Polysomnography findings in spinocerebellar ataxia type 6.

Spinocerebellar ataxia type 6 (SCA6) is usually described as a pure ataxia syndrome. However, SCA6 patients may have sleep complaints. In this paper, sleep disorders were investigated in patients with SCA6. Twelve SCA6 patients and 12 subjects matched by gender, age and body mass index (control group) underwent polysomnography and clinical investigation for sleep disorders. SCA6 had a higher frequency of snoring (P = 0.01), a higher index of awakening due to respiratory events (P = 0.003) and central apnea events during sleep (P = 0.024), a longer sleep Stage N1 (P = 0.02) and a lower sleep Stage N3 (P = 0.05) in SCA6 patients than in control subjects. SCA6 patients had a reduction in slow wave sleep and a higher frequency of snoring and respiratory disorders during sleep when compared to the control group.