Dopa-Responsive Dystonia and gait analysis: A case study of levodopa therapeutic effects.

INTRODUCTION: Patients suffering Dopa-Responsive Dystonia present dystonia, abnormal postural balance and gait impairment. Treatment with levodopa typically improves these three symptoms. The present study provides an extensive analysis of gait and posture in a patient with Dopa-Responsive Dystonia, prior to and during levodopa therapy. METHOD: The patient was assessed with the Unified Dystonia Rating Scale, underwent motion analysis with an optoelectronic system and postural analysis with force plates. RESULTS: This study provides a detailed quantification of gait parameters in a Dopa-Responsive Dystonia patient. Prior to treatment, mean walking speed was severely reduced, gait cadence and step length were decreased and stride width was increased. Right lower limb and pelvis showed kinematic defects, trunk and Centre of Mass were backwards. During levodopa therapy, the walking speed was doubled, gait cadence and step length were increased and stride width was reduced. Nearly all kinematic parameters of lower limbs were significantly improved. The patient's Centre of Mass during gait and Centre of pressure in static position both shifted forward. CONCLUSION: Levodopa dramatically decreased dystonia and improved spatio-temporal, kinematic and posture parameters. Our main pathophysiological hypothesis is that trunk tilt and its consequences on the Centre of Mass position have a pivotal influence on gait and balance, explaining both the initial impairments and the therapeutic effects. Gait analysis proves to be an effective tool to understand the pathophysiology of this patient, the therapeutic effects and mild residual gait defects in order to plan further rehabilitation strategy for this DRD patient. We propose that it will also prove to be useful for the exploration of other dystonic patients.

Constraint therapy versus intensive training: implications for motor control and brain plasticity after stroke.

Many studies have demonstrated that constraint induced movement therapy (CIMT) improves upper limb motor impairment following stroke. This rehabilitation method combines constraint of the less-affected upperlimb with intensive training of the paretic limb. The aim of the present study was to evaluate, in a single case study, the respective effects of each of these two therapeutic interventions. The patient selected was a 32-year-old right-handed woman. Three and a half years prior to inclusion, she suffered a left capsular infarct responsible for a right hemiparesis. Several assessments were carried out before and after constraint therapy and then after intensive training. Each assessment included measures of hand function as well as a three-dimensional (3D) analysis of prehension. Results showed a significant improvement of motor performance after the constraint period and an additional amelioration after the intensive training period. Kinematic analysis showed that the transport phase of movement (movement time and velocity peaks) was improved after the constraint period, whereas the grasping phase (maximum grip aperture) was modified after intensive training. These data could reflect a specific effect of treatment on each phase of the prehension task, or a more general proximal-to-distal gradient of recovery. Although firm conclusions are not warranted on the basis of this single case study, we confirm the utility of 3D motion analysis to evaluate objectively the effectiveness of a therapeutic intervention. We also discuss the implications of our findings for understanding processes of motor control reorganisation.