Effects of transcranial direct current stimulation on grip force control in patients with cerebellar degeneration

Joachim Hermsdörfer,Dagmar Timmann,Michael Küper,Thomas Hulst,Liane John

doi:10.1186/s40673-017-0072-8

Abstract

BackgroundThe control of grip forces when moving a hand held object is impaired in patients with cerebellar degeneration. We asked the question whether after-effects of anodal transcranial direct current stimulation (tDCS) applied to the lateral cerebellum or M1 improved grip force control in cerebellar patients.MethodsGrip force control while holding an object during cyclic arm movements was assessed in patients with pure cerebellar degeneration (n = 14, mean age 50.2 years ± SD 8.8 years) and age- and sex-matched control participants (n = 14, mean age 50.7 years ± SD 9.8 years). All subjects were tested before and after application of tDCS (2 mA, 22 min) in a within-subject design. Each subject received anodal tDCS applied to the cerebellum, anodal tDCS applied to M1 or sham-stimulation with a break of 1 week between the three experimental sessions.ResultsThere were no clear after-effects of tDCS on grip force control neither in control participants nor in cerebellar patients. Cerebellar patients showed typical impairments with higher grip forces, a higher variability of movements.ConclusionIn the present study, deficits in grip force control were neither improved by tDCS applied over the cerebellum nor M1 in cerebellar degeneration.

Highlights

The control of grip forces when moving a hand held object is impaired in patients with cerebellar degeneration
Five participants presented with autosomal dominant cerebellar ataxia (ADCA) type III
The only significant effect was an increase of frequency after the stimulation compared to pre-stimulation values for all participants including patients and controls (pre transcranial direct current stimulation (tDCS): 0.72 ± 0.16 Hz, post tDCS: 0.74 ± 0.15 Hz, main effect of “time”: F(1,25) = 7.8, P = 0.010)

Summary

Introduction

The control of grip forces when moving a hand held object is impaired in patients with cerebellar degeneration. The impaired grip force control found in Because of its ability to modify cerebellar excitability and to induce plastic modifications without significant side effects, cerebellar transcranial direct current stimulation (tDCS) may be a powerful tool in the rehabilitation of cerebellar patients [9]. As yet, it is unknown whether tDCS improves deficits of cerebellar patients in grip-force control

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Results

Discussion

Conclusion