Eye Deviation in Patients with One-and-a-Half Syndrome

Abstract

To understand malalignments of the visual axes in one-and-a-half syndrome, we measured eye positions in 4 patients with this syndrome under two conditions: with Frenzel goggles to prevent eye fixation and without Frenzel goggles. When fixation was prevented with the Frenzel goggles, all patients showed mild outward deviation in both eyes. Removal of the Frenzel goggles elicited adduction of the eye ipsilateral to the side of the lesion for fixation, with greater outward deviation of the contralateral eye (acute stage), or adduction of both eyes to midposition for biocular fixation (convalescent stage). In 3 patients whose outward eye deviation with Frenzel goggles was greater on the ipsilateral side, a transition from one-and-a-half syndrome to ipsilateral internuclear ophthalmoplegia was noted, whereas a transition to ipsilateral gaze palsy was seen in the one patient whose deviation was greater on the contralateral side. These findings suggest that in one-and-a-half syndrome patients, the eyes tend to be in divergent positions when fixation is prevented; ipsilateral eye deviation may result from medial longitudinal fasciculus involvement, and contralateral eye deviation may result from paramedian pontine reticular formation involvement. Viewing a target may lead to a secondary deviation or adaptation of eye positions for fixation.

A Rare Pontine Neuro-ophthalmic Syndrome: Eight-and-a-Half Syndrome

“…Central facial paralysis (75%), hemiparesis or hemiplegia (30%), hemihypoesthesia (30%) are the most common accompanying findings (3,4). Peripheral facial paralysis is another clinical finding that accompanies one-anda-half syndrome due to the anatomic structure of the nerve, as seen in our case.…”

“…Lesions in this area that involve the ipsilateral 6 th cranial nerve, PPRF, and MLF together cause one-and-a-half syndrome. PPRF and MLF lesions may cause this syndrome without involvement of this nerve nucleus because the 6 th cranial nerve and PPRF fibers converge (3,4). In one-and-ahalf syndrome, horizontal eye movements are lost at the side of the lesion; when looking to the contralateral side, only the contralateral eye can abduct and nystagmus is seen in that eye.…”

Postpartum Pons Kanamasi Sonrasi Geli̇şen Fi̇sher 1,5 Sendromu

“…Bir buçuk sendromu nadiren izole bir bulgudur. Olgularda santral fasiyal paralizi (%75), hemiparezi veya hemipleji (%30), hemihipoestezi (%30) en sık görülen diğer nörolojik bulgulardır (5)(6)(7).…”

Neurocysticercosis presenting as isolated wall-eyed monocular internuclear ophthalmoplegia with contraversive ocular tilt reaction

“…[1415] Similarly, an outward deviation in the contralesional eye can result from an imbalance of PPRF signals. [16] Another contradiction to the concept of medial rectus subnucleus involvement in WEBINO has come from the observations that exotropia also occurs ipsilaterally in unilateral INO, that is, in the WEMINO syndrome. Among four patients with WEMINO described by Johnston and Sharpe, pathologic analyses obtained for one patient showed that the lesion was confined to the pontine tegmentum.…”