Objective: To assess the influence of ventral intermediate thalamic nu
cleus stimulation on gait in idiopathic Parkinson disease. Design: Cli
nical and physiological assessments were compared in patients with and
without ventral intermediate thalamic nucleus stimulation. Setting: T
he research clinic of a university department of gait analysis. Patien
ts: Seven patients with idiopathic Parkinson disease who had long-term
monopolar stimulation of the ventral intermediate thalamic nucleus to
control a large-amplitude tremor. Main Outcome Measures: Gait kinemat
ic parameters were automatically recorded using the Vicon optoelectric
system for movement analysis. Measures of locomotor displacement (cad
ence, walking speed, stride and step times, single and double support
times, and stride and step lengths) were computed successively during
2 conditions: stimulation on and off. Traces of ankle joint position w
ere also analyzed for the left and right lower limbs and for the affec
ted and unaffected lower limbs. Results: NO difference in mean values
was observed between the 2 conditions. Conclusion: This study seems to
confirm that ventral intermediate thalamic nucleus stimulation, effec
tive in reducing tremor, does not modify gait parameters in idiopathic
Parkinson disease.