Screen Helps Detect Global Developmental Delay : Child-development professionals advocate an in-depth process called developmental surveillance.


BLAINE, WASH. — Pediatricians and family physicians need to be alert for the signs of global developmental delay in young children.

And when these signs are found they must be carefully followed up, Forrest C. Bennett, M.D., said at a conference sponsored by the North Pacific Pediatric Society.

Global developmental delay (GDD) refers to a constellation of delays in several areas, including motor, language, and cognitive skills, as well as in socioemotional development. Many of these children also have diffuse hypotonia as well.

“You can't find GDD in the DSM, but it is a term that most developmentalists, neurologists, and geneticists use,” said Dr. Bennett of the University of Washington (Seattle). “When you have low-tone kids and they present with development that's something like half their chronologic age in the first 3 years of life, that's a concerning presenting constellation.”

By the time these children reach school age, the most common ultimate diagnosis will be mental retardation. A smaller number of children will be diagnosed with autism spectrum disorders or pervasive developmental disorder. An even smaller number of children are able to close the gap, emerging with specific learning disorders. The least common outcome is a child who overcomes the delay entirely, returning to the normal developmental track.

“Parents ask, 'Doctor, have you ever seen a child like this turn out just fine?' And I try to look at them honestly and say, 'It's possible [but] I don't see it a lot,'” Dr. Bennett said.

Pediatricians have typically screened for GDD at well-child visits by using parental questionnaires such as the PDQ (Prescreening Development Questionnaire) and ASQ (Ages & Stages Questionnaire), but some child-development professionals say that screening isn't enough. They advocate a more in-depth process called developmental surveillance.

“[Developmental surveillance] means asking the right questions at the right times, knowing that some milestones are more important than others,” Dr. Bennett said. “It's really important to be sitting by 9 months, to have a pincer grasp by 12 months, to understand body parts at 18 months, … to put two words together at 2 years of age. In a busy office, some milestones are just more important and a little more relevant than others.”

In addition, “You don't think developmentally just at the well-child visit. You see the family in the parking lot at the grocery store [and] you can whip a few developmental questions in there.”

Developmental surveillance is not always practical, Dr. Bennett said. He admitted that he often forgets the milestones, even though he's raised three children of his own. And, in busy urban settings, it's not likely that physicians can count on running into their patients at the grocery store or anywhere else.

As a reminder to ask developmental questions, Dr. Bennett has placed a laminated poster on the wall of the exam room with developmental milestones based on the Denver II, an instrument intended to be used by professionals.

He also recommended having the parents complete the PDQ II, which consists of 10–12 age-appropriate questions and takes 4–5 minutes, or the ASQ, a 35-item questionnaire that takes 10–15 minutes. These can be mailed to the parents in advance of a well-child visit or handed to them in the waiting room. Many similar instruments exist, but most physicians use “home-grown” checklists, Dr. Bennett said.

This screening is just a first step if any red flags present themselves. “Screening does not make you a psychologist,” Dr. Bennett said. “It should be just like when we find an abdominal mass unexpectedly. That triggers a whole bunch more questions, a much more careful physical exam, you probably order some laboratory [tests], and then perhaps you refer to subspecialists.”

Assess the child's growth, health, vision, hearing, and medications in terms of their impact on development and behavior. Search for contributing factors to the problem by characterizing its nature, its timing, and whether it seems to be static or progressive.

Dr. Bennett finds that asking parents, “When did you first worry,” yields some good information. “Unless they bring in the baby book, a lot of parents don't remember exactly when the child sat, crawled, pulled up, stood alone,” he said. “But most parents in my experience are pretty good at remembering when they first got the sick feeling in their gut that something wasn't quite right about this kid.”

For example, they may have noticed that in utero, the child didn't move as much as their other children; or in the nursery they may have had to wake the child to feed; or at 8 weeks of age, they couldn't get a responsive smile.


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