Neuropathology and Neuroradiology Diagnostics — WACS Viva & Clinical Scenarios (Basic Neurosciences and Neurosurgical Critical Care)

Exam-style neuropathology and neuroradiology diagnostics viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: Primary and Membership Viva Voce: A 42-year-old patient presents with new-onset seizures and a solitary, non-enhancing frontal lobe lesion showing high signal intensity on T2-weighted MRI and the T2-FLAIR mismatch sign. Explain the current World Health Organization classification of diffuse adult-type gliomas, detail the essential molecular markers required for definitive diagnostic reporting, and outline the magnetic resonance spectroscopy and perfusion characteristics that differentiate low-grade from high-grade gliomas.
• SCENARIO 2: Membership OSCE Station: You are presented with non-contrast brain CT, diffusion-weighted MRI, apparent diffusion coefficient maps, and post-contrast T1-weighted images of a 35-year-old immunocompetent male with headache, fever, and a solitary subcortical ring-enhancing mass. Systematically interpret the radiological findings, provide a structured differential diagnosis including pyogenic abscess, high-grade glioma, metastasis, and tuberculoma, and detail the distinctive histopathological stages of cerebral abscess capsule formation.
• SCENARIO 3: Primary Written / Oral Examination: Outline the structural histopathology and diagnostic neuroradiological evaluation of cerebrovascular malformations. Compare and contrast saccular intracranial aneurysms, arteriovenous malformations, cavernomas, and developmental venous anomalies with respect to vessel wall architecture, spontaneous rupture risks, non-contrast CT, susceptibility-weighted MRI findings, and digital subtraction angiography flow dynamics.
• SCENARIO 4: Membership Clinical Station: A 50-year-old woman presents with progressive paraparesis, sensory level at T6, and sphincter dysfunction. Contrast-enhanced thoracic spine MRI reveals a well-circumscribed, homogeneously enhancing intradural extramedullary mass with a dural tail sign. Detail the radiological differential diagnosis for spinal intradural lesions, explain the histopathological variants of spinal meningiomas and schwannomas, and describe the specific immunohistochemical stains used to confirm each diagnosis.
• SCENARIO 5: Primary and Membership Viva Voce: Describe the acute and subacute histopathological reactions of cerebral tissue to ischemic and traumatic injury, including ischemic neuronal necrosis, astrogliosis, and Wallerian degeneration. Correlate these pathological changes with neuroimaging indicators of impending cerebral herniation across uncal, central transtentorial, subfalcine, and tonsillar compartments on non-contrast CT and MRI.