Synergic control of action in levodopa-na ïve Parkinson's disease patients: I. Multi-finger interaction and coordination.

Synergic control of action in levodopa-naïve Parkinson's disease patients: I. Multi-finger interaction and coordination. Exp Brain Res. 2019 Dec 14;: Authors: de Freitas PB, Freitas SMSF, Reschechtko S, Corson T, Lewis MM, Huang X, Latash ML Abstract We explored the origin of the impaired control of action stability in Parkinson's disease (PD) by testing levodopa-naïve PD patients to disambiguate effects of PD from possible effects of long-term exposure to levodopa. Thirteen levodopa-naïve PD patients and 13 controls performed single- and multi-finger force production tasks, including producing a self-paced quick force pulse into a target. A subgroup of patients (n = 10) was re-tested about 1 h after the first dose of levodopa. Compared to controls, PD patients showed lower maximal forces and synergy indices stabilizing total force (reflecting the higher inter-trial variance component affecting total force). In addition, PD patients showed a trend toward shorter anticipatory synergy adjustments (a drop in the synergy index in preparation to a quick action) and larger non-motor equivalent finger force deviations. Lower maximal force, higher unintentional force production (enslaving) and higher inter-trial variance indices occurred in PD patients after one dosage of levodopa. We conclude that impairment in synergies is present in levodopa-naïve patients, mainly in indices reflecting stability (synergy index), but not agility ...
Source: Experimental Brain Research - Category: Neuroscience Authors: Tags: Exp Brain Res Source Type: research