Botulinum toxin therapy for neurogenic detrusor overactivity

Detrusor injection of botulinum toxin (BTX) has shown great promise in the treatment of neurogenic detrusor overactivity (NDO) refractory to conservative therapy. Despite a paucity of prospective evidence, there exists a growing consensus that BTX injection therapy is a well-tolerated, low-risk therapy. Injections result in substantial subjective improvement in continence and quality of life. Moreover, assessment of urodynamic parameters demonstrates objective changes: (1) an increase in maximum cystometric capacity; (2) when applicable, a reduction in maximal detrusor voiding pressures; and (3) an increase in bladder compliance in cases where baseline bladder compliance measures were abnormal. While BTX bladder injection offers both objective and subjective measures of incontinence control, treatment duration is limited by the gradual reinnervation of injected tissue over an approximately 6- to 9-month interval. However, repeat injection cycles do appear to achieve similar levels of efficacy. The objective of this review is to provide a focused summary of the current body of literature, investigating the safety and efficacy of bladder BTX injection in patients with NDO.