Sleep disorder, chorea, and dementia associated with IgLON5 antibodies

A novel syndrome characterized by a distinctive sleep disorder accompanied by variable symptoms of brainstem involvement and a highly restricted haplotype was recently described in association with antibodies to a neuronal cell adhesion protein named IgLON5. Because of the symptoms and chronic disease progression, most of these patients are primarily seen by specialists in sleep and neurodegenerative disorders. Since the initial description of this encephalopathy in 2014, only 1 additional patient has been reported.1 In order to improve clinical recognition we report a new patient who presented with the characteristic sleep dysfunction and subsequently developed chorea. Acknowledgment: The authors thank Dr. Leandro Tavares Lucato (Radiology Institute, Hospital das Clinicas, Sao Paulo University) for reviewing neuroradiologic images and Dr. Maira Okada de Oliveira (Behavioral and Cognitive Neurology Unit, Hospital das Clinicas, Sao Paulo University) for the neuropsychological testing data.