Publications (5)14.15 Total impact
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Article: Visual and visuospatial development in young children with Williams syndrome.
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ABSTRACT: This study investigated the relation between sensory visual problems and the severity of visuospatial difficulties in a large group of young children with Williams' syndrome (WS). A questionnaire describing visual and associated problems was completed by the families of 108 children with WS and detailed follow-up assessments were conducted, including visual, spatial, motor, visuocognitive, and linguistic tests of 73 of these children (mean age 7 years 3 months; 40 males, 73 females). Children with WS showed a much higher incidence of common paediatric sensory vision problems (strabismus, visual acuity loss, amblyopia, reduced stereopsis) than normally developing children. It was found that delays with respect to age normative values increased with age on all tests. No significant correlation was found between the presence of a visual deficit and the severity of the visuospatial problems, suggesting that the difficulties children with WS have in understanding spatial arrangements are not simply a result of their earlier sensory visual problems. Results confirm the dissociation between visuospatial and language abilities in children with WS, and support the neurobiological model of a split between ventral and dorsal stream processing of visual information with a generalized deficit in dorsal stream processing in young children with WS.Developmental Medicine & Child Neurology 06/2001; 43(5):330-7. · 2.92 Impact Factor -
Article: A specific deficit of dorsal stream function in Williams' syndrome.
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ABSTRACT: Williams' syndrome (WS) is a rare, genetically based disorder of cognitive development. Affected individuals show a severe deficit of spatial cognition but a relative sparing of language and face recognition. To examine the possible neural basis of the spatial deficit, we tested a group of WS children, aged 4-14 years, on two measures specific to dorsal cortical stream function: global motion coherence thresholds, in comparison with an analogous form-coherence test, and visuo-manual accuracy in posting a card through a slot, compared with matching the slot orientation. Deficits in these tasks provide the first evidence of specific involvement in WS of the dorsal stream, the cortical system believed to encode information about spatial relationships and the visual control of action.Neuroreport 06/1997; 8(8):1919-22. · 1.66 Impact Factor -
Article: Visual function and perinatal focal cerebral infarction.
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ABSTRACT: To evaluate the visual function of infants with perinatal cerebral infarction in whom the site and size of the lesion has been determined using magnetic resonance imaging (MRI). Twelve infants with cerebral infarction on MRI were studied with a battery of tests specifically designed to evaluate visual function in infancy. This included tests: for visual attention (fixation shifts); of cerebral asymmetry (optokinetic nystagmus, visual fields); for assessment of acuity (forced choice preferential looking); and neurophysiological measures of vision (phase reversal and orientation reversal visual evoked potential). A considerable incidence of abnormalities on at least one of the tests for visual function used was observed. The presence or severity of visual abnormalities could not always be predicted by the site and extent of the lesion seen on imaging. Early focal lesions affecting the visual pathway can, to some extent, be compensated for by the immature developing brain. These data suggest that all the infants presenting with focal lesions need to be investigated with a detailed assessment of various aspects of vision.Archives of Disease in Childhood - Fetal and Neonatal Edition 10/1996; 75(2):F76-81. · 3.05 Impact Factor -
Article: Pharmacokinetics of zidovudine and dideoxyinosine alone and in combination in children with HIV infection.
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ABSTRACT: The pharmacokinetics of zidovudine (ZDV) and dideoxyinosine (ddI) were investigated following administration alone and in combination to children with symptomatic HIV disease. The children were studied on three separate occasions and received ZDV 200 mg m-2, ddI 100 mg m2 or a combination of ZDV 200 mg m-2 plus ddI 100 mg m-2. The administration of ddI did not significantly alter ZDV pharmacokinetics. The area under the curve (AUC) was 14.2 +/- 4.9 and 15.8 +/- 7.2 mumol l-1 h and elimination half-life (t1/2, z) was 1.4 +/- 0.4 and 1.2 +/- 0.2 h in the absence and presence of ddI respectively. The peak concentration (Cmax), time to peak (tmax) and apparent oral clearance (CL/F) were also unchanged. The administration of ZDV had no significant effect on ddI Cmax, tmax, t1/2,z, or CL/F, however the AUC was reduced by 19% (5.9 +/- 2.9 to 4.8 +/- 2.7 mumol l-1 h; P < 0.05). This study suggests that ZDV and ddI may be co-administered to children with symptomatic HIV disease without concern of a clinically relevant pharmacokinetic drug interaction.British Journal of Clinical Pharmacology 05/1995; 39(5):527-30. · 2.96 Impact Factor -
Article: Antibody responses to Haemophilus influenzae type b and Streptococcus pneumoniae vaccines in children with human immunodeficiency virus infection.
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ABSTRACT: Antibody responses to Haemophilus influenzae type b (Hib) conjugate (ActHIB; Pasteur Merieux) and pneumococcal (Pneumovax II; Morson) vaccines were measured in 56 infected children (VI) and 44 uninfected children (U) older than 18 months of age, born to human immunodeficiency virus-positive mothers. Preimmunization, 21% U and 20% VI had protective concentrations of anti-Hib polysaccharide antibodies. Postimmunization, 100% U and 86% VI achieved protective titers (P = 0.008). The geometric mean increase in anti-Hib polysaccharide antibody was 7.6 (95% confidence interval, 3.5 to 16.3; P = 0.0001) times higher in U than in VI children after adjusting for age and ethnicity. Sixty-one percent U compared to 54% VI showed a 2-fold increase in antibody levels to at least one of the four pneumococcal vaccine serotypes (3, 6, 19, 23) measured (P = 0.4). For both vaccines there was a significant trend toward poorer responses in children with acquired immunodeficiency syndrome but no correlation with age adjusted CD4 counts. These data suggest that human immunodeficiency virus-infected children should be immunized with these polysaccharide vaccines early in the course of their disease.The Pediatric Infectious Disease Journal 03/1995; 14(2):129-35. · 3.58 Impact Factor
