Arab Board Neurosurgery Final Clinical & Oral key terms

The principle that the skull is a rigid container holding brain, blood, and cerebrospinal fluid; an increase in one component must be offset by a decrease in another, otherwise intracranial pressure rises.

The pressure gradient driving blood flow through the brain, calculated as mean arterial pressure minus intracranial pressure; it must be maintained to prevent ischemic injury.

The pulsatile recording of pressure inside the skull, with three peaks per cardiac cycle; the height and shape of these peaks help assess intracranial compliance and risk of herniation.

A 15-point clinical score assessing eye opening, verbal response, and motor response; it grades level of consciousness and is used to classify traumatic brain injury severity.

Widespread traumatic damage to white matter tracts from acceleration-deceleration forces, often causing prolonged coma without a large mass lesion; MRI shows characteristic shear hemorrhages.

A bruise of brain tissue caused by blunt trauma, typically at the crests of gyri, with petechial hemorrhage and edema that may expand over hours to days.

A collection of blood between the skull and dura mater, usually from a torn middle meningeal artery after temporal bone fracture; it appears biconvex on CT and requires urgent evacuation.

Blood accumulating between the dura and arachnoid, often from torn bridging veins; it appears crescent-shaped on CT and may be acute, subacute, or chronic.

The intrinsic ability of cerebral arterioles to constrict or dilate to maintain constant blood flow despite changes in arterial pressure, typically within a mean arterial pressure range of 50–150 mmHg.

A non-invasive MRI technique that measures brain tissue stiffness by observing how mechanical waves propagate; it is used to assess intracranial pressure and tumor consistency.

A quantitative map derived from diffusion-weighted MRI that reflects the magnitude of water molecule movement; low values indicate restricted diffusion, as in acute ischemia or highly cellular tumors.

MRI or CT techniques that measure blood flow, blood volume, and transit time in brain tissue; they help distinguish tumor progression from radiation necrosis and identify salvageable penumbra in stroke.

An MRI method that measures concentrations of metabolites such as choline, N-acetylaspartate, and lactate within a selected brain region, aiding tumor grading and differentiation from infection or necrosis.

A molecular alteration in gliomas that silences the MGMT gene, reducing DNA repair capacity and predicting greater benefit from alkylating chemotherapy such as temozolomide.

A genetic change in IDH1 or IDH2 genes common in lower-grade gliomas and secondary glioblastomas; it is associated with younger age and better prognosis than IDH-wildtype tumors.

Combined loss of chromosome arms 1p and 19q, a defining feature of oligodendroglioma that predicts sensitivity to chemotherapy and radiotherapy and a more favorable outcome.

A usually benign tumor arising from arachnoid cap cells of the meninges; it is often extra-axial, enhances uniformly, and may be observed, resected, or treated with radiosurgery.

A benign tumor of Schwann cells on the vestibular division of cranial nerve VIII, typically in the cerebellopontine angle; it causes hearing loss and may be managed with observation, radiosurgery, or microsurgery.

A surgical corridor that removes or traverses bone at the skull base to reach deep lesions with minimal brain retraction, often involving multidisciplinary teams and complex reconstruction.

A balloon-like outpouching of an artery wall, most often at branch points of the circle of Willis; rupture causes subarachnoid hemorrhage and can be treated by clipping or coiling.

Bleeding into the space between the arachnoid and pia mater, commonly from a ruptured aneurysm; it presents with sudden severe headache and risks vasospasm, hydrocephalus, and rebleeding.

A tangle of abnormal blood vessels connecting arteries and veins without an intervening capillary bed, creating high-flow shunts that may rupture and cause hemorrhage or seizures.

A progressive narrowing of the distal internal carotid arteries with compensatory fragile collateral vessels, causing strokes or hemorrhages; revascularization surgery can improve cerebral blood flow.

Age-related loss of disc hydration and height with annular tears and endplate changes, which may cause back pain, radiculopathy, or stenosis; treatment ranges from conservative care to surgery.

Narrowing of the spinal canal or nerve root canals in the lower back, often from degenerative changes, causing leg pain and weakness that worsens with walking and improves with flexion.

Forward displacement of one vertebra over another, commonly from degenerative changes or a pars defect; it can narrow the canal and cause back pain, radiculopathy, or neurogenic claudication.

A congenital condition in which the cerebellar tonsils descend below the foramen magnum, potentially obstructing cerebrospinal fluid flow and causing headache, syringomyelia, or brainstem symptoms.

A fluid-filled cavity within the spinal cord that expands and damages nerve fibers, causing cape-like loss of pain and temperature sensation, weakness, and spasticity; it often accompanies Chiari malformation.

An abnormal accumulation of cerebrospinal fluid in the brain ventricles, raising intracranial pressure and enlarging the head in infants; it may be treated with shunts or endoscopic fenestration.

A functional neurosurgical treatment that implants electrodes in deep brain targets to modulate abnormal neural activity, used for movement disorders such as Parkinson disease, tremor, and dystonia.

A therapy that delivers intermittent electrical pulses to the left vagus nerve via an implanted device, reducing seizure frequency in some patients with drug-resistant epilepsy.

A minimally invasive technique that delivers a single high dose of focused radiation to a precise intracranial target, used for small tumors, vascular malformations, and functional disorders.

Damage to the network of nerves supplying the arm, often from traction during birth or trauma, causing weakness and sensory loss; treatment may include nerve repair, grafting, or tendon transfers.

An electrodiagnostic test that measures how fast electrical signals travel along a nerve and the size of the response, helping localize nerve injury and distinguish axonal from demyelinating lesions.

The process of explaining a proposed treatment, its risks, benefits, and alternatives to a patient with decision-making capacity, who then voluntarily agrees; it is both ethical and legal requirement.

A collaborative process in which clinicians and patients exchange information about options, outcomes, and patient values to reach a mutually agreed treatment plan.

A brief, structured team meeting before or during clinical work to identify risks, coordinate care, and prevent errors; it supports a culture of safety and open communication.