Hinman Syndrome

Hinman syndrome (HS) or non-neurogenic neurogenic bladder is a voiding dysfunction of the bladder of neuropsychological origin that is characterized by functional bladder outlet obstruction in the absence of neurologic deficits.

Epidemiology

Prevalence is not known.

Clinical description

The syndrome typically occurs in early to late childhood but some adult cases have been observed. It typically manifests at some point after toilet training in early to late childhood. Patients present with enuresis, urgent voiding with incontinence, infrequent voiding, intermittency, straining, urinary tract infections and diffuse abdominal pain.

Etiology

The syndrome is probably caused by acquired behavioral and psychological disorders manifested by bladder dysfunction mimicking neurologic disease. The dysfunction is associated with abnormal family dynamics in 50% of cases. Individuals under psychosocial pressure try to inhibit enuresis by voluntarily contracting the external sphincter. These voluntary contractions lead to an obstruction of the urinary tract, characterized by an intermittent stream, increased residual urine and increased intravesicular pressure. The resultant destruction of the urinary tract simulates true neurogenic bladder.

Diagnostic methods

Diagnosis is based on the presence of the clinical and radiographic manifestations of neurogenic bladder in the absence of an underlying neurogenic abnormality. The diagnosis of HS should be considered at uroradiography in any child with unexplained bladder trabeculations, residual urine, incontinence or posterior urethral distention. The observation of posterior urethral distention following voluntary contraction of the external sphincter using a voiding cystourethrogram is suggestive of the condition.

Differential diagnosis

Differential diagnoses include neurogenic bladder, enuresis and urinary tract infection. HS can be differentiated from neurogenic bladder by five criteria: a) intact perineal sensation and anal tone, b) normal anatomy and function of the lower extremities, c) absence of skin lesions overlying the sacrum, d) normal lumbosacral spine at plain radiography, and e) normal spinal cord and magnetic resonance imaging (MRI). It is important to distinguish between true neurogenic bladder and HS because true neurogenic bladder requires surgery.

Management and treatment

Treatment for HS focuses on helping the child void normally through alleviating psychosocial pressures which are likely to be causing the problem with voiding through suggestion therapy including hypnosis, bladder retraining and timed voiding. Catheterization may be used if the bladder does not empty completely and if the bladder has uninhibited contractions. Antispasmodic drugs may be of benefit. Occasionally external sphincterotomy is required.

Prognosis

HS can result in trabeculated bladder, ureterovesical obstruction, dilation of the upper tracts and renal damage and is often associated with urinary tract infections. However, improvements in patients with HS have been seen with bladder retraining and suggestion therapy.