Freezing of Gait (FOG) is a disabling symptom of Parkinson's disease (PD) and a leading cause for falls. Current medical management is inadequate to alleviate FOG so there is need for improved treatments. A major draw-back in the development of better treatments for FOG is the difficulty in detecting episodes and our poor understanding of its underlying pathophysiology.

This study will investigate the cortical signature of FOG using ambulatory electroencephalography (EEG) to help improve FOG detection algorithms and provide novel insights into the underlying pathophysiology, which together will guide therapy development.

Inclusion Criteria:

1. Clinical diagnosis of Parkinson's disease (PD) made by a Neurologist*
2. Modified Hoehn & Yahr (H&Y) Stage I to IV in the ON medication state
3. Age above 18 years*
4. Able to walk 5 minutes while unassisted by a walker or another person (the use of a cane is allowed).*
5. Mini Mental State Examination>= 21
6. At least three hours in-between regular medication intakes to allow for stable testing time.*
7. Self-reported FOG with a severity of at least 1 FOG episode per day, based on items 1 and 2 of the New Freezing of Gait Questionnaire, irrespective of FOG occurring ON- or OFF-medication.*
8. Stable medication scheme for at least 7 days before enrollment.

Exclusion Criteria:

1. Participation in another clinical intervention study*

2. Acute musculoskeletal or other neurological, psychiatric, or cardiovascular conditions affecting gait or any other medical condition which, in the opinion of the investigator, may prevent the participant from completing the protocol in full

3. Unable to adhere to assessment procedures leading to missing or unusable data, as determined by the investigators

4. Not a stable medication scheme for at least 7 days before the assessment.*

5. Occurrence of any of the following within 3 months prior to informed consent:

   • Orthopedic surgery of the lower extremity
   • Myocardial infarction
   • Hospitalization for unstable angina
   • Coronary artery bypass graft
   • Percutaneous coronary intervention
   • Implantation of a cardiac resynchronization therapy device
   • Implantation of deep brain stimulation

6. Substance abuse that may interfere with the patient's compliance

People with Parkinson's Disease who self-report to experience FOG more than once a day.

The datasets could be made available under restricted access after publication of the results, following ethical approval and a data-transfer agreement. GDPR and privacy regulations will be adhered to.