noninvasive peripheral nerve stimulation for restless legs syndrome during opioid medication reduction

Conditions: Restless Legs Syndrome

Summary: prospective open-label single-arm feasibility study assessing the tolerability of opioid medication reduction in conjunction with noninvasive peripheral nerve stimulation (npns) for patients taking prescription opioids to treat moderate-severe primary rls.

for rls patients taking a stable dose of prescription opioid medications prior to study entry, iterative opioid dose reduction is performed in conjunction with open-label npns treatment. for each of two iterative step-downs in opioid dose (step-down #1 and step-down #2), a 1-2-week run-in phase to allow resolution of opioid withdrawal symptoms unrelated to rls is followed by a 1-wk assessment phase to evaluate if rls symptoms have increased. study participation is terminated if there is a clinically significant increase in rls severity during the assessment phase or if there are intolerable opioid withdrawal symptoms at any time. participants who tolerate both step-downs have the option of an extension phase involving a third step-down with the same format.

Eligibility criteria:
inclusion criteria: * subject has received a medical diagnosis of primary restless legs syndrome (rls) * subject is currently taking a stable dose of at least one prescription opioid for rls, where the total opioid dose is less than or equal to 60mg morphine milligram equivalents (mme) per day. * rls symptoms are most significant in the subject's legs and/or feet. * subject possesses the necessary equipment, internet/phone accessibility, and communication ability to complete electronic questionnaires and respond to electronic communications and phone calls from the research staff throughout the in-home portion of the study. * subject is 18 to 89 years of age (inclusive) when written informed consent is obtained. * subject has signed a valid, institutional review board (irb)-approved informed consent form, can understand the requirements of the study and instructions for device usage, and can converse in english. * subject has been taking a stable dose and schedule of prescription opioids for rls for at least 3 months prior to enrollment. exclusion criteria: * subject has rls that is known to be caused by another diagnosed condition (i.e. secondary rls). * subject was misdiagnosed with rls, as determined by the investigator (e.g. actual diagnosis of periodic leg movement disorder (plmd), arthritis, leg spasms or neuropathy without comorbid rls). * subject has primary sleep disorder other than rls that significantly interferes with sleep at the present time (e.g. unmanaged sleep apnea or general insomnia). * subject has been diagnosed with one of the following conditions at any time: epilepsy or other seizure disorder, severe movement disorder symptoms (parkinson's disease, huntington's disease, dyskinesia, dystonia), deep vein thrombosis, multiple sclerosis * subject has an active diagnosis of one of the following conditions: acute or chronic infection other than viral upper respiratory tract infections, stage 4-5 chronic kidney disease or renal failure, iron-deficient anemia, severe edema affecting lower legs * subject has any of the following at the location of device application: acute injury, cellulitis, open sores * subject has a malignancy within the past 5 years (not including basal or squamous cell skin cancer) * subject is on dialysis or anticipated to start dialysis while participating in the study * subject has severe peripheral neuropathy affecting the lower legs and/or subject has neuropathy and is unable to clearly distinguish between symptoms of neuropathy and symptoms of rls. * during npns calibration, subject has a sensation threshold above the upper-cutoff value (e.g. 30ma), the subject finds stimulation intensities less than 15 ma to be uncomfortable or distracting, or the device does not properly fit the subject. * subject has significantly changed dose or schedule of a medication that may impact rls symptoms within the 30 days prior to enrollment, as judged by the investigator (e.g. antidepressants, sleep medications, sedative antihistamines). * subject has received an investigational drug or device within the last 30 days or is planning to receive an investigational device during the duration of the study. * subject has another medical condition that may affect validity of the study as determined by the investigator. * subject is unable or unwilling to comply with study requirements. * moderate or severe cognitive disorder or mental illness. * subject has prior experience with noctrix health npns devices. * subject has active implantable medical devices anywhere in the body (including pacemakers), or metal implant at the site of study device electrode application. * subject has known allergy to electrode gel, polyurethane foam, or lycra. * subject is pregnant or trying to become pregnant. * subject has undergone a major surgery (excluding dental work) in the previous 30 days. * subject has another medical condition that may put the subject at risk as determined by the investigator.