With a nice handful of medications for PSP approaching clinical trials, it would be great to be able to assess the participants’ movement ability not just every few weeks to months at the research center, but also much more frequently at home.  The reduced need for clinic visits would ease participation for patients who for whatever reason have difficulty tolerating or obtaining travel.  It could also provide a more “real-world” picture of how the patient is doing in their home environment.

One relatively easy step in that direction arose from a project published last year (in which I, full disclosure, was senior author).   It modified the 28-item PSP Rating Scale, omitting the exam items that might not work well by video and used existing databases of PSPRS scores over time to assess the correlation between the modified and unmodified scores.  In short, the correlation was excellent.

But a PSP Rating Scale modified for video still requires a video connection, and that can be tough for the PSP age group and their caregivers, especially those where cell service is spotty.  Besides, video visits can’t happen every day or even close to it.  So, some other gadget would be nice.

Now, a group led by Dr. Alexander Pantelyat of Johns Hopkins and Dr. Anne-Marie Wills of Mass General (the co-senior authors) with Dr. Mansi Sharma of Mass General (the first author) have published a first-blush look at a simple gait monitoring system in PSP and Parkinson’s. 

Other versions of the same idea for PSP have had to be used in a lab at a research facility and required a complex array of sensors pasted to various parts of the body.  But this one is used in the patient’s home and requires only three sensors: one strapped to the lower back with a belt and one fastened to each shin by what looks like an old-fashioned garter strap like my father used to wear.  For reasons of safety, only patients with histories of very few falls and ability to walk unassisted qualified for this early trial.  Patients with PSP and Parkinson’s were compared on their performance of four standard gait tasks.  They received instructional videos and the three sensors communicated with an app on a tablet provided.

Of the 22 patients who qualified and consented, only two (both with Parkinson’s) couldn’t manage the technical requirements.  For the others (10 with PD and 10 with PSP), the device proved able to quantify and time the movements well and to differentiate PSP from Parkinson’s. Most important was that managing the experimental hardware and software while avoiding falls or other complications was perfect.

The next step will be to assess the device over a period of several months for its ability to track PSP progression.  This should be successful because the Spearman correlation coefficients of the three gait measures with the modified PSP Rating Scale, were pretty good: 0.62, 0.64 and 0.84; and we know that the PSPRS tracks PSP progression well.  (Correlation of 1.0 is perfect and 0 is random.) 

Another reason to be optimistic about the device to track progression is that it’s already been accomplished, although with a more complex, six-electrode device implemented in a research lab.

A reason for caution is that not every patient in a drug study walks unassisted at home as safely as these 20 hand-picked participants, especially toward the end of a one-year trial period.  Furthermore, using this device at home in routine clinical practice would involve patients at all levels of gait instability.  But for people in remote areas or whose caregiver can’t afford to take time off from work for a clinic visit, this could be the ticket to research trial participation.