The Role of Age and Biological Sex in Autonomic Dysreflexia after Spinal Cord Injury: A Narrative Review of Clinical Data

Autonomic dysreflexia (AD) is a life-threatening condition characterized by acute episodic hypertension (systolic blood pressure [BP] >20 mmHg above baseline), with or without bradycardia, that occurs primarily after high-level (T6 spinal segment or above) spinal cord injury (SCI). Multiple stimuli arising below the level of injury can trigger AD, with bladder and bowel distension accounting for most cases. Despite its life-threatening nature and high prevalence among individuals with SCI, the effects of age, both at the time of injury and injury duration, and biological sex on AD severity and prevalence remain understudied. In this narrative review, we examine how age and sex influence AD following SCI across clinical studies, including pediatric-onset and adult-onset SCI, as well as induced AD paradigms, particularly during urodynamic studies (UDS). We synthesize evidence on how age at injury, duration post-injury and biological sex shape AD presentation and detection, while highlighting that relatively few studies include within-study comparisons across age groups or between males and females. Across studies, injury level emerges as the most consistent correlate of AD, whereas associations with age at injury, injury duration, and sex remain variable and often not directly tested. Pediatric studies highlight age-specific challenges in AD recognition and BP thresholds, while UDS provide quantitative evidence that aging may shift AD toward asymptomatic or “silent” presentations, complicating detection and prevalence estimates. We conclude that substantial gaps remain, underscoring the need for rigorously designed studies to better define the contributions of age and sex to AD following SCI.