Therapeutic and "dose-dependent" effect of repetitive microelectroshock induced by transcranial magnetic stimulation in Parkinson's disease.

Transcranial magnetic stimulation (TMS) has been used in the diagnosis of neurological lesions and has been introduced into the therapy of central nervous diseases. Lately it has been claimed that TMS would be useful not only in the treatment of depression, but also in relieving symptoms of Parkinson's disease. In this study, we sought evidence of the effect of repetitive TMS on the symptoms of Parkinson's disease, the dose dependency between the applied elecromagnetic field and the Parkinsonian symptoms, and the maintenance of the improvement. Forty-nine patients with Parkinson's disease were divided into four groups, each given one stimulus, repeated 30 times, once or twice a day ( approximately 0.34Tesla (T), approximately 0.57T, approximately 0.80T). Patients were followed for 3 months and assessed using two different parkinsonian scales: the graded clinical rating scale and Unified Parkinson Disability Rating Scale (UPDRS), and with a short-term memory test (Ziehen-Ranschburg word pair test). No effect was seen in the group treated with approximately 0.34T\30 stimuli once a day. In all of the groups receiving TMS twice a day, the parkinsonian scores were significantly decreased compared with that of baselines after 1 month of treatment. The greatest improvement in the hypokinesia was detected in the group treated with approximately 0.57T\30 stimuli twice a day (baseline total UPDRS: 30.62 +/- 15.23; 1 month after treatment: 17.08 +/- 7.04, P < 0.01; 3 months after treatment: 16.08 +/- 7.06, P < 0.01). A dose-dependent difference was observed between the two groups after 3 months. The total UPDRS in Group II ( approximately 0.34T\30 stimuli twice a day) significantly differed from Group III ( approximately 0.57T\30 stimuli twice a day; 22.43 +/- 8.87, 16.08 +/- 7.06, P < 0.05). The long-lasting improvement effect with TMS would seem to suggest it as an appropriate tool in the therapy of Parkinson's disease. Copyright 1999 Wiley-Liss, Inc.