Reversible splenial lesion syndrome with a hyperosmolar hyperglycemic state and neuroleptic malignant syndrome caused by olanzapine.

A 27-year-old woman with panic disorder taking 20 mg olanzapine daily for 4 months was admitted to Mito Kyodo General Hospital, Mito, Ibaraki, Japan, because of disturbed consciousness with fever, hyperglycemia, hyperosmolarity and elevated creatine phosphokinase. She was diagnosed with a hyperosmolar hyperglycemic state and neuroleptic malignant syndrome. Brain magnetic resonance imaging showed transiently restricted diffusion in the splenium of the corpus callosum, with a high signal intensity on diffusion-weighted imaging.