Physical Therapy and Aminopyridine for Downbeat Nystagmus Syndrome: A Case Report

Abstract

Background and purpose: Individuals with downbeat nystagmus (DBN) syndrome present with DBN, dizziness, blurred vision, and unsteady gait. Pharmacological intervention with 4-aminopyridine (4-AP) may be effective in improving oculomotor function, but there is minimal evidence to date that it improves gait. This suggests the possible benefit of combining pharmacotherapy with physical therapy to maximize outcomes. This case report documents improvements in gait and balance after physical therapy and aminopyridine (AP) in an individual with DBN syndrome. Case description: The patient was a 70-year-old man with a 4-year history of worsening dizziness and imbalance, diagnosed with DBN syndrome. He demonstrated impaired oculomotor function, dizziness, and imbalance, which resulted in falls and limited community ambulation. Intervention: The patient completed a customized, tapered course of physical therapy over 6 months. Outcome measures included the 10-meter walk test, the Timed Up and Go (TUG), the Dynamic Gait Index (DGI), and the modified clinical test of sensory integration and balance. Outcomes: Improvements exceeding minimal detectable change were demonstrated on the TUG and the DGI. Gait speed on the 10-meter walk test did not change significantly, but the patient was able to use a cane to ambulate in the community and reported no further falls. Discussion: Controlled studies are needed to explore the potential for AP to augment physical therapy in people with DBN syndrome. Physical therapists are encouraged to communicate with referring medical providers about the use of AP as pharmacotherapy along with physical therapy for individuals with DBN syndrome.