Medical treatment of nystagmus and ocular motor disorders.

An increased compendium of drugs useful in ocular motor system dysfunction has expanded our capacity to treat selected ocular motility disorders. Adjunctive therapeutic modes (e.g., Fresnel prisms and orthoptic exercises) can also be beneficial. PAN and see-saw nystagmus can be treated with baclofen. Downbeat nystagmus may respond to clonazepam therapy, and prisms may help if the nystagmus can be modified with convergence. Congenital nystagmus may respond minimally to drugs (e.g., baclofen), but prisms or surgical procedures, or both, are still the primary treatment modalities. Innovar may be helpful in patients with severe, incapacitating vestibular disorders, and scopolamine alone or in combination with promethazine may be beneficial in patients with milder ambulatory acute peripheral vestibular disorders. Benign positional vertigo is best treated initially with positional exercises before drug therapy is instituted. Opsoclonus and ocular flutter have been treated successfully with corticosteroids, propranolol, and clonazepam, while microflutter, an extremely rare disorder, can resolve with baclofen. Although therapy with carbamazepine, 5-hydroxtryptophan, and scopolamine has been useful in selected patients with ocular palatal myoclonus, most do not respond to drug treatment. It is not usually necessary to treat voluntary nystagmus, but Fresnel prism lenses should be remembered in refractory patients. Potentially reversible and pseudointernuclear ophthalmoplegias also were discussed. Orthoptic exercises can be beneficial in posttraumatic internuclear ophthalmoplegia. Selected supranuclear palsies can be improved completely with the proper drug regimen. Lastly, superior oblique myokymia can be treated successfully with carbamazepine, with tight surveillance for possible adverse side effects. Descriptive phenomenology and pathophysiological localization must be correlated with brain stem neurochemistry and neuropharmacology to medically treat additional ocular motor system disorders.