title: Effects of DBS, premotor rTMS, and levodopa on motor function and silent period in advanced Parkinson's disease.
abstract: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and highly effective treatment for patients with advanced Parkinson's disease (PD). Repetitive TMS (rTMS) applied to motor cortical areas has also been shown to improve symptoms in PD and modulate motor cortical excitability. Here, we compared clinical and neurophysiological effects of STN stimulation with those of 1 Hz rTMS given to the dorsal premotor cortex (PMd) and those following intake of levodopa in a group of PD patients with advanced disease. Ten PD patients were studied on 2 consecutive days before and after surgery. Clinical effects were determined using the UPDRS motor score. Motor thresholds, motor-evoked potential (MEP) amplitudes during slight voluntary contraction, and the cortical silent periods (SP) were measured using TMS. Before surgery effects of levodopa and 1 Hz PMd rTMS and after surgery those of STN stimulation with or without additional levodopa were determined. Levodopa significantly improved clinical symptoms and increased the SP duration. STN stimulation improved clinical symptoms without changing the SP duration. In contrast, 1 Hz PMd rTMS was not effective clinically but normalized the SP duration. Whereas levodopa had widespread effects at different levels of an abnormally active motor network in PD, STN stimulation and PMd rTMS led to either clinical improvement or SP normalization, i.e., only partially reversed abnormal motor network activity.
authors.affiliation: Department of Neurology, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany. baeumer@uke.de
authors.forename: Tobias
authors.initials: T
authors.lastname: Bäumer
authors.forename: Ute
authors.initials: U
authors.lastname: Hidding
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hamel
authors.forename: Carsten
authors.initials: C
authors.lastname: Buhmann
authors.forename: Christian K E
authors.initials: CK
authors.lastname: Moll
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.forename: Michael
authors.initials: M
authors.lastname: Orth
authors.forename: Hartwig Roman
authors.initials: HR
authors.lastname: Siebner
authors.forename: Alexander
authors.initials: A
authors.lastname: Münchau
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D046690:Deep Brain Stimulation / Q000379:methods*; D004567:Electrodes, Implanted; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009044:Motor Cortex / Q000187:drug effects / Q000503:physiopathology; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus / Q000502:physiology; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa