Egyptian Board Neurology cheat sheet

Broca area = posterior inferior frontal gyrus (dominant hemisphere); Wernicke area = posterior superior temporal gyrus; damage gives nonfluent vs fluent aphasia respectively.

Internal capsule: anterior limb (thalamocortical), genu (corticobulbar), posterior limb (corticospinal, sensory); lenticulostriate arteries supply it - hypertension-related lacunes.

Lateral medulla (Wallenberg) syndrome: PICA/vertebral occlusion → ipsilateral Horner, facial numbness, ataxia, dysphagia; contralateral pain-temperature loss.

Dopamine synthesis: tyrosine → L-DOPA (tyrosine hydroxylase, rate-limiting) → dopamine (DOPA decarboxylase); MAO-B and COMT degrade it.

Excitotoxicity: glutamate excess → NMDA receptor Ca2+ influx → calpain, NO synthase, mitochondrial failure; basis of ischemic penumbra loss.

Cerebral blood flow thresholds: ~50 mL/100 g/min normal; 15-20 mL/100 g/min electrical failure; <10 mL/100 g/min membrane/infarct core.

Neuropathology hallmarks: Alzheimer - amyloid plaques and tau tangles; Parkinson - alpha-synuclein Lewy bodies; prion - spongiform change, PrP-res.

Axonal transport: fast anterograde (kinesin, 200-400 mm/day), retrograde (dynein); rabies and tetanus toxin travel retrogradely.

EEG frequency bands: delta <4 Hz, theta 4-7 Hz, alpha 8-13 Hz, beta 14-30 Hz; alpha attenuates with eye opening (reactivity).

Normal adult wake EEG: posterior alpha rhythm 8-13 Hz, symmetric, with anterior-posterior gradient; sleep spindles 11-16 Hz mark N2.

Nerve conduction: demyelination → slowed conduction velocity, prolonged distal latency, conduction block; axonal loss → reduced amplitude.

EMG spontaneous activity: fibrillations and positive sharp waves = active denervation; myotonic discharges = waxing/waning sound in myotonia.

Myasthenia gravis: repetitive nerve stimulation shows >10% decrement; Lambert-Eaton shows increment >100% at high-frequency or post-exercise.

ALS EMG: active denervation plus chronic reinnervation (large polyphasic units) in multiple myotomes and both bulbar/limb regions.

Evoked potentials: VEP P100 delay in optic neuritis; BAEP interpeak I-III/V prolongation in acoustic neuroma or brainstem lesion; SSEP for coma prognosis.

Status epilepticus EEG: continuous or recurrent spikes/sharp waves >30 min; periodic lateralized discharges (PLEDs) suggest focal structural lesion.

IV thrombolysis window: alteplase up to 4.5 h from onset; mechanical thrombectomy up to 6 h (extended to 24 h with perfusion imaging selection).

NIHSS ≥6 plus large vessel occlusion (ICA, M1) = thrombectomy candidate; ASPECTS ≤5 indicates large established infarct and poorer benefit.

ICH: basal ganglia most common site; hematoma expansion occurs in ~30% within 24 h; BP target systolic ~140 mmHg per current guidance.

SAH: thunderclap headache; CT sensitivity near 100% within 6 h; xanthochromia in CSF after 12 h; nimodipine prevents delayed cerebral ischemia.

Cerebral venous thrombosis: headache, seizures, papilledema; empty delta sign on contrast CT; D-dimer often elevated; anticoagulation even with hemorrhagic infarct.

Stroke thrombolysis contraindications: BP >185/110 mmHg, platelets <100,000, INR >1.7, recent surgery, prior ICH, glucose <50 mg/dL.

Cardioembolic stroke: atrial fibrillation most common; anticoagulation (DOAC preferred) starts 4-14 days depending on infarct size.

Malignant MCA infarction: swelling days 2-5; decompressive hemicraniectomy reduces mortality in patients <60 years with large infarct.

Seizure onset classification: focal (aware/impaired awareness, focal to bilateral tonic-clonic) vs generalized (absence, myoclonic, tonic-clonic) vs unknown.

Focal onset: temporal lobe most common; automatisms, déjà vu, postictal confusion; often hippocampal sclerosis on MRI.

Absence epilepsy: 3 Hz spike-and-wave, onset in childhood, no postictal state; ethosuximide first line; sodium channel blockers may worsen.

Status epilepticus: benzodiazepine first (IV lorazepam 0.1 mg/kg or IM midazolam), then fosphenytoin/valproate/levetiracetam; refractory → anesthetic infusion.

Teratogenicity: valproate highest risk (neural tube defects); avoid in women of childbearing age; lamotrigine and levetiracetam preferred.

Enzyme inducers (carbamazepine, phenytoin, phenobarbital) reduce OCP and DOAC levels; lamotrigine levels fall with estrogen-containing pills.

Juvenile myoclonic epilepsy: morning myoclonus, generalized tonic-clonic seizures; valproate is highly effective; lifelong therapy usually needed.

SUDEP risk factors: generalized tonic-clonic seizures, nocturnal seizures, poor adherence, early-onset epilepsy, polytherapy.

Migraine: ≥5 attacks of 4-72 h, unilateral, pulsating, moderate-severe, aggravated by activity, plus nausea or photophobia/phonophobia.

Triptans: 5-HT1B/1D agonists; contraindicated in coronary disease, uncontrolled hypertension, and within 24 h of ergotamine.

Cluster headache: severe periorbital pain with ipsilateral lacrimation, rhinorrhea, ptosis; high-flow oxygen and subcutaneous sumatriptan abort.

Medication overuse headache: headache ≥15 days/month with regular acute medication use; treat by withdrawal plus prophylaxis.

Giant cell arteritis: age >50, scalp tenderness, jaw claudication, ESR/CRP elevated; give steroids immediately, biopsy within 2 weeks.

Red flags (SNOOP): systemic symptoms, neurologic deficit, onset sudden, older age, pattern change; require imaging or CSF.

Idiopathic intracranial hypertension: papilledema, normal CSF, elevated opening pressure; acetazolamide plus weight loss.

Trigeminal neuralgia: lancinating V2/V3 pain, triggered by touch; carbamazepine first line; MRI to exclude neurovascular compression or mass.

Guillain-Barré syndrome: ascending areflexic weakness, albuminocytologic dissociation after 1-2 weeks; IVIG or plasma exchange; monitor vital capacity.

CIDP: progressive/relapsing over >8 weeks, demyelinating NCS, responds to steroids, IVIG, or plasma exchange.

Diabetic neuropathy: distal symmetric sensory first; autonomic features; tight glycemic control and symptomatic agents (duloxetine, pregabalin).

Myasthenia gravis: fatigable ptosis/diplopia, anti-AChR or anti-MuSK; thymoma workup with chest CT; pyridostigmine plus immunosuppression.

Lambert-Eaton: proximal weakness, hyporeflexia improving with exercise, anti-VGCC; associated with small cell lung cancer.

Duchenne muscular dystrophy: X-linked dystrophin defect, calf pseudohypertrophy, Gowers sign, elevated CK; cardiomyopathy and respiratory failure.

ALS: upper and lower motor neuron signs without sensory loss; riluzole and edaravone modestly slow progression; noninvasive ventilation improves survival.

Myotonic dystrophy type 1: CTG repeat, distal weakness, myotonia, cataracts, cardiac conduction block; monitor ECG.

MS diagnosis (McDonald criteria): dissemination in space (≥2 of 4 typical regions) and time, or CSF-specific oligoclonal bands substituting for time.

Typical MS regions: periventricular, cortical/juxtacortical, infratentorial, spinal cord; MRI shows ovoid T2 lesions perpendicular to ventricles (Dawson fingers).

Acute MS relapse: high-dose IV methylprednisolone 1 g daily for 3-5 days shortens relapse but does not alter long-term disability.

Disease-modifying therapy: high-efficacy options (natalizumab, anti-CD20, alemtuzumab) for active disease; monitor JC virus antibody for natalizumab.

NMOSD: anti-aquaporin-4, longitudinally extensive transverse myelitis (≥3 segments), optic neuritis; treat with rituximab or eculizumab, avoid interferons.

MOGAD: anti-MOG antibody, optic neuritis with disc edema, ADEM-like presentation; often steroid-responsive with relapse on withdrawal.

ADEM: post-infectious multifocal demyelination in children, encephalopathy required; steroids first line.

CSF in MS: oligoclonal bands present in >90%, IgG index elevated, normal protein; pleocytosis usually <50 cells.

Parkinson disease: bradykinesia plus rigidity or rest tremor; asymmetric onset; levodopa remains most effective; motor fluctuations after 5-10 years.

Parkinson-plus: MSA (autonomic failure), PSP (vertical gaze palsy, falls), CBD (asymmetric cortical signs), DLB (early dementia, hallucinations).

Drug-induced parkinsonism: dopamine antagonists and metoclopramide; symmetric, no rest tremor; resolves after withdrawal over weeks to months.

Essential tremor: bilateral postural/kinetic tremor, improves with alcohol; propranolol and primidone first line.

Huntington disease: CAG repeat >36, chorea, psychiatric features, autosomal dominant; genetic counseling before testing.

Alzheimer disease: episodic memory first, medial temporal atrophy; cholinesterase inhibitors for mild-moderate, memantine for moderate-severe.

Frontotemporal dementia: behavioral variant or progressive nonfluent aphasia; MRI shows frontal/temporal atrophy; no approved disease-modifying therapy.

Ataxia: Friedreich (GAA repeat, cardiomyopathy), spinocerebellar ataxias (autosomal dominant), vitamin E and B12 deficiency are reversible causes.

Bacterial meningitis: empiric ceftriaxone plus vancomycin, add ampicillin for Listeria (age >50, immunocompromised); dexamethasone before first antibiotic dose.

TB meningitis: subacute, basal meningeal enhancement, hydrocephalus, CSF lymphocyte-predominant with low glucose; treat with 4-drug regimen plus steroids.

HSV encephalitis: fever, seizures, temporal lobe changes on MRI; start IV acyclovir before LP results; PCR on CSF confirms.

HIV neurology: toxoplasmosis (multiple ring-enhancing lesions) vs primary CNS lymphoma (periventricular, elevated EBV PCR in CSF).

HIV-associated neurocognitive disorder: screen with MoCA; treat with antiretrovirals; avoid drugs with high CNS penetration issues if adherence poor.

Neurosyphilis: CSF VDRL specificity high, sensitivity low; treat with IV penicillin G for 10-14 days.

Cryptococcal meningitis: India ink, CSF cryptococcal antigen; treat with amphotericin B plus flucytosine, then fluconazole.

Autoimmune encephalitis: anti-NMDA receptor (psychiatric onset, dyskinesias) or anti-LGI1 (faciobrachial dystonic seizures); steroids, IVIG, plasma exchange.

Brain metastases: most common adult brain tumor; multiple at gray-white junction; MRI with contrast; steroids reduce edema, whole-brain RT or SRS per number/size.

Glioblastoma: ring-enhancing with necrotic center, IDH wild-type; treat with resection, temozolamine plus radiotherapy; median survival ~15 months.

Meningioma: extra-axial, dural tail, homogeneously enhancing; observation if small and asymptomatic.

Pituitary adenoma: bitemporal hemianopia from chiasm compression; prolactinoma treated with dopamine agonists.

Paraneoplastic syndromes: anti-Hu (small cell lung cancer, encephalomyelitis), anti-Yo (ovarian, cerebellar degeneration), anti-NMDAR (ovarian teratoma).

Spinal cord compression: back pain plus motor/sensory/autonomic deficits; dexamethasone immediately, MRI whole spine, urgent decompression.

Hepatic encephalopathy: asterixis, elevated ammonia, EEG triphasic waves; treat with lactulose and rifaximin.

Wernicke encephalopathy: confusion, ataxia, ophthalmoplegia; thiamine before glucose; MRI shows medial thalamic and periaqueductal changes.

CT head: hyperdense acute blood (60-80 HU), hypodense infarct after 6-12 h; loss of insular ribbon and dense MCA sign in early ischemia.

MRI sequences: DWI positive within minutes of infarct, T2/FLAIR after hours, GRE/SWI for hemorrhage, contrast for blood-brain barrier breakdown.

Hemorrhage age on MRI: acute (deoxyhemoglobin, T1 iso, T2 dark), subacute (methemoglobin, T1 bright), chronic (hemosiderin, dark on all).

Vascular imaging: CTA for large vessel occlusion and aneurysm; MRA without contrast; DSA remains gold standard for vasculitis and small aneurysms.

Carotid Doppler: peak systolic velocity >230 cm/s suggests >70% stenosis; confirm with CTA/MRA before intervention.

MRI contraindications: pacemakers without MRI-conditional status, metallic intraocular foreign bodies, cochlear implants; gadolinium caution in severe renal failure.

Ring-enhancing lesion differential: abscess, metastasis, glioblastoma, tuberculoma, toxoplasmosis; MR spectroscopy and DWI (restricted in abscess) help.

CT perfusion: core (CBF <30%) vs penumbra (Tmax >6 s); mismatch guides late-window thrombectomy.

Coma examination: GCS, pupillary light reflex, oculocephalic/oculovestibular reflexes, corneal and gag reflexes, motor response to pain.

Herniation: unilateral blown pupil = uncal herniation; Cushing triad (hypertension, bradycardia, irregular respiration) signals raised ICP.

Raised ICP: head elevation 30 degrees, hyperventilation to PaCO2 30-35 mmHg as bridge, mannitol or hypertonic saline, urgent neurosurgical consult.

Brain death: documented cause, unresponsive coma, absent brainstem reflexes, apnea test with PaCO2 rise; confirmatory test when apnea test not tolerated.

Status epilepticus and stroke are time-critical; door-to-needle target <60 min for thrombolysis; glucose and temperature control in neurocritical care.

Ethics: assess decision-making capacity (understanding, appreciation, reasoning, choice); surrogate decision-making and advance directives guide care.

Patient safety: medication reconciliation for anticoagulants and antiepileptics; hand hygiene prevents ventriculostomy-related infection.

Do-not-resuscitate orders require informed consent from patient or surrogate; document discussions; withdrawal of life support follows local legal framework.