Anti-Neutrophil Cytoplasmic Antibody-Associated Central and Peripheral Nervous System Vasculitis.

The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) usually manifests as systemic vasculitis. AAV with central nervous system involvement in the form of mesenrhombencephalitis and peripheral neuropathy is extremely rare. We report a 59-year-old male patient who presented to a tertiary care hospital in Muscat, Oman, in 2024. He had a subacute presentation of altered sensorium, multiple cranial nerve palsy and ataxia with 3 months history of bilateral foot drop. Brain imaging was suggestive of mesenrhombencephalitis with subarachnoid and intraparenchymal haemorrhage. Nerve conduction studies revealed sensorimotor axonal neuropathy. Vasculitis profile showed perinuclear-ANCA positivity and the nerve biopsy was suggestive of vasculitic neuropathy. He was treated with intravenous steroids and maintained on rituximab. His neurological deficits improved with residual bilateral foot drop.