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USMLE Step 2 (Fach) / Neurology (Lektion)

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  • Mnemonic: MCA stroke can cause CHANGes Contralateral paresis and sensory loss in the face and arm Hemiparesis Aphasia (dominant) Neglect (nondominant) Gaze preference toward the side of lesion
  • Stroke Symptoms - ACA - Contralateral paresis and sensory loss in the leg - Cognitive or personality changes - Abulia: flat affect and lack of motivation→ E.g., inability to complete goal-directed tests
  • Stroke Symptoms - PCA - Vertigo - homonymous hemianopsia
  • Stroke Symptoms - Lacunar - pure motor - pure sensory - ataxic hemiparesis - dysarthria
  • Stroke Symptoms - TIA - depend on location of vascular lesion - neurologic deficit lasts <24 hours (most last <1h) - often without findings on MRI
  • Subarachnoid hemorrhage Epidemiology:- Traumatic: head trauma is the most common cause of SAH- Peak incidence: around the age of 50- ♀ > ♂ (3:2) Etiology:- Traumatic- Ruptured aneurysm usually in the circle of Willis→ Berry aneurysm- Ruptured arteriovenous malformation (AVM)- Others: cortical thrombosis, angioma, neoplasm, infection Triggers: May be triggered by an acute rise in blood pressure (e.g., caffeine consumption, acute anger, physical exertion) Risk factors:- Smoking- Hypertension- Alcohol use disorder- Positive family history- Methamphetamines and cocaine use Clinical features:- Thunderclap headache: sudden, severely painful headache - spreads over the entire head (holocephalic) and radiates to the neck and back (may present with opisthotonus)- Meningism: neck stiffness, photophobia, nausea and vomiting, meningeal stretch signs (e.g., Kernig's sign and Brudzinski's sign)- Impaired consciousness (somnolent to comatose) - Fever- Sweating, hemodynamic instability- Mass effects: Cranial nerve palsies, hemiparesis or quadriparesis, spasticity, aphasia, hemispatial neglect, rarely focal/generalized seizures Diagnosis:- immediate head CT without contrast- LP if CT is - to look for RBCs, xantochromia, ↑ protein, and ↑ ICP- Four-vessel angiography Treatment:- Surgical clipping (treatment of choice) and/or endovascular coiling (increasingly used alternative for poor surgical candidates)- Prevent rebleeding by maintaining systolic BP < 150 mmHg- Prevent vasospasm and subsequent ischemic stroke (4-10 days after) with nimodipine- ↓ ICP by raising the head of bed and instituting hyperventilation
  • Conditions associated with berry aneurysms that can make a SAH more likely - Marfan syndrom- Aortic coarctation- Kidney disease (autosomal dominant, polycystic)- Ehlers-Dahnlos syndrom- Sickle-cell anemia, smoking tobacco- Atherosclerosis- Hypertension, hyperlipidemia
  • Cavernous sinus syndrome Etiology:- Cavernous sinus thrombosis (e.g., due to sinusitis)- Carotid-cavernous fistula- Cavernous sinus tumors- Carotid artery aneurysms- Tolosa-Hunt syndrome (idiopathic granulomatous inflammation of the cavernous sinus) Clinical features:- Swelling of the conjunctiva- Proptosis- Signs of CN palsy due to compression (CN III, IV, V1, V2, and VI pass through the cavernous sinus)→ Painful ophthalmoplegia: partial/complete paresis of oculomotor nerve, trochlear nerve, and abducens nerve → Absent corneal reflex: paresis of the ophthalmic branch of the trigeminal nerve (V1)→ Loss of sensation to the upper face may occur due to damage to trigeminal branches V1 and V2- Horner syndrome Diagnosis:- MRI (with gadolinium and MR angiography), CT angiography/venography can also be used- ↑ WBC count- Blood cultures reveal causative agent in 50% of cases Treatment:- Broad-spectrum antibiotics
  • Cluster headache Epidemiology: - Sex: ♂ > ♀ (3:1)- Peak incidence: 20-40 years Etiology:- Risk factor: tobacco use- Possible triggers: alcohol, histamine, seasonal fluctuations Clinical features:- Agonizing pain- Strictly unilateral, periorbital, and/or temporal- Short, recurring attacks that usually occur in a cyclical pattern (“clusters”)- May become chronic (less common), with interruptions of less than one month between cluster bouts- Attacks often wake patients up during sleep- Conjunctival injections and/or lacrimation- Rhinorrhea and nasal congestion- Partial Horner syndrome: ptosis and miosis, but no anhidrosis- Restlessness and agitation While patients with migraine headaches tend to rest motionlessly in a quiet, dark room, individuals with cluster headache pace around restlessly in excruciating pain! Diagnosis:- First episode requires workup (i.e. MRI, carotid artery ultrasound) to exclude structural brain lesion or disorders associated with Horner syndrom (i.e., carotid artery dissection, cavernous sinus infection) Treatment:- High-flow O2- Triptans (e.g., sumatriptan) or zolmitriptan (subcutaneous or intranasal administration)- Prophylactic therapy: Verapamil or other CCB→ Steroids (e.g., prednisone) are very effective at ending a cluster cycle and may be used to bridge the time until verapamil becomes effective.
  • Epidural hematoma Epidemiology: - Sex: ♂ > ♀ (4:1)- Peak incidence: 20-30 years Pathophysiology: Head trauma (usually severe) → skull fracture (often temporal bone) → rupture of a middle meningeal artery → ↑ intracranial pressure → CN III palsy , herniation Clinical features:1. Initial loss of consciousness following head trauma2. Temporary recovery of consciousness (lucid interval)3. Renewed decline in mental status- Elevated intracranial pressure→ Headache→ Nausea and vomiting→ Ipsilateral anisocoria→ Hypertension, bradycardia, and respiratory irregularity (Cushing's reflex) → Contralateral focal symptoms/hemiplegia→ Impaired mental status, seizures, coma- Clinical signs of skull fracture (e.g., local hematoma, swelling, laceration) Diagnostics:- Imaging of choice: noncontrast head CT scan → Biconvex, hyperdense lesion→ Hematomas are limited by suture lines Treatment:- Initial resuscitation: IV fluids (if hypotension is present), intubation- Management of elevated intracranial pressure: Head elevation; if patient is intubated, hyperventilation; osmotic diuresis with mannitol or hyperosmotic saline solution- Surgical management: Urgent craniotomy and hematoma evacuation
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  • Subdural hematoma Etiology:- Blunt head trauma (most common)→ Shaken baby syndrome→ Frequent falls (e.g., due to old age, alcohol abuse, epilepsy, hyponatremia)- Nontraumatic intracranial hemorrhage→ Anticoagulation therapy or coagulopathy→ Ruptured intracranial aneurysm→ Arteriovenous malformation→ Intracranial tumors Pathophysiology:- Tearing in bridging veins → low-pressure venous bleeding- Blood accumulates between the dura mater and arachnoid membrane Clinical features:- Headache - Impaired consciousness and confusion- Focal neurologic signs (i.e., hemiparesis, gait, speech, or visual impairment, personality changes, or a dilated or nonreactive pupil)- Memory impairment Diagnostics:- Non-contrast head CT scan is the modality of choice. - MRI is indicated when CT scan is inconclusive but suspicion for subdural hematoma is high. Treatment:- Conservative treatment→ Indicated if no clinical signs of herniation are present and the neurological status is stable, midline shift < 5 mm, and the hematoma is < 10 mm→ Monitoring with serial CT scans- Surgical decompression→ Indications: Clinical signs of herniation, unstable neurologic status, midline shift > 5 mm, hematoma > 10 mm
  • Seizure disorders Etiology:- Metabolic and electrolyte disturbances: hypoglycemia and hyperglycemia, hyponatremia and hypernatremia, hypocalcemia, uremia, thyroid storm, hyperthermia- Mass: brain tumors and metastases, hemorrhage- Alcohol/drug withdrawal- Intoxication: cocaine, ecstasy- Infections: encephalitis, brain abscess, meningitis, septic shock- Ischemia: stroke, perinatal injuries- Trauma: traumatic brain injury- Eclampsia- Fever in infants and children Provocative factors: Excessive physical exertion, sleep deprivation, strobe light flashing, loud music Classification:1. Focal seizures- Focal seizures without dyscognitive features- Focal seizures with dyscognitive features2. Primary generalized seizures- Classic tonic‑clonic seizures (see grand mal seizure)- Absence (see also generalized epilepsies in childhood)- Myoclonic (see juvenile myoclonic epilepsy)- Clonic seizures- Tonic seizures- Atonic seizures Clinical features:- Ictal phase: Sudden onset, rapid progression of symptoms, duration usually 1-3 minutes- Postictal phase: Varying degree of confusion, impaired alertness, residual neurologic symptoms (e.g., Todd's paralysis), duration usually minutes or hours Diagnostics:- Patient history (from patient or witnesses)- EEG (during the seizure)- Exclude an underlying condition: ECG, CT/MRI, labs, LP if infection is suspected Treatment:- First seizure: Long-term medical therapy is usually not required, unless there are abnormalities seen on EEG or MRI or the patient is in status epilepticus- Focal seizures: lamotrigine, levetiracetam, phenytoin, carbamazepine, phenobarbital (children)- Tonic-clonic: lamotrigine, valproate, phenobarbital (children)- Absences: ethosuximide, valproate
  • Status epilepticus Criteria:- ≥ 5 min of continuous seizures- OR ≥ 2 seizures with consciousness not being fully regained in the interictal period Etiology:- Withdrawal from antiepileptic drugs- Metabolic disturbances (e.g., hyponatremia)- Drug toxicity (e.g., tricyclic antidepressants)- Structural brain lesions/injury (e.g., tumors, trauma, stroke)- CNS infections Treatment:1. Initial assessment- Establish secure IV access (two, if possible), collection of blood for routine blood tests (particularly electrolytes and glucose levels), toxicology screen, antiepileptic drug levels, and arterial blood gas (ABG) analysis- Supportive therapy as necessary (e.g., oxygen, glucose, thiamine, naloxone)2. Pharmalogical interruption of seizures- First line: IV lorazepam; second line: IV diazepam or midazolam → If the patient does not respond within 1 minute → administer additional lorazepam (or a second-line benzodiazepine)→ If the patient does not respond within another 10-20 minutes → saturation with fosphenytoin via separate access (alternatively: phenobarbital, levetiracetam, or valproate)→ No later than 45-60 min after onset: continuous administration of anesthetics with intubation and ICU monitoring; e.g., thiopental, propofol, or midazolam3. Nonbenzodiazepine therapy to prevent recurrence: fosphenytoin or valproate Status epilepticus is a life‑threatening event! If not interrupted, it can lead to cerebral edema, a dangerous rise in body temperature, rhabdomyolysis, and cerebral cardiovascular failure! Complications of seizures and epilepsy:- Hyperthermia, cardiorespiratory deficits, excitatory toxicity → potentially irreversible tissue damage (particularly to the CNS, for example in the form of cortical laminar necrosis)- Postictal transient anion gap metabolic acidosis with increased lactic acid and reduced serum bicarbonate → usually resolves spontaneously within 60–90 minutes after seizure activity stops- Physical trauma (e.g., posterior dislocation of the glenohumeral joint)
  • Benign paroxysmal positional vertigo A disease of the inner ear caused by small particles (otoliths) dislodging and migrating within the endolymph fluid into one of the semicircular canals. Epidemiology:- Most common type of peripheral vestibular vertigo- Sex: ♀ > ♂- Peak incidence: > 60 years of age Clinical features:- Sudden (“paroxysmal”) and recurrent- Triggered by certain head movements (“positional”)- Lasts several seconds (generally ≤ 1 minute)- A propensity to fall towards the healthy side- Typically associated with nystagmus (towards the affected side)- Sometimes nausea or even vomiting- Not associated with hearing or neurological symptoms Diagnosis: - Dix-Hallpike maneuver: have the patient turn head 45° right or left and go from a sitting to supine position. If vertigo and typical nystagmus (upbeat and toward affected side) are reproduced, BPPV is likelyConsider other diagnoses if attacks last > 1 minute, or if hearing or neurological symptoms (e.g., gait disturbances) are present. Treatment:- Epley maneuverAntivertigo drugs (e.g., dimenhydrinate) are contraindicated in BPPV because they may exacerbate unsteadiness by inhibiting central compensation!
  • Ménière disease Etiology: Endolymph hydrops (accumulation of fluid in the endolymphatic sac) Clinical features:- Acute, unilateral symptoms that last from minutes to hours- The frequency of these episodes decreases with increasing age- In 30% of patients, the disease eventually affects both sides- Ménière triad:1. Peripheral vertigo2. Tinnitus3. Sensorineural hearing loss (low frequency loss increases with each episode)- Ear fullness- Often notable for a horizontal nystagmus Diagnostics:- Weber test: lateralization to the healthy ear- Rinne test: bilaterally positive- Pure tone audiometry: low-frequency hearing loss- Suprathreshold audiometry: displays positive recruitment (outer hair cells are damaged by endolymph hydrops) Treatment:- Lifestyle adjustments: Avoid caffeine, alcohol, and stress; low-sodium diet- Acute: vestibular suppressants (e.g., dimenhydrinate); antiemetics- Prophylaxis: histamine analog (betahistine)- Interventional→ Intratympanic gentamicin injection: repeated application of gentamicin to the middle ear cavity through a small incisionin the eardrum (paracentesis)→ Sacculotomy: The endolymphatic sac and duct (part of the vestibular organ) is surgically exposed in order to promote drainage of endolymph.→ Vestibular neurectomy: Surgical lysis of the vestibular bundle entering the internal auditory canal. In some cases, the procedure is associated with hearing loss.
  • Myasthenia gravis Epidemiology:- Women: 2-3rd decade- Men: 6-8th decade Clinical features:- Fluctuating & fatigable proximal muscle weakness that is worse later in the day- Ocular: Diplopia, ptosis- Bulbar: Dysphagia, dysarthria- Weakness of respiratory muscles  Causes of exacerbations:- Antibiotics: Fluoroquinolones, aminoglycosides- Anesthetics: Neuromuscular blocking agents- Cardiac medications: Beta blockers, procainamide- Other: Magnesium sulfate, penicillamine- Pregnancy/chilbirth- Surgery (especially thymectomy)- Infection Diagnosis:- Bedsite: Edrophonium (Tensilon) test, ice pack test- Acetylcholine receptor antibodies (highly specific)- CT scan of chest to evaluate for thymoma Treatment:- Acetylcholinesterase inhibitors (e.g., pyridostigmine)- ± Immunotherapy (e.g., corticosteroids, azathioprine)- Thymectomy
  • Multiple sclerosis Chronic, degenerative disease of the CNS that is caused by an immune-mediated inflammatory process.- Sex: F > M (2:1)- Age of onset: 20-40 years of age- Ethnicity: ↑ prevalence among the white population- Prevalence is greater among people in temperate zones Most common sites of demyelination in MS1. Periventricular areas2. Brainstem3. Cerebellum4. Spinal cord Clinical features:- Optic neuritis (most often the earliest manifestation): impaired vision and color blindness- Internuclear ophthalmoplegia (INO) as a result of a lesion in the medial longitudinal fasciculus (MLF)- Demyelination of spinal cord tracts→ Lhermitte's sign: a shooting electric sensation that travels down the spine when the patient flexes his/her neck→ Pyramidal tract lesion: upper motor neuron weakness characterized by spasticity, hyperreflexia, and a positive Babinski's sign → Involvement of the dorsal spinal column: loss of vibration and fine touch sensations, numbness, paresthesias, sensory ataxia- Cerebellar involvement → Charcot's neurological triad:1. Scanning speech2. Nystagmus3. Intention tremors- Cranial nerve palsies- Autonomic dysfunction: bowel and bladder disorders, impaired sexual activity- Change in mental state: memory deficits, impaired concentration, and/or depression- Uhthoff's phenomenon: a reversible exacerbation of neurological symptoms following physical exertion, a warm bath, or fever Stages:1. Relapsing-remitting (90%)2. Secondary progressive (arises from above)3. Primary progressive (10%) Diagnostics:- Plain MRI (brain and spine)- Electrophysiological studies- Lumbar puncture: Lymphocytic pleocytosis, oligoclonal bands Treatment:- Acute exacerbations: High-dose glucocorticoid therapy for 3-5 days (methylprednisolone 500-1000 mg/d IV or PO)- Prevention of exacerbations:→ Relapsing remitting MS: Glatiramer acetate, interferon therapy, 2nd line: natalizumab→ Secondary progressive MS: Interferon therapy→ Primary progressive: Supportive Differential diagnosis:- Neuromyelitis optica (Devic's disease)- Acute disseminated encephalomyelitis (ADEM, acute demyelinating encephalomyelitis)
  • Amyotrophic lateral sclerosis Chronic, progressive degenerative disease, that is characterized by loss of upper and lower motor neurons.- ♂ > ♀- Mutations of superoxide dismutase 1 Clinical features:- Asymmetric limb weakness, often beginning with weakness in the hands and feet- Bulbar symptoms such as dysarthria and dysphagia (20% of cases at disease onset)- Fasciculations, cramps, and muscle stiffness- Cognitive impairment (approx. 15% of ALS patients meet the criteria for frontotemporal dementia)- Respiratory failure due to paralysis of respiratory muscles- Dysphagia due to bulbar weakness Diagnosis:- Physical examination (including testing reflexes, Babinski's sign, etc.)- Electromyography → Denervation: indicated, e.g., by fibrillations, positive sharp waves, and large amplitudes→ Fasciculations- Nerve conduction studies: usually normal- MRI and laboratory tests to exclude other potential diagnoses - Increased creatine kinase Treatment: Riluzole 
  • Normal pressure hydrocephalus Etiology:- Idiopathic (most common in adults > 60 years)- Possible secondary causes:→ Inflammatory diseases of the CNS (e.g., meningitis)→ Intraventricular hemorrhage→ Subarachnoidal hemorrhage Pathophysiology:- ↓ CSF absorption- Secondary: impaired CSF absorption caused by inflammation and subsequent fibrosis of the subarachnoid villi Clinical features: Triad1. Wacky: Dementia2. Wobbly: Frequent falls, broad-based gait with short steps (ataxic gait)3. Wet: Urinary incontinence - Depressed affect (frontal lobe compression)- Upper motor neuron signs in lower extremities Diagnostics:- Rule out other causes of symptoms: → Cognitive assessment→ Vitamin B12 level and thyroid function tests→ MRI (initial test), CT: Ventriculomegaly without sulcal enlargement→ Periventricular hypodensity due to periventricular edema- CSF tap test (Miller Fisher test): confirmatory test→ Opening pressure is normal or slightly elevated→ Improvement of symptoms after CSF removal confirms NPH Treatment: Lumbar puncture is both diagnostic and therapeutic- If improvement, surgical ventriculoperitoneal shunting is treatment of choice
  • Creutzfeldt-Jakob Disease Etiology:- Sporadic (∼ 85%): no identifiable cause- Familial (∼ 10-15%): various mutations in the PRNP gene- Iatrogenic CJD (< 1%): transmission during medical procedures (e.g., via organ transplantation, blood transfusion) Clinical features:- Rapidly progressing dementia- Other neuropsychiatric symptoms: e.g., visual hallucinations, depression- Myoclonus: can often be triggered by startling (e.g., loud noises)- Seizures- Cerebellar disturbances (e.g., gait instability) and extrapyramidal deficits- Akinetic mutism: State of alertness combined with the inability to move and/or to respond adequately Diagnosis:- CSF analysis: neuron‑specific enolase, S100 protein, tau protein, 14-3-3 protein- Imaging: MRI (Signal amplification in the basal ganglia and the head of the caudate nucleus)- EEG: triphasic periodic sharp‑wave complexes Treatment: none
  • Huntington disease Etiology:- Increased number of CAG repeats in the huntingtin gene on chromosome 4- Autosomal dominant- Anticipation Clinical features:- Chorea: involuntary, irregular, nonrepetitive, arrhythmic movements of the limbs, neck, head, and/or face- Oculomotor disorders: delayed saccades- Motor impersistence: inability to sustain simple voluntary acts, e.g., tongue protrusion- Dysarthria and dysphagia- Psychiatric: depression, irritability, psychosis, obsessive-compulsive symptoms- Cognitive decline: executive dysfunction Diagnosis:- Genetic testing, e.g. polymerase chain reaction- CT/MRI show cerebral atrophy (especially of the caudate and putamen)- Neuropathology: loss of GABA-ergic neurons Treatment:- Monoamine‑depleting drugs (e.g., tetrabenazine)- Atypical neuroleptics (e.g., clozapine)- NMDA-receptor antagonists (e.g., amantadine)- Psychosis: atypical neuroleptics (e.g., clozapine)- Depression: SSRIs (e.g., citalopram)
  • Parkinson disease Etiology:- Idiopathic- Secondary parkinsonism (pseudoparkinsonism)→ Medication with anti-dopaminergic effects: typical antipsychotics (e.g., haloperidol), some antiemetics (e.g., metoclopramide), some calcium channel blockers (e.g., flunarizine, amiodarone), valproate, and lithium→ Metabolic disorders: e.g., Wilson's disease→ Toxins: e.g., manganese, carbon monoxide, carbon disulfide→ Cerebrovascular disease (vascular parkinsonism): e.g., subcortical arteriosclerotic encephalopathy→ CNS infections Clinical features:- Resting tremor with a frequency of 4-6 Hz - Rigidity - Bradykinesia (small, shuffling steps without arm swing)- Postural instability- Rapid eye movement sleep behavior disorder (RBD)- Hyposmia or anosmia (potential early symptom)- Personality changes: e.g., withdrawal, apathy- Freezing: sudden inability to start or continue movements (e.g., while walking)- Propulsion: forward-leaning gait with risk of patient falling forward- Micrographia: size of handwriting is reduced- Low degree of facial expression (hypomimia), decreased blinking Diagnostics: Clinical- Levodopa challenge test: The result is positive if administration of levodopa relieves symptoms. Treatment:Patients under the age of 65 without comorbidities:- Non-ergot dopamine agonists (e.g., pramipexole, ropinirole, apomorphine): as monotherapy or in combination with levodopa/carbidopa- MAO-B inhibitors (e.g., selegiline): may be used as a monotherapy or in combination with dopamine agonists or levodopa/carbidopa- COMT inhibitors (e.g., entacapone): in combination with levodopa/carbidopa- Alternatives:→ Levodopa: Normally combined with a peripheral decarboxylase inhibitor like carbidopaMost effective symptomatic treatment but carries a higher risk of dyskinesias than other medications→ Ergot dopamine agonists (e.g., bromocriptine)→ NMDA antagonists (e.g., amantadine): used to reduce levodopa-induced dyskinesias → Anticholinergics/muscarinic antagonists (biperiden, benztropine, trihexyphenidyl): useful in patients < 65 years with tremor as the main complaintPatients over the age of 65 or multimorbid:- First-line treatment: levodopa + decarboxylase inhibitor (carbidopa) Treatment of associated symptoms:- Depression: SSRIs- Dementia: Cholinesterase inhibitors (e.g., donepezil)- Psychosis: Atypical antipsychotics (e.g., quetiapine, clozapine)- Dyskinesias: Anticholinergics with CNS effects (e.g., trihexyphenidyl, benztropine)Unresponsive to levodopa → Deep brain stimulation (DBS)
  • Neurofibromatosis Most common neurocutaneous disorder. Autosomal dominant. Neurofibromatosis type 1 (von Recklinghausen disease):- Café-au-lait spots- Neurofibromas (benign peripheral nerve sheath tumors), seizures when CNS is involved- Freckling in the axillary or inguinal area- Optic glioma- Lisch nodules (pigmented iris hamartomas)- Scoliosis in 1/3 of patients- Bone abnormality (fractures, pseudoarthrosis)- Associated with pheochromocytoma and Wilms' tumorNeurofibromatosis type 2:- Bilateral vestibular schwannomas → ipsilateral tinnitus, hearing loss, vertigo- Seizures, skin nodules, café au lait spots- Meningeomas- Multiple cerebral and spinal tumors Diagnosis:- MRI - Dermatologic exam, opthalmologic exam, family history
  • Tuberous sclerosis Autosomal dominant disorder that affects many organ systems (CNS, skin, heart, retina, kidneys) Clinical features:- Infantile spasms or seizures- ≥ 3 "Ash-leaf" hypopigmented lesions on the trunk and extremities- Intellectual disability- Adenomas sebaceum: Small red nodules on the nose and cheeks in the distribution of a butterfly- Shagreen patch in the lumbosacral region with orange-peel consistency- Cardiac rhabdomyosarcoma (> 50%)- Renal cysts or renal angiomyolipoma- Ungual fibromas Diagnosis:- Ash-leaf lesions are enhanced by a Wood UV lamp- MRI of brain: evaluate for subependymal giant cell astrocytoma and calcified tubers within the cerebrum of the periventricular area- Echocardiography: evaluate for rhabdomyoma of the heart- MRI of abdomen: evaluate for renal disease- EEG: evaluate for seizure activity
  • Ischemic stroke Etiology:- Large artery atherosclerosis: secondary to hypertension (∼ 20% of cases) E.g., carotid artery stenosis- Embolic stroke (∼ 20% of cases)→ Cardiac emboli: Atrial fibrillation, myocardial aneurysms→ Infectious emboli: bacterial endocarditis→ Atheroemboli: internal carotid artery, aortic arch→ Paradoxical embolism: in patients with right-to-left cardiac shunt (e.g., persistent foramen ovale or ASD)- Small vessel occlusion (∼ 20% of cases) → Lipohyalinotic thickening of the small vessels → occlusion of small arteries that originate directly from large vessels (e.g., middle cerebral artery, anterior cerebral artery) → lacunar stroke→ Primarily due to hypertension and diabetes mellitus - Systemic hypoperfusion results in Watershed stroke - Coagulopathies (e.g., polycythemia or due to hormonal contraceptive use or hormone replacement therapy during/after menopause)- Vasculitis (e.g., giant cell arteritis)- Dissection (e.g., due to trauma, fibromuscular dysplasia)- Sickle cell disease Clinical features:- Thrombotic stroke – The onset of symptoms may be rapid or stepwise. Classically the patient awakens from sleep with the neurologic deficits.- Embolic stroke – The onset of symptoms is very rapid (within seconds), and deficits are maximal initially.- Lacunar stroke – Clinical features are focal and usually contralateral pure motor or pure sensory deficits. → Pure motor lacunar stroke – if lesion involves the internal capsule→ Pure sensory lacunar stroke – if lesion involves the thalamus Diagnostics:- Noncontrast cranial CT (gold standard and most important initial imaging)→ Acute: Hyperdense occluded vessels (e.g., hyperdense MCA sign), parenchymal hypodensity→ After 12-24 hours: hypodense→ After days: hyperdense- MRI- ECG - Carotid duplex ultrasound - Magnetic resonance arteriogram (MRA) Treatment:- Acute – Supportive treatment (airway protection, oxygen, IV fluids)- Onset of symptoms ≤ 3 hours: Thrombolytic therapy (t-PA)- Onset of symptoms ≥ 3 hours: Aspirin only. If patient cannot take aspirin, give clopidogrel.- Protect airway, keep NPO, and elevate the head of the bed 30 degrees to prevent aspiration.- BP control if systolic > 220, diastolic > 120 mmHg- Mechanical thrombectomy: in patients with proximal large artery occlusion in the anterior cerebral circulation (usually in addition to IV thrombolytic therapy)- Intra-arterial thrombolysis- Carotid endarterectomy in symptomatic patients with carotid artery stenosis of >70%
  • Intracerebral hemorrhage Etiology:- Hypertension (most common cause)- Cerebral amyloid angiopathy (most common cause of spontaneous ICH in the elderly)- Ruptured arteriovenous malformations - Coagulation disorders (e.g., anticoagulant use)- Vasculitis (e.g., giant cell arteritis)- Neoplasms (e.g., meningioma)- Stimulants (e.g., cocaine and amphetamines) Clinical features:- Abrupt onset of a focal neurologic deficit that worsens steadily over 30 to 90 minutes- Altered level of consciousness, stupor, or coma- Headache, vomiting- Signs of increased ICP Diagnostics:1. CT scan of the head2. Neurovascular imaging, e.g., CT angiography, carotid duplex sonography Treatment:- Reverse anticoagulation- Treat hypertension (< 150 mmHg)- Craniotomy and clot evacuation
  • Resting tremor - Age of onset: ∼ 60 years Etiology: - Parkinson's disease- Drug induced parkinsonism (neuroleptics, metoclopramide)- Progressive supranuclear palsy Clinical features:- Typically, asymmetric resting tremor of the extremities at a low frequency (4-6 Hz, rarely up to 9 Hz) - “Pill-rolling” of hands that subsides with voluntary movements- In early Parkinson's disease, unilateral tremors are common.- Worsens with emotional stress- Reduced with target-directed movement- Often associated with rigidity, bradykinesia, and postural instability  Diagnosis:- Typically a clinical diagnosis- MRI for atypical presentations Treatment: Anticholinergic medication (e.g., benztropine, trihexyphenidyl, biperiden)
  • Essential tremor Epidemiology:- Most common form of tremor- Bimodal distribution: teens and 6th decade of life (common in elderly patients) Etiology: - Positive family history (50-70%; autosomal dominant inheritance) - Sporadic; benign form Clinical features:- Hands (about 90%) > arms > head (about 30%; "yes-yes” or "no-no” motion)- Bilateral - Frequency of 5-10 Hz- Slowly progressive- Worse with voluntary movement, stress, fatigue, and caffeine- Worse with outstretched arms or finger-to-nose testing- Resolves at rest- Improves with alcohol consumption Diagnosis: Usually a clinical diagnosis of exclusion Treatment:- Drugs of choice: propranolol or primidone (anticonvulsant)- In drug-resistant cases: Deep brain stimulation (DBS)
  • Intention tremor Etiology:- Cerebellar stroke, tumor, or trauma- Multiple sclerosis- Drug-induced: alcohol, lithium- Wilson's disease Clinical features:- Coarse hand tremor with a frequency of < 5 Hz- Worse with goal-directed movements- Dysmetria (abnormal heel-to-shin and finger-to-nose testing)- Dysdiadochokinesia (inability to perform rapid alternating hand movements)- Dysarthria, nystagmus and abnormal gait Diagnosis:- CT/MRI: cerebellar lesions- IgG in CSF if multiple sclerosis is suspected- Screen for alcohol abuse or toxic lithium blood levels Treatment:- Physical therapy- Thalamotomy
  • Dementia Etiology:- Neurodegenerative brain diseases: Alzheimer disease (> 50% of dementia cases), Parkinson disease, frontotemporal dementia, dementia with Lewy bodies, progressive supranuclear palsy, Huntington disease- Cerebrovascular disease (20% of dementia cases): → Multi-infarct dementia→ Diffuse white matter disease (subcortical arteriosclerotic encephalopathy)- Hypoxic brain damage- Normal pressure hydrocephalus- After head trauma, intracranial bleeding or brain tumors- Drug/alcohol‑related (e.g., Wernicke‑Korsakoff syndrome)- Wilson disease- Vitamin deficiencies (thiamine, B6, B12, folate)- Metabolic: exsiccosis, uremia, electrolyte imbalances, hypothyroidism and hyperthyroidism- Inflammatory/infectious: syphilis, progressive multifocal leukoencephalopathy, HIV, Creutzfeldt-Jakob disease Clinical features:- Memory impairment- Speech: aphasia, word-finding difficulties, semantic paraphasia- Intellectual capacities, reasoning, planning capabilities, and self-control- Spatial-temporal awareness (however, the awareness of oneself remains stable for a long time)- Apathy- Changes in personality, mood, and behavior: depression, seemingly unconcerned mood and cognitive impairment is downplayed Diagnostics:- Personal and collateral history of cognitive and behavioral changes- Drug history- Screening for depression- Physical and neurological examination- Cognitive assessment: Mini-Mental State Examination (MMSE), Clock-drawing test- Lab tests in all patients: screening for vitamin B12 deficiency (cobalamin) and hypothyroidism- Imaging in all patients: noncontrast head CT or MRI Treatment:- Cholinesterase inhibitors (mild to moderate cases): donepezil, rivastigmine, galantamine- Memantine (moderate to severe cases)
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  • Alzheimer disease Alzheimer disease is a chronic neurodegenerative disease and the leading cause of dementia. ApoE-2: ↓ risk of sporadic formApoE-4: ↑ risk of sporadic formAPP, presenilin-1, presenilin-2: familial forms (10%) with earlier onset Clinical features:- Common order of cognitive impairments1. Short term memory (insidious onset and slow progress)2. Language3. Temporal and spatial orientation- Apraxia (inability to perform coordinated movements), alexia (inability to read), agnosia, acalculia- Primary progressive aphasia- Impairment of executive functions and judgment- Patients are usually not oriented to person, place time and events- Behavioral changes: Apathy, aggression, irritability, and agitation- Mood disorders: Depression; later patients are often unconcerned and tend to downplay their cognitive impairments- Anxiety and mutism- Insomnia- Hallucinations and paranoia Diagnostics:- Neuropsychological testing (e.g., Mini-Mental State Examination): screens for patients with dementia- Fullfilment of DSM-5 criteria- Review medication- Laboratory tests (rule out hypothyroidism, B12 deficiency)- Cerebrospinal fluid: ↑ Phospho-tau protein, ↓ β-amyloidproteins Aβ1-42- CT: Signs of generalized or focal cerebral atrophy, disproportionate atrophy of hippocampus and/or medial temporal lobe- Clinical assessment for depression Treatment:- Mild to moderate (MMSE score of 19-26 for mild disease, 10-18 for moderate disease): donepezil, galantamine, rivastigmine (acetylcholinesterase inhibitors)- Moderate to severe (may be given in addition to acetylcholinesterase inhibitors): memantine (NMDA-receptor antagonist)- Lifestyle modifications (behavioral interventions for patients and care-givers)- Cognitive rehabilitation: memory training - Physical exercise- Occupational therapy Complications:- Infections: particularly aspiration pneumonia contributes to AD-related mortality. - Malnourishment/dehydration- Cerebral amyloid angiopathy increases the risk for intracerebral hemorrhage
  • Frontotemporal dementia Etiology:- Associated with pathological intracellular inclusion bodies (Pick bodies) that are caused by mutations in tau or progranulin proteins- Also associated with ubiquitin inclusion bodies hypothesized to be caused by dysfunction of the ubiquitin proteasome system- Familial predisposition (autosomal dominant): ∼ 10-25% of FTD cases Clinical features:- Early changes in personality and behavior → failure to observe social etiquette→ Apathy→ Disinhibition (e.g., hypersexual behavior)→ Exaggerated emotional display→ Irritability→ Binge eating (particularly of sweet foods)- Changes in cognitive functioning→ Intelligence, orientation, and memory initially intact→ Aphasia (but no apraxia)→ Lack of attention- Motor deficits: Parkinsonism (in later stages) Diagnostics:- Clinical diagnosis of a dementia syndrome in accordance with DSM-5- Other tests to rule out or confirm specific abnormalities→ CT/MRI: atrophy of the frontal and/or temporal lobes→ Laboratory tests: to rule out other etiologies of dementia (e.g., infections, hypothyroidism) Treatment: Symptomatic- Dementia symptoms: Cholinesterase inhibitors and memantine are usually not effective and may, in some cases, even worsen symptoms.
  • Lewy body dementia Second most common form of neurodegenerative dementia (10-20% of dementia cases). Clinical features:- Dementia- Fluctuating cognition/attention- Extrapyramidal motor symptoms- Visual hallucinations and paranoid episodes- Parkinsonism (e.g., rigidity, bradykinesia, postural instability)- Frequent falls- REM sleep behavior disorder (e.g., dream enactment)- Increased sensitivity to neuroleptic medication and metabolic perturbation Therapy: - Symptomatic treatment: Supportive therapy, behavioral therapy, physical therapy- Pharmacotherapy: Parkinsonian symptoms: generally analogous to treatment of Parkinson's disease- Dementia symptoms: generally analogous to treatment of major neurocognitive disorder
  • Vascular dementia Etiology:- VD may occur as a result of a prolonged and severe cerebral ischemia of any etiology; primarily → Large artery occlusion (usually cortical ischemia)→ Lacunar stroke (small vessel occlusion resulting in subcortical ischemia)→ Chronic subcortical ischemia Pathophysiology:- Small vessel disease: Lipohyalinosis, microatheroma and/or amyloid beta deposition- Large vessel disease: Atherosclerosis (risk factors include hypertension, diabetes, and hyperlipidemia) Clinical features:- Symptoms tend to progress gradually or stepwise- Impaired memory- Reduced executive functioning- Loss of visuospatial abilities- Confusion- Apathy- Motor disorders (e.g., gait disturbance, urinary incontinence) Diagnostics:- Dementia criteria based on DSM-5- Ultrasound: Doppler examination of critical vessels (particularly the carotid arteries) for signs of cerebrovascular risk- Cranial CT/MRI Treatment:- Symptomatic treatment of dementia: Cognitive training- Eliminate individual risk factors: e.g., antihypertensive therapy, treatment of diabetes, weight reduction- Consider antiplatelet drugs (assess risk of bleeding prior to administration!)
  • Persistent vegetative state Persistent vegetative state (PVS) is a clinical condition in which function of the cortex is impaired while function of the brainstem is preserved for a period of more than one month. Etiology:- Traumatic brain injury- Diffuse cerebral hypoxia following, e.g., strangulation, cardiac arrest, near drowning Clinical features:- Intact sleep-wake cycles with periods of wakefulness- Loss of perceptual and self-awareness- Autonomic function and reflexes retained to variable degrees→ Sufficient cardiovascular, respiratory, thermoregulatory, gastrointestinal and renal function but bowel and bladder incontinence→ Variable preservation of reflexes (e.g., pupillary, corneal, vestibulo-ocular, gag, cough) Diagnostics:- Clinical diagnosis based on ≥ 1 month of intact sleep-wake cycles, loss of perceptual and self-awareness, and autonomic functions retained to variable degrees- CT/MRI: nonspecific diffuse or multifocal abnormalities involving the gray and white matter; decrease in cerebral blood flow- EEG: diffuse generalized polymorphic delta and/or theta activity
  • Guillain-Barré syndrome Etiology:- About ⅔ of GBS patients experience symptoms of an upper respiratory or gastrointestinal tract infection 1-4 weeks prior to onset of GBS.- Pathogens associated with GBS: Campylobacter jejuni, Cytomegalovirus, Epstein-Barr virus, HIV, influenza, and Mycoplasma pneumoniae Clinical features:- Back and limb pain, esp. paresthesias affecting distal extremities- Ascending paralysis: Bilateral flaccid paralysis spreads from the lower to the upper limbs in a “stocking‑glove” distribution.- Cranial nerve involvement: frequently bilateral facial nerve involvement (facial diplegia)- Landry paralysis: involvement of the respiratory muscles- Reduced or absent muscle reflexes- Peripheral, symmetric paresthesias in the hands and feet- Neuropathic pain develops in about ⅔ of patients- Cardiovascular autonomic dysfunction (arrhythmia), voiding dysfunction, and/or intestinal dysfunction Diagnostics:- Cerebrospinal fluid: Albuminocytologic dissociation: elevated protein levels and normal cell counts in cerebrospinal fluid (CSF); CSF cell counts higher than 50 cells/μl CSF indicate that GBS is unlikely! - Serological screening to identify potential pathogens (e.g., Campylobacter jejuni)- Detection of antibodies directed against gangliosides (e.g., anti‑GM1 antibodies)- Electroneurography: reduced nerve conduction velocity (NCV) due to demyelination: increased F‑wave latency Treatment:- Monitor cardiac and respiratory function: in some cases, intensive care unit (ICU) treatment and intubation may be indicated- High dose of intravenous immunoglobulins
  • Idiopathic intracranial hypertension (Pseudotumor cerebri) Epidemiology: - Predominantly affects obese women aged 15-45 years Risk factors:- Obesity- Growth hormone- Tetracyclines- Excessive vitamin A or derivatives Clinical features: - Diffuse headaches- Transient vision loss- Photopsia (seeing flashes of light)- Diplopia- Retrobulbar pain- Pulsatile tinnitus- Cranial nerve palsies (especially CN VI) Diagnostics:- Opthalmoscopy: bilateral papilledema- Visual field test may show peripheral loss of vision- MRI: To rule out other causes of increased ICP- Lumbar puncture:→ Elevated opening pressure > 20-25 cm H2O (with patient lying on the side, legs extended)→ Normal CSF analysis with no signs of inflammation or bleeding Treatment: - Weight loss- First line: Acetazolamide→ Add furosemide if acetazolamide alone is not sufficient- Surgery: if conservative measures fail→ Optic nerve sheath fenestration→ CSF shunt
  • Infantile spasms (West syndrome) Epidemiology:- Age of onset: 3-7 months- Sex: ♂ > ♀ Etiology:- Perinatal infections- Hypoxic-ischemic injury- PKU- Tuberous sclerosis complex- Idiopathic Clinical features:- Sudden symmetric, synchronous spasms, usually in clusters of 5-10- Jerking flexion (jackknife movement) or extension of the neck, torso, and extremities- Followed by a tonic phase EEG:- Hypsarrhythmia: characteristic finding; high-voltage delta waves with irregular multifocal spikes and slow waves Treatment:- First-line treatment: ACTH, prednisone, or vigabatrin
  • Metastatic brain cancer Incidence:- Order of increased metastatic brain frequency: Lung > Breast > Melanoma > Colon Primary solitary brain metastases:- Breast- Colon- Renal cell carcinoma Multiple brain metastases:- Lung cancer- Malignant melanoma Treatment:- Limited brain metastases: Surgical resection or stereotactical radiosurgery- Extensive brain metastases: Stereotactic radiosurgery, whole brain radiation therapy, chemotherapy- Glucocorticoids to reduce tumor edema
  • Tethered cord syndrome Abnormal stretching of the spinal cord caused by adhesions or obstructions that tether the cord to the base of the spinal canal Etiology:- Meningeal adhesions- Terminal filament adhesions or thickening- Lipoma, dermoid cysts- Tumors Symptoms:- (Motion-dependent) back pain- Sensory and motor deficits, skeletal malformations (e.g., foot deformities, scoliosis)- Bladder/bowel dysfunction- Children may begin to stumble after learning to walk.- Skin lesion on lower back (e.g., discoloration, nevi, hemangioma) Diagnosis: MRI shows abnormally low position of the conus medullaris. Treatment: removal of structure tethering the spinal cord (e.g., adhesiolysis, resection of lipomas) → prevents progressive deterioration, corrects existing conditions (e.g., urinary retention)
  • Spinal cord compression Etiology:- Spinal injury (eg, motor vehicle crash)- Malignancy (eg, lung, breast, prostate cancers; myeloma)- Infection (eg, epidural abscess) Clinical features:- Gradually worsening, severe local back pain- Pain worse in the recumbent position/at night- Early signs: Symmetric lower extremity weakness, hypoactive/absent deep-tendon reflexes- Late signs: Bilateral Babinski reflex, decreased rectal sphincter tone, paraparesis/paraplegia with increased deep-tendon reflexes, sensory loss Treatment:1. Immediate management- IV glucocorticoids- Opioids for further pain control if necessary2. Emergency MRI3. Radiation-oncology & neurosurgery consultations
  • Central cord syndrome Injury to the central region of the spinal cord (central corticospinal tracts and decussating fibers of the lateral spinothalamic tract). Epidemiology:- Most common type of incomplete cord syndrome- Common in the elderly with preexisting degenerative changes in the cervical spine Etiology:- Syringomyelia- Degenerative spine disease- Cervical spondylosis- Traumatic disc herniation- Hyperextension injuries (e.g., car crash → whiplash injury) Clinical features:- Bilateral motor paresis (upper > lower extremities; distally > proximally)The impairment of the extremities is disproportionate since motor fibers supplying the arms are closer to the central part of the corticospinal tract. The leg fibers run more laterally.- Variable sensory impairment: Sometimes buring pain/loss of temperature in the arms- Reflex loss (e.g., tricep reflex) at the level of injury due to damage to fibers as they cross from the dorsal to ventral horn Diagnostics: MRI of the cervical spine without contrast
  • Spinal stenosis Etiology: Progressive narrowing of the central spinal canal, intervertebral neural foramen and/or lateral recess (cervical C2 or lumbar spine L1) caused by:- Degenerative joint disease (most common): Spondylolisthesis (antero- or posterior); Disc space narrowing; Facet joint hypertrophy- Iatrogenic: following spinal surgery such as laminectomy- Systemic disease: Paget's disease, ankylosing spondylitis, tumors Clinical features:- Lumbar stenosis- Load-dependent lower back pain- Bilateral radiation of pain to buttocks and/or legs- Associated cramping, numbness, weakness, or tingling in the legs- Exacerbating factors: Spinal extension (standing, walking downhill, or even at rest)- Relieving factors: Spinal flexion (sitting, cycling, walking uphill, bending forward)- Ankle-brachial index: Normal Diagnostics:- X-ray: degenerative joint changes- MRI (confirmatory test) Treatment:- NSAIDS- Physiotherapy, which focuses on exercises that promote stability and abdominal muscle strengthening- Epidural steroid injections if symptoms persist despite above treatment (may improve ∼ 50% of cases)- Surgery: if conservative therapy fails→ Removal of any bony attachments→ Laminectomy (decompression surgery): removal of the dorsal part of the vertebra (lamina) which covers the spinal cord
  • Pronator drift Physical examination finding that is relatively sensitive and specific for upper motor neuron or pyramidal/corticospinal tract disease. Upper motor neuron lesions cause more weakness in the supinator muscles compared to the pronator muscles of the upper limb.
  • Sleepwalking disorder Non-REM sleep arousal disorder (no memory of dream) Epidemiology:- Discrete episodes are common (up to 7% of adults and 30% of children), but the disorder is rare.- Associated with sleep deprivation, irregular sleep schedules Etiology: idiopathic or genetic (inherited in 80% of cases) Clinical features- Recurrent episodes during the first third of the sleep cycle, including sitting up, walking, or eating (rarely, violence)- Blank stare and difficulty arousing patient during the episode- Followed by amnesia of the event Treatment:- Education and reassurance- Ensuring safe sleep environment to reduce the risk of physical harm or wandering outdoors- In refractory cases, benzodiazepines
  • Sleep terror disorder Non-REM sleep arousal disorder (no memory of dream) Epidemiology: Discrete episodes of sleep terrors are relatively common (up to 2% of adults and 20% of children), but the disorder is rare. Etiology: unknown; thought to be genetic (family history) Clinical features:- Screaming or crying suddenly upon awakening- Intense fear and agitation- Tachypnea, diaphoresis, tachycardia during episodes- Difficulty arousing patients during episodes; patients will often return to sleep and not remember the episode the next day Treatment:- Education and reassurance (disorder is usually self-limited)- Remove dangerous objects from bedroom to reduce risk of self-injury- In refractory cases, benzodiazepines
  • Restless legs syndrome Relatively common, neurological sleep disorder characterized by unpleasant sensations in the legs and a strong urge to move them.  Etiology: - Idiopathic, but is familial in 25-75% of cases - Chronic conditions:→ Iron deficiency with or without anemia, vitamin deficiency→ Peripheral neuropathy (i.e., in diabetes mellitus)→ End-stage renal disease (uremia)→ Inflammatory conditions: celiac disease, rheumatoid arthritis, inflammatory bowel diseases- Psychiatric: depression, anxiety disorders- Neurological: Parkinson's disease, polyneuropathies, spinal cord diseases, multiple sclerosis- Drugs: antidepressants (e.g., TCAs, SSRIs, SNRIs), dopamine antagonists (neuroleptics, metoclopramide, MDMA), lithium, beta blockers- Pregnancy Clinical features:- A recurrent urge to move the legs that is typically relieved by movement and worsened by rest.- Often worse in the evening and at night. May occur exclusively at night.- Often accompanied by dysesthesias (e.g., pain, pins and needles, itching, tickling, or crawling sensations). Diagnostics:- Laboratory tests: Iron studies (best initial), kidney function, TSH, vitamin B12, folic acid, Mg2+, CBC- Polysomnogram: quantification of periodic limb movements of sleep (PLMS) Treatment:- Lifestyle changes: abstinence from coffee, nicotine, and alcohol- Supplemental iron if serum ferritin < 50 ng/mL- Medical therapy: indicated in patients with significant functional and sleep impairment→ Dopamine agonists (first-line drugs): pramipexole, ropinirole, rotigotine, cabergoline, levodopa with carbidopa → Anticonvulsants: gabapentin or pregabalin
  • Postconcussive syndrome Can occur a few hours or days after a traumatic brain injury. Clinical features:- Headache- Confusion- Amnesia- Difficulty concentrating or with multitasking- Vertigo- Mood alteration- Sleep disturbance- Anxiety Treatment:- Resolve with symptomatic within weeks to months- Some may have persistent symptoms lasting ≥ 6 months
  • Brain death Irreversible, complete loss of function of the entire brain (including the brainstem), even if cardiopulmonary functions can be upheld by artificial life support. Requirements for the diagnosis of brain death1. Clinical setting- Loss of brain function must be attributable to a specific cause- Irreversible loss of brain function- Factors that may impede proper clinical judgment must be absent. E.g., electrolyte imbalances, locked-in syndrome, abnormal core temperature, abnormal systolic blood pressure, intoxication or effects of CNS-depressing drugs/neuromuscular blockade2. Neurological examination- Coma (with a known cause)- Absence of brainstem reflexes→ Pupillary light reflex→ Vestibuloocular reflex→ Oculocephalic reflex→ Corneal reflex→ Gag reflex → Cough reflex → No reaction to irritation of trigeminal nerve branches (normally painful)- Deep tendon reflexes are occasionally seen in brain-dead patients who have intact spinal cords- Apnea (absence of breathing drive) 3. Ancillary tests: only to be performed if clinical examination and/or apnea testing are inconclusive, or if patient is < 1 year- Electroencephalography (EEG) Management: If brain death is proven, no consent is required to remove life support or other forms of treatment (e.g., antibiotic therapy) If spontaneous breathing is present, the medulla is intact! If the corneal reflex is present, the pons is intact! If the pupillary light reflex is present, the midbrain is intact!
  • REM sleep disorder Epidemiology:- Prevalence ~ 0.5%- Usually in older men (> 50 years) Risk factors: narcolepsy, psychiatric medications, neurodegenerative disorders Clinical features:- Physically acting out dreams during sleep (sometimes leading to injury to self or others)- Alert and orientated after awakening Treastment:- Remove dangerous objects from bedroom to prevent injury- Discontinue causative medications- Benzodiazepines (e.g., clonazepam)- Melatonin analogs

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