Cranial Neuralgias and Intractable Pain Syndromes — WACS Viva & Clinical Scenarios (Functional Neurosurgery, Epilepsy, and Pain)

Exam-style cranial neuralgias and intractable pain syndromes viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: A 58-year-old female presents with severe, lancinating, shock-like paroxysmal pain in the right maxillary (V2) and mandibular (V3) divisions, refractory to maximal tolerated doses of carbamazepine and baclofen. High-resolution 3D T2-weighted MRI cisternography demonstrates a loop of the superior cerebellar artery impinging on the superomedial aspect of the trigeminal nerve root entry zone. Outline the preoperative planning, patient positioning, operative steps of a retrosigmoid suboccipital craniectomy for microvascular decompression, methods of vascular neurolysis, and intraoperative avoidanc
• SCENARIO 2: A 76-year-old male with severe ischemic cardiomyopathy and recurrent medically refractory trigeminal neuralgia is scheduled for percutaneous balloon compression of the trigeminal ganglion. Describe the anatomical landmarks for the Hartel trajectory, the fluoroscopic monitoring criteria for successful cannulation of the foramen ovale, the radiographic appearance and volumetric parameters of balloon inflation in Meckel cave, and the immediate recognition and intraoperative management of the trigeminocardiac reflex.
• SCENARIO 3: Differentiate the clinical presentation, neurovascular anatomy, and surgical decompression technique of classic glossopharyngeal neuralgia from hemifacial spasm. Detail the offending vascular structures implicated in each syndrome at their respective brainstem root exit and entry zones, the key cisternal relationships in the cerebellopontine and cerebellomedullary angles, and the surgical nuances required to preserve the lower cranial nerves and labyrinthine/anterior inferior cerebellar arteries.
• SCENARIO 4: A 34-year-old male develops unrelenting, burning deafferentation pain and electric paroxysms in the upper limb following a traction-induced complete C5 to T1 brachial plexus root avulsion, completely unresponsive to conservative neuropharmacotherapy. Evaluate the neuroanatomical rationale, patient selection, and operative execution of microsurgical dorsal root entry zone (DREZ) lesioning (DREZotomy), contrasting this ablative approach with electrical neuromodulation strategies such as spinal cord stimulation and motor cortex stimulation.
• SCENARIO 5: Detail the etiology, clinical manifestations, prevention, and management strategies for major complications following cranial nerve rhizotomy and microvascular decompression, specifically addressing anesthesia dolorosa, neurotrophic keratitis, persistent cerebrospinal fluid rhinorrhea or otorrhea, cerebellar venous infarction, and sensorineural hearing loss.