A comparison between the response of patients with idiopathic detrusor overactivity and neurogenic detrusor overactivity to the first intradetrusor injection of botulinum-A toxin

Purpose: Several studies have shown that intradetrusor injections of botulinum neurotoxin type A (BoNT/A) may effectively treat intractable spinal neurogenic detrusor overactivity (NDO), but fewer reports exist on the use of BoNT/A in patients with idiopathic detrusor overactivity (IDO). The purpose of this study was to investigate whether comparable efficacy could be displayed in the response of patients with IDO to those with NDO. Materials and Methods: In a prospective, open label study, patients with urgency, and/or urgency incontinence due to urodynamically proven intractable detrusor overactivity received 300 units (NDO) or 200 units (IDO) of Botox injected into the bladder with a minimally invasive outpatient technique. Urodynamic maximum cystometric capacity and maximum detrusor pressure during filling, frequency of voids (frequency), number of incontinence episodes (leak) and number of voids associated with urgency per 24 hours (urgency) from 4-day voiding diaries were compared between the 2 groups at baseline and for changes at 4 and 16 weeks after treatment. Results: A total of 44 patients with spinal NDO and 31 with IDO were treated. At 16 weeks, mean standard error maximum cystometric capacity increased from 229.1 +/- 24.8 to 427.0 +/- 26.9 ml, p <0.0001 in NDO and from 193.6 +/- 24.0 to 327.1 +/- 36.1 ml, p=0.0008 in IDO. Maximum detrusor pressure during filling decreased from 60.7 +/- 6.8 to 26.1 +/- 3.7 cm H2O, p <0.0001 in NDO and from 62.1 +/- 10.8 to 45.1 +/- 8.1 cm H2O, p=0.027 in IDO. Frequency decreased from 12.3 +/- 0.7 to 6.6 +/- 0.6 voids per 24 hours, p <0.0001 in NDO and from 13.6 +/- 1.1 to 8.3 +/- 0.7, p=0.0002 in IDO. Leak decreased from 3.9 +/- 0.5 to 0.7 +/- 0.2 incontinence episodes per 24 hours, p <0.0001 in NDO and from 3.2 +/- 0.8 to 0.6 +/- 0.3, p=0.0017 in IDO, and urgency decreased from 7.5 +/- 0.6 to 1.44 +/- 0.3 episodes per 24 hours, p <0.0001 in NDO and from 10.9 +/- 1.7 to 4.9 +/- 1.1, p <0.0001 in IDO. The 2 groups were comparable for baseline data, but percent improvement in urgency was greater in patients with NDO at 4 weeks (78.2% vs 56.3%, p=0.019) and 16 weeks (78.3% vs 50.7%, p=0.013). Of patients with NDO 69% required self-catheterization de novo posttreatment compared with 19.3% of those with IDO. Conclusions: Patients with intractable IDO respond to intradetrusor BoNT/A with equally significant improvements in urodynamic and lower urinary tract symptom parameters as those with spinal NDO, despite the lower dose of toxin used.