An open study of repetitive transcranial magnetic stimulation in treatment-resistant depression with Parkinson's disease
Major depression is a common concomitant of chronic central nervous system disorders, notably Parkinson's disease (PD). Repetitive transcranial magnetic stimulation (rTMS) has been investigated as a potential treatment for depression in PD and for the movement disorder of PD, but comprehensive testing in multiple areas of performance has seldom been carried out within a single study. We studied the effect of left dorsolateral prefrontal rTMS on several different functional domains. Fourteen PD patients with treatment-resistant depression entered an open, 10-day inpatient study of 10-Hz rTMS, undergoing extensive psychiatric, neuropsychological, and motor testing from baseline to 6 weeks after treatment. Motor testing included a defined "off" state. rTMS was well tolerated. Highly significant improvement in depression scores was seen 3 days and 3-6 weeks after treatment. Improvement was also found in anxiety, movement scores (especially in the off state), and some neuropsychological measures. We found no evidence of increased risk from rTMS in this population. Further controlled trials of rTMS in PD appear worthwhile, and should include a defined "off" state. TMS may be beneficial for depressed PD patients in multiple functional domains.