Nocturnal Enuresis

1. Definition: Enuresis (DSM-IV Classification)
   1. Repeated voiding of urine into bed or clothes
      1. Involuntary or intentional
   2. Clinically Significant criteria (one of the following)
      1. Twice weekly for at least 3 consecutive weeks
      2. Significant distress
      3. Impaired functioning
   3. Age 5 years or older
   4. Secondary cause not present
      1. Medication (e.g. Diuretics)
      2. Diabetes Mellitus
      3. Spina bifida
      4. Seizure Disorder
2. Categories: Enuresis
   1. Causes
      1. Primary Enuresis (80%)
         1. No history of urinary continence for more than 6 months
      2. Secondary Enuresis (20%)
         1. Enuresis recurs after 6 months of urinary continence
   2. Timing
      1. Nocturnal Enuresis only (80%)
      2. Nocturnal and diurnal (20%)
3. Epidemiology: Prevalence of Enuresis
   1. Age 2 years: 82%
   2. Age 3 years: 49%
   3. Age 4 years: 26%
   4. Age 5 years: 15-25%
   5. Age 12 years: Boys: 8%; Girls 4%
   6. Age 18 years: Boys: 1%: Girls rare
4. Pathophysiology and Physiology
   1. Maturation delay
      1. Enuresis Prevalence decreases with age
      2. "Bladder full" signal does not yet work
   2. Strong association with Family History
      1. Gene markers on chromosome 5, 12, 13 and 22
      2. Both parents with Enuresis: 77% chance of Enuresis
      3. One parent with Enuresis: 44% chance of Enuresis
         1. Relative risk if Father with Enuresis: 7.1
         2. Relative risk if mother with Enuresis: 5.2
5. Causes: Secondary (3%)
   1. Bladder Dysfunction or unstable Bladder (3-5%)
   2. Medically treatable
      1. Urinary Tract Infection (especially girls)
      2. Diabetes Insipidus
      3. Diabetes Mellitus
      4. Hyperthyroidism
      5. Fecal Impaction or Constipation (often with comorbid Encopresis)
   3. Surgically treatable
      1. Ectopic Ureter
      2. Lower Urinary Tract Obstruction
      3. Neurogenic Bladder
      4. Bladder calculus or foreign body
      5. Sleep Apnea secondary to large adenoids
   4. Psychiatric illness (in only 20%)
      1. More common in enuretic girls
      2. Suggested by Enuresis both night and day
      3. More likely if Enuresis persists in older child
   5. Regressive Enuresis (occurs after being dry)
      1. Associated with stressful environmental event
6. History
   1. Voiding History (Two week voiding diary may be helpful)
      1. Does child meet DSM-IV criteria for Enuresis above?
      2. Has the child ever been dry? (primary or secondary)
      3. Is there daytime Enuresis? (complicated Enuresis)
   2. Bowel or Bladder habit changes
      1. Dysuria
      2. Infrequent or difficult stool passage
      3. Encopresis
   3. Functional Bladder disorder signs
      1. Voids >7 per day with urgency, and small volumes
      2. Withholding urine until last minute
      3. Wets more than once nightly
   4. Nocturnal polyuria
      1. Enuresis on only a few nights per week
      2. Voids large volumes when Enuresis occurs
   5. Other related history
      1. Birth complications
      2. Neurologic disorders
      3. Genitourinary surgeries
      4. Family History of Enuresis
7. Examination
   1. Gait Evaluation for neurologic deficits
   2. Head and neck exam for findings suggestive of pediatric Sleep Apnea
   3. Abdominal and flank exam
      1. Costovertebral angle tenderness (CVA tenderness)
      2. Abdominal masses
      3. Bladder enlargement
   4. Back exam
      1. Spinal Dysraphism signs
8. Labs: Urinalysis
   1. Signs of Urinary Tract Infection
   2. Urine Specific Gravity
   3. Urine Glucose
9. Management: General
   1. Reassure parents with age-related norms
   2. Assess for organic causes (see above)
      1. Complete history and physical with Urinalysis
      2. No further evaluation necessary if normal results
   3. Counsel family regarding conflict surrounding Enuresis
10. Management: Non-Pharmacologic Therapies
    1. Appropriate Toilet Training
       1. Scheduled voiding times (especially in evening)
       2. Behavior Modification
          1. Bed-Wetting Alarm
             1. Most effective treatment for Nocturnal Enuresis
          2. Visualization techniques
          3. Void just before bedtime
          4. Limit fluids 1 hour before bedtime
          5. Scheduled awakening during night to void
             1. Some experts do not recommend
       3. Positive reinforcement system
          1. Charts the child's progress of dry nights
          2. Given stickers on calendar or points per dry night
    2. General Recommendations
       1. Enlist support and cooperation of child
       2. Older children launder their own soiled clothes
          1. Should not be punishment
          2. Allows child's participation and responsibility
    3. Avoid harmful measures
       1. Waking child repeatedly during the night to void
          1. Interferes with sleep
          2. Aggravates child and parent
       2. Punishing or shaming the child for wetting the bed
       3. Intimidating the child or lowering his self esteem
       4. Postponing the child's bedtime to decrease Bedwetting
11. Management: Pharmacologic Therapies
    1. Try to avoid medications if possible
       1. Medications are only effective briefly
       2. Drug tolerance is common
       3. Symptoms are exacerbated after drug is discontinued
       4. Adverse effects are common
       5. If used, avoid in under age 6 years
    2. Medications: Primary Nocturnal Enuresis
       1. Imipramine (or Desipramine)
          1. Not first line due to cardiac arrhythmia risk
          2. As effective as Desmopressin
          3. Higher rate of adverse effects compared with dDAVP
       2. dDAVP (Desmopressin, ADH)
          1. Nasal form is no longer approved for Enuresis due to Hyponatremia (water intoxication)
             1. Can also occur with oral form, but less commonly
             2. Robson (2007) J Urol 178(1):24-30.
          2. For intermittent use on overnights or summer camp
          3. Effective but high relapse rate
    3. Medications: Urge Incontinence or Diurnal Enuresis
       1. Oxybutynin (Ditropan)
          1. Dose: 2.5 to 5 mg orally three times daily
          2. Anticholinergic side effects
          3. Consider in combination with dDAVP
12. Course
    1. Annual resolution rate of Nocturnal Enuresis: 15%
13. References
    1. Cendron (1999) Am Fam Physician 59(5):1205-20
    2. Evans (2001) West J Med 175:108-11
    3. Redsell (2001) Child Care Health Dev 27(2):149-62
    4. Thiedke (2003) Am Fam Physician 67:1499-510
    5. Ullom (1996) Am Fam Physician 54(7):2259-71
    6. Wan (1997) Pediatr Clin North Am 44:1117-31