Neuropsychologic performance in school-aged children with sickle cell disease: a report from the Cooperative Study of Sickle Cell Disease.

OBJECTIVES: To compare the results of serial neuropsychologic testing in children with sickle cell disease with the results of serial magnetic resonance imaging (MRI) examinations, particularly to evaluate neuropsychologic function in the absence of overt stroke. STUDY DESIGN: In the Cooperative Study of Sickle Cell Disease, serial neuropsychologic and MRI tests were performed in 373 patients (255 with hemoglobin SS and 118 with hemoglobin SC), 6 to 18 years of age. MRI of the brain and a neuropsychologic battery that included the Wechsler Intelligence Scale for Children (WISC-R or WISC-III) and the Woodcock-Johnson Math and Reading Achievement Tests were performed concurrently and repeated every 2 to 3 years. A silent infarct was defined as an MRI finding of increased signal intensity on T(2) imaging in a patient without a history of stroke. RESULTS: Twenty-seven patients, all with hemoglobin SS, had overt strokes and 62 had silent infarcts (52 with hemoglobin SS). Patients with hemoglobin SS and silent infarcts had significantly lower scores for math and reading achievement, Full-Scale IQ, Verbal IQ, and Performance IQ, when compared with those with normal MRI findings. In children with hemoglobin SS and normal MRI findings, the scores for Verbal IQ, math achievement, and coding (a subscale of Performance IQ) declined with increasing age. CONCLUSIONS: School-aged children with sickle cell disease had compromised neuropsychologic function in the presence of silent infarcts. In addition, they had declines in performance in certain areas of function over time. Therapeutic interventions that prevent or lessen cognitive impairment are needed before school entry for children with sickle cell disease.

The effects of HIV on cognitive and motor development in children born to HIV-seropositive women with no reported drug use: birth to 24 months.

OBJECTIVE: This study documents delays in the mental and motor functioning of infants perinatally infected with human immunodeficiency virus (HIV) while controlling for confounding effects of prenatal drug exposure, ethnicity, socioeconomic status, and maternal separation and death. METHODS: The cognitive and motor development of 126 infants born to nondrug-using, HIV-seropositive Haitian women was assessed at 3-month intervals through 24 months of age using the Bayley Scales of Infant Development. By 18 months of age, 28 of the infants were diagnosed as HIV-infected, and the 98 uninfected infants served as a control group. The infected and uninfected infants did not differ with respect to mean gestational age, birth weight, ethnicity, or rates of maternal separation and death. RESULTS: By 3 months of age, the mean mental and motor scores of the infected infants were significantly lower than those of the uninfected controls. Furthermore, the initial differences between the two groups increased over time, as many of the infected infants became increasingly delayed. Although the infected infants tended to perform more poorly than the uninfected infants, nearly one third of the infected infants exhibited relatively normal cognitive development and half demonstrated relatively normal motor development. CONCLUSIONS: Over the first 24 months of life, the mean rate of development of HIV-infected infants is significantly slower than that of noninfected infants born to seropositive mothers. This occurs even when the effects are not confounded with those of prenatal drug exposure.