Sleep disruption in spinocerebellar ataxia type 3: A genetic and polysomnographic study

Background: Sleep structure disruption and rapid eye movement (REM) sleep behavior disorders (RBD) have been previously reported in patients with neurodegenerative diseases. However, similar studies have rarely been quantitatively conducted in type 3 spinocerebellar ataxia (SCA3). Methods: Fifteen patients with SCA3 and 16 healthy controls were recruited and evaluated by clinical history, International Cooperative Ataxia Rating Scale (ICARS), Epworth sleepiness scale (ESS), and polysomnography. Results: Patients with SCA3 had reductions in sleep efficiency and percentage of REM sleep, which were negatively correlated with the severity of ataxia as evaluated by ICARS. REM sleep reduction occurred regardless of the presence of RBD, and severe reduction of REM sleep may significantly disturb the assessment of RBD. Conclusion: Poor sleep efficiency and REM sleep aberrations are the characteristics of sleep structure disruption in SCA3 as the disease progresses. The incidence of respiratory disturbance during sleep or excessive daytime sleepiness was not significantly higher in SCA3 patients than controls.