Evaluating Spinal Cord Stimulation for Stiff Person Syndrome

Inclusion Criteria:

• Is 18 years of age or older at the time that the Informed Consent Form (ICF) issigned.

• Has been clinically diagnosed with stiff person syndrome

• Has clinical symptoms of muscle rigidity and spasms in the truncal (includingabdominal, thoracic paraspinal, and pectoral) or proximal lower limb musculature

• Has Cerebrospinal fluid (CSF) Anti-glutamic acid decarboxylase 65 (anti-GAD65)antibodies or serum anti-GAD65 antibodies present at any titer

• Is currently trying or has tried in the past at least two conventional therapieswith insufficient symptomatic relief or intolerable side effects (such asnonsteroidal anti- inflammatory drugs, topical patches/creams/gels/ointments,physical therapy, acupuncture, bracing, assistive devices, and lifestylemodification).

• If taking oral medications, is willing to maintain a stable regimen for the durationof the study period.

• Is cleared for an implantable medical device by licensed mental health provider.

• Is an appropriate candidate for the surgical procedures required in this study basedon clinical judgement of the study physician.

• Is willing to and capable of giving written informed consent.

• Is willing and able to comply with study-related requirements and procedures andattend scheduled visits.

Exclusion criteria:

• Is less than 18 years of age at the time at the time that the Informed Consent Form (ICF) is signed.

• Has a Body Mass Index (BMI) > 45.

• Has a history of spine surgery or is planning to receive a spinal injection orprocedure while participating in the study, unless this procedure can be postponeduntil after study completion.

• Has radiological findings or evidence of moderate to severe central spinal canalstenosis or neuroforaminal stenosis at any thoracic level or laterality.

• Has radiological findings or evidence of moderate/severe central spinal canalstenosis at any cervical or lumbar level.

• Has had an epidural steroid injection within 6 weeks of enrollment.

• Has a history of infection of the spine within 6 months of enrollment.

• Has received intravenous immunoglobulin therapy within 30 days or is unwilling tomaintain a stable regimen (no change in dosage or frequency) during the studyperiod.

• Has a history of opioid misuse or current chronic opioid therapy.

• Has evidence of a coagulation abnormality or low platelet count (<120,000) indicatedon Complete Blood Count test at screening, or has a history of abnormal bleeding, orif unable to pause anticoagulation therapy in accordance with accepted guidelinesfor a spinal cord stimulator trial.

• Has a current local infection at the anticipated surgical entry site, activesystemic infection, or active malignancy.

• Has a medical condition or pain in other area(s) not intended to be treated in thisstudy, that could interfere with study procedures, accurate pain reporting, and/orconfound evaluation of study endpoints, as determined by the Investigator (such asradicular pain, post-herpetic neuralgia, central canal stenosis of the cervical,thoracic or lumbar spine, critical limb ischemia due to peripheral vascular disease,or small vessel disease).

• Has a history of untreated major depressive disorder, or history of any mentalhealth disorder with psychotic features, such as schizophrenia.

• Is pregnant (confirmed via pregnancy test) or plans on becoming pregnant during thestudy period.

• Has had, within six months of enrollment, a significant untreated addiction todependency producing medications, alcohol or illicit drugs.

• Is concomitantly participating in another interventional clinical trial.

• Is involved in an injury claim for a study-related chronic pain that is undercurrent litigation.

• Is a recipient of temporary Social Security Disability Insurance (SSDI) benefits dueto study related chronic pain.

• Has a pending or approved worker's compensation claim for study-related chronicpain.

• Has low English language literacy interfering with the ability to complete studyrequirements.