Event-Related Desynchronization/Synchronization in Spinocerebellar Ataxia Type 3

Abstract

Introduction: Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominant, cerebellar degeneration predominant disease caused by excessive CAG repeats. We examined event-related dysynchronization/synchronization (ERD/ERS) in patients with SCA3. Methods: We assessed ERD/ERS of self-paced voluntary hand movements in 15 patients with genetically proven SCA3 in comparison with healthy controls. Results: In ERS, a significant interaction effect between group, frequency, and period (F = 1.591; p = 0.005; ρI = 0.86) was observed. The post-hoc two-tailed independent t-test showed significant differences in high beta and low beta ERS. By contrast, in ERD, no apparent differences were observed in the pattern of patients with SCA3 in comparison with healthy controls (F = 1.01; p = 0.442). Conclusion: The study revealed a decreased ERS in patients with SCA3, especially at the frequency of 20-30 Hz. This study elucidates the significant role of cerebellum in motor control.

Keywords: ERD; ERS; SCA3; cerebellar ataxia; motor control.

Figure 1

Illustration of processed averaged EMG of Normal and SCA3 during the EEG recording.

Figure 2

An illustration of averaged event-related spectral perturbation at movement onset (0 ms) across all control (B) and SCA3 (A). A clear ERD (color blue) followed by ERS (color red) was presented in both control and SCA3 groups between alpha and beta range at C3 electrode when epoched between −3 and 4.5 s with baseline corrected by −3 to −2 s.

Figure 3

(A) Averaged power change at movement onset between alpha, low beta, and high beta bands both in normal controls and SCA3 patients. (B) Averaged power change at movement offset between alpha, low beta, and high beta bands in both control and SCA3 groups. post-hoc independent t-test showed significant difference in high beta ERS (marked as ^*).