Arab Board Neurosurgery Final Written flashcards

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

Monro-Kellie doctrine

The intracranial volume is fixed because the skull is rigid; brain, CSF, and blood must remain constant, so any added mass raises ICP unless compensation occurs.

Cushing reflex

Hypertension, bradycardia, and irregular respiration occurring with raised intracranial pressure, indicating brainstem compromise and impending herniation.

Hunt and Hess scale

Clinical grading of subarachnoid hemorrhage from grade I (asymptomatic or mild headache) to grade V (deep coma), used to predict outcome and guide management.

Modified Fisher grade

CT grading of subarachnoid hemorrhage based on thickness of blood and presence of intraventricular hemorrhage; higher grades predict greater vasospasm risk.

Spetzler-Martin grading

A scale for arteriovenous malformations combining nidus size, eloquence of adjacent brain, and deep venous drainage to estimate surgical risk.

Wallerian degeneration

Degeneration of the axon distal to a nerve injury, occurring within 24 to 48 hours, followed by regeneration at roughly 1 mm per day.

Seddon nerve injury classes

Neuropraxia is conduction block with full recovery; axonotmesis is axonal loss with spontaneous recovery; neurotmesis is complete transection requiring surgical repair.

Erb palsy

Brachial plexus injury of C5-C6 roots causing arm adduction, internal rotation, and forearm pronation, producing the classic waiter's tip posture.

Carpal tunnel syndrome

Median nerve compression at the wrist causing nocturnal paresthesias, thenar weakness, and atrophy; diagnosed by EMG/NCS and treated by ligament release.

Rotterdam CT score

A head CT scoring system for traumatic brain injury using basal cistern status, midline shift, epidural mass, and traumatic subarachnoid hemorrhage to predict outcome.

Epidural hematoma

Blood between skull and dura, usually from middle meningeal artery injury; biconvex on CT, often with a lucid interval and rapid deterioration.

Cauda equina syndrome

Compression of lumbosacral nerve roots causing saddle anesthesia, bowel and bladder dysfunction, and bilateral leg weakness; requires urgent surgical decompression.

Meyerding classification

A grading of lumbar spondylolisthesis from grade I (0-25% slip) to grade V (complete displacement) based on percentage of vertebral body translation.

Chiari II malformation

Hindbrain herniation with myelomeningocele, tectal beaking, and hydrocephalus; almost always associated with a neural tube defect present at birth.

Craniosynostosis

Premature fusion of one or more cranial sutures producing characteristic skull shapes such as scaphocephaly, plagiocephaly, or trigonocephaly; surgery before age one.

Normal pressure hydrocephalus

Ventricular enlargement with normal CSF pressure presenting with gait apraxia, urinary incontinence, and cognitive decline; a large-volume tap test predicts shunt response.

Endoscopic third ventriculostomy

A CSF diversion procedure creating a stoma in the third ventricle floor; preferred for obstructive hydrocephalus such as aqueductal stenosis.

Programmable shunt valve

A valve whose opening pressure can be adjusted noninvasively; settings must be checked and reset after exposure to strong magnetic fields such as MRI.

Pseudotumor cerebri

Idiopathic intracranial hypertension with elevated opening pressure, normal CSF, and normal imaging; treated with weight loss, acetazolamide, or optic nerve sheath fenestration.

Glioblastoma

A WHO grade 4 IDH-wildtype astrocytoma with necrosis or microvascular proliferation, often showing EGFR amplification and TERT promoter mutation; median survival about 15 months.

IDH mutation

A mutation in isocitrate dehydrogenase genes, most common in lower-grade gliomas; IDH-mutant tumors have a better prognosis than IDH-wildtype tumors.

Medulloblastoma

An embryonal cerebellar tumor of childhood with molecular groups WNT, SHH, group 3, and group 4; WNT carries the best prognosis and drop metastases may occur.

Pilocytic astrocytoma

A WHO grade 1 glioma with BRAF-KIAA1549 fusion, typically cystic with a mural nodule in the cerebellum; gross total resection is often curative.

Primary CNS lymphoma

A periventricular enhancing tumor with restricted diffusion that responds markedly to steroids; biopsy is preferred before steroid administration to preserve diagnostic yield.

Radiation necrosis

Delayed radiation injury appearing months after treatment with progressive enhancement and edema; distinguished from tumor progression by perfusion MRI, spectroscopy, or PET.

SRS dose falloff

Stereotactic radiosurgery delivers a single high dose with a steep gradient, sparing adjacent tissue; lesions over 3 cm are usually treated with fractionation or surgery.

Leksell stereotactic frame

A rigid head frame using Cartesian coordinates to target intracranial structures for biopsy, radiosurgery, or functional procedures.

Deep brain stimulation targets

Subthalamic nucleus or globus pallidus internus for Parkinson disease, ventral intermediate thalamus for essential tremor, and globus pallidus internus for primary dystonia.

Status epilepticus

Continuous seizure activity lasting five minutes or more; first-line treatment is a benzodiazepine, followed by levetiracetam, fosphenytoin, or valproate.

Brain death criteria

Irreversible coma with absent brainstem reflexes and a positive apnea test, after excluding sedation, hypothermia, and metabolic confounders.

DWI and ADC

Diffusion-weighted imaging with an apparent diffusion coefficient map; restricted diffusion appears bright on DWI and dark on ADC, indicating cytotoxic edema.

Xanthochromia

Yellow discoloration of CSF from bilirubin breakdown, most reliable 12 hours to two weeks after subarachnoid hemorrhage when CT sensitivity declines.