What is Fowler Syndrome?
Fowler syndrome is a rare cause of urinary retention in young women characterized by impaired relaxation of the external urethral sphincter, often associated with polycystic ovary syndrome, and treated primarily with sacral neuromodulation. 1
Clinical Features
Fowler syndrome presents with a distinct constellation of findings that differentiate it from other causes of urinary retention in young women:
- Painless urinary retention with large bladder capacity and reduced bladder sensation 1, 2
- Increased maximal urethral closure pressure due to a poorly relaxing external urethral sphincter 1
- Detrusor underactivity secondary to the sphincter dysfunction 1
- Association with polycystic ovary syndrome (PCOS) in more than 50% of cases 3
- Increased urethral sphincter volume on imaging 3
- Abnormal electromyography patterns of the striated urethral sphincter showing direct spread of impulses between muscle fibers 2
Pathophysiology
The underlying mechanism involves a poorly relaxing urethral sphincter that generates increased urethral afferent activity. This heightened afferent signaling inhibits bladder afferent signals from reaching the brain by potentiating a spinal mechanism of urinary continence, ultimately leading to poor bladder sensation and detrusor underactivity 1, 2.
Several hypotheses explain the sphincter dysfunction:
- Hormonal changes associated with PCOS causing abnormal muscle membrane stabilization
- Primary failure of striated urethral sphincter muscle relaxation
- Excessive urethral afferent activity blocking normal bladder signaling 1
Treatment
Sacral neuromodulation (SNM) is currently the only intervention that can restore normal voiding patterns in women with Fowler syndrome 1, 3. The therapeutic effectiveness exceeds 70%, though the revision rate is relatively high at over 50% 1.
Important Caveats:
- No effective pharmacotherapy or surgical alternatives exist beyond SNM 2
- During pregnancy, SNM devices are often deactivated due to limited safety data, requiring intermittent self-catheterization as an alternative 4, 5
- The condition occurs exclusively in young women and should be considered after ruling out neurological, iatrogenic, and local anatomical causes 3
Common Pitfall:
Do not confuse this urological Fowler syndrome with the genetic disorder also called Fowler syndrome (proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome/PVHH), which is a completely different autosomal recessive disorder of brain angiogenesis 6, 7. The context of the clinical presentation—urinary retention in young women versus severe prenatal neurological abnormalities—makes the distinction clear.