Iraqi Board Neurosurgery flashcards

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

Monro-Kellie doctrine

The cranial vault is a rigid container holding brain, CSF, and blood at constant total volume; increases in one compartment must be offset by decreases in others or intracranial pressure rises.

Cerebral perfusion pressure

Calculated as mean arterial pressure minus intracranial pressure; normal target is 60-70 mmHg in adults, and lower values risk cerebral ischemia after traumatic brain injury.

Uncal herniation signs

Ipsilateral dilated pupil from CN III compression, contralateral hemiparesis from cerebral peduncle compression, and progressive decline in consciousness from brainstem compression.

DWI restricted diffusion

Bright signal on diffusion-weighted imaging with low apparent diffusion coefficient, indicating cytotoxic edema in acute infarction, abscess, or high cellularity tumors.

Xanthochromia in CSF

Yellowish CSF due to bilirubin from red cell breakdown, detectable by spectrophotometry at least 6-12 hours after subarachnoid hemorrhage; helps distinguish true hemorrhage from traumatic tap.

Glasgow Coma Scale

Scores eye opening, verbal response, and motor response from 3 to 15; severe injury is 8 or less, moderate 9-12, and mild 13-15, guiding airway and monitoring decisions.

Epidural hematoma features

Biconvex hyperdense collection from middle meningeal artery injury, often with temporal bone fracture and a lucid interval; requires urgent evacuation when symptomatic or expanding.

Diffuse axonal injury

Traumatic shearing of white matter tracts at gray-white junctions, corpus callosum, and brainstem; CT may be normal while MRI susceptibility sequences show petechial hemorrhages.

MGMT promoter methylation

Epigenetic silencing of the DNA repair gene in glioblastoma that predicts improved response to temozolomide and longer survival with alkylating chemotherapy.

Pilocytic astrocytoma

WHO grade 1 glioma, most common pediatric brain tumor, typically cerebellar cystic lesion with mural nodule and BRAF-KIAA1549 fusion; complete resection is usually curative.

Spetzler-Martin grading

Arteriovenous malformation grading based on size (1-3 points), eloquence of adjacent brain (1 point), and deep venous drainage (1 point); grades 4-5 carry high surgical risk.

Nimodipine in subarachnoid hemorrhage

Calcium channel blocker given 60 mg every 4 hours for 21 days after aneurysmal subarachnoid hemorrhage; reduces delayed ischemic neurologic deficit and poor outcome, though not angiographic vasospasm.

Cavernous malformation MRI

Well-circumscribed lesion with popcorn appearance of mixed signal and a complete hemosiderin ring on T2 or susceptibility sequences; no intervening brain parenchyma.

Cauda equina syndrome

Saddle anesthesia, bladder or bowel dysfunction, and bilateral leg weakness from compression of lumbosacral nerve roots; requires urgent decompression to prevent permanent deficit.

Spinal epidural abscess

Purulent collection in the epidural space causing fever, back pain, and progressive deficit; MRI with contrast is diagnostic and urgent decompression with antibiotics is required.

Syringomyelia

Fluid-filled cavity within the spinal cord, often associated with Chiari I malformation, producing cape-like suspended sensory loss and weakness; treated by addressing the underlying cause.

Subthalamic nucleus stimulation

Deep brain stimulation target for advanced Parkinson disease with motor fluctuations and dyskinesia; best results in levodopa-responsive patients without significant dementia.

Microvascular decompression

Surgical relocation of a compressing vessel, usually the superior cerebellar artery, from the trigeminal nerve root entry zone; most durable treatment for trigeminal neuralgia.

Chiari II malformation

Congenital hindbrain herniation with myelomeningocele, tectal beaking, and hydrocephalus; prenatal repair reduces shunt dependence and improves motor outcomes.

Craniosynostosis

Premature fusion of one or more cranial sutures causing skull deformity and possible raised intracranial pressure; surgical remodeling is usually performed before 12 months of age.

Normal pressure hydrocephalus

Triad of gait disturbance, urinary incontinence, and dementia with ventriculomegaly and normal opening pressure; high-volume lumbar tap predicts response to shunting.

Endoscopic third ventriculostomy

Creation of a stoma in the floor of the third ventricle to bypass aqueductal obstruction; preferred in obstructive hydrocephalus in children older than 2 years.

Idiopathic intracranial hypertension

Elevated CSF opening pressure above 25 cm H2O with papilledema and normal CSF composition, typically in obese young women; acetazolamide and weight loss are first-line.

Carpal tunnel syndrome

Median nerve compression at the wrist causing nocturnal paresthesia, thenar atrophy, and positive Phalen and Tinel signs; treated by release of the transverse carpal ligament after conservative failure.

Prolactinoma treatment

Dopamine agonists such as cabergoline are first-line and normalize prolactin and shrink tumor; surgery is reserved for resistance, intolerance, apoplexy, or visual loss.

Cushing disease

ACTH-secreting pituitary adenoma causing hypercortisolism; inferior petrosal sinus sampling distinguishes pituitary from ectopic ACTH, and transsphenoidal resection is first-line.

Cerebral salt wasting

Hyponatremia with hypovolemia after subarachnoid hemorrhage from renal sodium loss; treated with volume and sodium replacement, unlike SIADH which requires fluid restriction.

Diabetes insipidus after pituitary surgery

Deficiency of antidiuretic hormone causing polyuria, dilute urine, and hypernatremia; treated with desmopressin and careful fluid replacement.

Apnea test

Brain death criterion in which ventilation is withdrawn and PaCO2 allowed to rise above 60 mmHg; absence of respiratory effort confirms loss of brainstem respiratory drive.

Informed consent elements

Capacity, disclosure of diagnosis, proposed procedure, alternatives, and material risks, plus voluntary agreement; documented before surgery and revisited if circumstances change.

Pterional craniotomy

Frontotemporal craniotomy centered on the sphenoid wing and sylvian fissure; provides access to anterior circulation aneurysms and suprasellar lesions.

Retrosigmoid approach

Lateral suboccipital craniotomy bounded by transverse and sigmoid sinuses; exposes cerebellopontine angle and lower cranial nerves for vestibular schwannoma and microvascular decompression.