Skull Base and Cranial Nerve Disorders
What the candidate must own
Know the anatomy of the skull base in compartments - anterior (cribriform, orbit), middle (cavernous sinus, Meckel cave, petrous apex), and posterior (cerebellopontine angle, jugular foramen, foramen magnum) - and the approaches to each (endoscopic endonasal, pterional, retrosigmoid, far lateral). Be fluent in the cranial nerve disorders: trigeminal neuralgia (and the role of microvascular decompression versus radiosurgery versus percutaneous procedures), hemifacial spasm, vestibular schwannoma, glomus tumour, and pituitary adenoma. Understand the principles of cerebrospinal fluid leak repair and the complications of skull base surgery (CSF leak, meningitis, cranial nerve deficits, vascular injury).
Traps that appear in questions
- Assuming trigeminal neuralgia is always vascular - multiple sclerosis and tumours are important mimics.
- Forgetting that microvascular decompression is the most durable treatment for classic trigeminal neuralgia in a fit patient.
- Confusing a vestibular schwannoma with a meningioma in the cerebellopontine angle - the internal auditory canal component favours schwannoma.
- Missing the endocrine workup in a pituitary adenoma (prolactin, GH, ACTH, cortisol).
Rule of thumb
For a skull base lesion, define the compartment, then the approach, then the morbidity. Worked example: a patient with paroxysmal lancinating facial pain in the V2/V3 distribution, triggered by touch, with a normal MRI - classic trigeminal neuralgia; in a fit patient, microvascular decompression offers the best long-term pain relief, while radiosurgery is preferred in the elderly or medically unfit.