Suprasacral spinal cord injury (SCI) frequently leads to neurogenic detrusor overactivity (NDO), resulting in elevated bladder storage pressures, urinary incontinence, and an increased risk of upper urinary tract damage. Early regulation of bladder function is a key objective of SCI rehabilitation, particularly during the subacute phase when pathological spinal reflex pathways are still developing.

Pharmacological treatments are considered first-line therapy for NDO; however, adequate control may not be achieved in all patients, and treatment tolerance may be limited. Non-invasive neuromodulation techniques have emerged as alternative or adjunctive approaches for managing lower urinary tract dysfunction, but evidence regarding their effectiveness in SCI-related NDO-especially when applied during the subacute period-remains limited.

This prospective randomized comparative study aims to evaluate and compare the effectiveness of transcutaneous sacral neurostimulation (TSNS) and transcutaneous tibial neurostimulation (TTNS) applied during the subacute phase of suprasacral SCI in preventing the development of neurogenic detrusor overactivity. A secondary objective is to assess the effects of these interventions on the severity of neurogenic bowel dysfunction.

Eligible adult patients with subacute suprasacral SCI will be randomized into three groups: TTNS, TSNS, or a control group receiving standard care without neuromodulation prior to urodynamic assessment. Urodynamic parameters including detrusor pressure, bladder compliance, and maximal cystometric capacity, will be compared between groups. Functional outcomes and symptom severity related to neurogenic bladder and bowel dysfunction will also be evaluated.

By investigating non-invasive neuromodulation strategies applied early after SCI, this study aims to contribute evidence regarding the prevention of NDO development and to support the optimization of neuromodulation use in clinical practice for individuals with suprasacral SCI.

Neurogenic detrusor overactivity (NDO) is a common consequence of suprasacral spinal cord injury (SCI) and represents a major risk factor for urinary incontinence and upper urinary tract deterioration. During the subacute phase following SCI, maladaptive spinal reflex pathways associated with detrusor overactivity are still evolving. Interventions applied during this period may influence the development and severity of long-term bladder dysfunction.

Non-invasive neuromodulation techniques have been shown to modulate afferent neural pathways involved in lower urinary tract control. Transcutaneous tibial neurostimulation (TTNS) has demonstrated efficacy in both neurogenic and non-neurogenic bladder dysfunction, while evidence regarding transcutaneous sacral neurostimulation (TSNS) remains limited. Comparative data evaluating these two transcutaneous approaches in subacute SCI-related NDO are lacking.

This prospective randomized comparative study is designed to evaluate the effects of TTNS and TSNS applied during the subacute phase of suprasacral SCI on the prevention of NDO development. Adult patients with traumatic or non-traumatic suprasacral SCI within six months of injury will be enrolled and randomly assigned to one of three groups: TTNS, TSNS, or a control group receiving standard care without neuromodulation prior to urodynamic evaluation.

Participants in the intervention groups will receive non-invasive transcutaneous neuromodulation administered 15 sessions. Following completion of sessions, all groups will undergo standardized urodynamic assessment in accordance with International Continence Society (ICS) recommendations. Urodynamic parameters including maximal detrusor pressure during filling, bladder compliance, and maximal cystometric capacity, will be evaluated and compared between groups.

In addition to urodynamic outcomes, functional status and symptom severity related to neurogenic bladder and neurogenic bowel dysfunction will be assessed using validated clinical scales. A secondary analysis will examine the impact of TTNS and TSNS on the severity of neurogenic bowel dysfunction during the subacute SCI period.

This study aims to clarify the role of early, non-invasive neuromodulation in modulating bladder and bowel dysfunction following suprasacral SCI. The findings are expected to contribute to evidence-based decision-making regarding early intervention strategies and to support the development of standardized transcutaneous neuromodulation protocols in SCI rehabilitation.

Inclusion Criteria:

1. ≥18-65 years of age
2. Injury duration <6 months
3. Traumatic and non-traumatic SCI;
4. Patients with spinal cord injury above T11

Exclusion Criteria:

1. Patients with a cardiac pacemaker
2. Patients with other neurological diseases that may affect neurogenic bladder (Parkinson's disease, polyneuropathy, neurodegenerative disease, cerebrovascular disease, etc.)
3. Patients with structural abnormalities in the genitourinary system (pelvic floor dysfunction, BPH, etc.)
4. Patients with acute urinary tract infection
5. Patients with a history of pelvic fracture associated with SCI
6. Patients using medications that may affect NDO (anticholinergic-sympathomimetic, etc.)
7. Patients who have undergone another neuromodulation technique after injury
8. Patients who have previously undergone pelvic radiation, bladder cancer, or other surgical procedures performed on the bladder that may affect bladder physiology will not be included in the study.