Postictal Todd's Paralysis Mimicking Acute Ischemic Stroke in Medullary Melanocytoma: A Multimodal Diagnostic Challenge.

Acute focal neurologic deficits in patients with intracranial malignancy frequently prompt emergent evaluation for ischemic stroke. However, seizure-related deficits such as Todd's paralysis may closely mimic cerebrovascular events. Todd's paralysis consists of transient postictal neurological deficits that may persist from minutes to several days, particularly in patients with structural brain disease. We report a 45-year-old man with medullary melanocytoma who presented with acute left-sided weakness, facial droop, and dysarthria. CT perfusion demonstrated focal hypoperfusion suggestive of ischemic penumbra, and his National Institutes of Health Stroke Scale (NIHSS) score was 14. Diffusion-weighted MRI showed no evidence of acute infarction, and CT angiography demonstrated no large vessel occlusion. Electroencephalography revealed focal slowing over the left hemisphere without epileptiform discharges, consistent with a postictal state. His neurological deficits resolved within 24 hours. In the context of transient symptoms, absence of diffusion restriction, electrophysiologic findings, hyponatremia, and extensive structural brain disease, a diagnosis of focal nonconvulsive seizure with postictal Todd's paralysis was favored. This case highlights the potential for perfusion imaging to mimic ischemia in neuro-oncology patients and underscores the importance of integrating multimodal imaging, metabolic evaluation, electrophysiologic data, and clinical evolution in acute stroke assessment.