top of page



Between 40,000 and 120,000 U.S. and Canadian children are born each year with global developmental delay (mental retardation). While incurable, early testing and diagnosis of global developmental delay may help determine the cause of the disorder, and assist physicians and parents in developing a plan for treatment.

The guidelines are based on a review of all of the scientific studies on global developmental delay published from 1980 to 2000. The guidelines are published in the February 11 issue of Neurology, the scientific journal of the American Academy of Neurology.

"Careful evaluation of the research showed that some of the newer tests, such as cytogenetic studies, should be used more often than they are, and others, such as routine metabolic screening, do not need to be used on every child with global developmental delay," said child neurologist Michael Shevell, MD, Montreal Children's Hospital, who is a co-author of the guidelines.

Among the guideline recommendations:
    •    Routine cytogenetic studies and molecular testing for the Fragile X mutation
    •    Serum lead level evaluations restricted to those with risk factors for excessive lead exposure
    •    Electroencephalograms are not needed unless there is a history of seizures
    •    Neuroimaging is recommended, especially if abnormalities are found on physical exam
    •    Routine metabolic screening is not needed for the initial evaluation
    •    Thyroid tests are not needed if the child had screening as a newborn, unless there are signs of thyroid dysfunction
    •    Rett syndrome should be considered in girls with unexplained moderate to severe developmental delay

Shevell noted that while many of these disorders have no specific therapy, it is important to determine the cause of the disorder. "An accurate diagnosis has specific implications for treatment, prognosis, management of related conditions, and assessment of the risk of the disorder recurring in the family," he said. "Making a diagnosis also limits additional unnecessary testing and empowers the family to plan for their child."

Global developmental delay affects one to three percent of all children under age 5. It is defined as significant delay in two or more of these developmental areas: gross/fine motor, speech/language, cognition, social/personal, and activities of daily living.
Guidelines are not a substitute for the experience and judgement of a physician and are developed to enhance the physicians' ability to practice evidence-based medicine.

The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research.

Source: Science Blog. Copyright © 2004


bottom of page