In-clinic event related potentials after sports concussion: A 4-year study

Abstract

PURPOSE: Electrophysiological event-related potentials (ERP's) have been reported to change after concussion. The objective of this study is to use a simple 2-tone auditory P300 ERP in routine clinical settings to measure changes from baseline after concussion and to determine if these changes persist at return to play when other standard measures have normalized. METHODS: Three-hundred sixty-four (364) student athletes, aged 17-23 years, participating in contact sports were tracked over consecutive years. In this blinded study P300, plus physical reaction times and Trail Making tests, were collected alongside standard clinical evaluations. Changes in these measures after concussion were compared to clinical outcomes over various stages of post-injury recovery. RESULTS: Concussed players experienced significant reaction time and/or P300 amplitude changes compared to pre-concussion baseline measurements (p < 0.005). P300 changes persisted in 38% of the players after standard measures, including reaction times, had cleared. Many of those players slow to normalize were part of the sub-concussive symptom group and/or appeared more prone to repeat concussions. CONCLUSION: These data suggest significant P300 amplitude changes after concussion that are quantifiable and consistent. These changes often normalized slower than other standard assessments. More data are needed to determine if slow normalization relates to sub-concussive or repeated events.

Role of biomarkers and emerging technologies in defining and assessing neurobiological recovery after sport-related concussion: a systematic review

“…Studies consistently found lower resting EEG power in one or more frequency bands (ranging from delta to gamma) post-SRC,73–75 with SRC-related effects potentiated in standing (vs seated) positions 73 74. Similarly, seven studies found altered amplitudes of numerous ERPs to auditory and visual stimuli after SRC,76–82 with all but one80 finding lower amplitude in SRC (vs non-SRC) groups and concussed athletes with more severe symptoms. P3/P300 was the most commonly studied ERP76–78 80–82; others were N1, P2, N4 and a brainstem potential to speech sounds (frequency following response (FFR)) 77 79 80.…”

“…Similarly, seven studies found altered amplitudes of numerous ERPs to auditory and visual stimuli after SRC,76–82 with all but one80 finding lower amplitude in SRC (vs non-SRC) groups and concussed athletes with more severe symptoms. P3/P300 was the most commonly studied ERP76–78 80–82; others were N1, P2, N4 and a brainstem potential to speech sounds (frequency following response (FFR)) 77 79 80. Studies have been mixed in whether80 82 or not76 81 ERP latency was associated with SRC.…”

“…P3/P300 was the most commonly studied ERP76–78 80–82; others were N1, P2, N4 and a brainstem potential to speech sounds (frequency following response (FFR)) 77 79 80. Studies have been mixed in whether80 82 or not76 81 ERP latency was associated with SRC. Five studies indexed functional connectivity using various indices extracted from the proprietary brain network algorithm (BNA), all of which reported either significant SRC versus control group differences or different trajectories of BNA scores across groups 83–87…”

Incremental Effects of Subsequent Concussions on Cognitive Symptoms in the Sport Concussion Assessment Tool

“…19 Numerous studies have reported ERP-related changes years after mTBI, even after neuropsychological measures became normal. [20][21][22] In these studies, changes in latency and amplitudes of P300, N2, and other components of the time-locked ERP were abnormal even when reaction time and accuracy on cognitive tasks have improved. 23,24 Palacios et al demonstrated neurite density loss at 6 months compared with 2 weeks after mTBI, in patients with or without significant recovery of neuropsychological measurements during the same period.…”

Electrophysiological trajectories of concussion recovery: From acute to prolonged stages in late teenagers

“…The acute concussion data and the control group for this study were from a previous study that followed athletes over the course of up to four sports seasons and at five different sites [ 32 ]. The injury groups were compared to the pre-injury baselines (to get a sense of trajectory), and a reference group was taken from pre-season baselines of 120 subjects who were not part of the acute concussion group and who had no history of previous concussion.…”