Afraid of brain damage from judo?

Contact-collision: sports do carry a risk of concussion & head & neck injuries. Read http://www.teamusa.org/~/media/USA_Judo/Images/Sports%20Med/basicsinthejudoathletepdf.pdf & decide if the benefits of the sport outweigh the risks for you or for a juvenile family member, whoever is participating in judo.

Generally small: Accidents do happen, but you would be more likely to get a concussion playing football or soccer. Since judo does not involve strikes or kicks to the head, it is pretty safe in that regard. The first thing you learn is how to fall without hitting the back of your head. I took judo for close to 20 yrs without a single head injury - but if you play rough, the risk increases just like other sports

Blows to head: If you experience repeated blows to the head, either directly from a strike or from falls, you are at risk for chronic traumatic encephalopathy.