NeuroTalk Support Groups - Does the brain blood flow after concussion(s)?

Interesting study.

Quote:

Following a head impact there are several systemic secondary effects, such as decreased cerebral blood flow and altered heart rate variability, which can be objectively assessed. Unfortunately, return-to-play guidelines do not include any objective measurements. The purpose of this study was to evaluate cerebrovascular reactivity after a sport-induced concussion by monitoring the middle cerebral artery blood velocity, based on transcranial Doppler ultrasonography, and end tidal carbon dioxide (PETCO2) measurements, based on an expired gas analyzing system. Thirty-one athletes were placed into 2 groups: 21 healthy athletes and 10 athletes that had a concussion within the last seven days.

After measurements at rest, the athletes were instructed to hold their breath or hyperventilate (5 trials each) and the researchers measured the middle cerebral artery blood velocity and PETCO2. At rest there were no significant differences between groups. After trials 3, 4, and 5 of holding their breath concussed athletes’ middle cerebral artery blood velocity did not return to normal. In contrast, the control group’s middle cerebral artery blood velocity returned to normal after each trial.

While the concussed athletes showed a different response to breath holding than the control participants these differences were not significant between groups. There were also no significant differences in mean PETCO2 after each breath hold between groups. Both control and concussed athletes showed significant decreases in middle cerebral artery velocity and PETCO2 following hyperventilation trials.

Following a head impact there are several systemic secondary effects, such as decreased cerebral blood flow and altered heart rate variability, which can be objectively assessed. Unfortunately, return-to-play guidelines do not include any objective measurements. The purpose of this study was to evaluate cerebrovascular reactivity after a sport-induced concussion by monitoring the middle cerebral artery blood velocity, based on transcranial Doppler ultrasonography, and end tidal carbon dioxide (PETCO2) measurements, based on an expired gas analyzing system.

Thirty-one athletes were placed into 2 groups: 21 healthy athletes and 10 athletes that had a concussion within the last seven days. After measurements at rest, the athletes were instructed to hold their breath or hyperventilate (5 trials each) and the researchers measured the middle cerebral artery blood velocity and PETCO2.

At rest there were no significant differences between groups. After trials 3, 4, and 5 of holding their breath concussed athletes’ middle cerebral artery blood velocity did not return to normal. In contrast, the control group’s middle cerebral artery blood velocity returned to normal after each trial. While the concussed athletes showed a different response to breath holding than the control participants these differences were not significant between groups. There were also no significant differences in mean PETCO2 after each breath hold between groups. Both control and concussed athletes showed significant decreases in middle cerebral artery velocity and PETCO2 following hyperventilation trials.

source: http://www.sportsmedres.org/2012/01/...nge-after.html