Acute and longitudinal changes in motor cortex function following mild traumatic brain injury. (September 2014)

• Record Type: Journal Article
• Authors: Miller, Nick R.; Yasen, Alia L.; Maynard, Logan F.; Chou, Li-Shan; Howell, David R.; Christie, Anita D.
• Is Part Of: Brain injury. Volume 28:Number 10(2014)
• Page Start: 1270
• Page End: 1276
• Publication Date: 2014-09
• Subjects: Brain damage -- Periodicals; Brain -- Wounds and injuries -- Periodicals; Brain Injuries -- Periodicals; 617.481
• DOI: 10.3109/02699052.2014.915987
• Languages: English
• ISSNs: 0269-9052

Abstract

<abstract> <title>Abstract</title> <p> <italic>Primary objective</italic>: To evaluate excitability and inhibition of the motor cortex acutely and longitudinally following mild traumatic brain injury (mTBI).</p> <p> <italic>Research design</italic>: A longitudinal paired case-control design was used to examine cortical excitability and inhibition in 15 adults who had sustained an mTBI (mean age = 20.8 ± 1.2 years) and 15 matched control participants (mean age = 21.1 ± 1.3 years).</p> <p> <italic>Methods and procedures</italic>: Participants visited the lab within 72 hours of injury and again at 1, 2, 4 and 8 weeks post-injury. During each visit, transcranial magnetic stimulation was used to examine resting motor threshold (RMT), motor evoked potential peak-to-peak amplitude (MEP<sub>amp</sub>) and cortical silent period (CSP) duration of the first dorsal interosseous muscle.</p> <p> <italic>Main outcomes and results</italic>: There were no differences between groups in RMT (<italic>p</italic> = 0.10) or MEP<sub>amp</sub> (<italic>p</italic> = 0.22) at 72 hours post-injury or across the 2-month testing period (<italic>p</italic> ≥ 0.68), indicating similar cortical excitability. However, the CSP duration was higher in individuals with mTBI, indicating greater intra-cortical inhibition compared with the control group at 72 hours post-injury (<italic>p</italic> = 0.03) and throughout the 2 months of recovery (<italic>p</italic> = 0.009).</p> <p> <italic>Conclusions</italic>: mTBI appeared to have little effect on cortical excitability, but an acute and long-lasting effect on intra-cortical inhibition.</p> </abstract>