A Prospective Cohort Study on the Effect of Spinal Spinal Cord Injury on Sexual Function in Male Patients

Spinal cord injury (SCI) induces complex pathophysiological alterations extending beyond motor-sensory impairments, with sexual dysfunction emerging as a clinically significant yet insufficiently characterized sequela. This investigation specifically targets three critical knowledge gaps in SCI-related sexual dysfunction: First, regarding neurogenic versus psychogenic differentiation, supraspinal lesions manifest through autonomic dysreflexia-mediated hemodynamic alterations in genital perfusion, while psychological comorbidities predominantly modulate libido and arousal domains. Second, concerning temporal progression dynamics, our institutional pilot data demonstrated 68% of male SCI patients developed clinically significant sexual impairment within 24 months post-injury, though precise trajectory patterns remain uncharacterized. Third, from a biomarker integration perspective, this study will employ cortisol/DHEA-S ratio analysis combined with nocturnal penile tumescence (NPT) monitoring to objectively delineate the endocrine-neurological crosstalk underlying post-SCI sexual dysfunction pathophysiology.

This study employs a robust methodological framework comprising a primary prospective observational cohort (N=180), stratified by both anatomical lesion level and neurological impairment severity. The research architecture incorporates three integrated substudies utilizing advanced multimodal assessment protocols: Substudy A applies penile duplex ultrasonography (PDU), coupled with Rigiscan® technology, International Index of Erectile Function-5 (IIEF-5) and the Premature Ejaculation Diagnostic Tool (PEDT) to quantitatively evaluate sexual parameters; Substudy B conducts high-sensitivity LC-MS/MS serum assays (testosterone, prolactin, SHBG) to systematically characterize hypothalamic-pituitary-adrenal axis dysregulation patterns post-SCI; while Substudy C employs grounded theory methodology to analyze semi-structured interviews, establishing an evidence-based model of psychosocial coping strategy efficacy validated through the International Spinal Cord Injury Male Sexual Function (ISCI-MSF) Basic Data Set and the ICIQ-ADPHS instrument. This tripartite approach ensures comprehensive mechanistic investigation across biomechanical, endocrine, and psychosocial dimensions of post-SCI sexual dysfunction.

The study implements a comprehensive data acquisition protocol employing validated quantitative metrics across multiple domains. Longitudinal data collection occurs at predetermined intervals throughout the 60-month study period. For analytical rigor, we employ group-based trajectory modeling (GBTM) to characterize IIEF score evolution, LASSO-penalized Cox regression for time-to-recovery analysis, and partial least squares path modeling (PLS-PM) to examine mechanistic relationships between lesion level and autonomic function, endocrine profiles and arousal metrics, and depression (PHQ-9) and desire domains. Normative data development utilizes kernel density estimation to establish age-stratified IIEF reference curves, while minimum detectable change (MDC) is determined through anchor-based methods incorporating the PGIC scale, ensuring clinically meaningful interpretation of results.

This investigation incorporates several cutting-edge technical innovations to enhance methodological rigor and analytical precision: standardized biobanking procedures maintain serum aliquots to facilitate future omics-based investigations; and advanced convolutional neural networks (CNNs) automate penile duplex ultrasonography (PDU) waveform analysis to ensure objective, reproducible measurements. To maintain the highest standards of data quality, we implement robust quality assurance protocols including centralized blinding procedures for IIEF scoring (inter-rater reliability κ>0.85), multiple imputation by chained equations (MICE) to address missing data, and quarterly phantom testing of Rigiscan® equipment to verify measurement accuracy (maintaining <5% error tolerance). These integrated technological and methodological safeguards ensure the collection of high-fidelity data while enabling novel multidimensional analyses of post-SCI sexual dysfunction pathophysiology.