Neurodevelopmental delay and focal seizures as presenting symptoms of human immunodeficiency virus I infection

Late diagnosis of human immunodeficiency virus infection is linked to higher rates of epilepsy in children in the Eastern Cape of South Africa

BACKGROUND

Human immunodeficiency virus (HIV)-positive children may present with a wide range of neurological disorders. Among these, epilepsy is of key concern because of its lifelong impact and potential for damage to the central nervous system (CNS). Few studies in developing regions have investigated the prevalence and aetiology of epilepsy in HIV-infected children as a key population.

OBJECTIVES

We describe the prevalence of epilepsy, associated neurological disabilities, immunological status, clinical stage and history of CNS infection at epilepsy diagnosis in a cohort of HIV-infected children receiving antiretroviral therapy (ART) in the Eastern Cape of South Africa.

METHODS

We conducted a retrospective study (2004-2014) at two major referral sites for HIV-infected children diagnosed with epilepsy aged 0-16 years. Eligible subjects were extracted from the electronic medicine bridging access to care in excellence (EMBRACE) Paediatric Cohort using the Paediatric ART Data Management Tool (PADMT). Fixed data fields were interrogated for exposures to antiepileptic drugs. Unstructured 'comments' fields were searched for the terms: epilepsy, seizures, fits and szs, as well as abbreviated versions of common antiepileptic drug names. Eligible subject folders were then retrieved to validate the digital data.

RESULTS

From 2139 children enrolled in the two sites, 53 children were diagnosed with epilepsy (2.48%). In these, the median CD4 count was 591 cells/mm3, and the mean viral load was 4.9 log copies/mL, with undetectable viral loads in only seven children (14.0%). World Health Organization (WHO) clinical HIV stage was available for 46 patients of the sample, with 3, 6, 26 and 11 children graded at stages 1, 2, 3 and 4, respectively. Forty percent children had a history of CNS infection prior to the epilepsy diagnosis, and 55% children were reported to have school problems.

CONCLUSIONS

In this descriptive study, the prevalence of epilepsy among children with HIV was 2.48%, mostly diagnosed in advanced HIV-disease stages. Our findings support the usefulness of early detection and initiation of ART in HIV-infected children in order to reduce the risk of epilepsy. In addition, our study demonstrates that novel techniques are effective in accessing cohort-level data that allow interrogation of both structured and unstructured clinical data.

Hyperhomocysteinaemia and folate deficiency in human immunodeficiency virus-infected children

BACKGROUND

Our aim was the detection of possible deficiencies of folate and cobalamin by the measurement of plasma total homocysteine (tHcy) in 69 human immunodeficiency virus (HIV) -infected children on antiretroviral treatment. We studied the relationship of these vitamins and methionine with tHcy values.

MATERIALS AND METHODS

Plasma tHcy was determined by high-performance liquid chromatography with fluorescence detection, folate and cobalamin by competitive protein-binding chemiluminescence, and methionine by ion exchange chromatography.

RESULTS

Significant differences were observed between tHcy concentrations in the HIV-infected patients and the reference values for children of similar ages (P < 0.0001). Folate values were significantly lower in HIV-infected children compared with our reference paediatric population (P < 0.0001), but cobalamin concentrations were similar between patients and reference values. A significantly negative correlation was found between tHcy and folate (r = - 0.596; P < 0.0001), and a significantly positive correlation between folate and the methionine : tHcy ratio (r = 0.501; P < 0.0001). Plasma tHcy was significantly higher (P = 0.008), while folate values and methionine : tHcy ratios were significantly lower (P = 0.007 and P = 0.042), in patients on protease inhibitor treatment than in patients on other antiretroviral therapies.

CONCLUSIONS

The hyperhomocysteinaemia and low methionine : tHcy ratios observed in our group of HIV-infected children are probably a consequence of the low folate values, which interfere in the remethylation of homocysteine to methionine. Patients on protease inhibitor treatment showed significantly higher plasma tHcy concentrations, and lower folate values and methionine : tHcy ratios, compared with patients on other antiretroviral therapies. Hyperhomocysteinaemia is associated with the risk of premature stroke, which may have adverse consequences in the evolution of disease.

Vertical human immunodeficiency virus-1 infection: involvement of the central nervous system and treatment

Involvement of the central nervous system (CNS) contributes substantially to morbidity and mortality of vertical infection with the human immunodeficiency virus (HIV)-1. The clinical spectrum ranges from minor developmental disabilities to severe and progressive encephalopathy. Progression of the disease varies considerably. Both direct viral and indirect host-related pathogenic mechanisms have been proposed. The diagnosis depends on neurological and neurodevelopmental assessments. So far, HIV-1-specific antiviral treatment has shown limited effects on neurological manifestations in symptomatic children. Thus, efforts are needed to improve prevention and treatment of CNS involvement. It is still unclear whether early use of antiretroviral agents is of benefit.

CONCLUSION

Since experience of treatment of HIV-1 infections in adults cannot easily be translated to children, paediatric clinical trials are needed to answer questions specific to the unique characteristics of children.

Metabolic abnormalities and new-onset seizures in human immunodeficiency virus-seropositive patients

Seizures are a recognized complication of human immunodeficiency virus (HIV)-type-1 infection. CNS disease processes in these patients include encephalitis, focal brain lesions, and meningitis. Metabolic causes of seizures have received little attention. In a retrospective study, we selected 68 HIV-seropositive patients with new-onset seizures and information available for specified metabolic factors on the day of the first seizure. We sought an association of metabolic abnormalities with convulsive status epilepticus (CSE), which was the initial seizure in 12 patients, predominantly intravenous (i.v.) drug users. HIV-seropositive patients with new-onset seizures and hypomagnesemia or renal failure appeared to be at increased risk for CSE. All HIV-seropositive patients with new-onset seizures should undergo metabolic screening including renal function and serum magnesium levels.

Effects of arginine, S-adenosylmethionine and polyamines on nerve regeneration

INTRODUCTION

Axon growth and axon regeneration are complex processes requiring an adequate supply of certain metabolic precursors and nutrients.

MATERIAL AND METHODS

This article reviews the studies examining some of the processes of protein modification fundamental to both nerve regeneration and to the continuous and adequate supply of specific factors such as arginine, S-adenosylmethionine and polyamines.

RESULTS

The process of arginylation notably increases following nerve injury and during subsequent regeneration of the nerve, with the most likely function of arginine-modification of nerve proteins being the degradation of proteins damaged through injury. It appears that defective methyl group metabolism may be one of the leading causes of demyelination, as suggested by the observation of reduced cerebrospinal fluid concentrations of s-adenosylmethionine (SAMe) and 5-methyltetrahydrofolate, the key metabolites in methylation processes, in patients with a reduction in myelination of corticospinal tracts. Polyamine synthesis, which depends strongly on the availability of both SAMe and arginine, markedly increases in neurons soon after an injury. This "polyamine-response" has been found to be essential for the survival of the parent neurons after injury to their axons. Polyamines probably exert their effects through involvement in DNA, RNA and protein synthesis, or through post-translational modifications that are indicated as the most relevant events of the "axon reaction."

CONCLUSIONS

Nerve regeneration requires the presence of arginine, s-adenosylmethionine, and polyamines. Further studies are needed to explore the mechanisms involved in these processes.

HIV-related encephalitis presenting as convulsant disease

Because of the growing incidence of neurological disorders in HIV-infected patients, an early detection of the disease seems to be of paramount importance, especially in asymptomatic subjects. By using electroencephalography coupled with computerized spectral analysis and "mapping" (EEG-CSA), paroxysmal sharp activity was detected in 26 patients belonging to different stages of HIV infection. Seven of them (27%) were also symptomatic, (table; see text) showing signs of convulsant disease. The presence of focal or generalized paroxysmal activity, often associated with seizures, might suggest an early localization of HIV in cortical structures.

Central-nervous-system methyl-group metabolism in children with neurological complications of HIV infection

To assess methyl-group metabolism in the central nervous system in infection with human immunodeficiency virus (HIV), levels of 5-methyltetrahydrofolate, methionine, and S-adenosylmethionine were measured by high-performance liquid chromatography in cerebrospinal fluid (CSF) from six children with congenital HIV infection and neurological complications. Total neopterins were also measured, as a marker of macrophage activation. In all six children concentrations of one or more methyl-group carriers were lower than those in a reference population of children, and all of the five in whom CSF neopterins were measured had higher than normal levels. Defective methylation may play a part in the neurological damage caused by HIV infection.