A T6 AIS A SCI with neurogenic bladder shows detrusor contraction with external sphincter tightening; this condition is called?

A T6 AIS A SCI with neurogenic bladder shows detrusor contraction with external sphincter tightening; this condition is called?

• A. Areflexive bladder
• B. Reflexive bladder with coordinated sphincter
• C. Overflow incontinence
• D. Detrusor-sphincter dyssynergia

Answer: (D)

When the bladder contracts to void, the external sphincter should relax to allow urine to pass. In a spinal cord injury above the sacral center, the pathways that normally coordinate detrusor contraction with sphincter relaxation can be disrupted. This leads to detrusor contractions occurring together with the sphincter tightening instead of relaxing. That mismatch is detrusor-sphincter dyssynergia, a common pattern after upper motor neuron SCI like at T6. So, seeing detrusor contraction with the external sphincter tightening fits detrusor-sphincter dyssynergia because the sphincter is not relaxing during bladder contraction, creating a functional outlet obstruction. This is different from an areflexive bladder (no detrusor contraction) or a reflexive bladder with coordinated sphincter (sphincter relaxes during voiding), and it’s not simply overflow incontinence, which stems from underactive detrusor or outlet obstruction without this dyssynergic pattern.

When the bladder contracts to void, the external sphincter should relax to allow urine to pass. In a spinal cord injury above the sacral center, the pathways that normally coordinate detrusor contraction with sphincter relaxation can be disrupted. This leads to detrusor contractions occurring together with the sphincter tightening instead of relaxing. That mismatch is detrusor-sphincter dyssynergia, a common pattern after upper motor neuron SCI like at T6.

So, seeing detrusor contraction with the external sphincter tightening fits detrusor-sphincter dyssynergia because the sphincter is not relaxing during bladder contraction, creating a functional outlet obstruction. This is different from an areflexive bladder (no detrusor contraction) or a reflexive bladder with coordinated sphincter (sphincter relaxes during voiding), and it’s not simply overflow incontinence, which stems from underactive detrusor or outlet obstruction without this dyssynergic pattern.