ABNS Neurological Surgery flashcards

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

Cushing triad

Hypertension with widened pulse pressure, bradycardia, and irregular respirations; indicates rising intracranial pressure and impending herniation requiring urgent decompression.

Lucid interval

Transient return of consciousness after head injury before neurologic decline; classically associated with epidural hematoma from middle meningeal artery injury.

Diffuse axonal injury

Shear injury at gray-white junctions from rotational acceleration; MRI shows punctate susceptibility foci; often causes prolonged coma with poor outcome.

Nimodipine in SAH

Calcium channel antagonist given orally or enterally for 21 days after aneurysmal subarachnoid hemorrhage; improves neurologic outcome and reduces delayed ischemic deficits without reversing angiographic vasospasm.

Spetzler-Martin grading

AVM grading summing points for nidus size (<3, 3-6, >6 cm), eloquent location, and deep venous drainage; higher grades carry greater surgical risk.

Sentinel headache

Sudden severe headache days before aneurysmal rupture, reflecting minor leak; warrants urgent CT angiography to identify and treat the aneurysm.

MGMT promoter methylation

Epigenetic silencing of the DNA repair enzyme MGMT in glioblastoma; predicts improved response to temozolomide and longer survival.

Simpson grade

Grading of meningioma resection extent from complete dural excision (grade I) to biopsy only (grade V); lower grades correlate with reduced recurrence.

Drop metastasis

Tumor spread through cerebrospinal fluid to distant neuraxis sites, typical of medulloblastoma, ependymoma, and germ cell tumors; requires craniospinal imaging.

Hoffmann sign

Involuntary thumb and index flexion when the middle fingernail is flicked; indicates cervical cord compression with upper motor neuron dysfunction.

S1 radiculopathy

L5-S1 disc herniation compressing the S1 root causes posterior leg and lateral foot pain with diminished ankle reflex and plantar flexion weakness.

Cauda equina syndrome

Compression of lumbar nerve roots causing saddle anesthesia, urinary retention or incontinence, and bilateral leg weakness; requires emergent surgical decompression.

Chiari II malformation

Congenital hindbrain anomaly with small posterior fossa and tonsillar herniation, nearly always with myelomeningocele; causes hydrocephalus and brainstem dysfunction.

Scaphocephaly

Elongated narrow skull from premature sagittal suture fusion; most common craniosynostosis, often managed with cranial vault remodeling.

Vein of Galen malformation

Arteriovenous fistula draining to the median prosencephalic vein causing high-output cardiac failure and hydrocephalus in neonates; treated by staged embolization.

VIM thalamus target

Ventral intermediate nucleus of the thalamus; lesioning or deep brain stimulation there relieves medication-refractory essential tremor and tremor-dominant Parkinson disease.

Microvascular decompression

Posterior fossa craniectomy with Teflon padding between a compressing vessel and the trigeminal nerve; durable relief for classic trigeminal neuralgia.

Intrathecal baclofen

Pump-delivered GABA-B agonist into CSF for severe spasticity; overdose causes hypotonia and respiratory depression, withdrawal causes rigidity and fever.

Wada test

Intracarotid amobarbital injection to lateralize language and assess memory reserve before temporal lobectomy, reducing risk of postoperative amnesia.

Corpus callosotomy

Sectioning the corpus callosum to interrupt seizure spread; palliative procedure most effective for atonic drop attacks in Lennox-Gastaut syndrome.

Hippocampal sclerosis

Atrophy and gliosis of the hippocampus with T2 hyperintensity, the most common pathology in medically refractory temporal lobe epilepsy and a favorable surgical predictor.

Normal pressure hydrocephalus

Triad of magnetic gait, urinary incontinence, and dementia with enlarged ventricles but normal CSF pressure; high-volume lumbar tap predicts shunt responsiveness.

Endoscopic third ventriculostomy

Creation of a stoma in the third ventricle floor to divert CSF into the basal cisterns, treating obstructive hydrocephalus without implanted hardware.

Pseudotumor cerebri

Idiopathic intracranial hypertension with papilledema, headache, and elevated opening pressure but normal CSF and imaging; managed with acetazolamide and weight loss.

Translabyrinthine approach

Lateral skull base approach sacrificing hearing and labyrinth to reach the cerebellopontine angle, used for large vestibular schwannomas with nonserviceable hearing.

Cavernous sinus syndrome

Combined ophthalmoplegia with V1/V2 sensory loss and Horner signs from mass or thrombosis; CN VI is usually affected earliest due to medial location.

Pituitary apoplexy

Acute hemorrhage or infarction of a pituitary adenoma causing thunderclap headache, visual loss, ophthalmoplegia, and adrenal insufficiency; treat with steroids and urgent decompression.

Cerebral salt wasting

Hypovolemic hyponatremia after subarachnoid hemorrhage or brain injury from renal sodium loss; treated with volume and sodium replacement rather than fluid restriction.

Propofol infusion syndrome

Complication of high-dose prolonged propofol causing metabolic acidosis, rhabdomyolysis, hyperkalemia, and arrhythmia; requires stopping the drug.

Idarucizumab

Monoclonal antibody fragment that reverses dabigatran anticoagulation, used for urgent neurosurgical intervention or intracranial hemorrhage.

Diffusion-weighted imaging

MRI sequence showing restricted water diffusion as bright signal; detects acute infarction within minutes and distinguishes abscess or epidermoid from other lesions.

Dense MCA sign

Hyperdense middle cerebral artery on noncontrast CT from acute thrombus; an early sign of large vessel occlusion amenable to thrombectomy.

Choline-to-NAA ratio

MR spectroscopy metric elevated in neoplasm due to increased membrane turnover and neuronal loss; helps distinguish tumor from radiation necrosis.

Cerebral autoregulation

Intrinsic mechanism maintaining constant cerebral blood flow across a mean arterial pressure range of roughly 60 to 150 mmHg; impaired after trauma and ischemia.

Cytotoxic edema

Intracellular water accumulation from energy failure and ion pump dysfunction, typical of acute ischemia; appears as hypodensity with loss of gray-white differentiation.

Nigrostriatal pathway

Dopaminergic projection from substantia nigra pars compacta to striatum; degeneration causes the motor features of Parkinson disease.