Study to Evaluate the Feasibility of Syde® Digital Endpoints for Monitoring Patients With Progressive Supranuclear Palsy - Richardson Syndrome (PSP-R)

Inclusion Criteria: 1.18 years old or older 2.Participants affiliated to, or beneficiary from, a social security. 3.Ambulant patients (i.e. able to walk 10 meters without assistance) 4.Signed informed consent form by the patient himself or, by caregivers if the patient is not capable to fill, date and sign the form due to fine motor function difficulties.. 5.Possible or probable PSP-R according to MDS criteria 2017(Hoglinger et al., Mov Disorder, 2017). Exclusion Criteria: 1. Patients with extreme cognitive disorders that limit their understanding of the data collection process (training of device use and 4-week recording periods every 4 months, device return at the end of the study), tests to be performed including eye movement recording (every 8 months), the implication of the study and consent. 2. Patients who do not tolerate to keep the sensors on their ankles. 3. Patients who have undergone a surgical procedure or who have experienced recent trauma (within fewer than 6 months) affecting the lower limbs. 4. A concomitant chronic or acute neurological, endocrine, infectious, allergic, or inflammatory pathology within the 3-week period immediately prior to inclusion. 5. Patients affected by any other disorder having a significant impact on gait or lower limb function. 6. Participant covered by a legal protection measure (guardianship, curatorship or safeguarding of justice) or who is unable to express their consent. 7. Absence of caregiver.