Heart rate variability in type 2 spinocerebellar ataxia

Objectives - To explore cardiovascular autonomic regulation in Spinocerebellar ataxia type 2 (SCA2) patients, using heart rate variability (HRV) analysis and neurophysiologic autonomic reflex tests, and determine relations and causal related factors of dysautonomia in SCA2. Materials and methods - Heart rate variability indices for 5 min series of RR intervals were analyzed in 97 SCA2 patients, assessed quantitatively for somatic and autonomic nervous system complaints applying the International Cooperative Ataxia Rating Scale and Scales for Outcomes in Parkinson's disease (SCOPA-AUT), respectively. Autonomic testing included: resting control, standing, Valsalva maneuver and deep breathing. Results - Mean RR, long- and short-term variability indices and spectral density power (LF, HF) indices were lower in the patients group, whereas LF/HF ratio and LF (nu) were higher. Highly differences between groups were observed for seven diagnostic autonomic test indices. Significant correlations were found between different clinical and demographic indices and between clinical indices and some HRV indices. Conclusions - We confirm the presence of cardiovascular autonomic dysfunction in a large group of SCA2 patients.