Fractal dimension analysis of static stabilometry in Parkinson's disease and spinocerebellar ataxia

The static stabilometry patterns associated with Parkinson's disease (PD, n = 15) and spinocerebellar ataxia (SCA, n = 15) were compared with those of normal control (n = 15) by measuring the fractal dimensions. Fractal dimen sions were estimated using the modified pixel dilation (mPD) method. The fr actal dimensions with closed eyes showed a significant correlation with Env ironmental area for SCA group (p < 0.05). The fractal dimension for SCA gro up was significantly higher with closed eyes than that with open eyes (p < 0.05). The fractal dimension with closed eyes was significantly higher in P D and SCA groups than that in normal group (p < 0.05). The fractal dimensio n with closed eyes was higher when the clinical stage was more severe with PD and SCA group while Environmental and Longitude/Environmental areas were not These findings suggest that the fractal dimension is more sensitive th an traditional stabilometric analysis in an evaluation of postural instabil ity in PD and SCA.