Matsuo Y, Asai Y, Nomura T, Sato S, Yoneda T, Inoue S, Miki A, Mizukura I, Abe K; Rehabilitation Unit, Osaka University Hospital, Osaka, Japan. yos-matsuo@umin.ac.jp.

PURPOSE: To characterize interlimb and intralimb coordination in cerebellar ataxia (CA) compared with Parkinson disease(PD). SUBJECTS: Thirteen patients with CA, twenty-seven patients with PD and fifteen normal volunteers. METHODS: We measured the rotational velocity of the pedals during pedaling with a bicycle ergometer (Strength Ergo 240W) newly developed by Mitsubishi Electric Engineering (Nagoya, Japan). The left and right pedals of this bicycle ergometer can be rotated independently. ANALYSES: All data for the single six-minute exercise included one set of velocity profiles of the left and right pedals and two associated time series of the amplitude and relative phase. For characterization of coordination during the exercise, five indices were defined. A set of the five indices for each data was considered as a point located in the five-dimensional index space and this space was used for a cluster analysis. As was described in our previous paper concerning coordinative dysfunction in PD (Abe K et al., 2003), sets of recorded data from the 27 patients with PD, were divided into four clusters. Validity of the clustering was statistically tested. All data could be classified into four clusters. To test exercise results for patients with CA and PD with for similarities and dissimilarities, we located all the data for patients with CA on the cluster map generated from the data for patients with PD. Statistical analyses between CA and PD was performed by Mann-Whitney U test. RESULTS: Twenty-two data for patients with CA were classified into cluster 1 to which all controls belonged, two data were classified into cluster 2. The indices mean and variant relative phase were different for CA than for PD (p < 0.005). The mean slope of regression lines was larger for CA (p < 0.001). CONCLUSIONS: Impairment of intralimb coordination in CA may result in the inability to keep amplitude and speed of pedaling constant, even though interlimb coordination is mostly preserved. These coordinative features in CA are quiet different from those in PD. FUNDING SOURCE: None.

Copyright 2004 by the American Physical Therapy Association

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