TY - JOUR
T1 - The long-term effects of sports concussion on retired Australian football players: a study using transcranial magnetic stimulation
AU - Pearce, Alan J
AU - Hoy, Kate Elizabeth
AU - Rogers, Mark Andrew
AU - Corp, Daniel T
AU - Maller, Jerome Joseph
AU - Drury, Hannah G K
AU - Fitzgerald, Paul Bernard
PY - 2014
Y1 - 2014
N2 - This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired
elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male
AF players who played at the elite level (n = 20; mean age 49.7 ? 5.7 years) or amateur level (n = 20; mean age 48.4 ? 6.9
years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched
male controls (mean age 47.56 ? 6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction
time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used
to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125 of active
motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition
(SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity ( p = 0.003),
reaction ( p = 0.003), and movement time ( p = 0.037) than did both AF groups. Differences between AF groups were found
in AL ( p = 0.027) and SWM ( p = 0.024). TMS measures revealed that both AF groups showed reduced cSP duration at
125 aMT ( p > 0.001) and differences in SR curves ( p > 0.001) than did healthy controls. Similarly, SICI ( p = 0.012) and
LICI ( p = 0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant
contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of
inhibition differed, however, in terms of which performance measure they had a significant and unique predictive
relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences
in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two
decades previously.
AB - This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired
elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male
AF players who played at the elite level (n = 20; mean age 49.7 ? 5.7 years) or amateur level (n = 20; mean age 48.4 ? 6.9
years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched
male controls (mean age 47.56 ? 6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction
time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used
to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125 of active
motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition
(SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity ( p = 0.003),
reaction ( p = 0.003), and movement time ( p = 0.037) than did both AF groups. Differences between AF groups were found
in AL ( p = 0.027) and SWM ( p = 0.024). TMS measures revealed that both AF groups showed reduced cSP duration at
125 aMT ( p > 0.001) and differences in SR curves ( p > 0.001) than did healthy controls. Similarly, SICI ( p = 0.012) and
LICI ( p = 0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant
contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of
inhibition differed, however, in terms of which performance measure they had a significant and unique predictive
relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences
in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two
decades previously.
UR - http://online.liebertpub.com/doi/abs/10.1089/neu.2013.3219
U2 - 10.1089/neu.2013.3219
DO - 10.1089/neu.2013.3219
M3 - Article
SN - 0897-7151
VL - 31
SP - 1139
EP - 1145
JO - Journal of Neurotrauma
JF - Journal of Neurotrauma
IS - 13
ER -