Neuropsychiatry presentation of acute disseminated encephalomyelitis in a young adult

Abstract

Acute disseminated encephalomyelitis (ADEM) is an autoimmune inflammatory demyelinating disease of the central nervous system (CNS) involving the spinal cord and white matter of the brain, usually affecting children and young adults after vaccination or an infection. Neuropsychiatric manifestations are common but are less frequently reported in literature. This case details a young man with no previous comorbidities, who presented with a range of neuropsychiatric manifestations including blank stares, catatonic-like symptoms, selective mutism, irritability, aggression, and visual hallucination. Magnetic resonance imaging showed focal abnormal signal intensity at the splenium of the corpus callosum, notably mildly hypointense on T1W, hyperintense on T2W/FLAIR with restricted diffusion on ADC/DWI. Minimal patchy enhancement was noted postcontrast. Subtle T2/FLAIR hyperintensities were also seen involving the right medial thalamus. He was diagnosed with monophasic ADEM and initiated on intravenous methylprednisolone 1 g daily; however, he developed potential steroid-induced psychosis and was subsequently changed to orodispersible olanzapine and intravenous immunoglobulin (IVIG) 0.4 g/kg/h for 5 days to which he responded satisfactorily. This case report highlights the importance of treating ADEM with steroids and immunoglobulins as it can result in high psychiatric and physical morbidity and mortality if untreated early.