My son is suffering from problem of cerebellum

My son has following problem:

1) He is no balance when is sitting or standing. His hand and leg is doing compulsion.
2) His eye ball moves frequently. Doctor is called "Nystigmus"
3) He can not stand or sit with balance

Birth History: My son was born by seizer caused by CDP. He is full time baby. When he was born then he was crying after birth. Birth weight was 3.4 kg. He has no compulsion till date.

It is needed to mention that my wife and I i.e. we are first cousin in mother side.

What is treatment of my son?