Theta burst stimulation to characterize changes in brain plasticity following mild traumatic brain injury: A proof-of-principle study.
OBJECTIVE
Recent studies investigating the effects of mild traumatic brain injury (mTBI) suggest the presence of unbalanced excitatory and inhibitory mechanisms within primary motor cortex (M1). Whether these abnormalities are associated with impaired synaptic plasticity remains unknown.


METHODS
The effects of continuous theta burst stimulation (cTBS) on transcranial magnetic stimulation-induced motor evoked potentials (MEPs) were assessed on average two weeks and six weeks following mTBI in five individuals.


RESULTS
The procedure was well-tolerated by all participants. Continuous TBS failed to induce a significant reduction of MEP amplitudes two weeks after the injury, but response to cTBS normalized six weeks following injury, as a majority of patients became asymptomatic.


CONCLUSIONS
These preliminary results suggest that cTBS can be used to assess M1 synaptic plasticity in subacute phase following mTBI and may provide insights into neurobiological substrates of symptoms and consequences of mTBI.
Département de psychologie, Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Canada, H3C3J7.|Centre de Recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte Justine, 3175 Chemin de la Côte Ste-Catherine, Montréal, Canada, H3T1C5.
Sara
S
Tremblay
Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, USA, 02215.
Marine
M
Vernet
Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, USA, 02215.
Shahid
S
Bashir
Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, USA, 02215.
Alvaro
A
Pascual-Leone
Département de psychologie, Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Canada, H3C3J7.|Centre de Recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte Justine, 3175 Chemin de la Côte Ste-Catherine, Montréal, Canada, H3T1C5.
Hugo
H
Théoret
D000328:Adult; D001930:Brain Injuries / Q000503:physiopathology* / Q000628:therapy*; D004576:Electromyography; D019054:Evoked Potentials, Motor; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D055815:Young Adult
Traumatic brain injury; concussion; motor cortex; plasticity; transcranial magnetic stimulation