Article

Defined as the transient state between standing and walking, gait initiation is
negatively affected in Parkinson's disease (PD), which often results in
significant disability. Although deep brain stimulation (DBS) is the most common
surgical procedure for PD, the long-term effects of DBS on gait initiation are
not well studied. The present study evaluated the long-term effects of
subthalamic nucleus (STN) DBS on the preparation phase of gait initiation using
principal component (PC) analysis. Six patients with PD who had undergone STN DBS
and 24 healthy control subjects were evaluated. PD subjects were assessed
11.3+/-10.3 (P1) and 78.9+/-10.6 (P2) months after surgery. PD subjects were
tested with STN DBS in two conditions: without medication and with medication. PC
analysis was applied separately for the vertical, anterior-posterior and
medial-lateral components of ground reaction force (GRF) recorded during gait
initiation. Three PC scores were chosen by the scree test for each GRF component
and all these PC scores were used for calculating a standard distance between
healthy controls and PD subjects. The Friedman test showed a significant
difference in standard distance among conditions (P=0.004), with the post-hoc
test recognizing differences among P1 conditions and P2 medication-on condition.
The eigenvector loading factors pointed to major differences between PD
conditions surrounding the maximum amplitude of vertical and anterior-posterior
GRF. For the studied sample, all distances increased in the follow-up evaluation
(P2) with and without medications, indicating a worsening in gait initiation
after seven years.
CI - Copyright A(c) 2011 Elsevier B.V. All rights reserved.

Langue : ANGLAIS