Biofeedback to Ameliorate Freezing of Gait

• Number of freezing of gait episodes [ Time Frame: 2 hour ] [ Designated as safety issue: No ]
  Freezing episodes will be counted during lab check.
  
  

• Duration of freezing episodes [ Time Frame: 2 hours ] [ Designated as safety issue: No ]
  The duraiton of the freezing episodes will be measured.
  
  

The freezing burden will be quantified in subjects with PD before and after 6 weeks of training. Two types of interventions (20 subjects in each group) will be tested: 1) Open-loop group (OLG); 2) Closed-loop group (CLG). Each session of the OLG training includes walking courses aimed at provoking freezing episodes. The experimenter will trigger an auditory rhythmic stimulation (RAS) in walking conditions likely to invoke freezing (e.g., turning) and the subject will learn to synchronize his/her gait with the auditory cues, i.e., to keep the walking pace and coordination and, as a result, to avoid freezing. Similar principles will apply for the CLG training; however, the RAS will be elicited automatically by a device that recognizes an approaching freezing episode.

We anticipate that after intensive training, the central nervous system (CNS) of subjects with PD will be able to anticipate impending freezing episodes based on awareness of the environmental conditions (e.g., an approaching turn) and/or based on sub-conscious response to a deteriorating gait pattern. As a result, an automated motor response that paces and coordinates gait will be internally triggered by the CNS and the approaching freezing episode will be averted. The overall freezing burden will therefore decrease in trained subjects.