Can Depakine cause problems with walking?

I beg for help. Our disabled son is 26 years old. Since 18 years of the Year He has had epilepsy. Since March this year he has been getting a depakine from which we have been going down for a month. From August he began to walk strangely, i.e. the left leg goes to the side instead of forward and slowly began to turn over to the right side. We were in the hospital but no one knows anything. Once he walked normally and now he himself does not function at all Can depakibe cause such side effects. It looks as if he is afraid to walk and belaying throws his left leg to the side which causes strong falls