PAROXYSMAL TONIC UPGAZE - A REAPPRAISAL OF OUTCOME

Paroxysmal tonic upgaze (PTU) of childhood is a distinctive neuro-opht halmological syndrome of unknown etiology and pathogenesis that is cha racterized by episodes of sustained upward deviation of the eyes, ofte n with incomplete downward saccades on attempted downgaze. It is gener ally regarded as having a benign outcome. We observed 16 children with PTU, from 10 months to 11 years from onset (mean, 5.4 years), to stud y the natural history and possible etiology. Five cases were from two unrelated families. Onset of PTU occurred either during or after an in tercurrent infection or vaccination in 5 children. No antecedent was i dentifiable in the rest. PTU had completely resolved in 10 children (6 2%) (mean age at offset, 2.5 years), whereas 2 children intermittently manifest a modified form of the disorder. At follow-up, 11 children ( 69%) had developmental delay, intellectual disability or language dela y and 9 (56%) had ocular motility problems other than PTU. Only 3 chil dren (19%) had normal development and neurological findings. PTU is a heterogeneous syndrome with respect to associations and outcome and ma y simply be an age-dependent manifestation of a variety of disorders a ffecting corticomesencephalic control of vertical eye movement. This d isorder may be an early sign of more widespread neurological dysfuncti on.