A Case of Anti-NMDAR Encephalitis Misinterpreted as Bacterial Meningitis

BackgroundSarcoidosis is associated with stroke, usually via cardiac involvement.Cerebral vasculopathy associated with neurosarcoidosis is rare. Design/Methods N/A. ResultsA man in his late 40s with past medical history of diabetes, end-stage renal disease, peripheral artery disease complicated by right below the knee amputation, hypertension, hyperlipidemia, obstructive sleep apnea, and heart failure with reduced ejection fraction, presented to our hospital with two weeks of new-onset intractable headache.MRI brain demonstrated a punctate acute ischemic stroke in the right uncus.CT angiography of the head and neck found intracranial calcified atherosclerosis, and occlusion of the distal left V4 vertebral artery.He subsequently developed right arm weakness and episodes of cough syncope and encephalopathy.MRI brain vessel wall imaging demonstrated concentric enhancement of the left V4 artery segment as well as interval infarcts in left temporal lobe, left posterior limb of the internal capsule, anterior left frontal lobe, and left brachium pontis.Lumbar puncture with CSF analysis demonstrated lymphocytic pleocytosis with elevated protein, IgG synthesis index, and oligoclonal bands; metagenomic sequencing was negative for pathogenic organisms.Diagnostic catheter angiogram did not find unequivocal evidence of medium vessel vasculitis, but noted a right M4-M5 branch occlusion and the previously noted left V4 occlusion.Cardiac echocardiography noted a small filamentous mitral valve echodensity felt to represent degenerative mitral annulus calcification.CT chest, abdomen, pelvis demonstrated 2 cm right external iliac lymph node and additional mildly enlarged abdominal and pelvic lymph nodes.Biopsy of the largest lymph node demonstrated non-caseating granulomas.A diagnosis of probable neurosarcoidosis was made based on clinical and diagnostic evaluation with evidence of systemic granulomatous disease.He was started on corticosteroids and rituximab in addition to aspirin and atorvastatin. ConclusionsEven in a patient with multiple vascular risk factors, inflammatory vasculopathy should be considered when headache and encephalopathy are prominent clinical features.