Understanding Bedwetting (Nocturnal Enuresis) in Children

Bedwetting (NE) is the involuntary loss of urine during sleep in children 5 or older who have never been dry. It can have severe effects on the quality of life for the child and family, including low self-esteem, mood problems, stress, poor peer socialization, and diminished academic performance.

Anxiety from being discovered by siblings or friends also contributes to the child’s level of stress; sleepovers are frequently avoided. The parents also must wake frequently to change sheets and pajamas, and punishment or emotional abuse must be avoided. Nonetheless, nearly all children ultimately gain nighttime bladder control as they get older.

NE may be primary or secondary. Healthy children older than five years who have not had nighttime dryness lasting longer than 6 months have primary NE (PNE); this accounts for roughly 80% of cases. The remaining 20% have secondary NE, the return of bedwetting after at least 6 months of nighttime dryness. Secondary NE includes patients who have at least 1 additional lower urinary tract symptoms such as urgency, frequency, painful urination, or dribbling. It may also have other medical or psychological causes including daytime wetting, constipation, neuropsychiatric conditions, emotional stress, and abuse. In this article, we will principally focus on children with primary NE.

What causes primary NE?

NE occurs when the bladder cannot hold the amount of urine made at night, and the child does not wake up to go to the bathroom. In otherwise healthy children, causes include:

Specific genetic factors: These are frequently found in those with NE. These factors have roles associated with urine production, bladder function, and sleep. If one parent was a bedwetter, around half of their children will be affected; if both were bedwetters, the risk increases to around 75%.

A hormone called antidiuretic hormone or vasopressin (ADH): can play an important role in NE. ADH is mainly produced at night. It naturally decreases the amount of urine made during sleep. Without nighttime ADH there is an abnormally high volume of urine that exceeds the bladder’s ability to prevent bedwetting.

The bladder is small or empties spontaneously before it is filled. Frequently, these children also have problems controlling daytime urination.

The child does not sense bladder fullness: The brain sends signals that control whether the bladder remains relaxed or needs to empty. This “brain-bladder” control usually improves over time.

The child does not awake when there are signals that the bladder will soon empty. Some physicians point out that many deep sleepers do not have NE. However, around half of NE children who have sleep-disordered breathing or sleep apnea will stop wetting when the airway problem is eliminated

Chronic constipation, attention deficit disorders, and other types of developmental delay are frequently associated with NE.

How is PNE managed?

While most PNE eventually goes away, many children and parents want to shorten its duration. Several principal treatment approaches may be used. Children and their parents must be highly motivated and consistent since successful treatment may require weeks or even months. Conventional and more recent types of enuresis treatment provide some flexibility when choosing which is best for the child and the family.

Simple behavioral therapies

These are often used alone or in combination with other therapies as first-line PNE treatment. Reward systems such as star charts for dry nights can earn extra time for favorite activity, a special meal, or buying a book. Other behavioral interventions include arousing the child to go to the bathroom, scheduled awakenings, and bladder training to better control urine retention. Overall, simple behavioral therapy is more effective than no therapy, but not as effective as other interventions such as the use of an alarm or medications. In special cases, more complex behavioral interventions may be recommended. The use of negative reinforcement or punitive measures has repeatedly been shown to be inappropriate, ineffective, or even harmful.

Enuresis Alarms (EA)

These are devices that emit a signal (such as ringing or vibration) to awaken the child as soon as moisture is detected when wetting begins. They are usually worn on underwear or bedclothes. The alarm is a first-line treatment for PNE. It is a form of conditioning therapy. When startled awake, the wetting stops; the child must become completely awake and walk to the bathroom to complete urination. Treatment is successful when the child awakes to go to the bathroom or holds the urine throughout the night. Around 50–80% obtain dryness, although up to 3–6 months of treatment may be necessary.

Comparative studies of the effectiveness of the alarm and desmopressin have varied. Although desmopressin and the alarm have similar treatment responses, within several months after the end of treatment there are significantly lower relapse rates for the alarm compared to desmopressin. Unlike desmopressin, the alarm has few to no adverse effects but the dropout rate for EA is high, most likely due to resistance by the child, non-arousal of either the child or the parents when the alarm is triggered, and the prolonged length of therapy.

Medications

Desmopressin (DDAVP) is the most commonly used drug as a first-line NE treatment. It is a synthetic form of AVP and works similarly. For those children with high urine volumes, desmopressin can reduce the amount of nighttime urine. When used for PNE, around three-quarters have reduced nighttime urine production and about one-third become completely dry. However, around 70% relapse when treatment stops. Desmopressin has potentially serious adverse effects, although its frequency when used for PNE, is low. It begins to work almost immediately and therefore can be used for short-term goals. For instance, when taken before sleepovers or other similar social activities, many children can stay dry through the night.

Imipramine is a tricyclic antidepressant that causes relaxation of the bladder muscles and a decrease in nightly urine volume. This leads to fewer wet nights, particularly in those with small bladders that must empty more frequently. Its effectiveness is roughly similar to desmopressin but significantly lower than the enuresis alarm. The response rate is close to 50%, but only 25% remain dry after treatment stops. Although uncommon in patients taking the correct doses, there are potentially serious adverse effects.

Other non-drug treatments for PNE

Transcutaneous Electrical Nerve Stimulation (TENS) treatment improves symptoms of daytime overactive bladders/incontinence. This has led to NE studies in children with daytime bladder problems. Using skin patches, TENS transmits a small amount of electrical current that affects underlying nerve signaling. The patches can be placed on both sides of the lower spine but their effects on NE have been inconsistent. By contrast, placement over the ankle and lower leg significantly reduces bedwetting frequency and increases bladder urine capacity. This technique may become suitable for home therapy.

Acupuncture (AP) therapies have been tested in PNE patients using several techniques. These include manual AP, laser-enhanced acupuncture (LAP), and electro-acupuncture (EA). Both AP and EA require the insertion of needles at specific body sides. By contrast, LAP does not require needle insertion, but instead applies a low-intensity laser over conventional acupoints. EA uses small electrical currents to enhance stimulation from the AP needles. Research suggests that all 3 techniques may decrease the frequency of PNE. However, there is a very large range of the effectiveness of AP therapies, especially between Chinese and Western research. The true value of AP is obscured by many patient treatment variables.

Overall, it appears that PNE patients treated with any of these techniques have varying improvements in wetting frequency. Combining an AP technique with conventional NE treatments may be superior to each, alone. Although the use and benefit of these AP methods are still under study, they show promise, especially when combined with other therapies.