Noninvasive brain stimulation for parkinson’s disease

Introduction: Dopamine replacement medications are an effective current medical management of Parkinson disease (PD), particularly for motor symptoms but later, the response declines and complications develop. The efficacy of Transcranial magnetic stimulation (TMS) on motor cortex in PD is controversial since subsequent studies show contradictory results. The most common adverse events are transient headaches and scalp discomfort. The aim of this work is to evaluate the effect of high frequency (15 Hz) of rTMS in the motor functions in a group of patients with PD. Patients and Methods: Forty three patients with Parkinson’s Disease (15 women and 28 men) aged from 51 to 76 years (mean 64 ± 8.2) were included in this study. Thirty one patients were randomly assigned to one of two groups; Group I (16) patient on antiparkinsonian medications only and group II (15) patients on antiparkinsonian medications and TMS. Group III (12) patients were chosen from those patient still not on medicine or stop it. Stimulation was delivered using a frequency of 15 Hz and stimulation intensity of 10% above motor threshold (MT) for 10 daily sessions. At each session, a train of 75 stimuli was delivered for 5 s followed by a 10-s interval. A total of 40 trains were delivered in each session, resulting in a total number of 3000 pulses per day. The assessment before and immediately after TMS sessions included a clinical evaluation by by mean of the motor section (part III) of the Unified Parkinson’s Disease Rating Scale (UPDRS) , Schwab and England and Hoehn and Yahr scales. Reevaluation was performed after1 months. Results: In the present study there is significant difference (improvement) in groups II and III resulting from, between base line and immediately after rTMS course also, between base line and 1 month after rTMS. There was a slight decrease (not significant) in score at 1 month after the rTMS in correlation to immediately after it. In group I the difference between base line compared to after antiparkinsonian medications and 1 month after it were significant. The comparison between (Group I vs. Group II), revealed a statistically significant difference (improvement) between base line and after the treatment, also after 1 month. But the comparison between (Group III vs. Group I), revealed a statistically no significant difference, between base line and immediately after, and also,1 month after rTMS. The difference between immediately after treatment and 1 month after it in Both (Group II vs. Group I) and (Group III vs. Group I), were not statistically significant. Conclusion: Our results showed that high-frequency TMS is a promising treatment of motor symptoms in PD. Future studies are also needed to clarify the optimal stimulation parameters, how the different stages of PD affect the response to TMS, and the effects of TMS on other aspects of the disease such as gait, cognition, and memory.