title: Using transcranial magnetic stimulation to quantify electrophysiological changes following concussive brain injury: a systematic review.
abstract: Mild traumatic brain injury (mTBI) and sports concussion are a growing public health concern, with increasing demands for more rigorous methods to quantify changes in the brain post-injury. Electrophysiology, and in particular, transcranial magnetic stimulation (TMS), have been demonstrated to provide prognostic value in a range of neurological conditions; however, no review has quantified the efficacy of TMS in mTBI/concussion. In the present study, we present a systematic review and critical evaluation of the scientific literature from 1990 to 2014 that has used TMS to investigate corticomotor excitability responses at short-term (< 12 months), medium-term (1-5 years), and long-term (> 5 years) post-mTBI/concussion. Thirteen studies met the selection criteria, with six studies presenting short-term changes, five studies presenting medium-term changes, and two studies presenting long-term changes. Irrespective of time post-concussion, change in intracortical inhibition was the most reported observation. Other findings included increased stimulation threshold, and slowed neurological conduction time. Although currently limited, the data suggest that TMS has prognostic value in detecting neurophysiological changes post-mTBI/concussion.
authors.affiliation: School of Psychology, Deakin University, Melbourne, Victoria, Australia.
authors.forename: Brendan P
authors.initials: BP
authors.lastname: Major
authors.forename: Mark A
authors.initials: MA
authors.lastname: Rogers
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Pearce
mesh_terms: D000818:Animals; D001924:Brain Concussion / Q000175:diagnosis* / Q000503:physiopathology; D004569:Electroencephalography; D004576:Electromyography; D019054:Evoked Potentials, Motor; D006801:Humans; D009044:Motor Cortex / Q000503:physiopathology*; D009431:Neural Conduction; D009433:Neural Inhibition; D011237:Predictive Value of Tests; D011379:Prognosis; D020127:Recovery of Function; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation
keywords: concussion; evoked potential; mild traumatic brain injury; systematic review; transcranial magnetic stimulation