Botulinum-a toxin for treating detrusor hyperreflexia in spinal cord injured patients: A new alternative to anticholinergic drugs? Preliminary results

Purpose: We evaluated the efficacy of botulinum-A toxin injections into the detrusor muscle in patients with spinal cord injury, detrusor hyperreflexi a and urge incontinence resistant to anticholinergic drugs. The purpose of treatment was to suppress incontinence episodes and increase functional bla dder capacity. Materials and Methods: Included in our prospective nonrandomized study done at 2 clinics were 31 patients with traumatic spinal cord injury who emptie d the bladder by intermittent self-catheterization. These patients had seve re detrusor hyperreflexia and incontinence despite a high dose of anticholi nergic medication. Pretreatment evaluation included a clinical examination and complete urodynamic investigation. Under cystoscopic control a total of 200 to 300 units of botulinum-A toxin were injected into the detrusor musc le at 20 to 30 sites (10 units per mi. per site), sparing the trigone. Clin ical and urodynamic followup was planned for 6, 16 and 36 weeks after treat ment. Patients were asked to decrease their intake of anticholinergic drugs during week 1 after treatment. Results: Of the 21 patients 19 underwent a complete examination 6 weeks aft er the botulinum-A toxin injections, and 11 at 16 and 36 weeks. At the 6-we ek followup complete continence was restored in 17 of 19 cases in which ant icholinergic medication was markedly decreased or withdrawn. Less satisfact ory results in 2 cases were associated with an insufficient dose of 200 uni ts botulinum-A toxin. After the injections overall mean reflex volume and m ean maximum cystometric bladder capacity plus or minus standard deviation s ignificantly increased from 215.8 +/- 90.4 mi. to 415.7 +/- 211.1 (p <0.016 ) and 296.3 +/- 145.2 to 480.5 +/- 134.1 (p <0.016), respectively. There wa s also a significant decrease after treatment in mean maximum detrusor void ing pressure from 65.6 +/- 29.2 cm. water to 35 +/- 32.1 (p <0.016). Mean p ost-void residual urine volume catheterized at the end of the urodynamic ex amination increased significantly fi om a mean of 261.8 +/- 241.3 mi. to 49 0.5 +/- 204.8 (p <0.016). Moreover, autonomic dysreflexia associated with b ladder emptying that manifested as a hypertensive crisis during voiding dis appeared after treatment in the 3 patients with tetraplegia. Satisfaction w as high in all successfully treated patients and no side effects were obser ved. Ongoing improvement in urodynamic parameters and incontinence was alre ady present in all patients reevaluated at 16 and 36 weeks. Conclusions: Botulinum-A. toxin injections into the detrusor seem to be a s afe and valuable therapeutic option in spinal cord injured patients with in continence resistant to anticholinergic medication who perform clean interm ittent self-catheterization. Successfully treated patients become continent again and may withdraw from or markedly decrease anticholinergic drug inta ke. A dose of 300 units botulinum-A toxin seems to be needed to counteract an overactive detrusor. The duration of bladder paresis induced by the toxi n is at least 9 months, when repeat injections are required.