Development and validation of a test battery to assess subtle neurodevelopmental differences in children

There is increasing concern over the impact of low-dose exposures to environmental chemicals on children's neurobehavioral function. To determine subtle alterations in children's function, it is necessary to move beyond global measures such as IQ and employ tests that can detect small, subtle neurodevelopmental effects across a broad array of behavioral domains. We investigated the sensitivity and specificity of a battery of 63 neurodevelopmental tests or tasks designed to detect outcomes representing the type of subtle neurodevelopmental deficits caused by exposure to neurotoxicants in school-aged children. We studied Neonatal Intensive Care Unit (NICU) graduates, a population known to be at risk for both major and mild anomalies in perception, motor functioning, learning, memory and cognition. This population served as a surrogate to evaluate the capacity of these tests and tasks to predict such deficits. The subjects' histories of previous exposures to any environmental neurotoxicants was not ascertainable, but exposures to elevated levels was not suspected. Over one-third of the 63 measures proved capable of detecting pre-diagnosed lower IQ, the presence of a learning disability (LD) or a neonatal risk profile with at least 70% sensitivity and specificity. Some tests were differentially sensitive and specific, depending upon the presence or absence of one or more of several covariates such as gender, age, hearing status, or familiarity with computers. Tests were also eliminated from the battery if they were affected by too many covariates. We propose calling the final battery of tests that are specific and sensitive to subtle neurodevelopmental changes the Rochester test battery (RTB). Further studies are needed to confirm the capability of the RTB to detect subtle changes associated with neurotoxic exposures.