The Expanding Spectrum of Anti-IgLON5 Disease: A Case Series from an Indian Cohort.

Anti-IgLON5 disease is an evolving entity that lies at the confluence of autoimmunity and neurodegeneration. Reports from India remain sparse. In this series, we describe seven Indian patients with anti-IgLON5-related disease. Patients presented across the fifth to eighth decades with a mean duration of illness of 16 months. All had movement disorders, which included gait ataxia, parkinsonism, and chorea. Six patients had sleep disturbances. Five had a frontal dysexecutive dementia phenotype. Two had epilepsy. Bulbar involvement was present in four, and one had amyotrophic lateral sclerosis (ALS)-like features. Magnetic resonance imaging was abnormal in two cases. Positron emission tomography of the brain also contributed to diagnosis. Combination immunotherapies were used in most of the patients, with three showing a sustained response and two deaths reported due to sepsis-related complications. It is important to recognize the increasing spectrum of IgLON5-related disease to enable timely initiation of immunotherapy before marked degeneration occurs.