Locked-in Syndrome

Overview

Definition

Locked-in syndrome (LIS) is a rare neurological disorder in which patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are awake and conscious but are unable to move their limbs or speak due to pathology affecting the brainstem.

Classification

• Classic form:
  • Total immobility
  • Preserved consciousness as determined via EEG EEG Seizures
  • Vertical eye movements intact
• Incomplete form: classic form with some remaining voluntary movements
• Total form:
  • Complete loss of motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology function
  • Includes the loss of vertical eye movements

Epidemiology

• Most common cause = ischemic or hemorrhagic stroke Hemorrhagic stroke Stroke due to rupture of a weakened blood vessel in the brain (e.g., cerebral hemispheres; cerebellum; subarachnoid space). Subarachnoid Hemorrhage
• 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:
  • 0.7/10,000 in one Dutch study of 187 nursing homes
  • Affects fewer than 1,000 people in the United States
• Many patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship have cardiovascular 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 (e.g., hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus).

Etiology

• Vascular causes:
  • Hemorrhagic or ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke 
  • Occlusion of the basilar artery
• Trauma:
  • Brainstem contusion
  • Penetrating trauma
• Space-occupying masses:
  • Astrocytoma Astrocytoma Astrocytomas are neuroepithelial tumors that arise from astrocytes, which are star-shaped glial cells (supporting tissues of the CNS). Astrocytomas are a type of glioma. There are 4 grades of astrocytomas. Astrocytoma
  • Pontine reticulum cell sarcoma
  • 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 from lung cancer Lung cancer Lung cancer is the malignant transformation of lung tissue and the leading cause of cancer-related deaths. The majority of cases are associated with long-term smoking. The disease is generally classified histologically as either small cell lung cancer or non-small cell lung cancer. Symptoms include cough, dyspnea, weight loss, and chest discomfort. Lung Cancer or melanoma Melanoma Melanoma is a malignant tumor arising from melanocytes, the melanin-producing cells of the epidermis. These tumors are most common in fair-skinned individuals with a history of excessive sun exposure and sunburns. Melanoma
• Infection: pontine abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
• Toxins: heroin Heroin A narcotic analgesic that may be habit-forming. It is a controlled substance (opium derivative) listed in the U.S. Code of federal regulations, title 21 parts 329. 1, 1308. 11 (1987). Sale is forbidden in the United States by federal statute. Nephrotic Syndrome abuse
• Demyelination Demyelination Multiple Sclerosis:
  • Osmotic demyelination Demyelination Multiple Sclerosis syndrome (previously called central pontine myelinolysis)
  • ALS ALS Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a sporadic or inherited neurodegenerative disease of upper motor neurons (UMNs) and lower motor neurons (LMNs). ALS is the most common progressive motor neuron disease in North America, primarily affecting men and individuals of Caucasian ethnicity. Amyotrophic Lateral Sclerosis

Pathophysiology

Ischemic or hemorrhagic stroke Hemorrhagic stroke Stroke due to rupture of a weakened blood vessel in the brain (e.g., cerebral hemispheres; cerebellum; subarachnoid space). Subarachnoid Hemorrhage can affect the vulnerable territory at the paramedian base of the pons Pons The front part of the hindbrain (rhombencephalon) that lies between the medulla and the midbrain (mesencephalon) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the cerebellum to the cerebrum. Brain Stem: Anatomy. The tegmentum (ventral part of the midbrain Midbrain The middle of the three primitive cerebral vesicles of the embryonic brain. Without further subdivision, midbrain develops into a short, constricted portion connecting the pons and the diencephalon. Midbrain contains two major parts, the dorsal tectum mesencephali and the ventral tegmentum mesencephali, housing components of auditory, visual, and other sensorimotor systems. Brain Stem: Anatomy) has collateral supply that often spares the lateral and medial tegmentum.

• Damage to the brainstem involves:
  • Corticospinal and bulbar tracts
  • Abducens nucleus Nucleus Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (cell nucleolus). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the endoplasmic reticulum. A cell may contain more than one nucleus. The Cell: Organelles
  • Paramedian pontine reticular formation Paramedian Pontine Reticular Formation Internuclear Ophthalmoplegia ( PPRF PPRF Internuclear Ophthalmoplegia) in the pons Pons The front part of the hindbrain (rhombencephalon) that lies between the medulla and the midbrain (mesencephalon) ventral to the cerebellum. It is composed of two parts, the dorsal and the ventral. The pons serves as a relay station for neural pathways between the cerebellum to the cerebrum. Brain Stem: Anatomy 
  • → Spastic quadriplegia Spastic Quadriplegia Cerebral Palsy: patient unable to move their extremities or face
• Disruption of the 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 V, VII, IX, X, XI, and XII → neurologic deficits Neurologic Deficits High-Risk Headaches
  • Bilateral sensory deficit Sensory Deficit Anterior Cord Syndrome to the face → bilateral peripheral facial palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies
  • Absent gag reflex Gag Reflex Cranial Nerve Palsies
  • Weak tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy movement
  • Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess weakness
  • Horizontal eye movements impaired
• The following are preserved/intact: 
  • Consciousness
  • Language comprehension
  • Vertical eye movements
  • Eyelid closure
  • Breathing regulation
  • Wakefulness 
  • Cognition
• Onset of symptoms
  • Acute onset: suggests vascular or demyelinating etiologies 
  • Subacute onset:  infectious etiologies Infectious Etiologies High-Risk Headaches
  • Chronic and recurrent presentations: autoimmune etiology

Clinical Presentation and Diagnosis

Diagnosis of LIS requires demonstration of preserved consciousness, alertness, and cognitive function in a patient with paralysis of the limbs and mouth.

Clinical presentation

Eye movement:

• Ask the patient to blink or make eye movements as a form of communication Communication The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups. Decision-making Capacity and Legal Competence.
• If the patient is fully awake and can communicate, eye movement is used as a code:
  • Upward movement means yes.
  • Downward movement means no.

Physical exam:

• Intact neurologic findings:
  • Vertical eye movements 
  • Blinking
  • Alertness and perception Perception The process by which the nature and meaning of sensory stimuli are recognized and interpreted. Psychiatric Assessment of the environment 
• Deficits:
  • Impaired horizontal eye movement
  • Anarthria and dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming “stuck.” Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia (bulbar palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies) → may cause aspiration pneumonia Aspiration pneumonia A type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper respiratory tract. Pneumonia
  • Difficulty with voluntary breathing or apnea: Some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may be intubated at the time of examination.
  • Quadriplegia
  • Bilateral sensory deficit Sensory Deficit Anterior Cord Syndrome to the face (cranial nerve V)
  • Bilateral peripheral facial palsy Palsy paralysis of an area of the body, thus incapable of voluntary movement Cranial Nerve Palsies (cranial nerve VII)
  • Absent gag reflex Gag Reflex Cranial Nerve Palsies (cranial nerve IX)
  • Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess weakness (cranial nerve XI)
  • Weak tongue Tongue The tongue, on the other hand, is a complex muscular structure that permits tasting and facilitates the process of mastication and communication. The blood supply of the tongue originates from the external carotid artery, and the innervation is through cranial nerves. Lips and Tongue: Anatomy movement (cranial nerve XII)

Diagnosis

• Labs:
  • 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
  • CBC
  • 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
  • CSF analysis CSF analysis Meningitis: if suspected infection
• Neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant:
  • CT/MRI: contrast to detect masses
  • CT/ MRA MRA Imaging of the Heart and Great Vessels: to diagnose a vascular cause of LIS
• Other tests
  • EEG EEG Seizures: documents normal sleep-wake cycles; patient is not unconscious Unconscious Those forces and content of the mind which are not ordinarily available to conscious awareness or to immediate recall. Psychotherapy 
  • Electrophysiologic studies: if demyelinating neuropathies Neuropathies Chédiak-Higashi Syndrome are considered (e.g., ALS ALS Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a sporadic or inherited neurodegenerative disease of upper motor neurons (UMNs) and lower motor neurons (LMNs). ALS is the most common progressive motor neuron disease in North America, primarily affecting men and individuals of Caucasian ethnicity. Amyotrophic Lateral Sclerosis)

Management

Medical treatments to promote recovery from LIS are rehabilitative and supportive therapies.

Initial management

• Mechanical ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing, if needed
• Tracheostomy Tracheostomy Surgical formation of an opening into the trachea through the neck, or the opening so created. Laryngomalacia and Tracheomalacia, if needed
• Wean off ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing, if possible.

Supportive management

• Prevent systemic complications of immobilization Immobilization Delirium:
  • Pressure ulcers
  • Deep vein thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus ( DVT DVT Deep vein thrombosis (DVT) usually occurs in the deep veins of the lower extremities. The affected veins include the femoral, popliteal, iliofemoral, and pelvic veins. Proximal DVT is more likely to cause a pulmonary embolism (PE) and is generally considered more serious. Deep Vein Thrombosis)
• Nutritional care
• PT to prevent limb contractures Contractures Prolonged shortening of the muscle or other soft tissue around a joint, preventing movement of the joint. Wound Healing
• Emotional support

Rehabilitation

• PT and speech therapy Speech Therapy Treatment for individuals with speech defects and disorders that involves counseling and use of various exercises and AIDS to help the development of new speech habits. Myotonic Dystrophies
• May require multimodal therapy for months to years 
• Functional neuromuscular stimulation:
  • May activate some paralyzed muscles
  • Devices to help communication Communication The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups. Decision-making Capacity and Legal Competence are available.

Complications

• Residual complete or partial paralysis
• Nosocomial infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease: ventilator-associated pneumonia Ventilator-Associated Pneumonia Multidrug-resistant Organisms and Nosocomial Infections (most common)

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

• Case studies: recovery from 30 minutes to several weeks after onset (depending on the cause)
• 60% mortality Mortality All deaths reported in a given population. Measures of Health Status rate in the first 4 months
• In nonvascular cases: Intensive rehabilitation measures can help significantly.
• Most survivors of LIS remain chronically locked in or severely impaired.

Differential Diagnosis

• Coma Coma Coma is defined as a deep state of unarousable unresponsiveness, characterized by a score of 3 points on the GCS. A comatose state can be caused by a multitude of conditions, making the precise epidemiology and prognosis of coma difficult to determine. Coma/disorders of consciousness: a deep state of unresponsiveness characterized by a score of 3 on the GCS GCS A scale that assesses the response to stimuli in patients with craniocerebral injuries. The parameters are eye opening, motor response, and verbal response. Coma, indicating a lack of response to verbal, tactile, and painful stimuli. The areas 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 involved are the bifrontal deep gray matter Gray matter Region of central nervous system that appears darker in color than the other type, white matter. It is composed of neuronal cell bodies; neuropil; glial cells and capillaries but few myelinated nerve fibers. Cerebral Cortex: Anatomy and upper brainstem. As with LIS, patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship show minimal responsiveness, but with LIS there is extreme motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology entrapment despite preserved awareness. Accurate diagnosis requires neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant to prevent misdiagnosis and appropriate rehabilitative opportunities. Management is based on the underlying cause.
• Akinetic mutism: a rare neurological condition characterized by severe loss of movement and speech, caused by injury to the prefrontal or premotor cortex, and that has been seen in children with 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 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 tumors. Diagnosis is by neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant to detect lesions to the prefrontal or premotor areas. Management includes treating the underlying cause, and medications such as methylphenidate Methylphenidate A central nervous system stimulant used most commonly in the treatment of attention deficit disorder in children and for narcolepsy. Its mechanisms appear to be similar to those of dextroamphetamine. Stimulants and atomoxetine have been used to increase levels of dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS and norepinephrine Norepinephrine Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the locus ceruleus. Receptors and Neurotransmitters of the CNS.
• Guillain-Barré syndrome Guillain-Barré syndrome Guillain-Barré syndrome (GBS), once thought to be a single disease process, is a family of immune-mediated polyneuropathies that occur after infections (e.g., with Campylobacter jejuni). Guillain-Barré Syndrome ( GBS GBS An acute inflammatory autoimmune neuritis caused by t cell- mediated cellular immune response directed towards peripheral myelin. Demyelination occurs in peripheral nerves and nerve roots. The process is often preceded by a viral or bacterial infection, surgery, immunization, lymphoma, or exposure to toxins. Common clinical manifestations include progressive weakness, loss of sensation, and loss of deep tendon reflexes. Weakness of respiratory muscles and autonomic dysfunction may occur. Polyneuropathy): an immune-mediated neuropathy Neuropathy Leprosy that may occur after bacterial or viral infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease. Guillain-Barré syndrome Guillain-Barré syndrome Guillain-Barré syndrome (GBS), once thought to be a single disease process, is a family of immune-mediated polyneuropathies that occur after infections (e.g., with Campylobacter jejuni). Guillain-Barré Syndrome is characterized by acute neuromuscular paralysis that is symmetric and ascending in nature. The syndrome can progress into respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure, which requires prolonged hospitalization Prolonged Hospitalization Surgical Infections. Diagnosis is by history and clinical exam. Management is mostly supportive and may require either plasma exchange Plasma exchange Removal of plasma and replacement with various fluids, e.g., fresh frozen plasma, plasma protein fractions (ppf), albumin preparations, dextran solutions, saline. Used in treatment of autoimmune diseases, immune complex diseases, diseases of excess plasma factors, and other conditions. Thrombotic Thrombocytopenic Purpura or IV immunoglobulin Iv Immunoglobulin Dermatomyositis. 
• Persistent vegetative state Persistent vegetative state The term “persistent vegetative state,” also called unresponsive wakefulness, describes the condition of individuals with severe anoxic brain injury who have progressed to a state of wakefulness without any meaningful response to their environment. A persistent vegetative state is distinguished from a coma in that individuals in a persistent vegetative state have intermittent sleep-wake cycles. Persistent Vegetative State: also called “ unresponsive wakefulness Unresponsive wakefulness The term “persistent vegetative state,” also called unresponsive wakefulness, describes the condition of individuals with severe anoxic brain injury who have progressed to a state of wakefulness without any meaningful response to their environment. A persistent vegetative state is distinguished from a coma in that individuals in a persistent vegetative state have intermittent sleep-wake cycles. Persistent Vegetative State” and formerly known as “ apallic syndrome Apallic Syndrome Coma.” The brainstem and the spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy maintain vegetative functions, but higher mental processes are no longer present. Visual fixation is not possible, nor is communication Communication The exchange or transmission of ideas, attitudes, or beliefs between individuals or groups. Decision-making Capacity and Legal Competence. The cause is traumatic brain injury Traumatic brain injury A form of acquired brain injury which occurs when a sudden trauma causes damage to the brain. Le Fort Fractures, surgical 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 injury, viral infection, or ischemic stroke Ischemic Stroke An ischemic stroke (also known as cerebrovascular accident) is an acute neurologic injury that occurs as a result of brain ischemia; this condition may be due to cerebral blood vessel occlusion by thrombosis or embolism, or rarely due to systemic hypoperfusion. Ischemic Stroke leading to diffuse cerebral hemisphere damage. Diagnosis is by exam, lab testing, and imaging. Management is supportive.
• Catatonia Catatonia A neuropsychiatric disorder characterized by one or more of the following essential features: immobility, mutism, negativism (active or passive refusal to follow commands), mannerisms, stereotypies, posturing, grimacing, excitement, echolalia, echopraxia, muscular rigidity, and stupor; sometimes punctuated by sudden violent outbursts, panic, or hallucinations. This condition may be associated with psychiatric illnesses (e.g., schizophrenia; mood disorders) or organic disorders (neuroleptic malignant syndrome; encephalitis, etc.). Major Depressive Disorder: a psychiatric behavioral syndrome in which patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are unable to move despite having the physical capacity to do so. The underlying psychopathology may be depression, psychosis, or autism spectrum disorder Autism spectrum disorder Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder). Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are unresponsive to verbal stimuli but are able to maintain body posture. There are no CNS abnormalities found on imaging. Diagnosis can be made in 80% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship after IV administration of lorazepam Lorazepam A benzodiazepine used as an anti-anxiety agent with few side effects. It also has hypnotic, anticonvulsant, and considerable sedative properties and has been proposed as a preanesthetic agent. Benzodiazepines. Treatment of the underlying disorder with medications may make the condition worse.