Composite autonomic severity scoring in spinocerebellar ataxia type 1 and 2

Objectives: The aim of the present study was to evaluate the integrity of autonomic nervous system in spino-cerebellar ataxia (SCA) type 1 and 2 patients using battery of autonomic function tests and their comprehensive scoring using composite autonomic severity score (CASS). Material and methods: Battery of autonomic function test comprising of cardiovascular (baroreflex dependent and non-baroreflex dependent) and sudomotor functions were assessed in age and gender-matched SCA1 (n = 31), SCA2 (n = 40) patients along with healthy controls (n = 40). To assess the grade of autonomic abnormalities, the composite autonomic severity score (CASS) was computed using the results of the standard autonomic function tests. Results: We found reduction in baroreflex dependent autonomic reactivity parameters predominantly a signifi-cant fall of systolic blood pressure (<0.001) and lower 30:15 ratio (<0.001) during head up tilt in both the SCA1 and SCA2 as compared to controls. On sudomotor assessment, distal leg latency of sweat response was prolonged in SCA1 than SCA2 patients. Moderate generalized autonomic failure was commonly found amongst SCA1 (80.65%) and SCA2 (85%) patients. Severe autonomic failure was found to be more in SCA1 (6.45%) than SCA2 (2.50%) patients. Conclusions: Cardiovascular autonomic function assessment in SCA1 and SCA2 patients revealed a significant impairment in the baroreflex loop integrity. Severity scoring using CASS suggests the existence of moderate autonomic failure in majority of both SCA1 and SCA2 patients.

Automated summary

This study aimed to evaluate the integrity of the autonomic nervous system in patients with spino-cerebellar ataxia (SCA) type 1 and 2 by conducting autonomic function tests and scoring with composite autonomic severity score (CASS). The results showed a reduction in cardiovascular autonomic reactivity parameters, particularly a significant decrease in systolic blood pressure and lower 30:15 ratio during head up tilt in both SCA1 and SCA2 patients compared to controls. Sudomotor assessment also revealed prolonged distal leg latency of sweat response in SCA1 patients. The use of CASS indicated the presence of moderate autonomic failure in the majority of SCA1 and SCA2 patients.