Single Oral Doses Study of Nerispirdine on Visual Function in Patients With Multiple Sclerosis

Inclusion Criteria: * Clinically definite MS (McDonald criteria), which includes patients with remitting-relapsing, secondary progressive, progressive-relapsing, or primary progressive MS who have had a past history of Optic Neuritis. Exclusion Criteria: * Multiple sclerosis exacerbation within 60 days of the Screening Visit and the relapse involved the visual fields or visual acuity * No eye with appropriate degree of lesions for this study as defined by criteria based on degree of visual acuity deficit, refractive error, VEP P100 latency and average retinal nerve fiber layer thickness of as measured by Optical Coherence Tomography (OCT) * Any MS-unrelated prior ophthalmological impairment (eg, compressive, ischemic, toxic, or nutritional optic neuropathies, Leber's hereditary optic atrophy) * Previously exposed to 3,4-diaminopyridine or 4-aminopyridine The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.