Movement Disorders and Neuromodulation — WACS Viva & Clinical Scenarios (Functional Neurosurgery, Epilepsy, and Pain)

Exam-style movement disorders and neuromodulation viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: A 62-year-old male with a 9-year history of idiopathic Parkinson disease presents with severe motor fluctuations, disabling peak-dose dyskinesias, and predictable end-of-dose wearing-off despite optimized medical therapy. Outline your comprehensive pre-surgical evaluation protocol, selection criteria for deep brain stimulation, and provide a comparative analysis for selecting the subthalamic nucleus versus the internal segment of the globus pallidus.
• SCENARIO 2: Describe the stereotactic localization principles and indirect coordinate calculation for targeting the ventral intermediate nucleus of the thalamus and the subthalamic nucleus relative to the anterior commissure-posterior commissure line. Detail the intraoperative neurophysiological microelectrode recording patterns, microstimulation threshold testing, and the clinical indicators that confirm accurate target placement versus proximity to critical adjacent internal capsule and brainstem structures.
• SCENARIO 3: In a resource-constrained healthcare setting where hardware-based deep brain stimulation is unavailable or cost-prohibitive, evaluate the indications, anatomical targets, surgical technique, and safety profiles of unilateral stereotactic radiofrequency ablative procedures (pallidotomy and thalamotomy) for medically refractory movement disorders.
• SCENARIO 4: A 34-year-old female presents with severe generalized dystonia refractory to high-dose anticholinergics, baclofen, and botulinum toxin injections. Detail the anatomical substrate, target selection, surgical implantation technique, and expected clinical time course for symptom improvement following deep brain stimulation.
• SCENARIO 5: Detail the diagnostic approach, acute medical stabilization, and surgical management of a patient presenting with suspected acute intrathecal baclofen withdrawal following pump malfunction. Furthermore, outline the management algorithm for an acute intracranial hemorrhage or hardware-related infection occurring after stereotactic lead implantation.