Beneficial effect of transcranial magnetic stimulation on sleep in Parkinson's disease.

Sleep disorders are common in Parkinson's disease (PD) and have profound negative influences on quality of life. Sleep structure in healthy participants can be changed by repetitive transcranial magnetic stimulation (rTMS), but this has never been studied systematically in PD. Therefore, we characterized sleep in PD patients and examined effects of rTMS using a combination of actigraphy and a pressure sensitive pad. Thirteen PD patients received 5 Hz rTMS over the motor or parietal cortex. Actigraphic sleep estimates were obtained before, during and after rTMS, as well as compared with 8 healthy, age-matched controls. Motor symptoms and mood were evaluated before and after rTMS. Mixed-model regression analyses indicated that PD patients slept shorter (350 +/- 17 vs. 419 +/- 24 min., P = 0.02), more fragmented (fragmentation index 41 +/- 4 vs. 22 +/- 2, P = 0.0004) and had a lower sleep efficiency (77 +/- 2 vs. 86 +/- 2%, P = 0.002) and longer nocturnal awakenings (3.4 +/- 0.2 vs. 2.3 +/- 0.2 min., P = 0.003) than healthy controls. rTMS over the parietal, but not over the motor cortex improved sleep fragmentation (P = 0.0002) and sleep efficiency (P = 0.0002) and reduced the average duration of nocturnal awakenings (P = 0.02). No change of motor symptoms or mood was observed. Disturbed sleep in PD patients may partly be reversed by parietal rTMS, without affecting motor symptoms or mood.