title: Neurophysiological and behavioral effects of tDCS combined with constraint-induced movement therapy in poststroke patients.
abstract: BACKGROUND
  Recovery of motor function after stroke may depend on a balance of activity in the neural network involving the affected and the unaffected motor cortices.
  
  
  OBJECTIVE
  To assess whether transcranial direct current stimulation (tDCS) can increase the training-induced recovery of motor functions.
  
  
  METHODS
  In an exploratory study, 14 patients with chronic stroke and mean Fugl-Meyer Upper Extremity Motor Assessment of 29 (range = 8-50) entered a double-blind sham-controlled study, aimed to investigate neurophysiological and behavioral effects of bihemispheric tDCS (cathodal stimulation of the unaffected motor cortex and anodal stimulation of the affected motor cortex), combined with constraint-induced movement therapy (CIMT).
  
  
  RESULTS
  Patients in both groups demonstrated gains on primary outcome measures, that is, Jebsen Taylor Hand Function Test, Handgrip Strength, Motor Activity Log Scale, and Fugl-Meyer Motor Score. Gains were larger in the active tDCS group. Neurophysiological measurements showed a reduction in transcallosal inhibition from the intact to the affected hemisphere and increased corticospinal excitability in the affected hemisphere only in the active tDCS/CIMT group. Such neurophysiological changes correlated with the magnitude of the behavioral gains. Both groups showed a reduction in corticospinal excitability of the unaffected hemisphere.
  
  
  CONCLUSIONS
  CIMT alone appears effective in modulating local excitability but not in removing the imbalance in transcallosal inhibition. Bihemispheric tDCS may achieve this goal and foster greater functional recovery.
authors.affiliation: Harvard Medical School, Boston, MA, USA. nadia.bolognini@unimib.it
authors.forename: Nadia
authors.initials: N
authors.lastname: Bolognini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vallar
authors.forename: Carlotta
authors.initials: C
authors.lastname: Casati
authors.forename: Lydia Abdul
authors.initials: LA
authors.lastname: Latif
authors.forename: Rasheda
authors.initials: R
authors.lastname: El-Nazer
authors.forename: Julie
authors.initials: J
authors.lastname: Williams
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Banco
authors.forename: Debora Duarte
authors.initials: DD
authors.lastname: Macea
authors.forename: Luigi
authors.initials: L
authors.lastname: Tesio
authors.forename: Cecilia
authors.initials: C
authors.lastname: Chessa
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy / Q000295:instrumentation / Q000379:methods*; D004311:Double-Blind Method; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D020521:Stroke / Q000150:complications / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D050781:Transcranial Magnetic Stimulation / Q000379:methods*