<prompt> Sea saw nystagmus is seen in :Anterior longitudinal fasiculusCraniopharyngiomaMedullary lesionG.B. Syndrome  <response>: Ans. is b Craniopharyngioma Ref Parson, 18e, p 336.In Parson it is given that sea-saw nystagmus occurs due to para chiasmatic masses and the only para chiasmatic mass in the option is craniopharyngioma. 