A rare case of vasculitis mimicking meningoencephalitis.

This case report describes a 47-year-old male presenting with headache, fever, and limb weakness, initially suggestive of meningoencephalitis. Despite comprehensive investigations, including cerebrospinal fluid (CSF) analysis and neuroimaging, infectious and autoimmune causes were ruled out. Magnetic resonance imaging (MRI) revealed multifocal hyperintensities in the brainstem, gangliocapsular regions, and bilateral cerebellar hemispheres, indicative of an inflammatory process. With a negative autoimmune profile and the absence of systemic symptoms, primary angiitis of the central nervous system (PACNS) was suspected. The patient was treated with high-dose intravenous corticosteroids followed by oral prednisone and azathioprine for long-term immunosuppression. Significant clinical improvement was observed, with resolution of headache fever, and marked improvement in limb strength and ocular symptoms. This case underscores the diagnostic complexity of CNS vasculitis, particularly when mimicking meningoencephalitis, and highlights the importance of considering CNS vasculitis as the differential diagnosis. Early recognition and aggressive immunosuppressive therapy are critical in managing this rare condition and preventing irreversible neurological damage. [ABSTRACT FROM AUTHOR]