Persistent ocular motor manifestations and related visual consequences in multiple sclerosis.

Abnormal eye movements in multiple sclerosis (MS) are often persistent and known to be associated with general disability. However, there is no precise knowledge concerning their incidence and resulting visual handicap. The aim of our study was to describe the persistent ocular motor manifestations in MS and relate them to visual functions tested with visual acuity and with a vision-related questionnaire. We selected 24 MS patients complaining of persistent visual disability associated with ocular motor manifestations without any anterior visual pathway deficit. Internuclear ophthalmoplegia was the most frequently observed symptom, followed by gaze-evoked nystagmus, saccadic hypermetria, and then pendular nystagmus. Pendular nystagmus, saccadic hypermetria, and the association of internuclear ophthalmoplegia and gaze-evoked nystagmus were associated with decreased visual acuity and visual functional scores. There was a correlation between the number of abnormal eye movements and visual functions. This study demonstrates that ocular motor dysfunction in MS induces specific visual dysfunction and handicap.

Acquired pendular nystagmus in multiple sclerosis and oculopalatal tremor.

OBJECTIVE: Acquired pendular nystagmus occurs mainly in multiple sclerosis (MS) and focal brainstem lesions. In the later case, it is part of the syndrome of oculopalatal tremor. Even though pathophysiology of acquired pendular nystagmus has been clearly characterized experimentally in both etiologies, there is a persisting ambiguity in clinical literature, which leads one to consider both clinical conditions as a common entity. The objective of our work was to compare in a prospective study clinical features, eye movement recording, and functional consequences of acquired pendular nystagmus in 14 patients with oculopalatal tremor and 20 patients with MS. METHODS: Besides complete neurologic evaluation, evaluation of visual function, 3-dimensional eye movement recording, and functional scores of the Visual Function Questionnaire were recorded. RESULTS: One patient with oculopalatal tremor and 15 patients with MS disclosed signs of optic neuropathy. The nystagmus in the oculopalatal group showed significant larger mean amplitude (8 deg vs 1 deg), higher mean peak velocity (16 deg/s vs 6 deg/s), lower mean frequency (1-3 Hz vs 4-6 Hz), and larger asymmetry and irregularity of ocular oscillations compared to the MS group. The vision-specific health-related quality of life was more deteriorated in the oculopalatal tremor group than in the MS group. CONCLUSIONS: This study emphasizes the need to consider acquired pendular nystagmus in MS and oculopalatal tremor as 2 different clinical entities. This is of particular importance regarding the future evaluation of potential specific effects of pharmacologic agents.