**2. Results**

A total of 200 patients were enrolled for analysis. There were 125 (62.5%) patients in the detrusor injection group, and 75 (37.5%) in the urethral sphincter injection group. The average age was 40.8 years, and 131 (65.5%) were men. The levels of injuries were 52 (26%) at the C-spine and 148 (74%) at the T-spine. Symptoms included 2 (1%) with normal voiding, 71 (35.5%) with difficult voiding, 107 (53.5%) with urgency incontinence, and 32 (16%) with urinary retention. Types of bladder managemen<sup>t</sup> among the participants included 38 (19%) self-voiding, 45 (22.5%) using diapers, 20 (10%) using abdominal pressure, 102 (51%) using percussion voiding, 41 (20.5%) using reflex voiding, 31 (15.5%) using intermittent catheterization, 11 (5.5%) using indwelling catheters, and 7 (3.5%) using cystostomy. The baseline characteristics of each group are summarized in Table 1.


**Table 1.** Baseline characteristics in detrusor injection and urethral sphincter injection groups.

\* *p*-value by Student's *t* test and Chi-square test.

The patient-reported improvements in AD are presented as GRA. Of the 200 patients, 28 (14%) reported no improvement, 50 (25%) reported mild improvement, 75 (32.5%) reported moderate improvement, and 47 (23.5%) reported marked improvement. There were more patients in the detrusor group reporting moderate or marked improvement in AD (Table 2). AD was found to increase immediately after intradetrusor injection in two patients, but in none after urethral sphincter injection. However, there were no patients who reported having a worsened GRA of AD after treatment at the follow-up time-point in this study.

**Table 2.** Subjective improvement after treatment.


\**p*-value by Chi-square test.

At baseline, the patients in the detrusor groups had more sensitive bladders, evidenced by a smaller filling volume at first sensation (171 mL vs. 210 mL, *p* = 0.019), urge sensation (189 mL vs. 235 mL, *p* = 0.015), as well as maximal bladder capacity (254 mL vs. 293 mL, *p* = 0.038). After Botox injection, the urethral group showed significant increases in Qmax, voided volume, and VE (Table 3).


**Table 3.** Baseline and post-treatment videourodynamic parameters in the detrusor and urethral Botox injection groups.

BCI: bladder contractility index, BOOI: bladder outlet obstruction index, CBC: cystometric bladder capacity, FS: full sensation, FSF: first sensation of filling, Pdet: detrusor pressure at maximum flow rate, PVR: post-voiding residual, Qmax: maximal flow rate, US: urge sensation, VE: voiding efficiency, \* *p*-value by Mann–Whitney U test.

In the detrusor group, patients who had moderate or marked improvement in AD had poorer bladder compliance (31.14 vs. 70.47, *p* < 0.001), higher Pdet (45.42 vs. 23.48 cmH2O, *p* < 0.001), and higher BOOI (35.93 vs. 9.83, *p* <0.001) at baseline compared to patients who had no or mild improvement. The post-treatment changes of the moderate or marked improvement subgroups and those of the no or mild subgroups were significantly different in bladder compliance and BOOI (Table 4). DO was present in 77 (61.6%) patients before Botox treatment and in 69 (55.2%) patients after Botox treatment (*p* = 0.052). DSD was present in 61 (48.8%) patients before Botox treatment and in 53 (42.4%) patients after Botox treatment (*p* = 0.268).


**Table 4.** Baseline and post-treatment videourodynamic parameters in the detrusor Botox injection patients.

BCI: bladder contractility index, BOOI: bladder outlet obstruction index, CBC: cystometric bladder capacity, FS: full sensation, FSF: first sensation of filling, Pdet: detrusor pressure at maximum flow rate, PVR: post-voiding residual, Qmax: maximal flow rate, US: urge sensation, VE: voiding efficiency. \* *p*-value by Mann–Whitney U test.

In the urethral sphincter group, patients who had moderate or marked improvement in AD had marginally higher Pdet (41.65 vs. 29.13 cmH2O, *p* = 0.050) and lower capacity (258.86 vs. 399.41 ml, *p* = 0.023) compared to patients who had no or mild improvement (Table 5). DO was present in 38 (50.7%) patients before Botox treatment and in 33 (44%) patients after Botox treatment (*p* = 0.180). DSD was present in 30 (40%) patients before Botox treatment and in 20 (26.7%) patients after Botox treatment (*p* = 0.031).


**Table 5.** Baseline and post-treatment VUDS parameters in the urethral sphincter Botox injection patients.

BCI: bladder contractility index, BOOI: bladder outlet obstruction index, CBC: cystometric bladder capacity, FS: full sensation, FSF: first sensation of filling, Pdet: detrusor pressure at maximum flow rate, PVR: post-voiding residual, Qmax: maximal flow rate, US: urge sensation, VE: voiding efficiency. \* *p*-value by Mann–Whitney U test.
