A 16 year-old African American male with past medical history of mild learning disability presented to the emergency department with subacute onset of right upper extremity paresthesias, dysphagia and left foot drop. Initial neurological exam was notable for left-sided central facial palsy, hemifacial spasms, left leg weakness, dysarthria and hyperreflexia. MRI brain revealed predominantly cortical T2 and FLAIR patchy hyperintensities without contrast enhancement. CSF autoimmune encephalitis panel revealed AMPAR-Ab by both CBA and IFA (1:32 titer). Malignancy work-up was negative. He was given intravenous methylprednisolone (1 g/day over 5 days) and intravenous immunoglobulins (2 g/kg divided over 3 days) followed by steroid taper. He was discharged on a 12-week IVIG (1g/kg) treatment plan and noted to have moderate improvement at his 2 month follow-up visit.
Our literature review indicated that focal motor weakness, paresthesia, and bulbar symptoms are an uncommon presentation for AMPARE in both pediatric and adult patients. The majority of adult patients with AMPARE present with features typical of limbic encephalitis, including seizures, encephalopathy, and psychiatric symptoms.