Following spinal cord injury (SCI), the development of neurogenic lower urinary tract dysfunction is closely related to the onset of neuroplasticity, which leads to the re-emergence of primitive spinal reflex pathways. This process occurs approximately six weeks after spinal cord injury, as soon as spinal shock ends. We hypothesized that timing may play a key role in the effectiveness of sacral neuromodulation (SNM), and that early intervention—within 6 weeks after SCI—could influence the development of neurogenic detrusor overactivity (NDO). The aim of this study was to evaluate the impact of early SNM on the occurrence of NDO in patients with complete SCI.

This prospective observational study included patients with complete SCI above the thoracolumbar junction (T12–L1) admitted to a single Trauma Center between June 2021 and June 2024. Patients were assessed during the acute phase and considered for early SNM implantation within 6 weeks from injury, provided that clinical conditions allowed and that the persistence of spinal shock was confirmed by neuro-urological evaluation and video-urodynamic testing. All procedures were performed by a single experienced operator. Patients who were not eligible for early SNM due to clinical contraindications or delayed evaluation, but who presented with comparable injury characteristics and were consecutively admitted during the same period, were included as a control group. All patients underwent standardized video-urodynamic studies at baseline and at 6 and 12 months. The primary outcomes were the development of NDO and urinary incontinence. Categorical variables were compared using Fisher’s exact test, with statistical significance set at p < 0.05.

Seven patients underwent early SNM implantation. The mean age was 39 years. The mean time from trauma to first urological evaluation was 15.8 days, and to first video-urodynamic study was 29.8 days. At enrollment, all patients were managed with indwelling urinary catheter. The mean time from trauma to SNM implantation was 42.3 days. At 6 months, no patient in the SNM group developed NDO (0/7, 0%), compared to 3/6 patients (50%) in the control group (p = 0.07). Urinary incontinence was observed in 2/7 patients (28.6%) in the SNM group and in 2/6 (33.3%) controls (p = 1.00). At 12 months, NDO was observed in 4/7 patients (57.1%) in the SNM group and in 2/6 (33.3%) controls (p = 0.60). Urinary incontinence was present in 2/7 patients (28.6%) in the SNM group and in 4/6 (66.7%) controls (p = 0.24).

The absence of NDO at 6 months in the SNM group, compared to a 50% rate in controls, suggests that early SNM may interfere with the initial phase of maladaptive neuroplasticity. Although this effect was not sustained at 12 months, the delayed onset of NDO may still be clinically relevant, potentially allowing for improved early bladder management and reducing the risk of complications. The lack of statistical significance is likely related to the small sample size and should not preclude consideration of the observed trends.

Early SNM in patients with complete SCI appears to delay the onset of NDO during the early post-injury phase, although this effect may diminish over time. While no statistically significant differences were observed, the findings suggest a potential modulatory role of early SNM on bladder neuroplasticity. Further studies with larger cohorts are needed to confirm these preliminary observations and to better define the optimal timing and long-term impact of this intervention.

Continence 19S (2026) 102550
DOI: 10.1016/j.cont.2026.102550