I can say this, as a person who has had multiple, multiple, multiple
concussions, that sex definitely has an impact on
concussion symptoms and recovery. Regarding masturbation, this I can not for certain, but if it involves somewhat strenuous movement to the head, then yes, it could affect and could exacerbate symptoms. I don't masturbate, but I have had, sex during concussion recovery and my symptoms always increase afterward, even if the sex is not strenuous.