Robust RT deficits were observed acutely following concussion .
Minimal magnitude differences were noted when comparing between- and within-subject effects , suggesting that pre-injury baselines may not add clinical value in determining post-injury RT impairment .
RT deficits persisted up till the intermediate-term ( 21–59 days post-injury ) timeframe and indicate lingering deficits exist .
Mean effect size differences were observed between RT measure types and computerized neurocognitive testing platforms ; however , all categories displayed negative effects consistent with impaired RT following concussion .
Reaction time ( RT ) deficits are reported following concussion , but it is unknown when these deficits normalize to pre-injury status .
It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT .
The purpose of this systematic review and meta- analysis was to ( 1 ) characterize acute post-concussion ( 0–3 days ) RT impairments , ( 2 ) examine RT recovery over time , and ( 3 ) explore moderating factors related to acute RT impairment following concussion .
Effects of concussion on attention and executive function in adolescents.
BACKGROUND Head trauma in adolescents has been linked with deficits in attention and executive function that can compromise the performance of everyday tasks . Although previous research has examined this issue using computerized neuropsychological testing , little work has been done using laboratory-based measurements of attention and executive function in this population . A longitudinal analysis of recovery patterns of these measures among adolescents is central to underst and ing the effects of concussions across the age spectrum . PURPOSE This study prospect ively and longitudinally examined laboratory-based measures of attention and executive function in concussed adolescents sequentially during a 2-month period after injury . METHODS Two measures of attention and executive function , the Attentional Network Test and the Task-Switching Test  , were administered to 20 concussed adolescents within 72 h postinjury as well as at 1 wk , 2 wk , 1 month , and 2 months postinjury . Twenty healthy , matched control subjects were similarly assessed at the same time intervals . Data were analyzed by two-way , mixed-effects ANOVA to determine the effect of group and time on the dependent variables . RESULTS Compared with control subjects , the concussed group exhibited a significantly greater switch cost on the Task-Switching Test ( P = 0.038 , mean difference value = 38 ms ) and a significantly greater reaction time for the Attentional Network Test conflict effect component ( P = 0.015 , mean difference value = 34 ms ) for up to 2 months after injury . CONCLUSIONS Concussed adolescents have difficulty recovering executive function after injury and may require extended recuperation time before full recovery is achieved . Evaluations focusing on attention and executive function can be useful additions in the assessment and follow-up after head injury
Robust RT deficits were observed acutely following concussion .
Minimal magnitude differences were noted when comparing between- and within-subject effects , suggesting that pre-injury baselines may not add clinical value in determining post-injury RT impairment .
RT deficits persisted up till the intermediate-term ( 21–59 days post-injury ) timeframe and indicate lingering deficits exist .
Mean effect size differences were observed between RT measure types and computerized neurocognitive testing platforms ; however , all categories displayed negative effects consistent with impaired RT following concussion .
Reaction time ( RT ) deficits are reported following concussion , but it is unknown when these deficits normalize to pre-injury status .
It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT .
The purpose of this systematic review and meta- analysis was to ( 1 ) characterize acute post-concussion ( 0–3 days ) RT impairments , ( 2 ) examine RT recovery over time , and ( 3 ) explore moderating factors related to acute RT impairment following concussion .