???? ??? ?? ?? ? ????? ? ?? ??? ?? ???? ??? ??? ? ??? ? ??? ? ?? ? ??? ??? ??????.?? ?? ????? ?? ??? ?? ??? ??? ???? ????. A standard neurological element of the condition is impaired myelin production (dysmyelination). Myelin is usually a fatty compound that insulates nerve cells and promotes the rapid transmission of nerve impulses.???? ??? ????