Night blindness

Disease Description (Causes and Symptoms)

• Definition: Enuresis is a condition in which a person unconsciously urinates during sleep despite being at an age when bladder control is possible (generally after age 5). Diagnosis is usually considered when it occurs frequently, 2 or more times per week.
• Classification: It is divided into primary enuresis (never having achieved nighttime dryness since birth) and secondary enuresis (recurrence after having remained dry for at least 6 months).
• Main causes and pathophysiology:
  • Genetic susceptibility (increased risk in children with a family history; some associated genes have been reported)
  • Delayed maturation of bladder function (immature bladder capacity/control ability)
  • Insufficient nighttime antidiuretic hormone (ADH) secretion → large amounts of urine during sleep (nocturnal polyuria)
  • Arousal problems (being unable to wake up and urinate) — however, sleep architecture is often normal
  • Rarely, structural urinary tract diseases (urethral stricture, vesicoureteral reflux, etc.) cause voiding dysfunction both day and night (in this case, it is complicated enuresis)
• Main symptoms:
  • Urination during sleep after age 5 (nocturnal enuresis)
  • If daytime urinary incontinence or voiding dysfunction is also present, complicated enuresis may be suspected (additional evaluation is needed)

Treatment Methods

• General principles:
  • Recommended time to start treatment: generally after age 5 or before entering elementary school. Since the spontaneous resolution rate is approximately 15% per year, the course according to age should be considered.
  • Basic lifestyle management: limiting fluids after the evening, urinating before bedtime, regular bowel movements (correcting constipation), etc. Parental criticism and punishment should be avoided, and positive reinforcement is recommended.
• Pharmacological treatment:
  • Desmopressin (an antidiuretic hormone analog): Effective for nocturnal polyuria (response rate approximately 60–80%). However, recurrence is common after discontinuation. Since there is a risk of hyponatremia, dosage and fluid restriction instructions must be followed.
  • Imipramine (a tricyclic antidepressant): Effectiveness is approximately 60–70%. Its exact mechanism is unknown. The recurrence rate is high after discontinuation, and caution is needed in children because of cardiovascular adverse effects (anticholinergic effects and risk of arrhythmia).
  • Oxybutynin (an antimuscarinic agent): It is generally not used for monosymptomatic enuresis. It may be considered when symptoms of overactive bladder (frequency, urgency, and daytime urinary incontinence) are present. Adverse effects include dry mouth, constipation, flushing, and dizziness.
• Behavioral / nonpharmacological treatment:
  • Enuresis alarm (alarm therapy): When the moisture sensor is activated, an alarm induces arousal and promotes a conditioned reflex. It is effective in children aged 6–7 years and older; approximately 80% improve after 6 months of treatment, with a recurrence rate of approximately 30%. Family cooperation is needed during the first few weeks.
  • Motivation/positive reinforcement (stickers, praise, etc.): Encourages gradual improvement over the long term.
  • Scheduled awakenings: May be used as temporary support.
• Additional tests and procedures:
  • If daytime urinary incontinence, frequency, weak urinary stream, residual urine, recurrent urinary tract infections, or constipation is present, detailed testing such as ultrasonography, voiding cystourethrography, and urodynamic testing is needed.
• Precautions (during treatment):
  • Avoid punishment and inducing shame (due to psychological adverse effects).
  • When administering desmopressin, restrict fluid intake and monitor for electrolyte abnormalities (especially at the beginning).
  • When using imipramine, pay attention to electrocardiography (especially in patients with a history of heart disease) and adverse effects.
  • For alarm therapy, the family must agree to wake up during the night, and the initial effect may be delayed.

Checklist Before an Outpatient Visit (Including Example Questions)

• Items/records to prepare:
  • List of medications currently being taken (name and dosage)
  • Recent test results (urinalysis, blood tests, ultrasonography, etc., if available)
  • Voiding diary (at least 2–7 days): number of daytime/nighttime urinations, approximate urine volume, frequency of bedwetting, and times of fluid intake
  • Whether constipation is present and bowel habits (stool continence and frequency)
  • History of urinary tract infections, surgical history, and history of heart or neurological disease
  • Sleep habits (bedtime and problems related to sleep depth)
• Main items the doctor may ask about during the consultation (it is useful for the patient/guardian to record these in advance):
  • When bedwetting began and its pattern (whether primary or secondary)
  • Whether urinary incontinence or frequency occurs during the day
  • Family history (whether the parents had enuresis)
  • Medication and allergy history
  • Social and emotional stress factors

Examples of General Questions to Ask the Doctor

• "What type of enuresis does my child have (primary/secondary, simple/complicated)?"
• "What initial tests are recommended, and why?"
• "What first-line treatment (lifestyle management, medication, or alarm therapy) do you recommend for my child, and what are the expected effects and duration?"
• "What are the main adverse effects of each medication, and how are they monitored?"
• "How likely is recurrence during treatment or after discontinuation?"

Examples of Disease-Specific Questions

• "My child produces a relatively large amount of urine at night (nocturnal polyuria). Is desmopressin appropriate? How should fluid restriction be managed when using it?"
• "My child also has frequency/urgency during the day (or severe constipation). Are additional tests or medications (e.g., oxybutynin) and bowel treatment needed?"