LONG TERM EFFECTS OF SPINAL CORD STIMULATION

Parkinson Disease (PD) patients experience a variety of motor issues such as walking difficulties, loss of balance, and freezing while walking, which impacts their quality of life. Some symptoms, like freezing of gait (FOG), do not respond to medications typically used to treat PD. Current surgical procedures used to alleviate PD symptoms also do not always improve FOG. Since many traditional therapies have failed for the treatment of FOG, researchers have proposed the use of newer treatments. Recent research in animal models and clinical human data using Spinal Cord Stimulation (SCS) has produced promising results, specifically showing improvement in FOG with the use of SCS in patients with PD.

The purpose of this study is to explore the long-term motor and non-motor effects of SCS in PD patients after completing participation on H-49023. The investigators hypothesize that SCS significantly decreases FOG episodes in patients with PD.

1. Assess the long-term safety, tolerability and preliminary evidence of effectiveness of upper thoracic spinal cord stimulation for freezing of gait in Parkinson's (PD) patients.
2. Allowing patients to choose between the two SCS programming paradigms based on their motor, nonmotor and quality of life measures in PD patients with freezing of gait.

Freezing of gait (FOG) is a devastating motor phenomenon which may occur in patients with Parkinson's Disease (PD) and other neurodegenerative disorders. It is characterized by episodes during which patients cannot generate effective forward stepping movements in the absence of motor deficits.

FOG leads to reduced mobility, loss of independence, social embarrassment, and caregiver stress. While most motor features of PD respond robustly to dopaminergic agents and deep brain stimulation (DBS), there are currently no effective treatments for FOG.

Indirect evidence from case reports of PD patients undergoing spinal cord stimulation (SCS) for neuropathic pain, has consistently described a positive effect of SCS on FOG. In addition, two recent reports demonstrated that thoracic SCS improved locomotion and FOG in patients with advanced PD. The promising role of SCS for the treatment of FOG in PD has encouraged us to assemble a multi-disciplinary team for the systematic investigation of the motor effects of SCS on FOG, locomotion and other parkinsonian features.

Patients with PD may be able to undergo SCS implantation through experimental protocols such as study H-49023 (NCT03526991) at BCM. We seek to understand the long-term effects of SCS in PD in patients who have participated in H-49023 at BCM.

The current study will use similar assessments as were used in H-49023. Patients will undergo assessments and questionnaires to help identify which setting and parameters produce the best results for the patient. These questionnaires will asses if the patient fell at home and if any non-motor symptoms arise.

Eligibility Criteria:
Inclusion Criteria:

* Ability to sign inform consent
* Underwent SCS implantation as part of participation in H-49023

Exclusion Criteria:

* Severe dementia Inability to participate in motor or cognitive assessments assessments