Myotonia with Urinary Incontinence: Diagnosis and Management

Diagnostic Approach

The American Urological Association suggests that myotonia characteristics, such as grip myotonia and percussion myotonia, should be documented in patients with myotonic dystrophy type 1 (DM1) 1, 2
The International Continence Society recommends determining the type of urinary incontinence (stress-type, urgency-type, mixed, or overflow) in patients with DM1 1, 2, 3
A neurologic assessment should be performed to evaluate cognitive impairment, motor skills related to toileting, and lower extremity function in patients with DM1 3
The European Association of Urology suggests reviewing medications that may worsen urinary symptoms or myotonia in patients with DM1 3

Urinalysis should be performed to rule out urinary tract infection and hematuria as contributing factors to urinary incontinence in patients with DM1 3
Post-void residual volume measurement is essential to identify neurogenic urinary retention in patients with DM1 3, 4
Urodynamic testing is indicated for patients with neurogenic lower urinary tract dysfunction, such as those with DM1 1, 2

The American Urological Association recommends avoiding antimuscarinic medications in patients with significant urinary retention, as they can worsen retention and exacerbate myotonia 3, 4
Behavioral interventions, such as bladder training and pelvic floor muscle training, should be attempted initially in patients with neurogenic urinary incontinence, although efficacy may be limited 5, 6, 4
Fluid management, such as regulating intake and reducing evening consumption, can help minimize nighttime symptoms in patients with neurogenic urinary incontinence 6

The International Continence Society advises against performing anti-incontinence surgery without extensive urodynamic evaluation in patients with neurogenic incontinence, as outcomes are unpredictable and complications are higher 1, 7, 5
The European Association of Urology recommends avoiding the use of duloxetine or other medications for stress incontinence in neurogenic cases, as they are ineffective and represent wrong treatment for the underlying pathophysiology 5
Post-void residual measurement should not be skipped, as missing urinary retention can lead to inappropriate treatment that worsens the condition 3, 4

Treatment response should be assessed after 2-4 weeks of behavioral interventions, and voiding diaries can be used to document frequency, volume, and incontinence episodes in patients with neurogenic urinary incontinence 6, 4
Medication side effects, particularly cognitive changes, constipation, and urinary retention, should be monitored closely in patients with neurogenic urinary incontinence 6, 4
Post-void residual should be reassessed if symptoms worsen or new voiding difficulty develops in patients with neurogenic urinary incontinence 3, 4