Vibrating socks: a novel cueing intervention to reduce freezing of gait in Parkinson*s disease.

Freezing of gait (FOG) is one of the most disabling symptoms of Parkinson*s
disease (PD). Non-pharmacological approaches, including external cueing, are
generating growing interest. However, it remains difficult to translate such
cueing strategies into an efficient ambulatory device that is effective, but at
the same time socially acceptable (i.e. *invisible* to outsiders). In this
regard, tactile cueing holds great promise. Here, we propose rhythmically
vibrating socks as a new ambulatory device to improve gait and alleviate FOG in
PD. The vibrating socks can offer tactile cueing in an open-loop (fixed
frequency) or closed-loop manner (vibration is activated when body weight is
placed on the sock. We expect both types of tactile cueing to be feasible and
effective, with tactile cueing being preferential over auditory cueing.

To test the clinical efficacy of vibrating socks, a new tactile cueing device,
for the management of FOG in patients with PD.

Using a within-subject design, we will test the ability of vibrating socks to
provide patients with FOG with cueing to successfully improve gait and
alleviate FOG. The study will be performed in two medical centres (Medisch
Spectrum Twente and RadboudUMC).

The vibrating socks, a new tactile cueing device.

Measurements will be conducted during two separate mornings (max. 4 hours per
session), one while ON dopaminergic medication and one while OFF dopaminergic
medication (>12 hours after intake of the last dose of medication). During both
sessions motor (MDS-UPDRS part III) and cognitive status (FAB and MMSE) will be
tested and a FOG questionnaire will be completed. Additionally, patients will
perform four different walking tasks ((1) walking at preferred speed for 10 m,
(2) turning while walking, (3) gait trajectory with narrow passages, (4) rapid
full turns) in four different conditions ((1) tactile cueing in a closed-loop
manner; (2) tactile cueing in an open-loop manner; (3) auditory cueing; or (4)
no cueing). Each walking task will be perfomed three times, and patients will
were a Xsense system for gait analysis. In addition all walking tests will be
recorded on video. At the end of each visit, patients* experience is evaluated
using a brief questionnaire in order to ensure that the developed device has
the potential to be suitable for use in daily life settings.

Short-term skipping of levadopamedication to achieve an OFF status, is a
frequently applied and safe strategy within Parkinson research and is safe for
patients. Parkinson medication is only symptomatic and it does not affect the
underlying disease process. In the OFF status, patients notice an increase in
Parkinson's symptoms, this increase is fully reversible on intake of
medication. This is not harmful to health and has no long-term effects for the
patient.

The potential risks of the investigational product are considered negligible.
The low-taxing tests ensure that the risk of the subject falling is no larger
during the test than in daily living. The chance of worsening of symptoms is
minimal, since the subject is gently stimulated to walk and no movements are
forced.