Teaching NeuroImage: Bilateral Middle Cerebellar Peduncle Stroke in Giant Cell Arteritis

A 78-year-old man presented with weeks of progressive fatigue and dysarthria. Brain MRI showed symmetrical middle cerebellar peduncle (MCP) infarctions (Figure, A, B, E). CT angiography showed multifocal bilateral cervical vertebral artery stenoses (Figure, H). Symptoms worsened over 2 weeks, despite antiplatelet therapy. Repeat MRI showed enlargement and mild enhancement of the MCP lesions (Figure, C, D, F, G). CRP was 185 mg/L, and ESR was 97 mm/h. Temporal artery biopsy revealed non-necrotizing arteritis (Figure, I). Isolated lesions of bilateral MCPs are extremely rare and arise from vascular, degenerative, inflammatory, and neoplastic disorders.(1,2) Giant cell arteritis is a rare cause of stroke and tends to preferentially affect the vertebrobasilar system.