Time course of
clinical and electrophysiological recovery after sport-related concussion

LS., McCrea M., Barr W., Powell M., Chabot RJ. Journal of Head Trauma
Rehabilitation, 2012; ahead of print

research has shown that the typical time for cognitive and behavioral signs and
symptoms to dissipate is within 7 to 10 days after an injury, however,
researchers utilizing functional neuroimaging techniques (e.g., functional magnetic
resonance imaging
have reported that neuronal dysfunction may be prolonged for up to several
weeks. Therefore, the purpose of this study was to examine the differences in a
calculated traumatic brain injury (TBI) index (via EEG patterns) and other
clinical outcomes between patients with mild or moderate severity of concussion
signs and symptoms as well as among patients with short (< 14 days) or
delayed (> 14 days) return-to-play time. Sixty-five athletes who
sustained a concussion were included in this study and went through a clinical
evaluation (i.e., Concussion Symptom

[CSI], Standardized
Assessment of Concussion
[SAC], Balance Error Scoring

[BESS] and Automated
Neuropsychological Assessment Metrics
[ANAM]), and an electrophysiological
evaluation to calculate the TBI index. These tests were conducted within 24
hours of the injury, and then at day 8 and day 45 after the injury. Concussion
severity was based on specific concussion signs and symptoms using the CSI and
SAC test (e.g., feeling in a fog, slowed down, memory impairment, loss of
consciousness). Athletes were placed into either the mild concussion group (n =
51) or the moderate concussion group (n = 14). 
At the time of injury, patients with a moderate concussion had more
severe signs and symptoms on the CSI and had poorer performances on the SAC and
ANAM tests compared to the mild concussed group. However, at days 8 and 45 there
were no differences in these outcomes between the two groups. The BESS test was
not significantly different between the mild and moderate concussion groups at
any of the time points. Despite the clinical outcomes not detecting differences
at days 8 and 45 between patients with mild or moderate concussions the TBI
index was higher among the moderately-concussed patients compared to the mildly-concussed
group at all of the time points (at time of injury, day 8, and day 45). The sensitivity (positively diagnose a patient who has
of the TBI index for moderate concussions at the time of
injury was 55% and the specificity (not falsely diagnosing a healthy patient) was
about 94%. Seventy-three percent of the patients returned to play within 14
days (mean = 5 days) and 27% took more than 14 days to return to play (mean =
20 days). At the time of injury, the TBI index was lower among patients that
returned to play in less than 14 days (TBI index = 5) compared to the group who
took 14 days or more to return to play (TBI index = 20).

recovery after a concussion injury may extend beyond clinical recovery.
Furthermore, the TBI index may be an objective indicator for concussion
severity and predictive of recovery time (based on return-to-play time). This
study offers preliminary data to suggest that the TBI index could be used as a
prognostic tool however, a study with a larger sample size will be necessary. In
this study the TBI index remained significantly elevated in the moderate group
compared to mild concussed group up to 45 days after the injury.  Based on these results, the TBI index could
help differentiate severity of the concussion. However, we need to keep in mind
that it only recognized a moderate concussion compared to a mild concussion 55%
of the time. Based on this study the researchers suggest that measuring brain
activity at the forehead could be used to calculate the TBI index on the sideline.
This may help assess concussion severity and assist in determining return-to-play
time. Do you have any experience with EEG? Is this a test you would consider
by: Jane McDevitt MS, ATC, CSCS
by: Jeffrey Driban


Prichep LS, McCrea M, Barr W, Powell M, & Chabot RJ (2012). Time Course of Clinical and Electrophysiological Recovery After Sport-Related Concussion. The Journal of Head Trauma Rehabilitation PMID: 22588360