High-Risk Headaches

Overview

Definition

A high-risk 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 is any new and sudden onset, typically severe, 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 with the potential to cause damage to cerebral or precerebral structures or functions.

Etiology

There are many etiologies of high-risk 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 that the clinician Clinician A physician, nurse practitioner, physician assistant, or another health professional who is directly involved in patient care and has a professional relationship with patients. Clinician–Patient Relationship should be aware of and work to rule out when a severe 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 is encountered. The most common etiologies are presented here, separated into vascular, infectious, neoplastic, and miscellaneous causes.

Clinical Presentation

Historical clues

• Sudden onset ( variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables onset among causes):
  • Peaks to maximum intensity in > 1 minute ( thunderclap headache Thunderclap Headache Subarachnoid Hemorrhage)
  • Generally lasts > 5 minutes; may persist or wax and wane
• Severe intensity
• No history of similar headaches:
  • “1st 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 of my life”
  • “ Worst headache of my life Worst Headache of My Life Subarachnoid Hemorrhage”
• Active or recent source of infection:
  • Direct spread from cranial/extracranial structures (e.g., ears, eyes, mouth)
  • Bacteremic spread (e.g., endocarditis Endocarditis Endocarditis is an inflammatory disease involving the inner lining (endometrium) of the heart, most commonly affecting the cardiac valves. Both infectious and noninfectious etiologies lead to vegetations on the valve leaflets. Patients may present with nonspecific symptoms such as fever and fatigue. Endocarditis)
• Altered mental status Altered Mental Status Sepsis in Children:
  • Altered level of consciousness Altered Level of Consciousness Intracerebral Hemorrhage
  • Personality change
  • Confusion
• 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 seizure
• Visual disturbance:
  • Visual loss
  • Visual-field deficit
  • Diplopia Diplopia A visual symptom in which a single object is perceived by the visual cortex as two objects rather than one. Disorders associated with this condition include refractive errors; strabismus; oculomotor nerve diseases; trochlear nerve diseases; abducens nerve diseases; and diseases of the brain stem and occipital lobe. Myasthenia Gravis
• Associated with exertion:
  • Walking
  • Climbing stairs
  • Sexual intercourse
  • Jaw claudication Jaw claudication Mandibular pain or fatigue during mastication that is relieved with rest Giant Cell Arteritis
• Associated with trauma:
  • Motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology vehicle accident
  • Fall
  • Cervical manipulation (chiropractic or osteopathic)
• Age > 50 years
• Immunosuppression (↑ risk of infection, lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum, and leukemia):
  • Autoimmune disease
  • HIV HIV Anti-HIV Drugs/ AIDS AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS
  • Chronic steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors
• 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/postpartum
• Hypercoagulable Hypercoagulable Hypercoagulable states (also referred to as thrombophilias) are a group of hematologic diseases defined by an increased risk of clot formation (i.e., thrombosis) due to either an increase in procoagulants, a decrease in anticoagulants, or a decrease in fibrinolysis. Hypercoagulable States state
• Bleeding diathesis Bleeding diathesis Wiskott-Aldrich Syndrome 
• Medications/ illicit drugs Illicit Drugs Drugs that are manufactured, obtained, or sold illegally. They include prescription drugs obtained or sold without prescription and non-prescription drugs. Illicit drugs are widely distributed, tend to be grossly impure and may cause unexpected toxicity. Delirium:
  • Anticoagulants Anticoagulants Anticoagulants are drugs that retard or interrupt the coagulation cascade. The primary classes of available anticoagulants include heparins, vitamin K-dependent antagonists (e.g., warfarin), direct thrombin inhibitors, and factor Xa inhibitors. Anticoagulants
  • Sympathomimetics Sympathomimetics Sympathomimetic drugs, also known as adrenergic agonists, mimic the action of the stimulators (î±, β, or dopamine receptors) of the sympathetic autonomic nervous system. Sympathomimetic drugs are classified based on the type of receptors the drugs act on (some agents act on several receptors but 1 is predominate). Sympathomimetic Drugs 
• Toxin exposure:
  • CO
  • Sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia hypochlorite (bleach)
  • Formaldehyde
• Insect vector exposure (or travel to endemic areas):
  • Ticks Ticks Blood-sucking acarid parasites of the order ixodida comprising two families: the softbacked ticks (argasidae) and hardbacked ticks (ixodidae). Ticks are larger than their relatives, the mites. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many tick-borne diseases, including the transmission of rocky mountain spotted fever; tularemia; babesiosis; african swine fever; and relapsing fever. Coxiella/Q Fever
  • Mosquitos

Physical examination findings

• Vital sign abnormalities:
  • Severe hypertension Severe hypertension A confirmed blood pressure ≥ 180 mm Hg systolic and/or ≥ 120 mm Hg diastolic. Uncontrolled Hypertension/ 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
  • Severe tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children/ bradycardia Bradycardia Bradyarrhythmia is a rhythm in which the heart rate is less than 60/min. Bradyarrhythmia can be physiologic, without symptoms or hemodynamic change. Pathologic bradyarrhythmia results in reduced cardiac output and hemodynamic instability causing syncope, dizziness, or dyspnea. Bradyarrhythmias
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever/ hypothermia Hypothermia Hypothermia can be defined as a drop in the core body temperature below 35°C (95°F) and is classified into mild, moderate, severe, and profound forms based on the degree of temperature decrease. Hypothermia
  • Hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage 
• Neurologic findings:
  • Cranial nerve palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies
  • Focal neurologic deficits
  • Mental status changes
• Altered level of consciousness Altered Level of Consciousness Intracerebral Hemorrhage
• Meningeal signs: neck stiffness Neck Stiffness Meningitis
• Ophthalmologic findings:
  • Papilledema Papilledema Swelling of the optic disk, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause optic atrophy and visual loss. Idiopathic Intracranial Hypertension
  • Retinal hemorrhage
  • Visual deficit Visual Deficit The Visual Pathway and Related Disorders
  • Elevated intraocular pressure Intraocular Pressure The pressure of the fluids in the eye. Ophthalmic Exam ( acute glaucoma Acute glaucoma An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. Osmotic Diuretics)
  • Corneal clouding ( acute glaucoma Acute glaucoma An ocular disease, occurring in many forms, having as its primary characteristics an unstable or a sustained increase in the intraocular pressure which the eye cannot withstand without damage to its structure or impairment of its function. The consequences of the increased pressure may be manifested in a variety of symptoms, depending upon type and severity, such as excavation of the optic disk, hardness of the eyeball, corneal anesthesia, reduced visual acuity, seeing of colored halos around lights, disturbed dark adaptation, visual field defects, and headaches. Osmotic Diuretics)
• Palpatory temporal artery findings ( temporal arteritis Temporal arteritis Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis):
  • Diminished pulses
  • Firmness/ edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema
  • Nodularity
• Rash Rash Rocky Mountain Spotted Fever:
  • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion migrans (Lyme meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis)
  • Petechiae Petechiae Primary Skin Lesions/purpura ( bacterial meningitis Bacterial meningitis Bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots. Meningitis) 
• Evidence of active purulent infection:
  • Sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis
  • Otitis
  • Facial/ orbital cellulitis Orbital cellulitis Orbital and preseptal cellulitis are infections differentiated by the anatomic sites affected in the orbit. Infection posterior to the septum is orbital cellulitis. Inoculation with the pathogen can occur through trauma or surgery. Cellulitis also occurs via extension from a nearby structure (such as from sinus infection or sinusitis). Orbital and Preseptal Cellulitis
  • Gingivitis Gingivitis Inflammation of gum tissue (gingiva) without loss of connective tissue. Chédiak-Higashi Syndrome

Diagnosis and Management

History

It is important to take a focused, thorough history: 

• 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 descriptors:
  • Onset
  • Location
  • Duration
  • Intensity
  • Similarity to previous headaches is reassuring.
• To narrow etiology, ask about:
  • Recent trauma
  • 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/postpartum
  • Recent/current infection
  • Vascular risk factors/ comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus
  • Cancer history 
  • Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis states

Physical examination

It is important to do a focused, thorough examination:

• Vital signs, especially:
  • Temperature
  • Blood pressure
• Neurologic exam:
  • Level of consciousness
  • Mental status/ orientation Orientation Awareness of oneself in relation to time, place and person. Psychiatric Assessment/cognition
  • Cranial nerves Cranial nerves There are 12 pairs of cranial nerves (CNs), which run from the brain to various parts of the head, neck, and trunk. The CNs can be sensory or motor or both. The CNs are named and numbered in Roman numerals according to their location, from the front to the back of the brain. The 12 Cranial Nerves: Overview and Functions
  • Screen limbs for motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology/ sensory deficit Sensory Deficit Anterior Cord Syndrome
  • Gait Gait Manner or style of walking. Neurological Examination/ coordination Coordination Cerebellar Disorders
• Extracranial exam:
  • Carotid bruit Carotid bruit Carotid Artery Stenosis
  • Meningismus Meningismus Subarachnoid Hemorrhage
  • Ear infection
  • Sinus tenderness
  • Facial/ orbital cellulitis Orbital cellulitis Orbital and preseptal cellulitis are infections differentiated by the anatomic sites affected in the orbit. Infection posterior to the septum is orbital cellulitis. Inoculation with the pathogen can occur through trauma or surgery. Cellulitis also occurs via extension from a nearby structure (such as from sinus infection or sinusitis). Orbital and Preseptal Cellulitis
  • Visual-field testing
  • Fundoscopic exam Fundoscopic Exam Head and Neck Examination: papilledema Papilledema Swelling of the optic disk, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause optic atrophy and visual loss. Idiopathic Intracranial Hypertension, hemorrhage
  • Intraocular pressure Intraocular Pressure The pressure of the fluids in the eye. Ophthalmic Exam testing
  • Temporal artery palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination
• Other pertinent exam findings:
  • Heart murmur
  • Abnormal heart rhythm
  • Splinter hemorrhages Splinter hemorrhages Endocarditis
  • Osler nodes Osler nodes Endocarditis
  • Janeway lesions Janeway lesions Endocarditis
  • Homan’s sign
  • Rash Rash Rocky Mountain Spotted Fever
  • Evidence of distant infection

Laboratory evaluation

Suspected infectious etiology:

• WBC count with differential
• Cultures:
  • Blood
  • CSF
  • Purulent nasal/otic/optic/ skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions discharge
  • Wound, urine, sputum, etc ETC The electron transport chain (ETC) sends electrons through a series of proteins, which generate an electrochemical proton gradient that produces energy in the form of adenosine triphosphate (ATP). Electron Transport Chain (ETC)., if distant spread is suspected
• CSF studies (obtained via lumbar puncture Lumbar Puncture Febrile Infant (LP)):
  • Opening pressure
  • Protein 
  • 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 
  • Cell counts
  • Gram stain Gram stain Klebsiella

Suspected hematologic/vascular etiology:

• Temporal arteritis Temporal arteritis Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis:
  • ESR ESR Soft Tissue Abscess
  • CRP
• Venous sinus/cerebral vein thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus:
  • D-dimer D-dimer Deep Vein Thrombosis
  • Hypercoagulation workup 
• Intracerebral/ intracranial hemorrhage Intracranial hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most sahs originate from a saccular aneurysm in the circle of willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage:
  • PT/PTT for evaluate for bleeding diathesis Bleeding diathesis Wiskott-Aldrich Syndrome (native or iatrogenic Iatrogenic Any adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment. Anterior Cord Syndrome)
  • CSF for the presence of erythrocytes Erythrocytes Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology (obtained via LP)
    • Performed after initial CT if negative for bleeding in suspected SAH SAH Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most SAHs originate from a saccular aneurysm in the circle of Willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage
    • Beware misinterpretation of a traumatic tap
    • If traumatic tap is suspected, opening pressure > 20 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma Hg indicates a pathologic intracranial process

Suspected neoplastic etiology:

• CSF examination for presence of malignant cells
• May consider liquid biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma for metastatic markers (approximately 1-week turnaround time)
• May consider measuring pituitary Pituitary A small, unpaired gland situated in the sella turcica. It is connected to the hypothalamus by a short stalk which is called the infundibulum. Hormones: Overview and Types hormone levels if suspected pituitary Pituitary A small, unpaired gland situated in the sella turcica. It is connected to the hypothalamus by a short stalk which is called the infundibulum. Hormones: Overview and Types involvement

Neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant

• CT of the head without contrast:
  • Rapidly available in most emergency triage settings
  • Often the 1st test performed regardless of suspected etiology 
  • Test of choice for thunderclap headaches to rule out SAH SAH Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most SAHs originate from a saccular aneurysm in the circle of Willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage
  • Perform before LP if the following restrictions exist:
    • Papilledema Papilledema Swelling of the optic disk, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause optic atrophy and visual loss. Idiopathic Intracranial Hypertension on fundoscopy Fundoscopy Cranial Nerve Palsies
    • Altered level of consciousness Altered Level of Consciousness Intracerebral Hemorrhage
    • Presence of new-onset neurologic deficit
    • Immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis state
    • Known or suspected intracranial mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect
    • 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 presents with new-onset seizure
  • 2nd-line method for head imaging in 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:
    • Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma is generally avoided in 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
    • Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma scatter for head CT is distant from the fetus
• CT of the head/ 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 with contrast
• CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests
• MRI of the head with and without contrast
• MRA MRA Imaging of the Heart and Great Vessels

Evaluation and management of specific high-risk headaches

Thunderclap headache Thunderclap Headache Subarachnoid Hemorrhage: 

• CT without contrast: initial test of choice
• LP should be performed if CT negative:
  • Evaluate for presence of erythrocytes Erythrocytes Erythrocytes, or red blood cells (RBCs), are the most abundant cells in the blood. While erythrocytes in the fetus are initially produced in the yolk sac then the liver, the bone marrow eventually becomes the main site of production. Erythrocytes: Histology
  • Measure opening pressure
• If CT or LP suggests hemorrhage, further imaging is warranted to evaluate for source:
  • CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests
  • MRA MRA Imaging of the Heart and Great Vessels
  • Traditional fluoroscopic angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery 
• If any of the above suggest hemorrhage/vasospasm → immediate consultation with a neurosurgeon or vascular interventionist 

Meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis or 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:

• On initial suspicion, obtain blood cultures 
• Begin antibiotics:
  • Antibacterials for common bacterial entities
  • Antivirals, antifungals, antiprotozoals, anti-rickettsials as guided by clinical suspicion

• Prior to performing LP, CT without contrast to evaluate for contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation to LP:
  • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast lesion
  • Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage
• LP if no contraindications Contraindications A condition or factor associated with a recipient that makes the use of a drug, procedure, or physical agent improper or inadvisable. Contraindications may be absolute (life threatening) or relative (higher risk of complications in which benefits may outweigh risks). Noninvasive Ventilation to obtain CSF and evaluate for:
  • Opening pressure
  • Protein 
  • 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 
  • Cell counts
  • Gram stain Gram stain Klebsiella
• Consider neurology and/or infectious disease consultation

Increased ICP Increased ICP Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage:

• MRI without and with contrast preferred to evaluate for intracranial mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast/pathology:
  • Neoplasm
  • Metastasis Metastasis The transfer of a neoplasm from one organ or part of the body to another remote from the primary site. Grading, Staging, and Metastasis
  • Abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
  • Hematoma Hematoma A collection of blood outside the blood vessels. Hematoma can be localized in an organ, space, or tissue. Intussusception
  • Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage
  • Cerebral edema Cerebral edema Increased intracellular or extracellular fluid in brain tissue. Cytotoxic brain edema (swelling due to increased intracellular fluid) is indicative of a disturbance in cell metabolism, and is commonly associated with hypoxic or ischemic injuries. An increase in extracellular fluid may be caused by increased brain capillary permeability (vasogenic edema), an osmotic gradient, local blockages in interstitial fluid pathways, or by obstruction of CSF flow (e.g., obstructive hydrocephalus). Increased Intracranial Pressure (ICP) from 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/infarction
• CT with and without contrast if MRI is contraindicated/unavailable
• LP for opening pressure and to evaluate for underlying infection if imaging negative

CO toxicity Toxicity Dosage Calculation:

• Administer high-flow supplemental oxygen Supplemental Oxygen Respiratory Failure.
• Obtain an arterial blood gas Arterial blood gas Respiratory Alkalosis (ABG) sample.
• Measure carboxyhemoglobin Carboxyhemoglobin Carbon Monoxide Poisoning to determine exposure. 
• Symptoms generally improve as CO levels diminish.

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 with neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:

• Stabilize any instability related to head/ neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess trauma.
• Neurologic exam for Horner syndrome Horner syndrome Horner syndrome is a condition resulting from an interruption of the sympathetic innervation of the eyes. The syndrome is usually idiopathic but can be directly caused by head and neck trauma, cerebrovascular disease, or a tumor of the CNS. Horner Syndrome/ cranial nerve palsies Cranial Nerve Palsies Cranial nerve palsy is a congenital or acquired dysfunction of 1 or more cranial nerves that will, in turn, lead to focal neurologic abnormalities in movement or autonomic dysfunction of its territory. Head/neck trauma, mass effect, infectious processes, and ischemia/infarction are among the many etiologies for these dysfunctions. Diagnosis is initially clinical and supported by diagnostic aids. Management includes both symptomatic measures and interventions aimed at correcting the underlying cause. Cranial Nerve Palsies
• CT without contrast is the initial test of choice to evaluate for intracranial pathology.
• CT and CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests of head and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess with contrast if initial CT negative to evaluate for:
  • Carotid artery dissection Carotid artery dissection The splitting of the vessel wall in one or both (left and right) internal carotid arteries. Interstitial hemorrhage into the media of the vessel wall can lead to occlusion of the internal carotid artery and aneurysm formation. Dissection of the Carotid and Vertebral Arteries
  • Vertebral artery Vertebral artery The first branch of the subclavian artery with distribution to muscles of the neck; vertebrae; spinal cord; cerebellum; and interior of the cerebrum. Lateral Medullary Syndrome (Wallenberg Syndrome) dissection

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 in adults > 50 years of age:

• Examine for temporal artery abnormalities.
• MRI with and without contrast to evaluate for:
  • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast
  • Hemorrhage
  • Elevated intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension ( ICP ICP Normal intracranial pressure (ICP) is defined as < 15 mm Hg, whereas pathologically increased ICP is any pressure ≥ 20 mm Hg. Increased ICP may result from several etiologies, including trauma, intracranial hemorrhage, mass lesions, cerebral edema, increased CSF production, and decreased CSF absorption. Increased Intracranial Pressure (ICP)) 
• CT with and without contrast, if MRI contraindicated/unavailable 
• Start corticosteroids Corticosteroids Chorioretinitis and obtain immediate ophthalmology consultation if temporal arteritis Temporal arteritis Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis suspected.
• Further management/consultation depending on findings

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 in immunosuppressed individuals:

• CT without contrast to evaluate for:
  • Infection
  • Lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum
  • Leukemia 
• MRI with and without contrast to evaluate for:
  • Abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease 
  • 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
  • Causes of elevated ICP ICP Normal intracranial pressure (ICP) is defined as < 15 mm Hg, whereas pathologically increased ICP is any pressure ≥ 20 mm Hg. Increased ICP may result from several etiologies, including trauma, intracranial hemorrhage, mass lesions, cerebral edema, increased CSF production, and decreased CSF absorption. Increased Intracranial Pressure (ICP):
    • Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage
    • Hemorrhage
    • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect
  • LP if imaging is negative to evaluate for:
    • Opening pressure
    • Infection
    • Malignant cells
  • Consider infectious disease, neurosurgery Neurosurgery Neurosurgery is a specialized field focused on the surgical management of pathologies of the brain, spine, spinal cord, and peripheral nerves. General neurosurgery includes cases of trauma and emergencies. There are a number of specialized neurosurgical practices, including oncologic neurosurgery, spinal neurosurgery, and pediatric neurosurgery. Neurosurgery, neurology consultation depending on findings.

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 in individuals with cancer:

• MRI with and without contrast to evaluate for metastases and infection 
• CT with and without contrast if MRI contraindicated or unavailable 
• Consider oncology, neurosurgery Neurosurgery Neurosurgery is a specialized field focused on the surgical management of pathologies of the brain, spine, spinal cord, and peripheral nerves. General neurosurgery includes cases of trauma and emergencies. There are a number of specialized neurosurgical practices, including oncologic neurosurgery, spinal neurosurgery, and pediatric neurosurgery. Neurosurgery, neurology consultation depending on findings.

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 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/postpartum:

• Evaluate for preeclampsia Preeclampsia A complication of pregnancy, characterized by a complex of symptoms including maternal hypertension and proteinuria with or without pathological edema. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease. Hypertensive Pregnancy Disorders/ eclampsia Eclampsia Onset of hyperreflexia; seizures; or coma in a previously diagnosed pre-eclamptic patient (pre-eclampsia). Hypertensive Pregnancy Disorders. 
• Blood pressure management/seizure stabilization as indicated
• Immediate obstetrics/maternal-fetal medicine consultation
• MRI without contrast is preferred method of neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant to evaluate for:
  • Cerebral vein or venous sinus thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
  • Causes of elevated ICP ICP Normal intracranial pressure (ICP) is defined as < 15 mm Hg, whereas pathologically increased ICP is any pressure ≥ 20 mm Hg. Increased ICP may result from several etiologies, including trauma, intracranial hemorrhage, mass lesions, cerebral edema, increased CSF production, and decreased CSF absorption. Increased Intracranial Pressure (ICP):
    • Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage
    • Hemorrhage
    • Mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect
• LP if neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant negative and increased ICP Increased ICP Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage or if infection suspected

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 with visual impairment, periorbital Periorbital Orbital and Preseptal Cellulitis pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, ophthalmoplegia Ophthalmoplegia Paralysis of one or more of the ocular muscles due to disorders of the eye muscles, neuromuscular junction, supporting soft tissue, tendons, or innervation to the muscles. Orbital and Preseptal Cellulitis: 

• MRI of the head and orbits to evaluate for:
  • Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
  • Infection
  • Inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation
  • Tumor Tumor Inflammation 
• Measure intraocular pressure Intraocular Pressure The pressure of the fluids in the eye. Ophthalmic Exam
• Start corticosteroids Corticosteroids Chorioretinitis and obtain immediate ophthalmology consultation if temporal arteritis Temporal arteritis Giant cell arteritis (GCA), also known as temporal arteritis, is a type of large-vessel vasculitis that predominantly affects the aorta and its major branches, with a predilection for the branches of the carotid (including the temporal artery). Giant cell arteritis is defined by inflammatory leukocytes in the vessel walls leading to reactive damage, ischemia, and necrosis. Giant Cell Arteritis is suspected.
• Immediate ophthalmology consultation if glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma suspected
• Outpatient ENT consultation if sinus involvement suspected
• Outpatient dental consultation if temporomandibular joint (TMJ), gingival, or dental disorder suspected 
• Outpatient neurology or pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways management consultation if trigeminal neuralgia Trigeminal neuralgia Trigeminal neuralgia (TN) is an often chronic and recurring pain syndrome involving the sensory distribution of the trigeminal nerve (cranial nerve (CN) V). The pain is typically unilateral and described as an acute, sharp, electric-shock-like pain involving the maxillary or mandibular areas and often associated with spasm of facial muscles. Trigeminal Neuralgia suspected

Clinical Relevance

• Cluster 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: may be of sudden onset and may be severe, but sufferers are generally very aware that frequent, sudden, and severe headaches are to be expected during a cluster period. Although neurologic symptoms are typical of cluster 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, they are autonomic in nature, predictable, reproducible, and transient. Thorough clinical evaluation with neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant is indicated at the initial workup for cluster 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 to rule out high-risk etiologies. A change in the pattern of headaches warrants emergent reevaluation. 
• 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 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: Although typically gradual in onset, 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 headaches may be severe and accompanied by neurologic symptoms. These neurologic symptoms are often part of the typical 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 milieu for the individual; they are predictable, reproducible, and transient. Clinical evaluation with neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant is indicated at the initial occurrence of 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 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 with neurologic symptoms to rule out high-risk etiologies. A change in the pattern of headaches warrants emergent reevaluation.
• Cervicogenic 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: 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 caused by referred pain Referred Pain Spinal Disk Herniation from the upper cervical joints. Typically unilateral, of moderate to severe intensity, and increased by movement of the head, with radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma from the occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy to the 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 regions. Many high-risk headaches also present with cervical symptoms. The distinguishing feature is the absence of structural cervical disease.