title: Resetting tremor by single and paired transcranial magnetic stimulation in Parkinson's disease and essential tremor.
abstract: OBJECTIVE
  The pathogenesis of tremor in Parkinson's disease (PD) and essential tremor (ET) is not fully understood. This study tested the role of primary motor cortex (M1), supplementary motor area (SMA) and cerebellar cortex on PD and ET tremor by single- and paired-pulse transcranial magnetic stimulation (TMS).
  
  
  METHODS
  Ten PD patients with resting tremor, six of them also with postural tremor, and ten ET patients with postural tremor were studied. Randomized single- and paired-pulse TMS with an interstimulus interval of 100 ms were delivered over M1, SMA and cerebellum. TMS effects were evaluated by calculating a tremor-resetting index (RI).
  
  
  RESULTS
  Single- vs. paired-pulse TMS showed no difference. M1-TMS and SMA-TMS but not by cerebellar TMS induced a significant RI in PD and ET. M1-TMS resulted in a significantly higher RI in PD than ET. Furthermore, M1-TMS in PD but not in ET resulted in a significantly higher RI than SMA-TMS.
  
  
  CONCLUSIONS
  Findings suggest a stronger involvement of M1 in resting and postural tremor in PD than postural tremor in ET.
  
  
  CONCLUSIONS
  RI provides a useful marker to explore the differential functional role of M1, SMA and cerebellum in PD vs. ET tremor.
authors: Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan; Graduate Institute of Neural and Cognitive Science, China Medical University, Taichung, Taiwan. Electronic address: d4297@mail.cmuh.org.tw.
authors: Ming-Kuei
authors: MK
authors: Lu
authors: School of Medicine, Medical College, China Medical University, Taichung, Taiwan; Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan.
authors: Shang-Ming
authors: SM
authors: Chiou
authors: Department of Neurology & Stroke, and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, Tübingen, Germany.
authors: Ulf
authors: U
authors: Ziemann
authors: Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan.
authors: Hui-Chun
authors: HC
authors: Huang
authors: Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan.
authors: Yu-Wan
authors: YW
authors: Yang
authors: Neuroscience Laboratory, Department of Neurology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan; Graduate Institute of Neural and Cognitive Science, China Medical University, Taichung, Taiwan. Electronic address: windymovement@yahoo.com.tw.
authors: Chon-Haw
authors: CH
authors: Tsai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020329:Essential Tremor / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Cerebellothalamocortical circuit; Cerebellum; Motor evoked potential (MEP); Primary motor cortex (M1); Supplementary motor area (SMA)