Repetitive transcranial magnetic stimulation to SMA worsens complex movements in Parkinson's disease

• Published in: Clinical neurophysiology Vol. 112; no. 2; pp. 259 - 264
• Main Authors: Boylan, L.S., Pullman, S.L., Lisanby, S.H., Spicknall, K.E., Sackeim, H.A.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.02.2001; Elsevier Science
• Subjects: Aged; Biological and medical sciences; Cross-Over Studies; Diseases of the nervous system; Female; Handwriting; Humans; Male; Medical sciences; Middle Aged; Motor Cortex - physiopathology; Movement; Parkinson Disease - physiopathology; Parkinson's disease; Physical Stimulation; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Reaction Time; Severity of Illness Index; Supplementary motor area; Transcranial Magnetic Stimulation; Walking; Parkinson's disease; Transcranial magnetic stimulation; Supplementary motor area; Human; Nervous system diseases; Treatment efficiency; Parkinson disease; Instrumentation therapy; Cerebral disorder; Central nervous system disease; Body movement; Magnetic stimulus; Repetitive stimulus; Degenerative disease; Extrapyramidal syndrome
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/S1388-2457(00)00519-8

Objectives: To evaluate the therapeutic potential of repetitive transcranial magnetic stimulation (rTMS) for Parkinson's disease (PD) by delivering stimulation at higher intensity and frequency over longer time than in previous research. Promising beneficial effects on movement during or after rTMS have been reported. Methods: Ten patients with idiopathic PD were enrolled in a randomized crossover study comparing active versus sham rTMS to the supplementary motor area (SMA). Assessments included reaction and movement times (RT/MT), quantitative spiral analysis, timed motor performance tests, United Parkinson's Disease Rating Scale (UPDRS), patient self-report and guess as to stimulation condition. Results: Two of 10 patients could not tolerate the protocol. Thirty to 45 min following stimulation, active rTMS as compared with sham stimulation worsened spiral drawing ( P=0.001) and prolonged RT in the most affected limb ( P=0.030). No other significant differences were detected. Conclusions: We sought clinically promising improvement in PD but found subclinical worsening of complex and preparatory movement following rTMS to SMA. These results raise safety concerns regarding the persistence of dysfunction induced by rTMS while supporting the value of rTMS as a research tool. Studies aimed at understanding basic mechanisms and timing of rTMS effects are needed.