In the most recent Medscape Medical News email, they presented an interesting research study on how freezing in Parkinson’s may not be a motor issue but rather a sensory-perceptual one (the article is copyrighted, so I can’t post it).
The study compared 15 patients with freezing, 16 with PD but no freezing, and 16 healthy controls and examined how doorway size affected gait – the narrower the door, the more gait variability, shorter steps, and wider BOS for those who experienced freezing, while those who did not were also affected in that they had a wider BOS.
They note that more study is needed as some studies also observed similar patterns (Exp Brain Res. 2003;149:187–194), whereas others found opposing data (Parkinsonism Relat Disord. 2006;12:21–27). One interesting idea they had was to use eye-tracking software to monitor gaze, and that it could either be a sensory issue (eyes aren’t analyzing the doorway correctly) or a cognitive problem with failing to perceive the door spatially (depth and width).
This study was published recently in J Neurol Neurosurg Psychiatry, and the lead investigator was Dr. Quincy Almeida.