title: Effectiveness of botulinum toxin administered to abolish acquired nystagmus.
abstract: We injected botulinum toxin into the horizontal rectus muscles of the right eyes of 2 patients who had acquired pendular nystagmus with horizontal, vertical, and torsional components. This treatment successfully abolished the horizontal component of the nystagmus in the injected eye in both patients for approximately 2 months. Both patients showed a small but measurable improvement of vision in the injected eye that may have been limited by coexistent disease of the visual pathways. The vertical and torsional components of the nystagmus persisted in both patients. In 1 patient, the horizontal component of nystagmus in the noninjected eye increased; we ascribe this finding to plastic-adaptive changes in response to paresis caused by the botulinum toxin. Such plastic-adaptive changes and direct side effects of the injections--such as diplopia and ptosis--may limit the effectiveness of botulinum toxin in the treatment of acquired nystagmus. Neither patient elected to repeat the botulinum treatment.
authors.affiliation: Department of Neurology, Case Western Reserve University, University Hospital, Cleveland, OH 44106.
authors.forename: R J
authors.initials: RJ
authors.lastname: Leigh
authors.forename: R L
authors.initials: RL
authors.lastname: Tomsak
authors.forename: M P
authors.initials: MP
authors.lastname: Grant
authors.forename: B F
authors.initials: BF
authors.lastname: Remler
authors.forename: S S
authors.initials: SS
authors.lastname: Yaniglos
authors.forename: L
authors.initials: L
authors.lastname: Lystad
authors.forename: L F
authors.initials: LF
authors.lastname: Dell'Osso
mesh_terms: D000328:Adult; D001905:Botulinum Toxins / Q000008:administration & dosage*; D005133:Eye Movements / Q000187:drug effects; D005260:Female; D006801:Humans; D007273:Injections, Intramuscular; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000188:drug therapy*; D012438:Saccades / Q000187:drug effects
chemical_list: D001905:Botulinum Toxins