Anatomy
The pterion is formed by the junction of which four cranial bones?
Frontal, parietal, temporal, and sphenoid
What is the normal range of intracranial pressure in a supine adult?
5–15 mmHg
For an external ventricular drain placed at Kocher's point, where is the entry site typically located?
2–3 cm lateral to midline and about 1 cm anterior to the coronal suture
A biconvex hyperdense extra-axial collection that does not cross suture lines is what diagnosis?
Epidural hematoma
Which device provides rigid three-pin skull fixation during cranial surgery?
Mayfield clamp/headrest
At which vertebral level does the conus medullaris typically terminate in an adult?
L1–L2
What formula defines cerebral perfusion pressure?
CPP = MAP − ICP
The pterional craniotomy provides direct access to which region?
Anterior/suprasellar and circle of Willis region
A crescent-shaped hyperdense extra-axial collection that crosses suture lines is what diagnosis?
Acute subdural hematoma
What does CUSA stand for?
Cavitron Ultrasonic Surgical Aspirator
Which cranial nerve travels freely within the cavernous sinus?
CN VI (abducens)
Cushing's triad consists of which three findings?
Hypertension, bradycardia, and irregular respirations
What is the primary purpose of awake craniotomy with cortical and subcortical mapping?
To identify and preserve eloquent cortex and tracts while maximizing resection
Hyperdensity in the basal cisterns and sylvian fissures in a star pattern indicates what diagnosis?
Subarachnoid hemorrhage
What is the eponym of the stereotactic apparatus first described in 1908?
The Horsley-Clarke apparatus
From which segment does the recurrent artery of Heubner most commonly arise?
A2 segment of the anterior cerebral artery, just distal to the ACoA
As an intracranial mass lesion enlarges, which compensatory mechanism is typically exhausted first?
Displacement of CSF into the spinal thecal sac
What key advantage does the retrosigmoid approach offer over the translabyrinthine approach for vestibular schwannoma?
Potential for hearing preservation
A jugular foramen mass with a salt-and-pepper MRI appearance is what tumor?
Glomus jugulare (paraganglioma)
What major contribution is Wilder Penfield best known for?
Intraoperative cortical stimulation mapping and the cortical homunculus
What do Lundberg A-waves signify?
Exhausted intracranial compliance and compensatory reserve
What do Lundberg A-waves signify?
Exhausted intracranial compliance and compensatory reserve
Which finding argues for meningioma rather than vestibular schwannoma?
Dural tail sign with adjacent hyperostosis
Which finding argues for meningioma rather than vestibular schwannoma?
Dural tail sign with adjacent hyperostosis
Which surgeon is associated with popularizing modern microneurosurgical technique?
M. Gazi Yasargil