Effect of thalamic stimulation on gait in Parkinson disease

Objective: To assess the influence of ventral intermediate thalamic nucleus stimulation on gait in idiopathic Parkinson disease. Design: Clinical and physiological assessments were compared in patients with and without ventral intermediate thalamic nucleus stimulation. Setting: The research clinic of a university department of gait analysis. Patients: 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 kinematic parameters were automatically recorded using the Vicon optoelectric system for movement analysis. Measures of locomotor displacement (cadence, 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 were also analyzed for the left and right lower limbs and for the affected 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, effective in reducing tremor, does not modify gait parameters in idiopathic Parkinson disease.