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

BACKGROUND

The 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.

METHODS

Grip force control while holding an object during cyclic arm movements was assessed in patients with pure cerebellar degeneration ( = 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.

RESULTS

There 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.

CONCLUSION

In the present study, deficits in grip force control were neither improved by tDCS applied over the cerebellum nor M1 in cerebellar degeneration.