[Kinematic evaluation of dystonic syndromes in patients treated with deep brain stimulation]

Quantification of motor functions of patients with dystonic syndromes treated by chronic high frequency stimulation of the internal globulus pallidus is a challenge.

Through a series of clinical examples this paper shows that kinematic analysis of movements in dystonic syndromes treated by deep brain stimulation (DBS) is a complement to clinical evaluation. In addition, it provides valuable information for early detection of improvement or impairment of movements associated with modifications of stimulation parameters.

Thirteen dystonic patients and eleven reference subjects completed three tests (i.e., rest: lying supine; posture: standing with arms held in front (at shoulder height); and alternative movements: bimanual finger-to-nose test). These tests were recorded with an electromagnetic system quantifying movement kinematics (position) in three-dimensional space.

From the recorded data, several indices were developed and provided a quantitative evaluation of movements during each test. In addition, a clinical evaluation (BMFDRS) was also completed. No correlation between clinical and kinematic evaluations was found.

It is shown that kinematic analysis is a useful complement of clinical evaluation and can assist clinicians in monitoring the evolution of movements in dystonic patients treated by DBS in a simple, reliable and valid fashion.