title: Low-frequency repetitive transcranial magnetic stimulation for dyskinesia and motor performance in Parkinson's disease.
abstract: Dyskinesias are one of the most frequent and disabling complications of the long-term treatment of Parkinson's disease (PD). Although the cause is not completely understood, it appears that an imbalance between excitatory and inhibitory inputs from the basal ganglia to the motor cortex leads to overactivation of motor and premotor areas. Overactivation of the supplementary motor area (SMA) has been observed in neuroimaging studies in dyskinetic PD patients. We investigated the effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) of the SMA on levodopa-induced dyskinesias (LID) and motor performance in PD. We tested whether longer duration (10days) and higher number of total pulses (1800 pulses) would enhance the beneficial effect. Seventeen dyskinetic PD patients were randomly assigned to real rTMS or sham (placebo) rTMS, and 1Hz rTMS or sham rTMS was applied over the SMA for 10 consecutive days. Patients were assessed at baseline and 1day after the last rTMS with a levodopa challenge test, and video recordings were taken. Dyskinesias and motor performance were rated off-line by two blinded raters using video recordings. After 10days of treatment with rTMS, we observed that 1Hz rTMS delivered over the SMA had decreased LID lasting for 24hours without a change in motor performance, whereas sham rTMS induced no significant change in dyskinesia scores. These results support a possible therapeutic effect of low-frequency rTMS in LID. However, in order to suggest rTMS as an effective treatment, long-term observations and further investigations with a larger patient population are essential.
authors.affiliation: Sakarya Yenikent State Hospital, Department of Neurology, Sakarya 54000, Turkey. Electronic address: smsayin@yahoo.com.
authors.forename: Sevgi
authors.initials: S
authors.lastname: Sayın
authors.affiliation: Dokuz Eylül University, Faculty of Medicine, Department of Neurology, İzmir, Turkey.
authors.forename: Raif
authors.initials: R
authors.lastname: Cakmur
authors.affiliation: Dokuz Eylül University, Faculty of Medicine, Department of Neurology, İzmir, Turkey.
authors.forename: Görsev G
authors.initials: GG
authors.lastname: Yener
authors.affiliation: Dokuz Eylül University, Faculty of Medicine, Department of Neurology, İzmir, Turkey.
authors.forename: Erdem
authors.initials: E
authors.lastname: Yaka
authors.affiliation: Yeditepe University, Department of Neurology, Faculty of Medicine, Istanbul, Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Uğurel
authors.affiliation: Dokuz Eylül University, Faculty of Medicine, Department of Neurology, İzmir, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Uzunel
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000627:therapeutic use; D004409:Dyskinesia, Drug-Induced / Q000628:therapy*; D005260:Female; D006801:Humans; D007980:Levodopa / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D010300:Parkinson Disease / Q000628:therapy*; D012720:Severity of Illness Index; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D016896:Treatment Outcome; D014741:Video Recording
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Dyskinesia; Motor performance; Parkinson’s disease; Repetitive transcranial magnetic stimulation; Supplementary motor area