Cerebrovascular Accident (Stroke) is Most Strongly Associated with Neurogenic Bladder Dysfunction and Intact Bladder Sensation
The correct answer is (e) cerebrovascular accident, as suprapontine lesions from stroke typically preserve bladder sensation while causing neurogenic bladder dysfunction, unlike lower lesions that disrupt sensory pathways.
Pathophysiology of Post-Stroke Bladder Dysfunction
Stroke causes neurogenic bladder through disruption of cortical control while preserving afferent sensory pathways from the bladder. 1, 2 Suprapontine lesions result in loss of cortical perception and coordination but maintain the intact sensory signals traveling from the bladder to the brain, which distinguishes stroke from lower neurological lesions. 3, 2
Key Anatomical Distinctions:
- Suprapontine lesions (stroke): Cause uninhibited bladder with preserved sensation because sensory pathways remain intact 2
- Lesions between pontine micturition center and sacral cord: Result in spastic bladder or detrusor-sphincter dyssynergia with impaired sensation 2
- Cauda equina lesions (option b): Damage sensory nerve roots, causing loss of bladder sensation 2
- Myelomeningocele (option c): Involves spinal cord malformation with absent or severely impaired sensation 2
- Paraplegia (option d): Spinal cord injury disrupts ascending sensory pathways, causing loss of sensation 2
Clinical Presentation After Stroke
Post-stroke bladder dysfunction affects 25-50% of stroke survivors, with urinary incontinence being the predominant symptom. 4 The most common urodynamic finding is detrusor overactivity (hyperreflexia with urge incontinence), though detrusor underactivity also occurs. 4, 5
Specific Urodynamic Patterns:
- Detrusor overactivity: Most common finding, causing urgency, frequency, and urge incontinence 5, 3
- Detrusor underactivity: Less prevalent but significant, requiring different management 5
- Detrusor-sphincter dyssynergia: Can occur but less common than in spinal lesions 2
- Uninhibited sphincter relaxation: Results from loss of cortical inhibition 2
Why Other Options Are Incorrect
Abdominoperineal resection (option a) causes bladder dysfunction through direct nerve injury during surgery, not neurogenic etiology, and typically impairs sensation. 2 This is a peripheral nerve injury rather than central neurogenic dysfunction.
Cauda equina lesions (option b), myelomeningocele (option c), and paraplegia (option d) all involve damage to spinal cord or nerve roots that disrupts both motor AND sensory pathways, resulting in impaired or absent bladder sensation. 2 These conditions damage the afferent sensory fibers traveling from the bladder, unlike stroke which affects only the cortical processing of intact sensory signals.
Critical Clinical Pitfall
A common error is assuming all neurogenic bladder presents with loss of sensation. 2 Stroke patients typically retain awareness of bladder fullness and urgency because the sensory pathways from bladder to brain remain anatomically intact—the problem is loss of cortical inhibition of the micturition reflex, not loss of sensation. 3, 2 This preserved sensation with loss of voluntary control creates the characteristic urgency and urge incontinence seen after stroke. 4, 5