Adding to this site’s database of combat sports safety studies, a recent study was published in the Scandinavian Journal of Medicine and Science in Sports addressing whether BJJ athletes, who are subjected to repeated strangulation, sustain impaired cognitive function or reduced arterial blood flow from the practice.
In the study, titled Elevated cerebral perfusion and preserved cognition in elite Brazilian Jiu-Jitsu athletes; evidence for neuroprotection, the authors compared 11 elite BJJ athletes against a control group of eleven non BJJ fitness practitioners. They performed psychometric testing to measure cognitive functioning between the groups and also measured carotid and vertebral arterial blood flow.
The results were that the BJJ athletes did not have cognitive impairment compared to the control group. Arterial blood flow was also not compromised and in fact was a bit stronger in the BJJ athletes compared to the control group leaving the authors to speculate that the repeated strangulation or other BJJ specific training pre-conditioned the BJJ athletes for better carotid and vertebral arterial blood blow.
The full abstract reads as follows:
Abstract
Brazilian Jiu Jitsu (BJJ) is a popular martial art that exposes participants to recurrent intermittent asphyxiation due to controlled application of neck chokes. To what extent the sport impacts the regulation of cerebral blood flow (CBF) and cognition has not been examined. This study compared eleven elite Brazilian Jiu Jitsu athletes (aged 30 ± 8 y) who trained 12 ± 6 hours/week for 8 ± 4 years against eleven cardiorespiratory fitness (CRF)- and age-matched controls. Internal carotid (ICA) and vertebral (VA) artery blood flow was measured via duplex ultrasound to determine global cerebral blood flow (gCBF). Mild cognitive impairment and sub-domains of memory, attention/concentration/visual motor co-ordination and executive function were determined by psychometric testing. There was no evidence of mild cognitive impairment in the athletes and cognitive function was comparable between groups (all P > 0.05). In contrast, resting gCBF was selectively elevated in the athletes (741 ± 186 mL∙min-1 vs. 573 ± 166 mL∙min-1 , P = 0.037) due to combined differences in ICA (+65 mL∙min-1 , P = 0.079) and VA (+19 mL∙min-1 , P = 0.277) flow. In conclusion, the sustained elevation in resting cerebral perfusion provides preliminary evidence for adaptive neuroprotection that is independent of CRF and likely mediated by choke-induced cerebral preconditioning and/or lifelong exposure to BJJ-specific high-intensity interval training.
Combat Sports Law 
Psychometric testing is NOT a diagnostic tool … it is a SCREENING TOOL .,…a series of testing – ie answering questions – and the results are based on STATISTICS [ie the margin of error is built into the test ] averages compared to a pool …. it has been used successively for decades for screening … NO CREDENTIALED practitioner would accept the results for a conclusive diagnosis [either positive or negative]
. The patient MUST be evaluated by a trained psychiatric provider to provide a diagnosis [again either positive or negative]
… the ONLY VALID way of testing if there have been any actual changes to the brain would be pre and post MRI’s with contrast Dye ….
there is NO MENTION of such testing …. WHY???? one can not make a diagnosis indicating NO damage without appropriate testing to see if there are changes to the brain – especially the base of the brain …. [I shouldn’t have to explain this but evidently these people do not understand that the are so many areas of the brain that be affected and which can NOT be tested with a verbal screening test …. this is ridiculous … this is a very bad joke …. ]
As far as ultrasound testing of the carotid ….
“age-matched controls. Internal carotid (ICA) and vertebral (VA) artery blood flow was measured via duplex ultrasound
In contrast, resting gCBF was selectively elevated in the athletes (741 ± 186 mL∙min⁻¹ vs. 573 ± 166 mL∙min⁻¹, P = 0.037) due to combined differences in ICA (+65 mL∙min⁻¹, P = 0.079) and VA (+19 mL∙min⁻¹, P = 0.277) flow. In conclusion, the sustained elevation in resting cerebral perfusion provides preliminary evidence for adaptive neuroprotection ”
WOW …. Ahh this is VERY concerning to me! Their finding of Dilation of the carotid arteries ….”adaptive NEUROPROTECTION”. WHY?????
…. WHY does the brain need any adaptation …. If there was no effect to the brain there would be ABSOLUTELY NO NEED for any adaptation. – especially at their Age. .. there is NO normal reason for such adaptation ……
There is something WRONG here … the brain / body does NOT adapt blood flow / dilate arteries …. without a significant reason …. If these were my patients I would IMMEDIATELY have them tested with MRIs – with and without contrast …..
NO I do not know what they would find ….and I will not make a prediction without facts … but there is something going on here [I have a guess — like areas of ischemic adaptation in the base of the brain – but I MUST say that but have no proof at this point .] …. but I am concerned for these people ….
Any ethical medical practitioners would be all over this demanding testing to ensure the patient is not having damage ……. [I know I would be and so would any neuropsychiatric medical practitioner that I have ever worked with! ]
The fact that they were not investigating clear warning flags ,…. with the type of tests needed to get real results [positive of negative] ….. tells me very clearly that They were deliberately NOT looking for any problems ….
[but very well may have found such …??? I do not know with out adequate testing …but I am concerned]
This is another study done by people that have decided the result before they ever did the so called testing
another spin paper ….
Flat out evidence shows that ANY period of unconsciousness is related to a degree of damage to the brain … a official belief of EVERY MEDICAL ASSOCIATION in the world …. I hope not – for the sake of these patients but these “researchers” may have added proof to this
Bruce E. Miller PA-C, MccP, MsMA
Major USA (ret.)
KE0UWL