Iran Specialty Board Neurology flashcards

36 cards. Read the term and the definition here. The deck at the top of this page is optional.

DWI-FLAIR mismatch

In wake-up stroke, restricted diffusion on DWI without FLAIR hyperintensity indicates onset within about 4.5 hours, supporting intravenous thrombolysis when other criteria are met.

Spot sign

Contrast extravasation on CT angiography within an intracerebral hematoma predicts hematoma expansion and worse outcome, prompting aggressive blood pressure control and reversal of anticoagulation.

Xanthochromia

Yellowish CSF supernatant from bilirubin breakdown, appearing about 12 hours after subarachnoid hemorrhage; it distinguishes true hemorrhage from traumatic lumbar puncture.

NIHSS large-vessel occlusion clue

A score of 6 or more with cortical signs such as gaze deviation, aphasia, or neglect suggests large-vessel occlusion and warrants immediate CT angiography for thrombectomy evaluation.

Status epilepticus definition

Continuous seizure activity or recurrent seizures without recovery lasting 5 minutes or more, requiring immediate benzodiazepines followed by a second-line antiepileptic loading dose.

Juvenile myoclonic epilepsy

Generalized epilepsy with morning myoclonic jerks, 3-4 Hz polyspike-wave discharges, and photosensitivity; valproate is highly effective but avoided in women of childbearing potential.

Breach rhythm

A benign EEG variant over a skull defect with faster, higher-amplitude activity; it must not be misinterpreted as an epileptiform discharge or seizure pattern.

SUDEP risk factors

Uncontrolled generalized tonic-clonic seizures, nocturnal seizures, poor medication adherence, and young adult male sex increase sudden unexpected death in epilepsy risk; supervision and adherence counseling help.

Albuminocytologic dissociation

Elevated CSF protein with normal cell count, typical of Guillain-Barre syndrome after the first week; it supports the diagnosis alongside progressive areflexic weakness.

Repetitive nerve stimulation decrement

A greater than 10% decline in compound muscle action potential amplitude with low-frequency stimulation supports myasthenia gravis, reflecting postsynaptic neuromuscular junction failure.

CMT1A genetics

Charcot-Marie-Tooth type 1A results from a PMP22 duplication on chromosome 17p11.2, causing uniform demyelinating conduction slowing, distal weakness, and pes cavus.

Fibrillation potentials

Spontaneous EMG discharges of denervated muscle fibers appearing weeks after nerve injury; they indicate active denervation and are absent in acute injury.

McDonald criteria

Multiple sclerosis diagnosis requires dissemination in space and time; CSF oligoclonal bands can substitute for dissemination in time when typical MRI lesions are present.

Area postrema syndrome

Refractory nausea, vomiting, or hiccups from a medullary lesion, a core clinical feature of neuromyelitis optica spectrum disorder associated with anti-aquaporin-4 antibodies.

Anti-LGI1 encephalitis

Autoimmune encephalitis with faciobrachial dystonic seizures, hyponatremia, and limbic MRI changes; it responds to corticosteroids and immunotherapy, often without a tumor.

Longitudinally extensive myelitis

A spinal cord lesion spanning three or more vertebral segments, characteristic of neuromyelitis optica spectrum disorder and also seen in MOG antibody disease.

Progressive supranuclear palsy

Atypical parkinsonism with vertical supranuclear gaze palsy, early falls, axial rigidity, and frontal cognitive impairment; levodopa response is poor and no disease-modifying therapy exists.

Huntington disease genetics

Autosomal dominant CAG trinucleotide repeat expansion in the HTT gene; 36 or more repeats is pathogenic, and larger repeats cause earlier onset with anticipation.

Tardive dyskinesia treatment

Involuntary orofacial movements after chronic dopamine antagonist exposure; VMAT2 inhibitors such as valbenazine or deutetrabenazine are first-line, while anticholinergics may worsen symptoms.

Cluster headache treatment

High-flow oxygen and subcutaneous sumatriptan abort attacks; verapamil is first-line prophylaxis, with a baseline ECG because of dose-dependent bradycardia and heart block.

Trigeminal neuralgia

Paroxysmal electric-shock facial pain in the V2 or V3 distribution triggered by touch or chewing; carbamazepine or oxcarbazepine is first-line, and MRI excludes vascular compression.

Medication-overuse headache

Headache on 15 or more days monthly with overuse of acute medications for more than three months; treatment requires withdrawal of the overused drug and prophylactic therapy.

MGMT promoter methylation

Methylation silences the DNA repair gene MGMT and predicts benefit from temozolomide in glioblastoma, guiding standard chemoradiation decisions.

Primary CNS lymphoma biopsy

Stereotactic biopsy is required before corticosteroids because steroids can rapidly lyse tumor cells and obscure histology; high-dose methotrexate is first-line therapy.

Dexamethasone for tumor edema

Corticosteroids reduce peritumoral vasogenic edema and intracranial pressure from brain tumors; they do not treat the tumor itself and are tapered after definitive therapy.

Listeria meningitis coverage

Ampicillin is added to empiric vancomycin plus ceftriaxone for adults over 50 or immunocompromised patients because Listeria is resistant to cephalosporins.

HSV encephalitis

Fever, altered consciousness, seizures, and temporal lobe MRI changes; start intravenous acyclovir immediately and confirm with CSF PCR, since early treatment improves outcome.

PML imaging

JC virus demyelination shows asymmetric, non-enhancing white matter lesions without mass effect; treatment is restoring immune function, and immune reconstitution inflammatory syndrome may follow.

Lewy body dementia

Dementia with fluctuating cognition, visual hallucinations, parkinsonism, and REM sleep behavior disorder; patients are highly sensitive to antipsychotics, and cholinesterase inhibitors may help.

Normal pressure hydrocephalus

Gait disturbance, urinary incontinence, and cognitive decline with ventriculomegaly; a large-volume lumbar puncture or lumbar drain trial predicts response to shunt placement.

Internuclear ophthalmoplegia

Impaired adduction with contralateral abducting nystagmus from a medial longitudinal fasciculus lesion; bilateral in multiple sclerosis, unilateral in brainstem infarction.

Pupil-involving third nerve palsy

Ptosis with a down-and-out pupil-dilated eye suggests a compressive lesion such as a posterior communicating artery aneurysm and requires urgent CT angiography.

Cauda equina syndrome

Saddle anesthesia, urinary retention, bilateral leg weakness, and areflexia require urgent MRI and surgical decompression within 24-48 hours to prevent permanent deficit.

Autonomic dysreflexia

In spinal cord injury above T6, noxious stimuli cause severe hypertension, bradycardia, and headache; treat by removing the trigger and using antihypertensives if needed.

Monro-Kellie doctrine

The rigid skull contains brain, blood, and CSF; an increase in one compartment must be offset by a decrease in another, or intracranial pressure rises.

Ischemic penumbra thresholds

Cerebral blood flow below about 20 mL/100 g/min causes electrical failure, while below about 10 mL/100 g/min causes membrane failure and infarction; the penumbra is salvageable tissue.