Levodopa effect on electromyographic activation patterns of tibialis anterior muscle during walking in XXXX .

@entity1 @entity191
Previous studies have reported that @entity1 with @entity191 ( @entity191 ) show, in the "off medication" state, a reduced activation of tibialis anterior (TA) in the late swing-early stance phase of the gait cycle. In @entity191 @entity1 the pathophysiological picture may cause differences among the stride cycles. Our aims were to evaluate how frequently TA activity is reduced in the late swing-early stance phase and if there is a relationship between the TA pattern and the clinical picture. Thirty @entity191 @entity1 were studied 2 h after Levodopa administration ("on-med") and 12 h after Levodopa wash-out ("off-med"). They were evaluated by the Unified @entity191 Rating Scale (UPDRS III) and surface electromyography of TA and gastrocnemius medialis (GM). The root mean square (RMS) of the TA activity in late swing-early stance phase (RMS-A) was normalized as a percent of the RMS of the TA activity in late stance-early swing (RMS-B). RMS-A was reduced in 30% of @entity1 in the "off-med" condition. Within these @entity1 , the percentage of stride cycles with reduced RMS-A, ranged between 28% and 83%. After Levodopa intake, no stride cycle showed reduced RMS-A. @entity1 with reduced RMS-A had a lower UPDRS III total score in the "on-med" rather than in the "off-med" condition (p=0.02). Our data confirm and extend previous observations indicating that, in "off-med" the function of TA is impaired in those @entity1 clinically more responsive to Levodopa. TA activation is reduced in a relatively high percent of gait cycles in the "off-med" state. Since the variability of TA activation disappears after Levodopa administration, this phenomenon could be the expression of an abnormal dopaminergic drive.
