The effects of 1HZ rTMS preconditioned by transcranial direct current stimulation on hypokinetic gait in Parkinson's disease

Background: Hypokinetic gait disorder is a common and very disabling symptom in Parkinsons's disease (PD). Repetitive transcranial magnetic stimulation (rTMS) has been shown to improve hypokinesia in PD. Here we present a pilot study designed to evaluate the effects of low frequency rTMS stimulation over the primary motor cortex (M1) preconditioned by transcranial direct current stimulation (tDCS) on hypokinetic gait in PD.

Methods: Three-dimensional kinematic gait analysis was performed i) prior to; immediately after ii) and 25 minutes after low frequency rTMS (1Hz, 900 pulses, 15min, 100% of resting motor threshold) over M1 contralateral to the more affected body side preconditioned by (i) cathodal, (ii) anodal or (iii) sham tDCS (amperage: 1mA, duration: 600 seconds for cathodal and anodal tDCS, 20 seconds for sham tDCS) in 12 subjects with PD (8 female and 4 male subjects; mean age 64.2±.10.1 years). The effects of tDCS preconditioned 1Hz rTMS were measured by the following parameters: number of steps; stride length; double support and cadence.

Results: Our data suggest an improvement of hypokinetic gait in PD after 1Hz rTMS alone (sham precondition) and after 1Hz rTMS preconditioned by anodal tDCS, whereas cathodal preconditioned 1Hz rTMS had no improving effect with a tendency to transient deterioration on movement kinematics.

Conclusion: Our results show that combining tDCS with rTMS is a safe and promising approach to improve hypokinetic gait disorder in PD.