A history of multiple concussions does not alter the transcranial doppler-based assessment of the neurovascular coupling response. Issue 11 (25th May 2017)

• Record Type: Journal Article
• Authors: Smirl, Jonathan D; Wright, Alexander D; Bouilane, Kevin; Bryk, Kelsey; Donkelaar, Paul van
• Is Part Of: British journal of sports medicine. Volume 51:Issue 11(2017)
• Page Start: A23
• Page End: A23
• Publication Date: 2017-05-25
• Subjects: Sports medicine -- Periodicals; 617.1027
• DOI: 10.1136/bjsports-2016-097270.59
• Languages: English
• ISSNs: 0306-3674

Abstract

Abstract : 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.