By Amy Norton
New York - Children's behavioural problems, including symptoms of attention-deficit hyperactivity disorder (ADHD), sometimes improve after they have their tonsils removed, a new study has found.
The findings, published in the journal Pediatrics, support the theory that nighttime breathing problems - and consequently poor sleep - contribute to some children's behavioural difficulties during the day.
When the tonsils at the back of the throat become enlarged, they can obstruct the breathing passages. Chronic breathing problems are a chief reason tonsillectomy is performed in children.
The new study followed 78 children, ages 5 to 13, who were scheduled to undergo tonsillectomy, most often due to suspected nighttime breathing problems.
Overnight sleep tests performed before surgery confirmed that half had obstructive sleep apnoea, a disorder in which breathing stops and starts repeatedly during the night - typically causing loud snoring and, often, daytime sleepiness.
The children also happened to have a high rate of behavioural problems, as measured from parents' reports and clinical assessments.
A full 28 percent were diagnosed with ADHD, compared with only two percent of 27 children who served as a comparison group.
One year after the surgery, however, the children's behavioural and sleep problems were no greater than those of their peers. The rate of sleep apnoea fell from 50 percent to 12 percent, and symptoms of sleepiness improved.
The particularly striking finding, according to the researchers, was that half of the children who had been diagnosed with ADHD before surgery no longer had the disorder one year later.
This doesn't mean that tonsillectomy is a "magic pill" for ADHD, Dr Ronald Chervin, the study's lead author, told Reuters Health.
But parents and doctors may want to consider the possibility of a sleep disorder when a child is either hyperactive or excessively sleepy during the day, according to Chervin, who directs the sleep disorders centre at the University of Michigan in Ann Arbor.
This is especially important when a child has a tell-tale breathing symptom such as loud, chronic snoring or a habit of breathing through the mouth.
"I think a substantial minority of children with ADHD could benefit from having sleep problems addressed," Chervin said.
Surprisingly, though, sleep problems and behavioural problems did not necessarily match up among children in this study.
Kids without full-blown sleep apnoea were just as likely to have ADHD symptoms as those with the sleep disorder, and both groups showed similar improvements after having their tonsils removed.
This is unexpected, according to Chervin, because children with greater nighttime breathing problems should, in theory, have a higher risk of behavioural symptoms.
Chervin said he suspects the finding reflects a limited ability of current tests to detect milder nighttime breathing problems. He and his colleagues are launching a study that will investigate newer measures of sleep-disordered breathing in children.
SOURCE: Pediatrics, April 2006.