Dalfampridine and Gait in Spinocerebellar Ataxias

• Change in Timed 25 Feet Walking Test (T25FW) [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  The patient is directed to one end of a clearly marked 25-foot course and is instructed to walk 25 feet as quickly as possible, but safely. The time is calculated from the initiation of the instruction to start and ends when the patient has reached the 25-foot mark. Patients may use walking assistance devices if needed.
  
  
• Change in Biomechanical Assessment of Gait (BAG) [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  Biomechanical Assessment of Gait is a sensitive, quantitative movement analysis system. The analysis includes walking velocity, stride length, step width, double support and single support times, and center of mass displacement.
  
  
• Change in Balance Test (BT) [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  For 20 seconds, patients will stand on a pad that measures sway and tests balance, once with eyes open and once with eyes closed.
  
  

• Change in Scale of Assessment and Rating of Ataxia (SARA) [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  SARA is a clinical scale including 8 items that are related to gait, stance, sitting, speech, finger-chase test, nose-finger test, fast alternating movements and heel-shin test.
  
  
• Change in Karnofsky Performance Scale (KPS) [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  Karnofsky Performance Scale (KPS) will be used to measure functional status. It was designed to measure the level of patient activity and medical care requirements. It is a general measure of patient independence.
  
  
• Change in World Health Organization Quality of Life (WHOQOL) Questionnaire [ Time Frame: Screening and week 10 ] [ Designated as safety issue: No ]
  The WHOQOL questionnaire is an international cross-culturally comparable quality of life assessment instrument. It assesses the individual's perceptions in the context of their culture and value systems, and their personal goals, standards and concerns.
  
  

• Dalfampridine plasma level [ Time Frame: week 4 and week 10 ] [ Designated as safety issue: No ]
  This is a blood test to monitor compliance by looking at Dalfampridine plasma level.
  
  
• Adverse Events [ Time Frame: Weeks 2, 4, 6, 8, 10 ] [ Designated as safety issue: Yes ]
  Patients will report on any adverse events they experienced that may or may not be due to treatment so that we may monitor safety.
  
  

Twenty spinocerebellar ataxia patients will be randomized to receive either Dalfampridine or placebo over a total period of 10 weeks. After entering the study, patients will return every 2 weeks for evaluation. After five weeks, intervention will be stopped and patient will enter a 2-week wash out period where they do not take any drug. Then, patients will be given the opposite treatment (Dalfampridine or placebo) and this "crossover" study will be performed for another 4 weeks. Investigators expect there will be improvement in walking speed and steadiness after taking Dalfampridine, thereby improving activities of daily living and enhancing social and occupational functions.