IGLON5 and viral encephalitis: Common sleep disturbances include rapid eye movement (REM), sleep behavior disorder and dream enactment behaviors (e.g., anti-LGI1 and CASPR2 encephalitis) [94], hypersomnia and fragmented sleep (e.g., anti-Ma encephalitis) [95], insomnia and periodic limb movements (e.g., anti-NMDA encephalitis and anti-DPPX encephalitis) [74], and REM sleep behavior disorders with stridor and disordered breathing (e.g., anti-IgLON5 encephalitis) [75].