Intradetrusor onabotulinumtoxinA injections ameliorate autonomic dysreflexia while improving lower urinary tract function and urinary incontinence-related quality of life in individuals with cervical and upper thoracic spinal cord injury.

Pilot data of our phase IV clinical trial (pre/post study design) highlighted a beneficial effect of intradetrusor onabotulinumtoxinA (200 IU) injections to reduce autonomic dysreflexia (AD) in individuals with chronic spinal cord injury (SCI) at T6 or above. After trial completion, we assessed whether our primary expectation (i.e., decrease of AD severity in 50% of participants during urodynamics) was met. Secondary outcome measures were spontaneous AD in daily life, amelioration of AD and urinary incontinence-related quality of life (QoL). In addition, we conducted injury-level-dependent analysis, i.e., cervical and upper thoracic, to explore group-specific treatment efficacy. Post-treatment, AD severity decreased in 82% (28/34) of all participants during urodynamics and in 74% (25/34) in daily life assessed with 24-hour ambulatory blood pressure monitoring. Additionally, urinary incontinence-related QoL was improved (all p<0.001), cystometric capacity was increased and maximum storage detrusor pressure (both p<0.001) was reduced. Further, the treatment was well tolerated, with only minor complications [grade I (n=7) and II (n=7)] in accordance with the Clavien-Dindo classification recorded in 11 individuals (cervical n=9, upper thoracic n=2). Injury-level-dependent analysis revealed lower incidence (cervical n=15/23, upper thoracic n=6/11) and lesser severity [cervical p=0.009; upper thoracic p=0.06 (Pearson's r= -0.6, i.e. large effect size)] of AD during urodynamics. Furthermore, reduced AD severity in daily life, improved urinary incontinence-related QoL, greater cystometric capacity, and lower maximum storage detrusor pressure (all p<0.05) were found in both groups post-treatment. Intradetrusor onabotulinumtoxinA injections are an effective and safe second-line treatment option that ameliorates AD while improving lower urinary tract function and urinary incontinence-related QoL in individuals with cervical and upper thoracic SCI.