Primary central nervous system vasculitis is a rare inflammatory disease affecting small to medium sized blood vessels of the brain and spinal cord. Major clinical manifestations include stroke, encephalopathy, headache and seizures. Diagnosis can be challenging and is based on the combination of clinical presentation, imaging, brain biopsy and CSF findings. Here we present a case of primary cerebral lymphocytic vasculitis presenting as encephalopathy and hallucinations.

64-year-old male with history of intracerebral hemorrhage, hypertension presented for evaluation of acute onset non-progressive encephalopathy. Patient was noted to have odd behavior and visual hallucinations. Neurologic exam was unremarkable. MRI brain showed mild leptomeningeal enhancement with probable acute hemorrhagic infarcts in bilateral parietal lobes with suggestions of vasogenic edema, punctate cortical infarcts of posterior left frontal lobe, bilateral occipital lobes and left temporal lobe, mild diffuse subarachnoid hemorrhage, chronic infarct in left occipital, bilateral basal ganglia, right thalamus, and right pons. CT angiogram head showed scattered stenosis of arteries of Circle of Willis. CT venogram was negative. CSF studies and CSF autoimmune panel were unremarkable. Video EEG showed occasional low amplitude sharp waves in the left tempo-parietal region. Cerebral angiogram showed scattered focal areas of irregularity and narrowing in both intracranial ICAs and posterior circulation. He underwent right parietal dural and cortical biopsy. Histopathology was consistent with lymphocytic vasculitis. Patient was started on methylprednisolone 1000 mg for 5 days; later cyclophosphamide was started with marked improvement in symptoms upon follow up. 

We report a case of lymphocytic vasculitis presenting as encephalopathy and hallucinations. Lymphocytic vasculitis is characterized by an inflammatory cell infiltration and necrosis of small and medium sized blood vessels in the brain, spinal cord and the meninges. The CNS complications are fatal without timely diagnosis and use of immunosuppression; thus, early diagnosis may prevent from damage and disability.