Understanding individual variability in symptoms and recovery following mTBI: A role for TMS-EEG?

The Neurophysiological Responses of Concussive Impacts: A Systematic Review and Meta-Analysis of Transcranial Magnetic Stimulation Studies

“…Concussive brain injury is a global health issue (World Health Organisation, 2006 ) affecting a broad range of people who experience accidents in workplaces, home environments, and road traffic incidents (Koerte et al, 2015 ; Lefebvre et al, 2015 ). However, concussions experienced in sport, while historically under-recognised and underreported, have received increased attention by the public over recent years due to growing media attention (Lefebvre et al, 2015 ; Coyle et al, 2018 ). Resultantly, there have been increased investigations studying the underlying neurological mechanisms to inform the development of diagnostic, monitoring, and treatment protocols (Koerte et al, 2015 ; Lefebvre et al, 2015 ; Kamins et al, 2017 ).…”

“…Concussion has been defined as a functional traumatic brain injury (McCrory et al, 2017 ). The absence of findings on medical imaging (Dimou and Lagopoulos, 2014 ; McCrory et al, 2017 ; Coyle et al, 2018 ) are interpreted as a lack of structural damage. Despite there being no findings on brain imaging scans, the subjects experience a raft of symptoms post-concussion, such as cognitive fatigue, light and noise sensitivity, and reduced cognitive processing capacity and executive functioning (Johansson et al, 2009 ; Johansson and Rönnbäck, 2012 , 2014 ; Koerte et al, 2015 ; Coyle et al, 2018 ).…”

“…The absence of findings on medical imaging (Dimou and Lagopoulos, 2014 ; McCrory et al, 2017 ; Coyle et al, 2018 ) are interpreted as a lack of structural damage. Despite there being no findings on brain imaging scans, the subjects experience a raft of symptoms post-concussion, such as cognitive fatigue, light and noise sensitivity, and reduced cognitive processing capacity and executive functioning (Johansson et al, 2009 ; Johansson and Rönnbäck, 2012 , 2014 ; Koerte et al, 2015 ; Coyle et al, 2018 ). These symptoms have rather been described as reflecting functional changes on a cellular metabolic level (Giza and Hovda, 2001 , 2014 ; McCrory et al, 2017 ; Coyle et al, 2018 ).…”

“…Despite there being no findings on brain imaging scans, the subjects experience a raft of symptoms post-concussion, such as cognitive fatigue, light and noise sensitivity, and reduced cognitive processing capacity and executive functioning (Johansson et al, 2009 ; Johansson and Rönnbäck, 2012 , 2014 ; Koerte et al, 2015 ; Coyle et al, 2018 ). These symptoms have rather been described as reflecting functional changes on a cellular metabolic level (Giza and Hovda, 2001 , 2014 ; McCrory et al, 2017 ; Coyle et al, 2018 ). For example, Giza and Hovda ( 2001 , 2014 ) describe a pathophysiological cascade whereby variations in metabolism and cerebral blood flow place stress in neuronal functioning in the acute phase (7–10 days) following injury (Giza and Hovda, 2001 , 2014 ).…”

“…In order to make progress toward better diagnostics and management of concussion, an increased understanding of the underlying pathophysiology is crucial (Koerte et al, 2015 ; Lefebvre et al, 2015 ; Coyle et al, 2018 ). Therefore, the aim of this systematic review and meta-analysis was to systematically determine the effect of concussive and sub-concussive injury on specific TMS responses in order to identify trends in neurophysiological parameters.…”