Movements Here Today, Gone Tomorrow

An 85-year-old man with history of left frontal encephalomalacia and non-insulin-dependent type-2 diabetes (hemoglobin A1c 8.5%) presented with right arm pain for 2 weeks followed by right arm and leg continuous, involuntary, writhing movements for 1 day (Supplemental Video). The glucose level was 223 mg/dL. Anion gap, electroencephalogram, and infectious workup were normal. Brain magnetic resonance imaging (MRI) with contrast demonstrated normal-appearing basal ganglia. His movements gradually resolved with subcutaneous insulin, correlating with a subsequently decreased but still abnormal glucose level