 1st-line therapy; well tolerated
  • Somnolence
  • Ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia
  • Irritability
Topiramate Topiramate A sulfamate-substituted fructose analog that was originally identified as a hypoglycemic agent. It is used for the treatment of epilepsy and migraine disorders, and may also promote weight loss. Second-Generation Anticonvulsant Drugs Blocks voltage-gated Na channels Voltage-gated Na+ channels A family of membrane proteins that selectively conduct sodium ions due to changes in the transmembrane potential difference. They typically have a multimeric structure with a core alpha subunit that defines the sodium channel subtype and several beta subunits that modulate sodium channel activity. Cardiac Physiology; also inhibits carbonic anhydrase Carbonic anhydrase A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of carbon dioxide from the tissues to the lung. Carbonic Anhydrase Inhibitors, causing acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification → partial protection against seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures Primary generalized onset tonic-clonic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
  • Fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
  • Cognitive problems
  • Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, appetite suppression Suppression Defense Mechanisms
  • Kidney stones Kidney stones Nephrolithiasis is the formation of a stone, or calculus, anywhere along the urinary tract caused by precipitations of solutes in the urine. The most common type of kidney stone is the calcium oxalate stone, but other types include calcium phosphate, struvite (ammonium magnesium phosphate), uric acid, and cystine stones. Nephrolithiasis
Valproic acid Valproic acid A fatty acid with anticonvulsant and anti-manic properties that is used in the treatment of epilepsy and bipolar disorder. The mechanisms of its therapeutic actions are not well understood. It may act by increasing gamma-aminobutyric acid levels in the brain or by altering the properties of voltage-gated sodium channels. First-Generation Anticonvulsant Drugs Multiple Focal seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures with impaired awareness, generalized and absence seizures Absence seizures Brief period of unresponsiveness thats lasts about 4–30 seconds and can occur multiple times per day Seizures in Children
  • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics/ vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
  • Weight gain
  • Hair loss
  • Hepatotoxic (hepatic inhibitor)
  • Pancreatitis Pancreatitis Inflammation of the pancreas. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of chronic pancreatitis. The two most common forms of acute pancreatitis are alcoholic pancreatitis and gallstone pancreatitis. Acute Pancreatitis
  • Teratogenic

Surgical therapies

  • Goals of treatment: 
    • Eliminate the epileptogenic neuronal area. 
    • Minimize neurologic deficit.
    • Increase quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement of life. 
  • Presurgery testing to visualize the focus Focus Area of enhancement measuring < 5 mm in diameter Imaging of the Breast of epileptic activity:
  • Indications for procedures:
    • Refractory seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures despite 1 year of medication therapy with ≥ 2 antiepileptic agents 
    • Well-operable epileptogenic focus Focus Area of enhancement measuring < 5 mm in diameter Imaging of the Breast 
    • Absence of progressive neuronal disease
  • Types of procedures:
    • Open resective surgery:
      • Disconnects epileptic neural networks (e.g., resection of the corticothalamic tract or medial temporal structures)
      • Palliative surgery: corpus callosotomy and multiple subpial transections
    • Radiosurgery: 
      • Noninvasive resective surgery: Gamma Knife or CyberKnife
      • Availability of this procedure is very limited. 
    • Vagal nerve stimulation Vagal nerve stimulation An adjunctive treatment for partial epilepsy and refractory depression that delivers electrical impulses to the brain via the vagus nerve. A battery implanted under the skin supplies the energy. Major Depressive Disorder:
      • For individuals at too high risk for major surgical procedures 
      • Involves placement of electrodes Electrodes Electric conductors through which electric currents enter or leave a medium, whether it be an electrolytic solution, solid, molten mass, gas, or vacuum. Electrocardiogram (ECG) on the left vagal nerve 
  • Seizure preventive measures: 
    • Education of individuals about avoiding common triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency):
      • Sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep deprivation
      • Alcohol use
      • Certain drug types: opioids Opioids Opiates are drugs that are derived from the sap of the opium poppy. Opiates have been used since antiquity for the relief of acute severe pain. Opioids are synthetic opiates with properties that are substantially similar to those of opiates. Opioid Analgesics, stimulants Stimulants Stimulants are used by the general public to increase alertness and energy, decrease fatigue, and promote mental focus. Stimulants have medical uses for individuals with ADHD and sleep disorders, and are also used in combination with analgesics in pain management. Stimulants, other prescription medications
    • In certain countries or states, restraint against operating motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology vehicles

Differential Diagnosis

  • Syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope: brief loss of consciousness and muscle tone Muscle tone The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. Skeletal Muscle Contraction with spontaneous recovery. Syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope has numerous causes but is usually a result of decreased blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure to the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification. Individuals with syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope do not have the postictal Postictal Period after the seizure episode during which the individual is disoriented. Seizures confusion or prolonged duration of unconsciousness, which are prevalent in those with seizure events. Diagnosis is based on history and appropriate cardiac testing or imaging. Management of syncope Syncope Syncope is a short-term loss of consciousness and loss of postural stability followed by spontaneous return of consciousness to the previous neurologic baseline without the need for resuscitation. The condition is caused by transient interruption of cerebral blood flow that may be benign or related to a underlying life-threatening condition. Syncope includes identifying and treating the secondary cause. 
  • Migraine Migraine Migraine headache is a primary headache disorder and is among the most prevalent disorders in the world. Migraine is characterized by episodic, moderate to severe headaches that may be associated with increased sensitivity to light and sound, as well as nausea and/or vomiting. Migraine Headache: primary headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess disorder characterized by unilateral headaches associated with photophobia Photophobia Abnormal sensitivity to light. This may occur as a manifestation of eye diseases; migraine; subarachnoid hemorrhage; meningitis; and other disorders. Photophobia may also occur in association with depression and other mental disorders. Migraine Headache, phonophobia Phonophobia Specific Phobias, and nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics. Migraines may be preceded by sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology auras similar to those seen with seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures; however, epilepsy does not present with severe headaches. Diagnosis is based on history, exam, and imaging to rule out other pathology. Management includes decreasing exposure to triggers Triggers Hereditary Angioedema (C1 Esterase Inhibitor Deficiency) and medications for acute episodes, as well as migraine Migraine Migraine headache is a primary headache disorder and is among the most prevalent disorders in the world. Migraine is characterized by episodic, moderate to severe headaches that may be associated with increased sensitivity to light and sound, as well as nausea and/or vomiting. Migraine Headache prophylaxis Prophylaxis Cephalosporins.
  • Psychogenic nonepileptic seizure (PNES): resembles epileptic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures; however, there is no defined cortical EEG EEG Seizures activity that would be diagnostic in epileptic seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures. Diagnosis of PNES includes subtle physical exam findings that differentiate it from true seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures, such as closed eyes in a convulsing individual with PNES, and video-EEG monitoring. Management includes psychologic therapy such as CBT and possibly medication for anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder.
  • Hypoglycemia Hypoglycemia Hypoglycemia is an emergency condition defined as a serum glucose level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic patients. In nondiabetic patients, there is no specific or defined limit for normal serum glucose levels, and hypoglycemia is defined mainly by its clinical features. Hypoglycemia: emergency condition defined as a serum glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic individuals. There is no specific or defined limit Limit A value (e.g., pressure or time) that should not be exceeded and which is specified by the operator to protect the lung Invasive Mechanical Ventilation for normal serum glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance levels in nondiabetic individuals, and hypoglycemia Hypoglycemia Hypoglycemia is an emergency condition defined as a serum glucose level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic patients. In nondiabetic patients, there is no specific or defined limit for normal serum glucose levels, and hypoglycemia is defined mainly by its clinical features. Hypoglycemia is mainly defined by its clinical features. Hypoglycemia Hypoglycemia Hypoglycemia is an emergency condition defined as a serum glucose level ≤ 70 mg/dL (≤ 3.9 mmol/L) in diabetic patients. In nondiabetic patients, there is no specific or defined limit for normal serum glucose levels, and hypoglycemia is defined mainly by its clinical features. Hypoglycemia may present with adrenergic symptoms and neuroglycopenic symptoms Neuroglycopenic Symptoms Hypoglycemia, including seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures. Diagnosis is based on serum glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance measurement and clinical presentation. Management is with oral glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance, IV dextrose IV dextrose Hypoglycemia, or IM glucagon Glucagon A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal glucagon-like peptides. Glucagon is secreted by pancreatic alpha cells and plays an important role in regulation of blood glucose concentration, ketone metabolism, and several other biochemical and physiological processes. Gastrointestinal Secretions.
  • Narcolepsy Narcolepsy Narcolepsy is a neurological sleep disorder marked by daytime sleepiness and associated with cataplexy, hypnagogic hallucinations, and sleep paralysis. There are 2 types of narcolepsy: type 1 is associated with cataplexy and type 2 has no association with cataplexy. Narcolepsy: neurologic sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep disorder that presents clinically with marked daytime sleepiness Daytime sleepiness Narcolepsy and is associated with cataplexy Cataplexy A condition characterized by transient weakness or paralysis of somatic musculature triggered by an emotional stimulus or physical exertion. Cataplexy is frequently associated with narcolepsy. During a cataplectic attack, there is a marked reduction in muscle tone similar to the normal physiologic hypotonia that accompanies rapid eye movement sleep (sleep, rem). Narcolepsy, hypnagogic hallucinations Hallucinations Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with mental disorders. Schizophrenia, and sleep paralysis Sleep paralysis A common condition characterized by transient partial or total paralysis of skeletal muscles and areflexia that occurs upon awakening from sleep or less often while falling asleep. Stimuli such as touch or sound may terminate the episode, which usually has a duration of seconds to minutes. This condition may occur in normal subjects or be associated with narcolepsy; cataplexy; and hypnagogic hallucinations. The pathophysiology of this condition is closely related to the normal hypotonia that occur during rem sleep. Narcolepsy. Diagnostic criteria are found using sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep studies that show a decrease in REM latency. Management includes good sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep hygiene. Medications that act as CNS stimulants Stimulants Stimulants are used by the general public to increase alertness and energy, decrease fatigue, and promote mental focus. Stimulants have medical uses for individuals with ADHD and sleep disorders, and are also used in combination with analgesics in pain management. Stimulants and antidepressants are used to target the cataplexy Cataplexy A condition characterized by transient weakness or paralysis of somatic musculature triggered by an emotional stimulus or physical exertion. Cataplexy is frequently associated with narcolepsy. During a cataplectic attack, there is a marked reduction in muscle tone similar to the normal physiologic hypotonia that accompanies rapid eye movement sleep (sleep, rem). Narcolepsy.

References

  1. Schachter S. (2021). Evaluation and management of the first seizure in adults. UpToDate. Retrieved July 18, 2021, from https://www.uptodate.com/contents/evaluation-and-management-of-the-first-seizure-in-adults 
  2. Drislane F. (2021) Convulsive status epilepticus in adults: treatment and prognosis. UpToDate. Retrieved July 18, 2021, from https://www.uptodate.com/contents/convulsive-status-epilepticus-in-adults-treatment-and-prognosis 
  3. Kapur J, et al. (2019). Randomized trial of three anticonvulsant medications for status epilepticus. New England Journal of Medicine 381:2103–2113. https://doi.org/10.1056/NEJMoa1905795
  4. Munakomi S, Das JM. (2021). Epilepsy surgery. StatPearls. Retrieved August 13, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK562151/
  5. Fiest KM, et al. (2017). Prevalence and incidence of epilepsy: a systematic review and meta-analysis of international studies. Neurology 88:296–303.
  6. Wilfong A. (2020). Seizures and epilepsy in children: classification, etiology, and clinical features. UpToDate. Retrieved August 13, 2021, from https://www.uptodate.com/contents/seizures-and-epilepsy-in-children-classification-etiology-and-clinical-features

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