Brief report: relationship between HIV infection and WPPSI-R performance in preschool-age children

Neurocognitive outcomes of children exposed to and living with HIV aged 3-5 years in Kilifi, Kenya

Introduction

Globally, 1.7 million children are living with HIV, with the majority of them residing in sub-Saharan Africa. Due to reduced rates of vertical transmission of HIV, there is an increasing population of children born to HIV-infected mothers who remain uninfected. There is a growing concern around the development of these children in the antiretroviral therapy era. This study examined the neurocognitive outcomes of children who are HIV-exposed infected (CHEI), HIV-exposed uninfected (CHEU) and HIV-unexposed uninfected (CHUU) and explored the relationship between child neurocognitive outcomes and child's biomedical and caregivers' psychosocial factors.

Methods

CHEI, CHUU and CHEU aged 3-5 years and their caregivers were recruited into the study. Neurocognitive outcomes were assessed using a validated battery of assessments. One-way analysis of variance and covariance (ANOVA and ANCOVA) were used to evaluate differences among the three groups by neurocognitive outcomes. Linear regression models were used to investigate the association between child neurocognitive outcomes and biomedical factors (nutritional status, HIV disease staging) and caregivers' psychosocial factors [symptoms of common mental disorders (CMDs) and parenting behaviour].

Results

The study included 153 children and their caregivers: 43 (28.1%) CHEI, 52 (34.0%) CHEU and 58 (39.9%) CHUU. ANOVA and ANCOVA revealed a significant difference in cognitive ability mean scores across the child groups. Post hoc analysis indicated that CHEU children had higher cognitive ability mean scores than the CHUU group. Better nutritional status was significantly associated with higher cognitive ability scores (β = 0.68, 95% CI [0.18-1.18], p = 0.008). Higher scores of CMDs were negatively associated with inhibitory control (β = -0.28, 95% CI [-0.53 to 0.02], p = 0.036). While comparing HIV stages 2 and 3, large effect sizes were seen in working memory (0.96, CI [0.08-1.80]) and cognitive ability scores (0.83 CI [0.01-1.63]), indicating those in stage 3 had poor performance.

Conclusions

Neurocognitive outcomes were similar across CHEI, CHEU and CHUU, although subtle differences were seen in cognitive ability scores where CHEU had significantly higher cognitive mean scores than the CHUU. Well-designed longitudinal studies are needed to ascertain these findings. Nonetheless, study findings underscore the need for strategies to promote better child nutrition, mental health, and early antiretroviral therapy initiation.

Clinico-Immunological Status and Neurocognitive Function of Perinatally Acquired HIV-Positive Children on cART: A Cross-Sectional Correlational Study in South Africa

Despite the undisputed benefits of combination antiretroviral therapy (cART), perinatally acquired human immunodeficiency virus (PHIV) children on treatment often present with a spectrum of neurological deficits known as HIV-associated neurocognitive impairment. Even higher CD4 cell count does not seem to prevent the development of neurocognitive impairment in children with PHIV. While CD4 cell count has shown to have the greatest prognostic value, its association with neurocognitive abilities remains to be clarified. This study aimed at determining the correlation between plasma CD4+ lymphocyte and neurocognitive function in children with PHIV on cART. In total, 152 purposively recruited hospital-based sample of children with PHIV on cART, aged 3 years to 7 years 6 months (mean age, 63.13 months), underwent neurocognitive assessment using the Wechsler Preschool and Primary Scale of Intelligence, Third Edition. Immunological status of each child was based on the plasma CD4+ lymphocyte levels. The mean CD4+ lymphocyte cell count at the time of neurocognitive assessment was 1,259.85 cells/mm3 (mean range, 139-2,717 cells/mm3), with significant age difference on CD4+ lymphocyte count levels [F (2, 149) = 13.58, p = 0.000]. CD4+ lymphocyte counts was significantly correlated with subdomains of neurocognitive function scores of task that measures working memory, processing speed, and perceptual reasoning. Global cognitive ability (Full Scale Intellectual Quotient) had no significant association with immunological status of the children. The findings support an association between immunological status of PHIV infection and executive function task. These neurocognitive faculties are critical for learning, school readiness and success in early childhood, and ultimately treatment adherence in adolescence. The need for early identification of neurodevelopment deficits in children, even when on cART, is crucial because early psychosocial and neurorehabilitative interventions can lead to better outcome for children with PHIV.

The Association of Home Environment and Caregiver Factors With Neurocognitive Function in Pre-school- and School-Aged Perinatally Acquired HIV-Positive Children on cART in South Africa

Background: Children with perinatally acquired HIV in low resource settings are at risk for neurocognitive impairments not only due to the direct effects of HIV on the brain and in utero ART exposure but also due to factors associated with their environment. Thus, the aim of this study was to examine the association between home environment and caregiver factors and the neurocognitive function of pre-school- and-school-aged HIV-positive South African children from low resource rural communities. Materials and Methods: The Wechsler Preschool and Primary Scale of Intelligence-III was administered to assess the neurocognitive functioning of 152 purposively sampled perinatally acquired HIV-positive children on cART, aged 3 years to 7 years 6 months (mean age 63.13 months). The primary caregivers (n = 152) completed the Home Screening Questionnaire to assess the quality of the home-environment of the children. Results :The results showed that unfavorable environment, caregiver type, and quality of stimulation in the home were negatively associated with the neurocognitive development of perinatally HIV-positive children on cART. Most of the HIV-positive children (n = 95) were under the care of an extended relative. Older HIV-positive boys, reared by biological mothers, who also lived in suboptimal and poor quality home-environments had poorer neurocognitive function when compared to HIV-positive children reared by non-biological (extended relatives) caregivers, [F _(2,149) = 14.42, p < 0.001]. Conclusion: The child's early home environment is associated with general neurocognitive development, which highlights the need for early psychosocial interventions that can promote better cognitive outcomes among children living with HIV.

Cognitive Deficits in HIV Infected Children

BACKGROUND AND OBJECTIVES

Children infected with HIV are at risk for significant neurological and neuropsychological problems. This study is aimed at identifying cognitive deficits in HIV-infected children and to compare them with equal number of normal controls.

MATERIALS AND METHODS

Twenty children with HIV infection who are currently on antiretroviral therapy were recruited. They were assessed for their intelligence using Malin's Intelligence Scale for Indian Children and also evaluated for their cognitive abilities with a comprehensive neuropsychological battery. They were matched with equal number of normal controls.

RESULTS

HIV-infected children have shown substantial impairments in the domains of attention, language, verbal learning and memory, visuomotor functions, fine motor performance, and executive functions.

CONCLUSION

HIV-infected children have average intelligence, but they performed poorly on several neuropsychological measures.

The burden and predictors of cognitive impairment among 6- to 8-year-old children infected and uninfected with HIV from Harare, Zimbabwe: a cross-sectional study

With long-term survival of children infected with HIV, information on cognitive function at school age is needed. To determine cognitive function among 6- to 8 year-old children exposed to HIV and to assess factors associated with cognitive impairment, we conducted a cross-sectional study from October 2010 to December 2011 among children whose mothers participated in a national HIV prevention program in Harare. Cognitive function was assessed using the McCarthy Scales of Children's Abilities (MSCA). Of the 306 assessed children, 32 (10%) were HIV infected, 121 (40%) exposed uninfected, and 153 (50%) unexposed uninfected. The mean (SD) General Cognitive Index for the whole study group was 82 (15). An overall of 49 (16%) out of the 306 children had cognitive impairment with no difference in general cognitive function among the three groups. Children with HIV infection scored lowest in perceptual performance domain, p = .028. Unemployed caregivers, child orphanhood and undernutrition were associated with impaired cognitive performance in univariate analysis. In multivariate analysis, caregiver unemployment status remained a factor associated with cognitive impairment with an ODDS ratio of 2.1 (95% CI 1.03-3.36). In a cohort of 6- to 8-year-olds, HIV infection did not show evidence of significant difference in general cognitive function. Children infected with HIV had major deficits in perceptive performance. Lower socioeconomic status was associated with cognitive impairment. In resource-constrained settings, strategies aimed at poverty alleviation and good nutritional management should complement early infant diagnosis and treatment of HIV in order to optimize neurocognitive potential.

Intra-uterine exposure to maternal opiate abuse and HIV: the impact on the developing nervous system

BACKGROUND

Both intra-uterine exposure to maternal drugs and HIV are known to adversely affect the developing central nervous system.

AIMS

(1) To describe the quality of GMs in infants who were intra-uterinely exposed to maternal opiate abuse and HIV; and (2) to analyze to what extent (a) perinatal events, (b) status of HIV-infection, and (c) the quality of GMs are associated with the neurodevelopmental outcome at 2 to 3years of age.

PATIENTS AND METHOD

Seventy-seven children intra-uterinely exposed to both maternal opiate abuse and HIV in utero (41 boys and 36 girls; 39 born preterm) were videoed twice: first during the first 2months after term (writhing GMs) and again at 3-5months (fidgety GMs). Neurodevelopmental outcome was assessed at 2-3years of age.

RESULTS

Thirty-eight infants showed abnormal writhing GMs; 25 infants had abnormal or absent fidgety movements; 22 children had an adverse neurodevelopmental outcome. The association between GM trajectories and outcome revealed a Cramer-V=0.75 (p<0.001). Those infants with active HIV-infection (n=10) did not differ from the 67 infants who were HIV-exposed but uninfected with respect to their GM quality or outcome.

CONCLUSIONS

Serial assessment of GMs in infants who were intra-uterinely exposed to maternal opiates and to HIV can be utilized for early identification of infants at a higher risk for later deficits and needing early intervention.

Neurodevelopment in children born to HIV-infected mothers by infection and treatment status

BACKGROUND

We reviewed the impact of HIV, HIV exposure, and antiretroviral therapy/prophylaxis on neurodevelopmental outcomes of HIV-infected and HIV-exposed-uninfected infants and children.

METHODS

A literature search of Medline, Embase, PsychINFO, Web of Science, PubMed, and conference Web sites (1990-March 2011) using the search terms, infant, child, HIV, neurodevelopment, cognition, language, and antiretroviral therapy, identified 31 studies of HIV/antiretroviral exposure using standardized tools to evaluate infant/child development as the main outcome. Articles were included if results were reported in children <16 years of age who were exposed to HIV and antiretrovirals in fetal/early life, and excluded if children did not acquire HIV from their mothers or were not exposed to antiretrovirals in fetal/early life.

RESULTS

Infants who acquired HIV during fetal and early life tended to display poorer mean developmental scores than HIV-unexposed children. Mean motor and cognitive scores were consistently 1 to 2 SDs below the population mean. Mean scores improved if the infant received treatment before 12 weeks and/or a more complex antiretroviral regimen. Older HIV-infected children treated with highly active antiretroviral therapy demonstrated near normal global mean neurocognitive scores; subtle differences in language, memory, and behavior remained. HIV-exposed-uninfected children treated with antiretrovirals demonstrated subtle speech and language delay, although not universally.

CONCLUSIONS

In comparison with resource-rich settings, HIV-infected and HIV-exposed-uninfected infants/children in resource-poor settings demonstrated greater neurodevelopmental delay compared with HIV-unexposed infants. The effects on neurodevelopment in older HIV-infected children commenced on antiretroviral therapy from an early age and HIV-exposed-uninfected children particularly in resource-poor settings remain unclear.

Neurologic and neurobehavioral sequelae in children with human immunodeficiency virus (HIV-1) infection

The range and extent of neurologic and neurobehavioral complications of human immunodeficiency virus (HIV-1) infection in children are under-described. Seventy-eight children with HIV-1 infection (32 females) were assessed for neurologic complications. Forty-six children had abnormal neurology examinations. Thirty-three children had global pyramidal tract signs, 5 had a hemiparesis, 4 had peripheral neuropathy, 18 had visual impairment, and 5 had hearing impairment. Thirty-nine of 63 children over 1 year of age had neurobehavioral problems. Of 24 children with HIV encephalopathy, 74% had severe immunosuppression and 45% were not receiving antiretroviral therapy. Twelve children had prior opportunistic central nervous system infections, and 9 had epilepsy. Diverse neurologic and neurobehavioral deficits are common in children with HIV-1 infection. Children with severe immunosuppression, who were not receiving antiretroviral therapy, were growth impaired and less than 1 year of age, were at greatest risk for developing neurologic complications.

Effects of perinatal HIV infection and early institutional rearing on physical and cognitive development of children in Ukraine

To study the effects of perinatal HIV-1 infection and early institutional rearing on the physical and cognitive development of children, 64 Ukrainian uninfected and HIV-infected institutionalized and family-reared children were examined (mean age = 50.9 months). Both HIV infection and institutional care were related to delays in physical and cognitive development, with a larger effect of the rearing environment. Family care, even of compromised quality, was found to be more favorable for children's physical and cognitive development than institutional care. The impact of the quality of child care on physical and cognitive development is discussed in light of future interventions.

Poor cognitive functioning of school-aged children in thailand with perinatally acquired HIV infection taking antiretroviral therapy

Neurocognitive outcome is an essential aspect of treatment for HIV-infected children. This study is aimed at assessing cognitive functioning in school-aged HIV-infected children and the change after receiving antiretroviral therapy (ART). We conducted a prospective cohort study of HIV-infected Thai children from 6-12 years of age compared with HIV-affected (children of HIV-positive mothers who were not infected with HIV), and normal control groups. Wechsler Intelligence Scale for Children-III (WISC-III) was administered at enrollment and 30 months of follow-up. Semistructured interviews of primary caregivers were performed. From April to October 2003, 121 children were enrolled; 39 HIV-infected, 40 HIV-affected, and 42 control children with a median age of 9.3 years. The HIV-infected group had a mean (standard deviation [SD]) CD4 percentage of 13.8% (5.3), 87% of whom had been receiving ART for a median of 35 weeks. At the first cognitive assessment, the mean (SD) of full-scale intelligence quotient (FSIQ) was 79 (13) and 88 (10) among HIV-infected and HIV-affected children, which was statistically lower than that of the control group at 96 (13; p < 0.01). The proportion of children with average intelligence level (FSIQ > 90) among 3 groups were 21%, 49%, and 76%, respectively (p < 0.01). At 30 months of follow-up, the HIV-infected group had a mean (SD) CD4 percentage of 25.6% (5.6); 77% had undetectable viral load. The mean (SD) FSIQ of children among three groups were 75 (12), 85 (12), and 91 (12), respectively. Compared with the baseline assessment, the verbal scale score significantly decreased in all groups, including the controls, whereas the performance scales did not change. In conclusion, school-aged HIV-infected children have lower cognitive function than HIV-affected and normal children. Cognitive function was not improved after receiving ART. Further study to address whether early ART can preserve cognitive functioning among HIV-infected children should be explored.

A review of pediatric HIV effects on neurocognitive development

There are 2.3-million children infected with HIV worldwide. Medical advances and therapies have increased the life expectancy of HIV-infected children and improved their quality of life. This article reviews the HIV literature over the past 15 years related to children's development including: (1) the effects of HIV on the neurocognitive development of children; (2) the relationship between disease status and developmental functioning in HIV-infected children; and (3) the influence of the environmental context on HIV-infected children's development. As children with HIV continue to live longer, they will become a population of children with special needs. This paper reflects the current evidence of these needs and explores the interventions available to HIV-infected children.

Dominican Children with HIV not Receiving Antiretrovirals: Massage Therapy Influences their Behavior and Development

Forty-eight children (M age = 4.8 years) infected with HIV/AIDS and living in the Dominican Republic were randomly assigned to a massage therapy or a play session control group. The children in the massage therapy group received two weekly 20-min massages for 12 weeks; the children in the control group participated in a play session (coloring, playing with blocks) for the same duration and length as the massage therapy group. Overall, the children in the massage therapy group improved in self-help abilities and communication, suggesting that massage therapy may enhance daily functioning for children with HIV/AIDS. Moreover, the HIV infected children who were six or older also showed a decrease in internalizing behaviors; specifically depressive/anxious behaviors and negative thoughts were reduced. Additionally, baseline assessments revealed IQ equivalence below normal functioning for 70% of the HIV infected children and very high incidences of mood problems (depression, withdrawn) for 40% of the children and anxiety problems for 20% of the children, suggesting the need for better monitoring and alternative interventions in countries with limited resources to improve cognition and the mental health status of children infected with HIV/AIDS.

Neurocognitive function profile in HIV-infected school-age children

OBJECTIVES

Evaluation of neurocognitive function of school-age children with HIV.

DESIGN

Cross-sectional observational study.

METHODS

Twenty-two children (median age 9.46 years) with perinatally acquired HIV infection were administered a global intelligence test and tests from the Amsterdam Neuropsychological Tasks (ANT) program. The relationship between various patient-, disease- and treatment factors and neurocognitive outcome variables was examined.

RESULTS

Compared with age-appropriate norms, mean IQ of the HIV-infected children was in the average range. However, the HIV-infected children performed poorer on several neuropsychological tests compared with age-appropriate norms. Executive function (attentional flexibility, visuospatial working memory) and processing speed emerged as the most sensitive cognitive measures in relation to HIV disease. The correlational analyses resulted in only two significant outcomes, showing that higher CD4% at initiation of highly active antiretroviral therapy (HAART) and longer treatment duration were associated with better working memory function and attentional control, respectively.

CONCLUSIONS

These exploratory data suggest that subtle neurocognitive impairments may exist in HIV-infected school-age children, in particular characterized by compromised executive function and slowed information processing. Further research with larger sample sizes is needed to confirm these findings.

Does HIV-1/AIDS-associated frontotemporal neuropathology following perinatal infection influence the development of moral behaviour?

While HIV encephalopathy and the AIDS dementia complex are considered hallmark neurologic manifestations of HIV-1 infection, increasing evidence of a continuum of nervous system involvement indicates the existence of an unrecognized number of individuals with milder, mostly cognitive and/or behavioural effects. Questions are raised whether HIV-related frontotemporal neuropathology during critical developmental stages could affect development of the brain networks documented to be involved in moral decisions, and whether this could contribute to the phenomenon of delinquency in an unknown percentage of the current generation of approximately 18-25 year old survivors of early childhood or vertically acquired HIV infection. Carefully planned and executed long term, prospective controlled studies using environmental, clinical, neurological, behavioural, genetic, immune and functional neuroimaging correlates would be required to elucidate whether HIV-specific neuropathology could indeed act as an independent risk factor for the development of a frontotemporal sociopathy syndrome. If such an association is proven, the accelerated development of neurospecific therapies should be a priority, especially for clinically and immunologically stable HIV-infected children. It may be necessary to institute such treatment as early as possible in perinatally infected cases, and maybe even during intrauterine life if HIV-1 is demonstrated to also act as a neurobehavioural teratogen for the developing fetal brain. It may, however, prove to be difficult to separate primary neurobiological from environmental factors, since the epigenetic effects on the host genome of retroviral insertion influencing behavioural gene expression characteristics, and altered gene expression following early life stresses may involve overlapping neurodevelopmental gene regulatory networks. In the meantime it remains necessary to prevent or ameliorate frequent neuropsychiatric morbidity from whatever causes.

Epidemiology and Etiology of Mental Retardation

Mental retardation (MR) is a manifestation of a heterogeneous set of impairments and conditions that result in cognitive limitation. It is a condition of medical, educational, and social importance. Physicians identify profound, severe, and moderate MR but rarely diagnose mild MR unless it is associated with a genetic or medical syndrome. From a medical perspective, the quest for etiology and the possibility of medical or surgical intervention to minimize deterioration are paramount. Educators, on the other hand are less concerned with causation than with academic achievement and school success. The majority of cases of mild MR is identified in school settings. Finally, the public uses the label to describe poor adaptive skills. Adults with MR who hold jobs, live independently, and participate in society are not always described as having MR. Thus some individuals characterized in childhood or adolescence as having mild MR become indistinguishable from the general population in adulthood.

Neurologic and neurodevelopmental manifestations of pediatric HIV/AIDS: a global perspective

Neurodevelopmental abnormalities associated with HIV infection have been described since the first reports of pediatric AIDS in the 1980s. Before antiretroviral therapy (ART) became widely available, progressive HIV-1 encephalopathy (PHE) was reported in the US in 13-35% of children with HIV-1 infection and in 35-50% of children with AIDS. Introduction of ART can prevent PHE and reverse PHE present at ART initiation, but a high prevalence of residual problems has been described. Even though 90% of HIV-infected children live in the developing world, few children have access to ART and little is known regarding the neurological manifestations of perinatal HIV infection in those regions. Mechanisms of pediatric HIV-1 neuropathogenesis and factors associated with neurodevelopmental abnormalities in perinatally infected children are not yet fully understood. Studies have demonstrated that HIV-1 enters the CNS soon after infection and may persist in this compartment over the entire course of HIV-1 infection. The CNS is a distinct viral reservoir, differing from peripheral compartments in target cells and antiretroviral penetration. Neurotropic HIV-1 likely develops distinct genotypic characteristics in response to this unique environment. We reviewed the literature on pediatric neuroAIDS and identified gaps in the current knowledge.

Effects of perinatal HIV infection and associated risk factors on cognitive development among young children

OBJECTIVE

We examined the effect of HIV, in combination with other important health and social factors, on the development of cognitive abilities of children perinatally exposed to HIV.

METHODS

Serial cognitive assessments were performed for 117 children who were infected vertically and 422 children who were exposed to but not infected with HIV, in a multicenter, natural history, longitudinal study. Repeated-measures analyses were used to evaluate the neurocognitive development of children between the ages of 3 and 7 years, as measured by the McCarthy Scales of Children's Abilities (MSCA).

RESULTS

Children with HIV infection and class C status scored significantly lower in all domains of cognitive development, across all time points, than did those who were HIV infected without an AIDS-defining illness and those who were HIV exposed but not infected. There were no significant differences between the 2 latter groups in General Cognitive Index or specific domain scores. Rates of change in cognitive development were comparable (parallel) among all 3 groups over a period of 4 years. Factors that were associated consistently and significantly with lower mean scores were HIV status, number of times an examination had been completed previously, primary language, maternal education, and gender. No factors were related to rate of change of any mean domain score.

CONCLUSIONS

An early AIDS-defining illness increased the risk of chronic static encephalopathy during the preschool and early school age years. Children with HIV infection but no class C event performed as well as noninfected children in measures of general cognitive ability. No significantly different profiles of strengths and weaknesses for verbal, perceptual-performance, quantitative, or memory functioning were observed among children with or without HIV infection. A number of factors were found to have significant effects on the mean scores of children in all 3 groups; however, they were not related to the rate at which learning occurred.

Health, neurologic, and cognitive status of HIV-infected, long-surviving, and antiretroviral-naive Ugandan children

OBJECTIVE

The purpose of this study was to assess the health status and school-age neurodevelopmental progress of antiretroviral treatment (ARVT)-naive, HIV-infected Ugandan children who had been followed as part of cohorts of children born to HIV-infected and -noninfected mothers between 1989 and 1993.

METHODS

Twenty-eight children, aged 6 to 12 years, vertically infected with HIV-1 and never treated with ARVT were evaluated in terms of health status, neurologic, and psychometric testing. A randomly selected group of 42 seroreverters and 37 HIV-1 negative children who were age- and gender-matched and who had been followed in the same cohorts were evaluated also. The families studied were homogenous in their socioeconomic status. None of the mothers or children had received ARVT or been exposed to illicit drugs.

RESULTS

The HIV-infected children showed significantly more evidence of acute malnutrition. They also had more illness, especially parotitis, otitis media, upper respiratory infections, and lymphadenopathy. However, they did not differ significantly in neurologic and cognitive assessments when compared with age- and gender-matched seroreverter and HIV-negative children. They were in the normal range with respect to neurologic and psychometric development measures.

CONCLUSIONS

These children seem to represent a significant subgroup of HIV-infected child survivors for whom the progress of the disease is less aggressive throughout early life. Given the fact that many infants, especially in developing countries, continue to be born without the benefit of perinatal ARVT, there will likely continue to be many older HIV-infected children in the same situation as those described in this follow-up study. They will not have been recognized as being HIV-infected. It is important that such children be identified and offered access to ARVT and other appropriate support services.

Neurocognitive outcomes in pediatric HIV

Cognitive impairment has long been associated with the natural history of HIV among vertically infected children. In children, HIV may have a direct or indirect impact on the developing brain, may lead to global or highly specific consequences, and may be responsible for minor cognitive consequences or, conversely, long-term and severe disability. This differential impact is related to multiple factors that influence the individual expression of the virus in any given child. This review provides an overview of the relevant literature on neurocognitive outcomes for infants, children, and youth vertically infected with HIV, with attention to those factors impacting neurocognitive outcome within a developmental framework. Research findings in both the era preceding and following the introduction of combined therapies are reviewed, since many of the issues identified prior to state-of-the-art treatment currently available in the United States and other developed countries still apply in much of the developing world. Intervention issues and directions for future research are also discussed.

Neuropsychological consequences of HIV in children

Pediatric HIV has reached epidemic proportions. In 1997, 1.1 million children younger than 15 were living with HIV or AIDS. The virus affects children cognitively and developmentally due to the immaturity of their nervous systems and immune systems. Studies in the area of neuropsychological deficits are as yet limited in number and less well developed than studies on adult HIV. However, despite methodological weaknesses, the literature has proven conclusively that pediatric HIV affects children cognitively, developmentally, emotionally, psychologically, behaviorally, and educationally. Although treatments are allowing these children to live longer, the effects of the virus remain, requiring special care. This review examines the mechanisms behind HIV in children, the neuropsychological findings to date, and the limitations of this work. Possible useful future approaches in understanding the neuropsychological course of the disorder, as well as directions for treatment and prevention are addressed.

Neurological and developmental effects of HIV and AIDS in children and adolescents

HIV-related encephalopathy is an important problem in vertically infected children with HIV. Infected infants may manifest early, catastrophic encephalopathy, with loss of brain growth, motor abnormalities, and cognitive dysfunction. Even without evidence of AIDS, infected infants score lower than serorevertors on developmental measures, particularly language acquisition. Children with perinatal or later transfusion-related infection generally are roughly comparable developmentally to their peers until late in their course. Symptoms similar to adult AIDS dementia complex are occasionally seen in adolescents with advanced AIDS, including dementia, bradykinesia, and spasticity. Opportunistic CNS infections such as toxoplasmosis and progressive multifocal leukoencephalopathy are less common in children and adolescents than in adults. Increasing evidence suggests that aggressive antiretroviral treatment may halt or even reverse encephalopathy. Neuroimaging changes may precede or follow clinical manifestations, and include early lenticulostriate vessel echogenicity on cranial ultrasound, calcifying microangiopathy on CT scan, and/or white matter lesions and central atrophy on MRI. Differential diagnosis of neurological dysfunction in an HIV-infected infant includes the effects of maternal substance abuse, other CNS congenital infections, and other causes of early static encephalopathy. Initial entry of HIV into the nervous system occurs very early in infection. The risk of clinical HIV encephalopathy increases with very early age of infection and with high viral loads. Virus is found in microglia and brain derived macrophages, not neurons. The neuronal effect of HIV is probably indirect, with various cytokines implicated. Apoptosis is the presumed mechanism of damage to neurons by HIV.