Abstract
It is often observed that left hemiplegics with motor impersistence (MI) in facial movements have also the clumsiness of unaffected extremities in practical actions such as driving a wheelchair. The authors previously reported that the MI patients were significantly inferior to the other patients without MI on driving speed of wheel chair, frequency of the stroke with their unaffected upper extremities and frequency of the antagonistic simultaneous strokes with their upper and lower extremities. The purpose of the present study is to analyse these disorders quantitatively by examining isometric movements of the extremities.
The subjects were 6 left hemiplegics (LH) with MI, 7 LH without MI and 7 right hemiplegics (RH) without MI. In the experiment, they were instructed to maintain pinching with the thumb and index finger of the unaffected hand, trampling with the unaffected foot and simultaneous both actions for 20 seconds respectively. The pressure of pinch and trample, and the duration of maintaning each actions were measured.
The results show that the mean pressure of pinch was not significantly different among the three groups whether in the course of single action or simultaneous actions. As to the mean pressure of trample, LH with MI was significantly lower than LH without MI only during the simultaneous actions, though not different from RH. The duration of pinch and trample was not significantly different among three groups, although one subject of LH with MI had. discontinued pinching during the simultaneous actions. In order to estimate the difference among three groups on the temporal decrement of pressure, the decrement index (d. i.) was calculated as (max. pressure within the first 10 min.―min. pressure with in the second 10 min.)/the mean pressure within 20 min. As to d. i. of pinch pressure, LH with MI was greater than those of other groups, in both cases of single action and simultaneous actions. D. i. of trample pressure was different only between LH with MI and RH in the condition of simultaneous actions.
These results suggest that MI phenomena grow rarer or gradually less in degree on the face, upper extemity and lower extemity in the order named. The authors consider it might be caused by that facial actions such as closing eyes and protruding tongue are less natural and demand more intentional efforts than simple actions of extremities.
