Locked-In Syndrome: A Rare Manifestation of Neuropsychiatric Lupus.

Neuropsychiatric systemic lupus erythematosus (SLE) is a rare condition that has a multitude of mechanisms resulting in the emergence of variable clinical presentations. We describe a peculiar case of a 33-year-old female with a history of SLE presented with two weeks of fever, headache, and vomiting. On admission, she became obtunded and was emergently intubated. Initial lumbar puncture revealed pleocytosis (46% neutrophils, 320 corrected nucleated cells/μL), elevated protein (244 mg/dL; normal, 15-40 mg/dL), normal glucose (63 mg/dL), and negative cultures. Empiric acyclovir, ampicillin, ceftriaxone, and vancomycin were initiated without clinical improvement. Neurological examination was notable for limited ability to follow commands, vertical nystagmus, horizontal gaze palsy, diffuse hyperreflexia, and quadriparesis. Electroencephalogram (EEG) was consistent with diffuse encephalopathy. Brain magnetic resonance imaging demonstrated restricted diffusion and contrast enhancement in the posterior and central pons with edema. A cerebral angiogram showed no signs of vasculitis. Treatment with intravenous (IV) methylprednisolone 1 g and IV immunoglobulin 2 g/kg was initiated for five days. Despite these interventions, no discernible clinical improvement was observed, prompting the commencement of 500 mg/m2 cyclophosphamide and daily maintenance of IV methylprednisolone at 2 mg/kg. A repeat MRI three weeks later revealed a marked reduction in the size of the lesion involving the pons. The patient also improved clinically over the month with successful extubation, complete return in mental capabilities, and the ability to ambulate short distances with assistance.