Spinal Cord Stimulation for Gait in Parkinson Disease

Inclusion Criteria: * Consenting male and female participants, aged 18 years to 80 years * Idiopathic PD with II-IV Hoehn-Yahn stage * A history of frequent falls, gait and balance dysfunction and postural instability * ON-freezing * Ability to perform a gait/walking task (under close supervision), * PD participants referred by Dr. Jog to the functional neurosurgeon for SCS implantation for treatment of their gait and balance dysfunction and/or for their freezing of gait. * SCS eligibility has been confirmed by neurologist and neurosurgeon * Patients who receive SCS for their gait and mobility must participate in this study in order to determine which SCS parameters provide the patient with the best outcome for their PD symptoms. * able to give informed consent * Able to attend all clinic visits and assessments * No dementia or psychiatric abnormalities on neuropsychological testing * No significant secondary causes (such as cerebrovascular disease, normal pressure hydrocephalus, peripheral neuropathy, severe degenerative lower limb or back disease). * we had a few devices to include exploratory trial in atypical PD (MSA, PSP, and CBD confirmed diagnosis from clinic). Exclusion Criteria: * History of stroke * History of ALS or Myasthenia Gravis * Offending medications (Lithium, valproate, steroids, amiodarone, beta-adrenergic agonists (e.g. salbutamol). * Persons prescribed zonisamide * Women reporting that they are pregnant * Persons medically unstable with contraindications to SCS will be excluded * Previous brain surgery or cardiac pacemaker * Eligibility for deep brain stimulation surgery * Moderately severe parkinsonism in the context of unstable pharmacological treatment * Dementia as assessed by DSM criteria or severe cognitive disturbances * Severe psychiatric symptoms (in particular, hallucinations and depression) * Bad general health * Lack of compliance at follow-up * Severe dyskinesias * Significant cognitive impairment