A rare case of vasculitis mimicking meningoencephalitis

Abstract

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.