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Autonomic Dysreflexia

Botulinum Toxin

Injection of Botulinum toxin into the detrusor muscle is a treatment for urinary incontinence secondary to neurogenic detrusor overactivity while injection into the external urethral sphincter is a treatment for detrusor-sphincter dyssynergia and high post void residual urines.

Author Year; 
Research Design
Sample Size
Methods Outcome
Fougere et al. 2016




Population: N=17 (12M, 5F) with chronic traumatic SCI at or above T6 and concomitant autonomic dysreflexia and neurogenic detrusor overactivity

Mean (SD) age: 44 (10)

Mean (SD) years post injury: 21 (11)

AIS-A/B/C = 9/5/3

11 cervical, 6 thoracic

Treatment: One cycle of Botox injection (200U in 20mL 0.9% saline, injected into 20 sites of detrusor muscle), 2wk after baseline measurements & 1mo before post-treatment measurements

Outcome Measures: Urodynamic studies (UDS), 24h ambulatory BP monitoring (ABPM), AD Health-related QoL questionnaire, I-QOL questionnaire

1.     Pre vs. post-botox during UDS (mean±SD):

Significantly lower SBP (mmHg) at:

First urge to preform CIC (112±17 vs. 114±14), at max volume infused (151±25 vs. 133±17), and at max SBP (153±25 vs. 134±16)

Significantly lower ΔSBP* (mmHg) at:

First urge to preform CIC (34±20 vs. 15±11), at max volume infused (40±24 vs. 18±12), and at max SBP (42±23 vs. 20±10)

Significantly lower ΔHR (bpm) at:

First urge to preform CIC (-8±11 vs. -6±10), at max volume infused (-17±12 vs. -9±14), and at max SBP (-16±13 vs. -8±14)

2.     Pre vs. post-botox during bladder events (mean±SD, from 24h ABPM):

Significantly reduced max SBP (157±21 vs. 139±21) & ΔSBP** during CIC

3.     AD eliminated in 10 participants (ΔSBP <20mmHg), attenuated in 7

4.     Significantly fewer participants reporting AD symptoms post-botox (15 to 9)

5.     Significantly reduced frequency of AD during CIC post-treatment (67% to 25%)

6.     Significant improvement in all subsections and in total scores of QoL measures

*change in measure vs. supine baseline

**change in measure vs. seated baseline

CIC = clean intermittent catheterization

Chen & Kuo 2012; Taiwan



(with AD=34)

Population: 49 patients (31M, 18F) with SCI and detrusor sphincter dyssynergia; Level of SCI: 27 cervical, 22 thoracic; mean age in yrs: 41.6, range 22-74; mean DOI in yrs: 8, range 1-35.

Treatment: Patients received two sets of 200 U BoNT-A injections into the detrusor at baseline and 6 months later.

Outcome Measures: Improvement in the severity of AD; net change in the grade of incontinence; net changes in the scores of the Urogenital Distress Inventory (UDI-6); Incontinence Impact Questionnaire; quality of life index; urodynamic parameters.

1.     15 patients did not have AD at baseline or after treatment.

2.     AD was completely resolved in 3 patients, and improved in 18; treatment made no difference in 3 patients and AD was exacerbated in 10.

3.     No significant differences in any urodynamic variables between patients with and without AD.

4.     A significantly greater improvement in the UDI-6 was noted in patients without AD and those in whom AD improved than in those with AD. Occurrence of AD was not significantly associated with persistent urinary incontinence after the BoNT-A injections.

5.     No significant difference in the quality of life index between patients with and without AD at the end point.

Chen et al. 2008;




(with AD=4)

Population: 20 suprasacral SCI subjects with detrusor external sphincter dyssynergia (DESD); Mean age 37.9 (15.7); 17 male; 12 cervical, 3 thoracic, 5 lumbar; AIS diagnosis: 11 AIS-A, 2 AIS-B, 4 AIS-C, 3 AIS-D.

Treatment: A single dose of 100 IU botulinum toxin A was applied into the external urethral sphincter via cystoscopy.

Outcome Measures: Maximal detrusor pressure, maximal urethral pressure, maximal detrusor leak point pressure, integrated electromyography (IEMG) of the external urethral sphincter and, maximal pressure on static urethral pressure profilometry, recorded before and 4 weeks after the injection; post-voiding residues, measured 1, 2, 3, and 6 months post-injection.

1.     4 patients who had AD symptoms before treatment reported decreased frequency and intensity of AD.

2.     There was significant reduction in the IEMG (from 16.7(13.6) to 12.5(12.9) uV), as well as static urethral pressure (from 139.4(40.5) to 104.8(30.5) cmH2O) and maximal urethral pressure (from 107.5(69.1) to 80.2(35.7) cmH2O).

3.     There was no significant difference in the maximal detrusor pressure or detrusor leak point pressure.

4.     Post-voiding residues were significantly reduced at 1st, 2nd, 3rd, and 6th months post-injection.

Kuo 2008




(with AD=6)

Population: 33 subjects suffering from detrusor sphincter dyssynergia and urinary incontinence (including 9 individuals with cervical SCI, 12 with thoracic SCI, 5 with lumbar SCI, 5 multiple sclerosis and 2 transverse myelitis patients); age range 23- 71.

Treatment: Transurethral sphincter botox injections, injecting 100 units of botox in 4 ml normal saline into eight sites of the urethral sphincter.

Outcome Measures: Video-urodynamic studies; Urogenital Distress Inventory short form (UDI-6); Incontinence Impact Questionnaire (IIQ-7) short form.

1.     3/6 patients experienced decreased symptoms of AD post-treatment.

2.     Urodynamic parameters showed significant improvement in voiding detrusor pressure (45.7(22.7) vs. 30.7(15.5) cmH2O), maximum flow rate (6.8(5.7) vs. 9.2(7.7) ml/sec) and postvoid residual volume (160(124) vs. 75(105) ml).

3.     IIQ-7 scores were significantly improved, but not the UDI-6 scores.

Schurch et al. 2000



N initial=31

N final=19

Population: Mean age: 36.7 yrs, mean DOI=60.2 months; 18 subjects with paraplegia, 3 with tetraplegia, 17 subjects with complete injuries, 4 with incomplete injuries, incontinence resistant to anticholinergic medication.

Treatment: Botulinum-A toxin was injected (200-300 units) into the detrusor muscle.

Outcome Measures: Voiding and detrusor pressure, diary of incontinence, AD symptoms at 6, 16, and 36-wks.

1.     At 6-week follow-up 17/19 patients were completely continent.

2.     3 patients with tetraplegia with severe AD with bladder emptying found this disappeared after treatment.

Dykstra et al. 1988




(with AD=7)

Population: Detrusor-sphincter dyssynergia.

Treatment: Low dose botulinum A toxin at the neuromuscular junction.

Outcome Measures: Urethral pressure, symptoms of AD.

1.     Urethral pressure profile decreased 27 cm H20 (n=7).

2.     Self-assessed improvement of AD symptoms in 5 of 7 AD patients.

3.     Toxin effects lasted an average of 50 days.


Five pre-post studies (n=132) (Dykstra et al. 1988Schurch et al. 2000Chen et al. 2008Kuo 2008Chen & Kuo 2012) found injection of Botulinum toxin into the detrusor muscle or bladder sphincter to be an effective method for treating urinary incontinence or retention secondary to neurogenic detrusor overactivity and bladder sphincter dyssynergia. In these conditions, injections of the Botulinum toxin either allowed increased urinary bladder capacity (i.e. reduced overactivity of the bladder) or facilitated improved evacuation of urine (reduced bladder sphincter dyssynergia). The duration of effect was reported to last up to 9 months (Schurch et al. 2000). All studies were level 4 and showed positive effects. In fact, following treatment with Botulinum toxin, 3 individuals reported fewer episodes of AD (Kuo 2008), 4 individuals reported decreased frequency and intensity of AD (Chen et al. 2008), 3 individuals who experienced severe AD during bladder emptying reported disappearance of these symptoms altogether (Schurch et al. 2000), 3 individuals reported AD was completely resolved (Chen & Kuo 2012), and 18 individuals experienced improvement in AD symptoms (Chen & Kuo 2012). While the evidence suggests that Botulinum toxin may be a viable treatment for neurogenic detrusor overactivity, the evidence supporting the application of Botulinum toxin specifically for the prevention of AD is inconclusive.


There is level 4 evidence (from 5 pre-post studies: Dykstra et al. 1988Schurch et al. 2000Chen et al. 2008Kuo 2008Chen & Kuo 2012) that Botulinum toxin injections into the detrusor muscle or external urethral sphincter seem to be a safe and valuable therapeutic option in SCI patients who perform clean intermittent self-catheterization and have incontinence resistant to anticholinergic medications.

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