Horizontal Tonic Conjugate Gaze Deviation in a 4-Week-Old Infant: What Can the Eyes (of the Parents) Tell?

A 4-week-old healthy infant failed to make eye contact when approached from the left. When evaluated by us at the age of 11 weeks, left tonic conjugate gaze deviation was noted. Brain MRI showed a left frontotemporal large tension arachnoid cyst causing right falcial herniation. During the insertion of an Ommaya reservoir, hemosiderin was found to be coating the inner wall of the cyst, which may indicate that the asymptomatic cyst evolved to a tension cyst due to spontaneous hemorrhage. Surgical decompression resulted in complete restoration of the horizontal gaze and considerable reduction in the size of the cyst. After 3 months a cystoperitoneal shunt was placed due to increased intracranial pressure secondary to impaired drainage of the cyst. Since then the infant has done well, with normal developmental and neurological examination during his last follow-up at the age of 5 years. Although gaze central ocular motor control is still underdeveloped and chaotic eye movements are present during early infancy, the present case report reminds us that a thorough examination of eye movements should not be overlooked during neurodevelopmental evaluation.