Rapidly progressive global cerebral atrophy in the setting of anti-LGI1 encephalitis

A 47-year-old man presented with complaints of breakthrough seizures, psychiatric and behavioural changes and catatonic features. MRI of the brain showed mild cerebral and right hippocampal atrophy, while the electroencephalogram showed intermittent right temporal slowing. With a presumed diagnosis of autoimmune encephalitis, he was treated with intravenous immunoglobulin (IVIG) and methylprednisolone, which significantly improved the symptoms. Serological testing later was positive for antileucine-rich glioma inactivated 1 antibody. Two months after the initial presentation, patient had a relapse of the symptoms without any further episodes of seizures. Repeat MRI of the brain showed a significant rapidly progressive diffuse cortical atrophy and hippocampal atrophy, more prominent on the right side along with hydrocephalus ex vacuo when compared with the initial MRI. He is currently on monthly IVIG therapy. At 4 months follow-up from the second imagining study, the patient had persistent MRI findings.