title: Inhibitory transcranial direct current stimulation enhances weak beta event-related synchronization after foot motor imagery in patients with lower limb amputation.
abstract: OBJECTIVE
  Sensorimotor rhythm patterns in patients with lower limb amputations might be altered because of reorganization of the sensorimotor cortices. The authors evaluated the sensorimotor rhythm of motor imagery (MI) in healthy subjects and patients with lower limb amputations. In addition, the authors investigated whether transcranial direct current stimulation (tDCS) could modulate sensorimotor rhythm control.
  
  
  METHODS
  Six healthy subjects and six patients with lower limb amputations were assigned to receive anodal, cathodal, or sham tDCS over the foot motor area in a randomized order. The authors evaluated event-related desynchronization and event-related synchronization (ERS) of unilateral hand and bilateral foot MI before and after tDCS.
  
  
  RESULTS
  Beta ERS of foot MI in patients with lower limb amputations was significantly lesser than that in healthy subjects. Compared with sham stimulation, cathodal tDCS enhanced beta ERS of foot MI in patients with lower limb amputations. In contrast, anodal tDCS decreased beta ERS of foot MI in healthy subjects.
  
  
  CONCLUSIONS
  This is the first study to demonstrate that cathodal tDCS can enhance a weak beta ERS of foot MI in patients with lower limb amputations. These findings might contribute in improving the effectiveness of sensorimotor rhythm-based brain computer interface for gait restoration after lower limb amputation.
authors.affiliation: *Department of Physical Medicine and Rehabilitation, Tohoku University Graduates School of Medicine, Sendai, Japan; and †Rehabilitation Support Center, Miyagi Prefectural Government, Natori, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Takeuchi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Mori
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nishijima
authors.forename: Takeo
authors.initials: T
authors.lastname: Kondo
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Izumi
mesh_terms: D000368:Aged; D000674:Amputees / Q000534:rehabilitation*; D003344:Cortical Synchronization / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology; D007866:Leg; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D065908:Transcranial Direct Current Stimulation