200 U vs. 300 U Botulinum Toxin a Injections for Patients with Neurogenic Detrusor Overactivity Secondary to Spinal Cord Injury

Objective: To evaluate the d the safety and efficacy of 200 U vs. 300 U botulinum toxin A (BTX-A) injections for patients with neurogenic detrusor overactivity (NDO) secondary to spinal cord injury (SCI). Methods: We retrieved the data for the patients who receive a single dose into the detrusor of BTX-A (300 U or 200 U). The clinical outcome included maximum detrusor pressure (Pdetmax) during cystometry, voiding volume, urinary incontinence (UI) episodes between CICs per 24 hour, and complete dryness. Related adverse events were recorded. Results: From July 2015 to June 2017, 28 cases received 300 U BTX-A injections (experiment group) while 19 cases received 200U BTX-A injections (control group). There were no significant differences in baseline evaluation items (gender, age, duration of spinal cord injury, level of neurological injury, AIS scores) between the two groups. There were significant improvement in Pdetmax, UI and I-QoL from baseline in the two groups. Patients in experiment group had statistically greater improvement than those in the control group for Pdetmax (-32.09 cm H2O vs. -28.02 cm H2O, P = 0.016), mean urinary incontinence episodes (-6.18/d vs. -5.01/d, P = 0.042), complete dryness (11 vs. 2, P = 0.031), mean voiding volume (160.52 ml vs. 133.66 ml, P <0.001), and I-QoL (28.53 vs. 20.41, P <0.001). Conclusion: Preliminary results indicate that 300 U BTX-A is more effective than 200 U BTX-A for SCI patients with NDO.