Movement Disorders P-MD001. Evaluation of gait in spinocerebellar ataxia type 12 (SCA-12)

Introduction. SCA12 an autosomal dominant ataxia, is characterized by tremor in hands at onset followed by gait ataxia and other cortical features during the course of illness. The aim of the study was to identify and quantify spatiotemporal parameters of gait in a group of SCA12 patients and to compare it with healthy subjects. Methods. Genetically confirmed SCA12 patients (n = 25) with mean age of 55.7 ± 10.2 years and age matched healthy individuals (n = 25) with 55.2 ± 10.1 years were studied. A walkway system (by Teckscan, USA) was used to evaluate spatiotemporal parameters of gait in both groups. All the participants were instructed to walk bare foot within comfortable normal speed on sensor plates of walkway system for 30 seconds. The two sampled t test was used with the level of significance p value Results. All spatial and temporal parameter mean values were significantly different from the control group, except for single support time and swing time. Most significant findings in spatial and temporal parameters concerned stride length (106.8 ± 7.4cm in control group vs 79.0 ± 19.4 cm in patients, p = 0.000), step width (7.8 ± 1.7 cm in control group vs 13.8 ± 2.8 cm in patients, p = 0.000), double support time (0.35 ± 0.6 sec in control group vs 0.61 ± 0.30 sec in patients, p=0.005) and gait velocity (83.5 ± 14.5 cm/sec in control group vs 48.86 ± 21.6 cm/s in patients, p = 0.000). Ten patients with normal gait had mean duration of illness 4.4 ± 1.2 year and mean CAG repeat number 55.7 ± 5.4. Mean duration of illness and mean CAG repeat number of 15 patients having abnormal gait was 6.8 ± 5.4 years and 53.8 ± 7.3. Conclusion. Gait ataxia in SCA12 patients was a late feature and developed after around 5 years of illness. Gait showed significant reduction in stride length, step length, gait velocity with mark increase in step width and double support time.