The Influence of Sensory Stimuli on Gait Imagery in Patients With Freezing of Gait

Background:

• Freezing of gait (FOG) is a common and very disabling symptom in people with Parkinson s disease, significantly affecting their quality of life. It has been defined as a sudden break or block in the walking motion, or as an inability to start walking. Although certain neural connections or neurological processes might contribute to FOG, more research is needed to produce consistent findings. Researchers are interested in investigating brain function involved in FOG.

Objectives:

• To obtain more information on brain function in individuals with freezing of gait.

Eligibility:

• Individuals between the ages of 45 and 80 who have been diagnosed with Parkinson s disease.
• Participants must be willing to go off their current Parkinson s disease medications for up to 12 hours at a time.

Design:

• Participants will be divided into two groups: those who do have freezing of gait (more than about once a day) and those who have not experienced this symptom.
• The study will involve a screening visit (1 hour) and a study visit (2 hours).
• During the screening visit, participants will be asked about medical history, and will have physical, neurological, memory, and walking tests.
• Participants should not take their Parkinson's disease medications for 12 hours before the study visit. Participants who cannot come to the clinic safely without their medications will be allowed to stay in the hospital overnight before the visit, and should bring their medications to the study in order to take them as soon as needed after the study.
• Participants will be asked to perform several tasks before the imaging study: (1) walking 10 yards back and forth down a hallway, (2) walking 10 yards back and forth while following horizontal lines on the floor, (3) walking 10 yards back and forth while listening to a metronome, and (4) being pushed back and forth in a wheelchair.
• After participants perform the actual tasks, participants will be asked to imagine performing the tasks and fill out questionnaires about how well they can imagine the tasks.
• Participants will be monitored with a functional magnetic resonance imaging (fMRI) scan while imagining the four tasks they have just performed.