Repeated sessions of functional repetitive transcranial magnetic stimulation increases motor cortex excitability and motor control in survivors of stroke.
OBJECTIVE
To determine the impact of a single-session of repetitive transcranial magnetic stimulation (rTMS) and an rTMS intervention on neurophysiology and motor control in survivors of stroke.


METHODS
Twelve stroke survivors were randomized into functional-rTMS or passive-rTMS conditions. Measures of short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), and force steadiness (coefficient of variation, CV) at 10 and 20% of maximum voluntary contraction were assessed at baseline and after a single-session of rTMS (post single-session), and again following an intervention of 8 rTMS sessions (2 sessions per day; post-intervention). Functional-rTMS required subjects to exceed a muscle activation threshold assessed by surface electromyography to trigger each rTMS train; the passive-rTMS group received rTMS while relaxed.


RESULTS
ICF scores significantly increased following the single-session of functional-rTMS compared to the decrease following passive-rTMS. The increase in APB SICI and ICF scores following the intervention was significantly greater for the functional-rTMS group compared to the decreases following passive-rTMS. The groups were significantly different in the CV of force (20%) following the single-session of rTMS, and in the 10 and 20% tasks following the intervention. The functional-rTMS group increased steadiness overtime, whereas the passive group demonstrated a return to baseline following the intervention session. No differences were observed in first dorsal interosseus (FDI) measures (SICI and ICF) between groups.


CONCLUSIONS
The functional-rTMS protocol enhanced cortical excitability following a single-session and after repeated sessions and improved steadiness, whereas the passive stimulation protocol tended to decrease excitation and no improvements in steadiness were observed.
Department of Physical Therapy & Rehabilitation Science, University of Maryland School of Medicine, Baltimore, MD, USA.
Crystal L
CL
Massie
Brian L
BL
Tracy
Roger J
RJ
Paxton
Matthew P
MP
Malcolm
D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009044:Motor Cortex / Q000503:physiopathology*; D009433:Neural Inhibition; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D017741:Survivors; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
Rehabilitation; force; motor control; repetitive transcranial magnetic stimulation; transcranial magnetic stimulation