[Seesaw nystagmus: symptom of a biochemical disorder (author's transl)].

A case of the rare seesaw nystagmus is presented and compared as for identity with an another case, reported by this author earlier. Some new finds were made, completing the first observation, published 1974 [27]. Both the cases of the seesaw nystagmus were found to have the same biochemical disorders: the cystathioninuria and the hypopyridoxalphosphatemie.