A commentary on ‘Efficacy of peripheral electrical nerve stimulation on improvements of urodynamics and voiding diary in patients with neurogenic lower urinary tract dysfunction: a systematic review and meta-analysis’
Authors: Yingying Cai, Shuwen Wu
Journal: International Journal of Surgery (2023)

Dear Editor, Patients suffering from spinal cord injury and neurological disorders (e.g. multiple sclerosis and Parkinson's disease) often present with neurogenic lower urinary tract dysfunction (NLUTD)1,2. The typical clinical symptoms of NLUTD usually manifest as dysuria, urgency, urinary incontinence, and impaired bladder emptying. Patients with severe NLUTD can develop renal failure and complicated urinary tract infections and may even die. At present, anticholinergic drugs are recommended as the first-line treatment for NLUTD3. Although some studies have reported that anticholinergic medications can effectively improve urodynamic parameters in patients with NLUTD, these medicines are associated with side effects that limit their use in the long term. Therefore, there is a clear need to develop novel, effective, and safe therapeutic modalities for NLUTD. Ge et al.4 performed a systematic review and meta-analysis to elucidate the efficacy and safety of electrostimulation and thus provide firm evidence for treating NLUTD. They concluded that peripheral electrical nerve stimulation might be effective and safe for managing NLUTD. Peripheral electrical nerve stimulation treatment is classified as a neuromodulation therapy5. It is a relatively convenient, cheap, and noninvasive therapy; in addition, it is free from pharmaceutical side effects. Although the stimulation sites are different and the exact mechanism of action remains to be elucidated, the modulation of spinal cord-mediated reflexes through interneurons and brain networks by peripheral afferents seems to be involved. The neuroregulation of urination consists of two nerve centers (supraspinal reflex and spinal reflex centers) and three sets of nerves (sympathetic, parasympathetic, and somatic nerves). These nerves arise from the lateral horn of L1–L4 and S1–S4, and they are distributed in the trigone of the urinary bladder, external urethral sphincter of the bladder neck, and transverse perineus. The conus medullaris (S2–S4), the spinal reflex center of parasympathetic and somatic nerves, plays a leading role in promoting urination among these nerves. This theoretical basis is extremely important in the location of peripheral electrical nerve stimulation, which has a direct influence on the outcomes. Although the findings of this meta-analysis are promising, plausibility has to be added through appropriately designed randomized controlled trials (RCTs), especially to assess the reproducibility of results for different underlying neurological disorders and stimulation parameters. RCTs investigating treatment effects in different neurological disorders using urodynamics, bladder diary, validated disease-specific and condition-specific questionnaires, as well as cost-effectiveness data are needed to generate high-level evidence allowing appropriate conclusions for daily clinical practice. Importantly, there are no treatment standards for peripheral electrical nerve stimulation and no guidelines for therapeutic regimes, and these need to be developed through further studies. Moreover, individual adjustment of stimulation parameters by analogy with sacral neuromodulation might improve outcomes and warrant additional investigations. Ethical approval None. Consent None. Sources of funding Hangzhou Biomedicine and Health Industry Development Support Science and Technology Special Programme (2022WJC205). Author contribution Y.C.: writing and data analysis; S.W.: study design. Conflicts of interest disclosure There are no conflicts of interest. Research registration unique identifying number (UIN) None. Guarantor Yingying Cai. Provenance and peer review None. Data availability statement None.