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Periodic alternating gaze deviation in infancy
R H Legge1, H S Weiss, T R Hedges
1Department of Ophthalmology, New England Medical Center, Tufts University, Boston, MA.
Insights
Periodic alternating gaze, a rare condition, was observed in two infants with early onset. This eye movement disorder is linked to congenital defects in the hindbrain, specifically the inferior cerebellar vermis.
Area of Science:
- Neurology
- Pediatrics
- Neuroscience
Background:
- Periodic alternating gaze (PAG) is a rare nystagmus variant.
- Its etiology and associated pathologies are not well-understood.
- Early-onset forms are exceptionally uncommon.
Observation:
- Two cases of congenital periodic alternating gaze are presented.
- Onset was noted at birth and in infancy.
- Magnetic Resonance Imaging (MRI) revealed significant congenital defects in the posterior cranial fossa in both infants.
Findings:
- A key shared finding was the absence of normal structures in the inferior cerebellar vermis region.
- These hindbrain abnormalities were consistently observed.
- The findings suggest a strong correlation between cerebellar vermis malformations and early-onset PAG.
Implications:
- Periodic alternating gaze may serve as a clinical indicator of underlying hindbrain pathology.
- Further research into cerebellar vermis development and its role in ocular motor control is warranted.
- Understanding these associations can aid in earlier diagnosis and management of related neurological conditions.
Abstract:
Periodic alternating gaze is a rarely reported phenomenon. We have observed two cases that are unique in their early onset at birth and infancy. Multiple congenital defects of the posterior cranial fossa were present on MRI in both cases. A prominent abnormality shared by both was absence of normal structures in the region of the inferior cerebellar vermis. Periodic alternating gaze appears to be associated with pathologic changes in the hindbrain in these and other reported cases.
