AIDS and Pediatric Neurology

Neurological Findings in HIV-infected Children: A Review of 49 Cases

Many HIV-infected children have neurological involvement. We present our observations in 49 cases, 58% of which had some form of clinical neurological impairment. Most of the patients affected (71%) presented with progressive encephalopathy, characterized by developmental delay with loss of acquisitions and cognitive decline, an impaired growth curve, microcephaly and corticospinal dysfunction. CT-scan imaging shows cerebral atrophy in all cases and basal ganglia calcifications in 29%. Non-specific abnormalities are found on the EEG in two-thirds of cases and in the CSF in slightly less than half the cases. Pathological studies sometime revealed HIV encephalitis or lateral corticospinal tracts degeneration. Neurological impairment secondary to vascular events, neoplasms or opportunistic infections were rare, especially when compared with the adult HIV population.

Cognitive and motor deficits associated with HIV-2(287) infection in infant pigtailed macaques: a nonhuman primate model of pediatric neuro-AIDS

Lentivirus-infected nonhuman primates exhibit behavioral and neurological pathology similar to human immunodeficiency virus (HIV)-infected humans and offer a means to examine the effects of lentivirus infection while controlling for confounding factors inherent in human populations. The purpose of this study was to examine cognitive and motor development in infant macaques vertically infected with HIV-2287. Subjects were 20 infant pigtail macaques (Macaca nemestrina); 8 controls born to uninfected dams, and 12 infants whose dams had been inoculated and infected with HIV-2287 in the third trimester of pregnancy. Eight of these pregnancies had undergone surgical procedures in the form of maternal amniotic catheters or maternal amniotic and fetal carotid artery and jugular vein catheters. Data indicated that catheterization had little or no impact on behavioral development. Seven infants were vertically infected (as measured by polymerase chain reaction (PCR) at birth) and five were not infected (as measured by PCR and coculture on repeated testing). Infected infants attained cognitive and motor milestones at significantly later ages than controls. Uninfected infants, born to infected dams, attained developmental milestones at later ages than controls on all tasks, but this reached statistical significance only for the Fine Motor Task. Attainment of milestones was not correlated with viral dose, maternal CD4+ levels at parturition or infant viral RNA levels at birth. Attainment of milestones was negatively correlated with infants' proportions of CD4+ lymphocytes at birth and significantly correlated with proportions of CD4+ lymphocytes 2 weeks after birth, indicating poorer performance in those infants with a more rapid CD4+ depletion. These cognitive and motor deficits closely resemble those observed in human infants and children infected with HIV and indicate that HIV-2287-infected infant macaques represent an excellent model of pediatric neuro-acquired immunodeficiency syndrome (neuroAIDS).

HIV-1 infection and AIDS

Since the initial descriptions of AIDS in the late 1970s, much has been learned about the biology of HIV-1 and the cells it infects. Much has also been learned about mother-to-infant viral transmission and the natural history of HIV-1 infection. Key studies led to strategies for interrupting mother-to-infant transmission, resulting in a significant decline in neonatal HIV-1 infection. More proficient diagnostic techniques made early diagnosis of HIV-1-infected neonates and infants possible during asymptomatic or mildly symptomatic disease stages. Major advances in treatment led to the control of viral replication and thereby altered the course of disease progression. HIV-1/AIDS-associated neurologic disorders declined in parallel. In countries where these therapies are readily available, a dramatic decline in the number of infants born HIV-1 infected has been realized as has a markedly improved survival rate of those infected. Many questions remain, however. The long-term effects of prenatal exposure to antiretroviral agents are not yet known and continue to be studied. Just exactly how HAART therapy may affect early signs of pediatric HIV-1/AIDS-associated CNS disease, should they develop, is unclear. As new anti-retroviral agents are developed and new combination drug regimens are instituted, the potential for neurologic complications, toxicities, and adverse drug interactions (e.g., with antiepileptic drugs (AEDS)) exists and needs to be identified and monitored.

Human Immunodeficiency Virus (HIV) in Children

Recent advances in antiretroviral treatment have changed the landscape of pediatric HIV--not only has perinatal treatment markedly diminished HIV transmission rates, but highly active antiretroviral treatments (HAART) have, with few exceptions, transformed HIV into a chronic nonfatal disorder. Antiretroviral therapies are complex and fraught with potential for side effects. The neurologist involved with HIV-infected children should have a firm grasp on the different therapeutic agents used among infected children, especially as regards drug metabolism and indications for treatment.

Stroke and seizures as the presenting signs of pediatric HIV infection

The authors report two pediatric patients with definite human immunodeficiency virus infection whose initial presentation was stroke and seizure. The first patient was a 3-year-old female who developed acute hemiparesis as the first manifestation. The other, a 2-month-old infant, had focal seizures secondary to cerebral infarction. Investigations revealed ischemic infarction of the thalamus, hypothalamus, and internal capsule in the first patient and cerebral cortex in the second. Further investigations failed to demonstrate any other causes of these cerebral infarctions. Opportunistic infection of the central nervous system was not documented. The authors emphasize that cerebrovascular accident may be the initial presentation in human immunodeficiency virus infection in children. Human immunodeficiency virus infection must be included in the differential diagnosis, and testing for the disease is mandatory in the investigation of stroke in any child who is at risk of having this infection.

Diagnostic value of multimodal evoked potentials in HIV-1 infected children

Evoked potentials (EP) help guide the diagnosis of central nervous system involvement in demyelinating pathologies regarding both children and adults, and in human immunodeficiency virus-1 (HIV-1) correlated pathologies only in regard to adult patients. EP have been shown to be useful in highlighting early signs of the disease. We therefore studied EP in HIV-1 infected children with the aim of verifying the association of results with disease progression, clinical signs and electroencephalogram, and individualizing the most reliable test. Thirty-six patients (20 male and 16 female subjects, age range: 10 months to 12 years) belonging to a group of 45 symptomatic subjects seen at the Pediatric Department were included into the study from November 1991 to December 1994. Ten presented with neurological signs as of disease onset, eight others developed encephalopathy during the follow-up. One hundred seventeen EP, i.e., 27 pattern visual, 64 flash visual and 26 brain stem auditory EP, were recorded. Univariate statistical analysis using the Wilcoxon-Mann-Whitney U test and Student's t test was done. As a whole, we found 22.5% of abnormal EP in subjects without neurological signs and 28.3% in subjects with neurological signs. Results that were obtained suggested a close relationship between both the pattern of visual and brain stem auditory EP exams and disease progression.

Case study: behavioral symptoms of pediatric HIV-1 encephalopathy successfully treated with clonidine

There are few reports of the behavioral manifestations in the pediatric population infected with human immunodeficiency virus type 1 (HIV-1). We report a case of a 4-year-old child with acquired immunodeficiency syndrome, whose initial manifestation of central nervous system involvement consisted of sudden onset of impulsivity, hyperactivity, initial insomnia, and aggressive behavior. This clinical picture may suggest an initial presentation of HIV-1 encephalopathy. Clonidine was helpful in ameliorating these behaviors.

EEG diagnostic and predictive value on HIV infection in childhood

This prospective study evaluated the electroencephalographic (EEG) diagnostic and prognostic value in childhood HIV infection. It was carried out on 125 subjects and included all Piemonte's seropositive children. The EEG was repeated every three months during the first 15 months of life, and then, at least, annually in the P1 and P2 group. Data of group P2 was compared blindly to that of the seroconverted control group of the same age and risk. EEG results were normal in P0, P1 and control patients. In group P2, EEG was abnormal in 35.5% of subjects, of these 54.6% developed an encephalopathy with a delay of 2.5 months to 2 years 11 months. EEG is therefore useful to evaluate early CNS damage and to identify onset features and evolution of encephalopathy in P2 patients.

Pediatric HIV infection: neurologic and neuropsychologic findings

Neurologic and neuropsychologic findings are early and important prognostic indicators of symptomatic HIV disease among infants and young children. The most common presentations include progressive encephalopathy, loss of motor milestones, and corticospinal tract abnormalities. It is hypothesized that, in some instances, the more severe neurologic manifestations of HIV noted in infancy may reflect the consequences of in utero HIV infection, or the increased vulnerability of infants to HIV infection during a time of rapid brain growth. Current research suggests that infants with basal ganglia calcification and those with plummeting or low CD4+ counts are at particular risk of severe central nervous disease progression. In contrast to infants and toddlers, older children and adolescents appear to demonstrate only subtle neurologic dysfunction until very late in their illness. Findings seen include attentional difficulties, fine motor tremors, visual sequencing problems, and depressive affect. One of the challenges for the 1990s will be rapidly to identify those infants who are at high risk of central nervous system disease progression, and to institute effective treatments that can halt the devastating effects of HIV on the developing brain. In addition to early identification of the high-risk infants, neuropsychologic, neuroimaging and laboratory measures need to be identified that will allow effective monitoring of responses to therapy.

Neurodevelopment in pediatric HIV infection. The use of CAT/CLAMS. Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale

Pediatric neuro-AIDS may be the first clinical manifestation of HIV infection in children born to HIV-infected mothers. As part of the neurodevelopmental examination of children, the Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS) was investigated as a tool for pediatricians to use to monitor the development of children at risk for HIV infection. The CAT/CLAMS was found to detect neurodevelopmental differences between HIV-infected and uninfected children at 12 and 18 months of age. Good correlations were found between the CAT/CLAMS and concurrently administered Bayley Scales of Infant Development. These findings suggest that the CAT/CLAMS should be considered as a part of the neurodevelopmental examination of children at risk for pediatric neuro-AIDS.

Neurologic syndromes

It is now well recognized that HIV-1 associated CNS disease may complicate the course of HIV-1 infection and AIDS in infants and children. It is also well recognized that the neurologic dysfunction in these young patients adds significantly to the morbidity of the disease and is often a devastating complication. It is apparent that HIV-1 CNS infection in infants and young children is complicated by numerous developmental issues. The effects, direct and indirect, of HIV-1 on the developing nervous system must be considered. The effects of HIV-1 on the immature immune system must also be considered. Moreover, the possible effects of HIV-1 on the many complex interactions between these two systems during development will clearly also require investigation. In order to care for these children and to design rational approaches for treatment and prevention, it is now critical to develop a better understanding of how HIV-1 affects the developing nervous system.

Pediatric AIDS: a longitudinal comparative MRI and CT brain imaging study

Fourteen consecutive children with acquired immune deficiency syndrome (AIDS) (age range, 4 months to 11 years; median 4 years) were studied prospectively comparing nonenhanced cranial magnetic resonance imaging (MRI) and computed tomographic (CT) scans. MRI and CT were performed twice: at time of entry into protocol and again at 1 year. In addition, sequential neurologic (every 2 months) and neuropsychological examinations (every 6 months) were performed. At entry, 12 children had abnormal neurologic examinations; of these, 10 had developmental delay; two children were normal by developmental history and neurologic examination. Five children performed in the normal range on a standardized neuropsychological test, whereas nine children showed significant delays in verbal or motor/perceptual development. Following 1 year of study, four children had normal and six had abnormal neurologic examinations (six stable and four improved). Neuropsychological examinations were normal in five children and abnormal in five (seven stable, one improved, and two deteriorated). At entry, the following neuroradiographic abnormalities were seen: brain parenchymal volume loss (eight, MR = CT), cervical lymphatic enlargement (four, MR = CT), striatal-thalamic calcification (one, CT > MR), delayed myelination (one, MR > CT), and focal white-matter lesions (one, MR > CT). At 1 year the following neuroradiographic changes were seen: brain parenchymal volume loss (10, MR = CT; two improved, eight stable); cervical lymphatic enlargement (one, MR = CT; three improved, one stable), striatal-thalamic calcification (one, CT > MR; one new), and focal white-matter lesions (one, MR > CT; one stable).(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral artery aneurysms in children infected with human immunodeficiency virus

More than 250 children treated at our institution on antiretroviral treatment protocols have been monitored with brain imaging studies. We documented the occurrence and progression of aneurysms of major cerebral arteries in two children with advanced human immunodeficiency virus infection. In both cases these lesions remained clinically silent initially, despite progression to marked dilation.

The neuropathology of pediatric acquired immunodeficiency syndrome

Central nervous system disease has emerged as an important manifestation of acquired immunodeficiency syndrome in both the adult and pediatric populations, with neurologic abnormalities occurring in up to 90% of pediatric patients in some series. Neuropathologic studies, based primarily on the autopsy, have provided valuable insights into the spectrum and pathogenesis of acquired immunodeficiency syndrome-associated neurologic disorders, including primary human immunodeficiency virus encephalopathy and as the spectrum of infectious, neoplastic, and cerebrovascular diseases that may complicate the course of acquired immunodeficiency syndrome. Progressive encephalopathy represents the single most common neurologic disorder in pediatric acquired immunodeficiency syndrome and appears to be caused in most cases by direct infection in brain parenchyma by human immunodeficiency virus. Central nervous system lymphoma and cerebrovascular disease continue to account for most focal central nervous system lesions in the pediatric population. In contrast to adults with acquired immunodeficiency syndrome, opportunistic central nervous system infections remain relatively uncommon in the pediatric population. Our understanding of acquired immunodeficiency syndrome-associated neurologic disease remains far from complete. A plea is made for regular postmortem examination of the central nervous system in all patients dying with human immunodeficiency virus infection.

Acquired immunodeficiency syndrome and the child's central nervous system

Human immunodeficiency virus-1 (HIV-1) associated central nervous system disease may complicate the course of HIV-1 infection in infants and children. Neurologic dysfunction in these young patients adds significantly to the morbidity of the disease and is often a devastating complication. It is apparent that HIV-1 infection in infants and young children is complicated by numerous developmental parameters. The developmental stage of the nervous and immune systems when exposed to the virus is likely to interact in complex ways with HIV-1 variables. In order to care for these children and to design rational approaches for treatment and prevention, it is now critical to develop a better understanding of how HIV-1 affects the developing nervous system.

Radiology of AIDS in the pediatric patient

The Acquired Immunodeficiency Syndrome (AIDS) has involved the pediatric age group and is especially prevalent in babies born of mothers who are intravenous drug abusers or prostitutes. Approximately 30% of children born to mothers who are seropositive for the human immunodeficiency virus (HIV) will develop HIV infection. There are several important differences in children and adults with AIDS. The incubation period of the disease is shorter, and initial clinical manifestations occur earlier in children. In addition, certain infections are more common in children, and the different types of malignancy, especially Kaposi's sarcoma, are unusual in the pediatric age group. The altered immune system involves both T cells and humoral immunity and increases susceptibility to a variety of infections, particularly opportunistic organisms. In this publication the complications of pediatric AIDS involving the lungs, cardiovascular system, gastrointestinal tract, genitourinary system, and neurological system are described. The most common pulmonary complications in our experience are Pneumocystis carinii pneumonia and pulmonary lymphoid hyperplasia. The spectrum of cardiovascular involvement in pediatric AIDS includes myocarditis, pericarditis, and infectious endocarditis. Gastrointestinal tract involvement is usually due to opportunistic organisms that produce esophagitis, gastritis, and colitis. Abdominal lymphadenopathy is a common finding either due to disseminating Mycobacterium avium-intracellulare infection or nonspecific lymphadenopathy. Although cholangitis is more commonly seen in adults, it may occur in children with AIDS and, in most cases, is due to related opportunistic infections. Genitourinary infections may be the first evidence of HIV disease. Cystitis, pyelonephritis, renal abscesses, and nephropathy with renal insufficiency are complications of pediatric AIDS. A variety of neurological abnormalities may occur in pediatric AIDS. The most common cause of neurological dysfunction in children with AIDS is HIV neuropathy. We present the many complications of AIDS in children demonstrated by a variety of imaging modalities, emphasizing the importance of diagnostic imaging in children with this disease.

Viral infections of the developing nervous system

Both clinical and experimental studies indicate that viruses can interact with the developing nervous system to produce a spectrum of neurological damage and brain malformations. Following infection of the pregnant woman, virus may indirectly or directly involve the fetus. Direct involvement is generally due to transplacental passage of the virus and invasion of fetal tissue. Resultant disease is determined by a variety of virus-host factors, including the developmental stage of the fetus at the time it is infected, the neural cell populations which are susceptible to infection, the consequent virus-infected cell interactions, and the mechanism and timing of viral clearance. There is a growing list of human viruses which injure the developing nervous system. There are also several experimental models in which congenital viral infections have been shown to result in a variety of brain malformations but with no evidence of the prior infection remaining at the time of birth.