PT  - JOURNAL ARTICLE
AU  - Smirl, Jonathan D
AU  - Wright, Alexander D
AU  - Bouilane, Kevin
AU  - Bryk, Kelsey
AU  - Donkelaar, Paul van
TI  - A history of multiple concussions does not alter the transcranial doppler-based assessment of the neurovascular coupling response
AID  - 10.1136/bjsports-2016-097270.59
DP  - 2017 Jun 01
TA  - British Journal of Sports Medicine
PG  - A23--A23
VI  - 51
IP  - 11
4099  - http://bjsm.bmj.com/content/51/11/A23.2.short
4100  - http://bjsm.bmj.com/content/51/11/A23.2.full
SO  - Br J Sports Med2017 Jun 01; 51
AB  - Objective To determine how a history of 3+ concussions alters elevations in cerebral blood velocity (CBV) in the posterior cerebral artery (PCA) during visual tasks.Design Retrospective Cohort.Setting Laboratory.Participants 136 male contact-sport athletes (19.1±1.4 years, 66 football, 70 hockey) were recruited; 39 presented with 0 previous concussions, 16 with 3+ previous concussions; exclusion criteria included history of concussion within 6 months.Intervention Transcranial Doppler ultrasound indexed PCA-CBV during a series of visual tasks. Participants closed their eyes (20-seconds) and, when prompted, opened their eyes to complete a visual task (40-seconds). Testing occurred prior to the start of their athletic season. The visual trial raw traces were averaged together to enhance the signal-to-noise ratio of outcome measurements. The independent variable tested was concussion history.Outcomes Eyes-closed CBV (cm/s), peak elevation in CBV after eyes-open (cm/s), relative change in CBV (%), and total activation during the first 30 seconds of the task (indexed via area under the curve-AUC)Main results Independent samples T-Tests indicated there were no effects of concussion history on any outcome: Eyes-closed CBV (p=0.950), peak CBV (p=0.903), % CBV elevation (p=0.593), and AUC (p=0.718).Conclusions A history of multiple concussions does not alter the cerebrovasculature’s ability to maintain nutrient delivery required for visual challenges in cortical areas supplied by the PCA. This is an important finding; despite the long-term neurocognitive deficits associated with a history of concussions, the transcranial Doppler assessment of neurovascular coupling appears intact for this population of younger adult contact-sport athletes.Competing interests None.