EEG signals predicting freezing of gait in Parkinson patients

Freezing of gait (FOG) is a common and debilitating phenomenon in Parkinson*s
disease (PD). FOG is defined as a brief, episodic absence or marked reduction
of forward progression of the feet despite the intention to walk. Recent
technological advances have improved the ability to provide compensation
strategies in daily life situations. Examples include wearable minicomputers in
the form of smart glasses that can provide rhythmic visual cueing or augmented
visual cues on top of the patient*s visual field. The feasibility of these
technological advances would further improve, if these cueing-strategies could
be applied in an on-demand manner (i.e. cueing only occurs when FOG is
detected, and preferably predicted). Hence, there is a need to introduce a
real-time system for FOG prediction and detection to automatically activate
external cues.

The main objectives of this study are to acquire EEG, ECG and motion data from
15 PD patients with FOG for the algorithm development to online detect and
predict FOG, and test the performance of developed algorithm in 15 PD patients
with FOG. We will perform two separate experiments. In the first (1st)
experiment, we will provoke FOG during stepping movements in place. Using these
data, we will develop an algorithm to detect and predict FOG. In the second
(2nd) experiment, we will test the developed algorithm during several walking
tasks.

We will perform two separate experiments. In the first experiment, we will
provoke FOG during stepping movements in place. Using these data, we will
develop an algorithm to detect and predict FOG. In the second experiment, we
will test the developed algorithm during several walking tasks. All procedures
of this study are non-invasive. In both experiments, 15 PD patients with FOG
will be included. All participants are tested at their *off* medication state,
following an overnight withdrawal (> 12 hours after intake) of anti-Parkinson
medication. The participants attending the 1st experiment (in-place movement)
will be asked whether would be willing to continue the 2nd experiment (daily
life movement). A new participant will be recruited if the participant does not
want to participate in the 2nd experiment.

The 1st experiment consists of the following parts: reception and explanation
about the study (15 minutes), questionnaires (45 minutes), system preparation
of EEG, motion sensors, ECG and footswitches equipment (50 minutes),
movement-in-place tasks (approximately 70 minutes, including several breaks).
The movement-in-place tasks are composed of 3 conditions: normal (at
self-selected speed) stepping in place, normal turning (a 180-degree turn) in
place, rapid turning (a 180-degree turn) in place. Every condition lasts 2
minutes. A single visit for 1st experiment takes approximately 3 hours.

The 2nd experiment consists of the following parts: reception and explanation
about the study (15 minutes), questionnaires (45 minutes), system preparation
of EEG, motion sensors and ECG equipment (40 minutes), movement tasks (80
minutes including several breaks). The movement tasks include rapid-turning in
place with or without dual tasks (Adjusted Auditory Stroop task, AAS task),
walking at a normal speed on a 8-meter trajectory including executing several
turns and walking through doorways, walking on the same trajectory at a rapid
speed with dual tasks (AAS task), and walking on the same trajectory at a
normal speed with dual tasks (AAS task and using a walking tray with a cup of
water). Every condition lasts 1 or 1.5 minutes. A single visit for 2nd
experiment takes approximately 3 hours.

All procedures are non-invasive. Experiments are conducted while participants
are in their 'off' state (>12 hours after last intake of dopaminergic
medication). This is expected to cause more FOG (increasing the power of the
study) and an increase of PD symptoms which will resolve upon medication intake
after the experiments. Studies in the 'off' state are common in PD research and
do not pose a risk to participants. Physical tiredness which might occur during
the in-place movement and walking tasks is minimized by allowing participants
to rest as often and long as needed. Persons with PD, and especially those with
FOG, are, due to the nature of their disease, at risk for falling. We do not
expect that walking with the portable EEG cap nor ECG equipment aggravates the
risk of falls. During the walking tasks, one of the researchers will walk with
the patient, to prevent the patient from falling. This study is therefore not
dangerous and poses no risk to the patients.