Arab Board Neurosurgery Part 1 flashcards

35 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; brain, CSF, and blood must balance, so expansion of one compartment or a mass raises intracranial pressure.

Cerebral blood flow normal

Average adult cerebral blood flow is about 50 mL/100 g/min; electrical failure occurs near 18 and infarction near 10 mL/100 g/min.

Broca area location

Broca area lies in the dominant inferior frontal gyrus and controls motor speech production; damage causes nonfluent aphasia with preserved comprehension.

Glioblastoma histology

Glioblastoma shows pseudopalisading necrosis and microvascular proliferation; it is the most common malignant primary brain tumor in adults.

Marcus Gunn pupil

An afferent pupillary defect detected by the swinging flashlight test indicates optic nerve or severe retinal dysfunction on the affected side.

Internuclear ophthalmoplegia

Impaired adduction ipsilateral to a medial longitudinal fasciculus lesion with nystagmus in the abducting eye, commonly due to multiple sclerosis.

Papilledema features

Bilateral optic disc swelling from raised intracranial pressure; visual acuity is usually preserved early, with an enlarged blind spot.

Decerebrate posturing

Extension posturing of arms and legs indicates a brainstem lesion between the red nucleus and pons and carries a poor prognosis.

Acute blood on CT

Acute intracranial hemorrhage appears hyperdense (about 50-80 Hounsfield units) on noncontrast CT and becomes isodense then hypodense over time.

Diffusion-weighted imaging

DWI shows restricted diffusion as bright signal with low ADC in acute cytotoxic edema, appearing within minutes of ischemic stroke.

Xanthochromia

Yellowish CSF from hemoglobin breakdown detected by spectrophotometry; it supports subarachnoid hemorrhage and can persist for days.

Ring-enhancing lesion

A ring-enhancing brain lesion suggests abscess, metastasis, or high-grade glioma; the pattern reflects breakdown of the blood-brain barrier.

Epidural hematoma shape

Epidural hematoma is biconvex or lens-shaped, often from middle meningeal artery injury, and may show a lucid interval.

Subdural hematoma shape

Subdural hematoma is crescent-shaped and crosses suture lines; acute blood is hyperdense on CT.

Glasgow Coma Scale

GCS scores eye 1-4, verbal 1-5, and motor 1-6; severe injury is 8 or less, moderate 9-12, mild 13-15.

Cushing reflex

Hypertension with bradycardia and irregular respiration indicates raised intracranial pressure and impending herniation.

Meningioma imaging

Meningioma is an extra-axial, dural-based mass with homogeneous enhancement and a dural tail; it may cause hyperostosis of adjacent bone.

Brain metastasis location

Brain metastases favor the gray-white junction; common primary sources include lung, breast, melanoma, renal, and colon cancers.

Primary CNS lymphoma

Periventricular, homogeneously enhancing mass in immunocompetent patients; high-dose methotrexate is a first-line treatment.

Vestibular schwannoma

Cerebellopontine angle tumor widening the internal acoustic meatus; bilateral tumors suggest neurofibromatosis type 2.

Aneurysm common sites

Anterior communicating artery is the most common intracranial aneurysm site; posterior communicating artery aneurysms can cause third nerve palsy.

Vasospasm timing

Cerebral vasospasm after subarachnoid hemorrhage peaks at 4-14 days; nimodipine is given to improve outcome.

Hypertensive ICH sites

Hypertensive intracerebral hemorrhage favors the putamen, thalamus, pons, and cerebellum; lobar hemorrhage suggests amyloid angiopathy in the elderly.

Spetzler-Martin grade

Arteriovenous malformation grading uses size, eloquence of adjacent brain, and venous drainage; higher grades indicate greater surgical risk.

Cauda equina syndrome

Saddle anesthesia, bowel or bladder dysfunction, and bilateral leg weakness from lumbosacral root compression; urgent decompression is indicated.

Brown-Séquard syndrome

Hemispheric cord injury causes ipsilateral motor and proprioceptive loss with contralateral pain and temperature loss below the lesion.

Central cord syndrome

Upper limbs are weaker than lower limbs, often after hyperextension in a stenotic cervical canal; it is the most common incomplete cord syndrome.

Chiari II malformation

Caudal displacement of cerebellar tissue with myelomeningocele, hydrocephalus, and tectal beaking; it is a congenital neural tube defect association.

Myelomeningocele repair

Neural tube defect closure is performed within 24-48 hours to reduce infection; assess for hydrocephalus and Chiari II malformation.

Craniosynostosis types

Sagittal synostosis causes scaphocephaly; metopic synostosis causes trigonocephaly; premature suture fusion restricts skull growth.

DBS targets

Deep brain stimulation targets the subthalamic nucleus or globus pallidus internus for Parkinson disease and the ventral intermediate nucleus for tremor.

Trigeminal neuralgia treatment

Carbamazepine is first-line; microvascular decompression relieves vascular compression of the trigeminal nerve root and can be curative.

Carpal tunnel syndrome

Median nerve entrapment at the wrist causes nocturnal paresthesias in the thumb, index, and middle fingers with positive Tinel and Phalen signs.

Seddon nerve injury

Neurapraxia is conduction block, axonotmesis is axon loss with intact sheath, and neurotmesis is complete nerve transection.

Cerebral perfusion pressure

CPP equals mean arterial pressure minus intracranial pressure; a target of 60-70 mmHg is used in adults after severe traumatic brain injury.