Home Neuromodulation for Neurogenic Bladder Management in Spinal Cord Injury

Inclusion Criteria: * Non-progressive chronic (\>1 year) SCI * Neurologic level of injury T9 and above * Stable over active bladder (OAB) medications (≥3 months) * No contraindication to MRI (per MRI Safety Questionnaire) * English or Spanish speaking * Tolerate and be able to evoke toe flexion bilaterally with transcutaneous tibial nerve stimulation (tTNS) (self or assisted) * Pass the tTNS competency checklist to perform or direct performance of tTNS. Exclusion Criteria: * Ongoing/active genitourinary oncologic diagnoses * History of other central nervous system disorder (CNS) disorders and/or peripheral neuropathy * Pregnancy or planning to become pregnant. * Lower Motor Neuron bladder * Restorative bladder surgery such as augmentation cystoplasty * Botulinum toxin-A injections in the bladder within 6 months of trial enrolment (injection in other sites is allowed) * Anticoagulation treatment or prophylaxis * Advanced peripheral vascular disease (gangrene, amputation, etc.) * History of intolerance to electrical stimulation, particularly of the leg