What is a Hinman bladder?

Hinman Syndrome: Non-Neurogenic Neurogenic Bladder

Hinman syndrome is a functional voiding dysfunction characterized by bladder-sphincter dyscoordination in the absence of neurological deficits, which can lead to severe bladder dysfunction and upper urinary tract damage if not properly diagnosed and treated. 1

Definition and Historical Context

• Hinman syndrome, previously known as non-neurogenic neurogenic bladder, occult neurogenic bladder, or detrusor-sphincter dyscoordination, was first described by Hinman in 1973 as a condition where patients exhibit neurogenic bladder-like symptoms without actual neurological abnormalities 1
• The term was clarified in the International Children's Continence Society (ICCS) guidelines to distinguish it from general dysfunctional voiding, which refers specifically to dysfunction during the voiding phase 1

Clinical Presentation

• Patients typically present with symptoms including:

  • Urinary retention and difficulty emptying the bladder 2
  • Recurrent urinary tract infections 2
  • Enuresis (bedwetting) 2, 3
  • Encopresis and constipation (present in up to 93% of cases) 3
  • Urinary incontinence 3

• Physical examination and neurological assessment are typically normal, which distinguishes this condition from true neurogenic bladder 2

Pathophysiology

• The condition involves habitual contraction of the urethral sphincter during voiding, creating functional bladder outlet obstruction 1
• It is currently understood as an acquired behavioral and psychological disorder, often associated with abnormal family dynamics or psychological trauma 2, 4
• Approximately 35% of patients have a history of significant familial life stresses 3
• Some cases have been associated with a history of sexual aggression or child abuse 4

Diagnostic Features

• Diagnosis requires:

  • Confirmation of staccato voiding pattern on repeat uroflow measurements or through invasive urodynamic investigation 1
  • Normal neurological examination and imaging (MRI typically shows normal results) 2
  • Exclusion of anatomical or neurological causes of voiding dysfunction 1

• Imaging findings often include:

  • Hydroureteronephrosis 2
  • Marked bladder wall thickening and trabeculation 2
  • Vesicoureteral reflux on voiding cystourethrogram (VCUG) 2

Prognostic Factors

• Factors associated with poor prognosis include:
  • Male gender 3
  • Severe fecal retention 3
  • Serious psychological disorders 3
  • Delayed diagnosis and treatment 3
  • Recurrent febrile urinary tract infections (more common in boys) 3

Management

• Treatment requires a multidisciplinary approach involving pediatric urologists, psychologists, and physiotherapists 4
• Non-surgical interventions are the mainstay of treatment:
  • Voiding retraining programs (effective in 67-71% of cases) 3
  • Intermittent catheterization (beneficial in 62-75% of patients) 3
  • Anticholinergic medications (helpful in 50% of cases with severe presentations) 3
  • Psychological support and therapy to address underlying issues 4
  • Treatment of constipation and bowel dysfunction 3

Clinical Course and Complications

• If left untreated, Hinman syndrome can progress to severe bladder dysfunction and even end-stage renal disease 5
• The condition can create a vicious cycle where psychosocial problems worsen voiding dysfunction, which in turn exacerbates psychological issues 6
• Early recognition and intervention are critical to prevent upper urinary tract damage and renal sequelae 6

Important Considerations

• Nighttime wetting should not be dismissed as benign, especially when persistent or associated with other symptoms 5
• Parental awareness about voiding disorders is crucial for early detection 5
• Distinguishing this condition from neurogenic bladder requires thorough evaluation, as the clinical and radiographic manifestations can be very similar 2