Periodic alternating esotropia associated with disorders of neural tube closure.

Objective: To report a series of children with periodic alternating esotropia (PAE) in the context of neural tube defects and hydrocephalus.

Methods: The medical notes of all patients presenting with a periodic alternating esotropia over a 20-year period were reviewed for details of ocular motility characteristics and underlying associated neurological pathology. Previously published cases are also reviewed.

Results: A total of 5 patients with PAE were identified. In all 5, PAE occurred in combination with periodic alternating gaze paresis (PAG) with contraversive head turn. The abducting eye was always preferred for fixation. All patients were born with neural tube defects, associated with hydrocephalus requiring ventriculoperitoneal shunt insertion in the first month of life.

Conclusions: These 5 cases, in combination of 5 previously published cases, describe a rare but consistent collection of ocular motility abnormalities, which seem to indicate a genuine clinical entity in some patients with neural tube closure defects. PAE should be considered in patients with a neural tube defect and a head turn.