Evaluation of a modified inverted walking stick as a treatment for parkinsonian freezing episodes

We evaluated a modified inverted walking stick [visual cue (VC) stick] in Parkinson's disease patients with freezing episodes. Patients underwent baseline trials on a 60-ft track with four walking conditions: unassisted, with a straight walking stick, with the VC stick, and on the track with parallel lines spaced every 12 in. Patients completed three trials of each condition in a randomized order, with total course time and number of freezes recorded. Patients were given the VC stick to use at home until subjective maximum functional benefit was obtained and were then brought back for a follow-up objective evaluation. Eight patients completed the study. The straight stick and VC stick worsened patient performance as a group, while the parallel lines significantly improved group performance. However, two of the eight patients showed benefit from the VC stick. Improvement with parallel lines did not predict improvement with the VC stick. On follow-up trials, the two who initially showed improvement with the VC stick continued to show improvement, while none of the other patients showed additional benefit from a learning effect. We conclude that the VC stick will help a small subpopulation of Parkinson's disease patients with freezing, and this subpopulation can be identified with the initial office visit trial.