Seizures in HIV-seropositive individuals: NIMHANS experience and review

Virus-Induced Epilepsy vs. Epilepsy Patients Acquiring Viral Infection: Unravelling the Complex Relationship for Precision Treatment

The intricate relationship between viruses and epilepsy involves a bidirectional interaction. Certain viruses can induce epilepsy by infecting the brain, leading to inflammation, damage, or abnormal electrical activity. Conversely, epilepsy patients may be more susceptible to viral infections due to factors, such as compromised immune systems, anticonvulsant drugs, or surgical interventions. Neuroinflammation, a common factor in both scenarios, exhibits onset, duration, intensity, and consequence variations. It can modulate epileptogenesis, increase seizure susceptibility, and impact anticonvulsant drug pharmacokinetics, immune system function, and brain physiology. Viral infections significantly impact the clinical management of epilepsy patients, necessitating a multidisciplinary approach encompassing diagnosis, prevention, and treatment of both conditions. We delved into the dual dynamics of viruses inducing epilepsy and epilepsy patients acquiring viruses, examining the unique features of each case. For virus-induced epilepsy, we specify virus types, elucidate mechanisms of epilepsy induction, emphasize neuroinflammation's impact, and analyze its effects on anticonvulsant drug pharmacokinetics. Conversely, in epilepsy patients acquiring viruses, we detail the acquired virus, its interaction with existing epilepsy, neuroinflammation effects, and changes in anticonvulsant drug pharmacokinetics. Understanding this interplay advances precision therapies for epilepsy during viral infections, providing mechanistic insights, identifying biomarkers and therapeutic targets, and supporting optimized dosing regimens. However, further studies are crucial to validate tools, discover new biomarkers and therapeutic targets, and evaluate targeted therapy safety and efficacy in diverse epilepsy and viral infection scenarios.

Early Initiation of Antiretroviral Therapy is Protective Against Seizures in Children With HIV in Zambia: A Prospective Case-Control Study

BACKGROUND

Seizures are relatively common among children with HIV in low- and middle-income countries and are associated with significant morbidity and mortality. Early treatment with antiretroviral therapy (ART) may reduce this risk by decreasing rates of central nervous system infections and HIV encephalopathy.

METHODS

We conducted a prospective, unmatched case-control study. We enrolled children with new-onset seizure from University Teaching Hospital in Lusaka, Zambia and 2 regional hospitals in rural Zambia. Controls were children with HIV and no history of seizures. Recruitment took place from 2016 to 2019. Early treatment was defined as initiation of ART before 12 months of age, at a CD4 percentage >15% in children aged 12-60 months or a CD4 count >350 cells/mm 3 for children aged 60 months or older. Logistic regression models were used to evaluate the association between potential risk factors and seizures.

RESULTS

We identified 73 children with new-onset seizure and compared them with 254 control children with HIV but no seizures. Early treatment with ART was associated with a significant reduction in the odds of seizures [odds ratio (OR) 0.04, 95% confidence interval: 0.02 to 0.09; P < 0.001]. Having an undetectable viral load at the time of enrollment was strongly protective against seizures (OR 0.03, P < 0.001), whereas history of World Health Organization Stage 4 disease (OR 2.2, P = 0.05) or CD4 count <200 cells/mm 3 (OR 3.6, P < 0.001) increased risk of seizures.

CONCLUSIONS

Early initiation of ART and successful viral suppression would likely reduce much of the excess seizure burden in children with HIV.

Epileptic seizures associated with progressive multifocal leukoencephalopathy in HIV-infected patients in Korea

We investigated the incidence and risk factors of seizures related to progressive multifocal leukoencephalopathy (PML) in Korean patients infected with HIV. Of the 34 patients, 14 (41.2%) developed epileptic seizures during a median follow-up of 82 months. The median time from PML diagnosis to seizure onset was 44 months, ranging from 0 to 133 months. Patients with PML who developed seizures more commonly had cognitive impairment and multiple or diffuse lesions on brain MRI. These findings highlight the increased seizure risk among HIV-infected patients with PML at any stage of the disease, particularly in cases with extensive involvement.

Clinical factors predictive of new-onset seizure in patients with AIDS-related brain parenchymal lesion

PURPOSE

This study aimed to determine the clinical characteristics and risk factors of new-onset seizure in patients with AIDS-related brain parenchymal lesion.

METHODS

A retrospective case-control study from January 2015 to December 2021 was conducted to determine the clinical characteristics and etiology of seizures in patients with AIDS-related brain parenchymal lesion. Univariate and multivariate logistic regression analyses were used to identify risk factors associated with seizures. Receiver operating characteristic (ROC) curve was used to analyze seizure prediction efficiency.

RESULTS

Among a total of 343 patients with AIDS-related brain lesions, 222 had brain parenchymal lesions. Of the 222 patients in the series (range: 16-81 y), 69 reported an episode of at least one seizure. A logistic regression analysis showed that tuberculoma, cortex involvement, and lesions in parietal lobe were found to have a strong association with higher incidence of seizures, whereas lesions in the periventricular area was less prone to seizure. The area under the ROC curve of these factors was 0.733, indicating these factors could predict seizure effectively. Amongst the 69 patients with seizures in multivariate analysis using logistic regression, multiple lesions significantly associated with focal to bilateral tonic-clonic seizures, and lesions in temporal lobe independently associated with focal impaired awareness seizure.

CONCLUSIONS

Our study identified the underlying predictors between seizures and the clinical characteristics in a large population of patients with AIDS-related brain parenchymal lesions. These findings would provide further insights into developing effective prevention and treatment strategies aimed at improving the quality of life in the HIV population.

Seizure in HIV-infected patients: clinical presentation, cause and treatment outcome in Ethiopia-a retrospective study

BACKGROUND

The estimated number of adult patients living with HIV infection in Ethiopia in 2012 was approximately 800,000. Seizure occurs in 2 to 3% and 6.1% to 34.3% in patients with HIV infection and patients with neurological complications of HIV infection, respectively. Studies on HIV infection and seizure are rare in Ethiopia. The purpose of this study was to assess clinical presentation, cause and treatment outcome of patients with HIV infection presented with seizure.

METHODS

In this retrospective study, patients aged ≥ 13 years with HIV infection presented with seizure were included. Medical records were reviewed and demographic and clinical data were collected.

RESULTS

Records of 146 patients were analysed. Males were 55.5% and the mean age was 34 years. The diagnosis of HIV infection was made after current hospital admission in 69% of patients. Almost all patients (98.6%) had stage 4 HIV infection with very low CD4 count (mean = 77/mm³). In almost all patients seizure was a recent onset at current admission; either it started after admission (42.5%) or within 3 months prior to admission (52.5%). The types of seizures were: generalized tonic-clonic seizure [GTCS] (69.2%), focal motor with secondarily generalization [FMWSG] (19.9%) and simple focal motor (11%). The common causes of seizure were: cerebral toxoplasmosis (46%), tuberculous meningitis (35.6%) and cryptococcal meningitis (13.7%). Case-fatality was 53% and predictors of mortality were: seizure started after admission, change in mentation and comatose at initial evaluation.

CONCLUSIONS

Most patients had stage 4 HIV infection with very low CD4 count and a recent onset seizure which started within 3 months at initial evaluation. GTCS was the commonest seizure type and most causes of seizure were central nervous system opportunistic infections. The case-fatality was high and change in sensorium was an independent predictor of mortality. To prevent the high mortality and morbidity prevention of HIV infection, early diagnosis and treatment, improving diagnostic facilities and access to non-enzyme inducing antiepileptic drugs are recommended.

Current epidemiological and etiological characteristics and treatment of seizures or epilepsy in patients with HIV infection

Seizures or epilepsy is one of the common serious complications in patients with advanced human immunodeficiency virus (HIV) infection or diagnosed with immune deficiency syndrome, with higher incidence and prevalence than in the general population. Generalized seizures are the most common type in the patients. Opportunistic infections are a stereotypical predisposing factor for seizures in HIV patients, but a variety of pathogenic factors can also be found in these patients, such as metabolic perturbation and drug-drug interactions. The diagnostic criteria for seizures in these patients are the same as those in the general population. As HIV patients with seizures need to take both antivirals and antiepileptic drugs, the risk of drug-drug interactions is greatly increased, and the side effects of drugs may also become more prominent. At present, most experience in antiepileptic drug usage has come from the general population, and there is still a lack of guidance of antiepileptic drug use in special groups such as the HIV-infected people. Unlike the old-generation drugs that involve metabolisms through CYP450, the first-line antiepileptic drugs usually bypass CYP450, thus having less drug-drug interactions. In this review, we summarize the recent research progress on the above-mentioned widely discussed topics and make a prospect on future research direction.

Seizures in Human Immunodeficiency Virus-Associated Cryptococcal Meningitis: Predictors and Outcomes

Background

Seizures commonly occur in patients with cryptococcal meningitis, yet risk factors and outcomes related to seizures are not well described.

Methods

We performed post hoc analyses on participants prospectively enrolled in 3 separate human immunodeficiency virus (HIV)-associated cryptococcal meningitis clinical trials during 2010-2017. Documentation of seizures at presentation or during hospitalization and antiseizure medication receipt identified participants with seizures. We summarized participant characteristics by seizure status via Kruskal-Wallis and χ ² tests. Cox proportional hazards models analyzed the relationship between seizures and mortality. We compared mean quantitative neurocognitive performance Z (QNPZ-8) scores, and individual domain z-scores, at 3-months using independent t tests.

Results

Among 821 HIV-infected cryptococcal meningitis participants, 28% (231 of 821) experienced seizures: 15.5% (127 of 821) experienced seizures at presentation, and 12.7% (104 of 821) experienced incident seizures. Participants with seizures at presentation had a significantly lower Glasgow coma scale ([GCS] <15; P < .001), CD4 count (<50 cells/mcL; P = .02), and higher cerebrospinal fluid (CSF) opening pressure (>25 cm H₂O; P = .004) when compared with participants who never experienced seizures. Cerebrospinal fluid fungal burden was higher among those with seizures at presentation (125 000 Cryptococcus colony-forming units [CFU]/mL CSF) and with seizures during follow-up (92 000 CFU/mL) compared with those who never experienced seizures (36 000 CFU/mL, P < .001). Seizures were associated with increased 10-week mortality (adjusted hazard ratio = 1.45; 95% confidence interval, 1.11-1.89). Participants with seizures had lower neurocognitive function at 3 months (QNPZ-8 = -1.87) compared with those without seizures (QNPZ-8 = -1.36; P < .001).

Conclusions

Seizures were common in this HIV-associated cryptococcal meningitis cohort and were associated with decreased survival and neurocognitive function.

Prevalence and incidence of new-onset seizures and epilepsy in patients with human immunodeficiency virus (HIV): Systematic review and meta-analysis

BACKGROUND

The prevalence and incidence of seizures are substantially higher in patients with human immunodeficiency virus (HIV) compared with the general population and is associated with higher mortality rates. Despite this, the condition remains poorly understood, and there is variation in reported epidemiological studies. The aim of this systematic review and meta-analysis was to investigate the risk factors associated with seizures in the population with HIV, explore the source of variations, and describe management plans that can aid clinicians in the acute and long-term treatment of these patients.

METHODS

A structured electronic database search of MEDLINE, EMBASE, and Cochrane Library was conducted. Studies were included if they described clinical details of patients with HIV with seizures or epilepsy. We extracted select variables from each included study, and we estimated pooled estimates of the incidence and prevalence of seizures using random-effects meta-analysis of proportions.

RESULTS

Information on 6639 cases of patients with HIV was extracted from 9 included studies. These comprised of 2 studies from the United States of America (USA), 3 from Europe, 3 from Asia, and 1 from Africa. The pooled prevalence and incidence rate of seizures in HIV were 62 per 1000 population and 60 per 1000 population respectively. Among those who presented with new-onset seizures, 63% had seizure recurrence. At the time of first seizure, 82.3% had acquired immunodeficiency syndrome (AIDS). Factors that appeared to be linked to seizures in HIV included advanced HIV disease, opportunistic infections particularly toxoplasmosis, and metabolic derangement. Most seizures were effectively controlled by common antiepileptic drugs (AEDs).

CONCLUSIONS

The prevalence and incidence of seizures and epilepsy in the population with HIV are substantially higher than the general population. Our results suggest that advanced HIV and opportunistic infections are associated with the majority of the seizures. Early initiation of highly active antiretroviral therapy (HAART), prophylactic use of cotrimoxazole (trimethoprim-sulfamethoxazole) and routine electroencephalogram (EEG) in patients with HIV may reduce seizure incidence and frequency and help in early diagnosis of nonconvulsive seizures in this population. We recommend long-term seizure management with AED, and for patients on HAART, enzyme-inducing AED should be avoided when possible.

Seizures in HIV: The case for special consideration

Purpose

This study aimed to determine the rate, cause and management of seizures in the context of potential ART–ASD interactions in a cohort of HIV + individuals.

Methods

Records of 604 HIV + patients were reviewed and those reporting epilepsy/seizure diagnosis were further evaluated.

Results

This cohort exhibited a seizure rate of 2.4%. HIV + patients treated for epilepsy displayed low serum ASD levels and failed to achieve seizure control. They were more likely to disengage from Neurology follow-up.

Conclusion

For HIV + patients presenting with seizures/epilepsy the ASD prescription and the provision of supplementary support services needs to be carefully considered.

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ID and Neurology services should be involved in the evaluation and treatment of seizures in the context of HIV infection.

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ART-ASD interactions could have been the cause of ineffective treatment and other poor outcomes in this small cohort.

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In this group of patients it is important to apply published guidelines when it comes to making treatment decisions.

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Counseling and supportive services need to be provided to ensure engagement with services and adherence to treatment.

Global developments in HIV neurology

Neurologic conditions associated with HIV remain major contributors to morbidity and mortality, and are increasingly recognized in the aging population on long-standing combination antiretroviral therapy (cART). Importantly, growing evidence suggests that the central nervous system (CNS) serves as a reservoir for viral replication with major implications for human immunodeficiency virus (HIV) eradication strategies. Though there has been major progress in the last decade in our understanding of the pathogenesis, burden, and impact of HIV-associated neurologic conditions, significant scientific gaps remain. In many low-income settings, second- and third-line cART regimens that carry substantial neurotoxicity remain treatment mainstays. Further, patients continue to present severely immunosuppressed with CNS opportunistic infections. Public health efforts should emphasize improvements in access and optimizing treatment of HIV-positive patients, specifically in resource-limited settings, to reduce the risk of neurologic sequelae.

Profile of 26 HIV Seropositive individuals with Cerebral Venous Thrombosis

BACKGROUND

HIV infection has been found to be prothrombotic condition. However, venous thromboembolism associated with HIV is restricted to peripheral vasculature with few reports of cerebral venous thrombosis (CVT).

OBJECTIVE

To examine the clinical manifestations of CVT among HIV seropositive individuals and explore the possible etiological factors.

METHODS AND RESULTS

It is a prospective study of 26 (M:F-18:8) patients of CVT associated with HIV seropositive status. Their age and duration of illness was 33.8±6.8years and 11.3±8.5days respectively. Headache and vomiting was the most common symptom followed by seizures. Drowsiness with GCS (Glasgow coma score) ranging from 9-14 was present in two-thirds of the patients. Serum homocysteine was elevated in 70% of patients. Vitamin B12 was low in 12.5% and insufficient levels in 25%. 88.5% of the patients recovered completely to GCS 15/15 in 2-7days during follow up; 11.5% patients expired during the acute state.

CONCLUSION

This study represents the largest series of CVT in HIV seropositive individuals. There is increased risk of thrombosis due to elevated homocysteine and low Vitamin B12. They have better sensorium inspite of extensive radiological involvement.

Role of cranial computed tomography in human immunodeficiency virus-positive patients with generalised seizures

Background: Emergency neuroimaging of human immunodeficiency virus (HIV)-positive patients with generalised new onset seizures (NOS) and a normal post-ictal neurological examination remains controversial, with the general impression being that emergency imaging is necessary because immunosuppression may blur clinical indicators of acute intracranial pathology. The objectives of our study were to establish whether cranial computed tomography (CT) affects the emergency management of HIV-positive patients with generalised NOS and a normal post-ictal neurological examination.Method: We conducted a prospective descriptive observational study. Consecutive HIVpositive patients of 18 years and older, who presented to the Kimberley Hospital Complex’s Emergency Department within 24 hours of their first generalised seizures and who had undergone normal post-ictal neurological examinations, were included. Emergency CT results as well as CD4-count levels were evaluated.Results: A total of 25 HIV-positive patients were included in the study. The results of cranial CT brought about a change in emergency care management in 12% of patients, all of them with CD4 counts below 200 cells/mm3 .Conclusion: We suggest that emergency cranial CT be performed on all HIV-positive patients presenting with generalised NOS and a normal post-ictal neurological examination, particularly if the CD4 count is below 200 cells/mm3.Keywords: HIV; Seizures; CT Brain

Astrocyte Hypertrophy Contributes to Aberrant Neurogenesis after Traumatic Brain Injury

Traumatic brain injury (TBI) is a widespread epidemic with severe cognitive, affective, and behavioral consequences. TBIs typically result in a relatively rapid inflammatory and neuroinflammatory response. A major component of the neuroinflammatory response is astrocytes, a type of glial cell in the brain. Astrocytes are important in maintaining the integrity of neuronal functioning, and it is possible that astrocyte hypertrophy after TBIs might contribute to pathogenesis. The hippocampus is a unique brain region, because neurogenesis persists in adults. Accumulating evidence supports the functional importance of these newborn neurons and their associated astrocytes. Alterations to either of these cell types can influence neuronal functioning. To determine if hypertrophied astrocytes might negatively influence immature neurons in the dentate gyrus, astrocyte and newborn neurons were analyzed at 30 days following a TBI in mice. The results demonstrate a loss of radial glial-like processes extending through the granule cell layer after TBI, as well as ectopic growth and migration of immature dentate neurons. The results further show newborn neurons in close association with hypertrophied astrocytes, suggesting a role for the astrocytes in aberrant neurogenesis. Future studies are needed to determine the functional significance of these alterations to the astrocyte/immature neurons after TBI.

Why the communicable/non-communicable disease dichotomy is problematic for public health control strategies: implications of multimorbidity for health systems in an era of health transition

In today's globalized world, rapid urbanization, mechanization of the rural economy, and the activities of trans-national food, drink and tobacco corporations are associated with behavioral changes that increase the risk of chronic non-communicable diseases (NCDs). These changes include less healthy diet, lower physical activity, tobacco smoking and increased alcohol consumption. As a result, population health profiles are rapidly changing. For example, the global burden of type 2 diabetes mellitus is expected to double by 2030, with 80% of adult cases occurring in low and middle-income countries (LMIC). Many LMIC are undergoing rapid changes associated with developing high rates of NCD while concomitantly battling high levels of certain communicable diseases, including HIV, TB and malaria. This has population health, health systems and economic implications for these countries. This critical review synthesizes evidence on the overlap and interactions between established communicable and emerging NCD epidemics in LMIC. The review focuses on HIV, TB and malaria and explores the disease-specific interactions with prevalent NCDs in LMIC including diabetes, cardiovascular disease, chronic obstructive pulmonary disease, chronic renal disease, epilepsy and neurocognitive diseases. We highlight the complexity, bi-directionality and heterogeneity of these interactions and discuss the implications for health systems.

HIV and new onset seizures: slipping through the cracks in HIV care and treatment

OBJECTIVES

The aim of the study was to describe patient characteristics and outcomes among HIV-positive adults presenting to a Zambian tertiary care hospital with new-onset seizures.

METHODS

From July 2011 to June 2013, adults with seizures and a known or probable diagnosis of HIV infection were screened for a cohort study. Demographic and clinical data were obtained, including information on engagement in HIV services and in-patient mortality. Analyses were conducted to identify characteristics associated with poor engagement in care and death.

RESULTS

A total of 320 of 351 screened adults were HIV-positive, with 268 of 320 experiencing new-onset seizures. Of these, 114 of 268 (42.5%) were female, and their mean age was 36.8 years. Seventy-nine of the 268 patients (29.5%) were diagnosed with HIV infection during the index illness. Among those who were aware of their HIV-positive status, 59 of 156 (37.8%) had disengaged from care. Significant functional impairment (Karnofsky score < 50) was evident in 44.0% of patients. Cerebrospinal fluid was not obtained in 108 of 268 (40.3%). In-patient mortality outcomes were available for 214 patients, and 47 of these 214 (22.0%) died during hospitalization. Patients with significant functional impairment were more likely to undergo lumbar puncture (P = 0.046). Women and the functionally impaired were more likely to die (P = 0.04 and < 0.001, respectively).

CONCLUSIONS

Despite the availability of care, less than half of HIV-infected people with new-onset seizures were actively engaged in care and in-patient mortality rates were high. In the absence of clinical contraindication, lumbar puncture should be performed to diagnose treatable conditions and reduce morbidity and mortality. Continued efforts are needed to expand community-based testing and improve HIV care retention rates. Qualitative studies are needed to elucidate factors contributing to lumbar puncture usage in this population.

Clinical features of seizures in patients with human immunodeficiency virus infection

Patients with human immunodeficiency virus (HIV) infection have a higher burden of seizures, but few studies have examined seizures in HIV-infected individuals in Korea. A retrospective study was conducted to determine the epidemiology and clinical characteristics of seizures in patients with HIV infection. Among a total of 1,141 patients, 34 (3%) had seizures or epilepsy; 4 of these individuals had epilepsy before HIV infection, and the others showed new-onset seizures. Most patients exhibited moderate (200 to 500, n = 13) or low (below 200, n = 16) CD4 counts. The most common seizure etiology was progressive multifocal leukoencephalopathy (n = 14), followed by other HIV-associated central nervous system (CNS) complications (n = 6). Imaging studies revealed brain lesions in 21 patients. A total of 9 patients experienced only one seizure during the follow-up period, and 25 patients experienced multiple seizures or status epilepticus (n = 2). Multiple seizures were more common in patients with brain etiologies (P = 0.019) or epileptiform discharges on EEG (P = 0.032). Most seizures were controlled without anticonvulsants (n = 12) or with a single anticonvulsant (n = 12). Among patients with HIV infection, seizures are significantly more prevalent than in the general population. Most seizures, with the exception of status epilepticus, have a benign clinical course and few complications.

Acute EEG findings in HIV-infected Zambian adults with new-onset seizure

OBJECTIVE

To describe acute EEG findings in HIV-infected adults with new-onset seizure, assess baseline clinical characteristics associated with EEG abnormalities, and evaluate the relationship between EEG abnormalities and recurrent seizure.

METHODS

Eighty-one HIV-infected adults with new-onset seizure had EEG recordings during their index admission. Baseline characteristics assessed included HIV stage, seizure semiology, serum and CSF studies, neuroimaging, cognitive function based on the Zambian Mini-Mental State Examination and International HIV Dementia Scale, and psychiatric symptoms using the Shona Symptom Questionnaire. We evaluated the relationship between baseline characteristics and EEG abnormalities. Patients were followed for seizure recurrence, and the association between acute EEG abnormalities and seizure recurrence was assessed. Death was a secondary outcome.

RESULTS

Fifty-five patients had abnormal EEGs (68%): 18 (22%) had interictal spikes (12) or a recorded seizure (6). Among baseline clinical characteristics, more advanced HIV disease (p = 0.039) and any imaging abnormality (p = 0.027) were associated with abnormal EEGs. Cortical (p = 0.008) and white matter (p = 0.004) abnormalities were associated with slow posterior dominant rhythm. Patients were followed for a median of 303 days (interquartile range 103-560). Twenty-four (30%) died and 23 (28%) had recurrent seizures. EEG abnormalities were not associated with recurrent seizure. There was a nonsignificant association between seizures recorded during EEG and death (67% vs 26%, p = 0.051).

CONCLUSIONS

EEG abnormalities are common in this population, particularly in patients with imaging abnormalities and advanced HIV. Acute EEG abnormalities were not associated with recurrent seizure, but high mortality rates during follow-up limited this analysis.

The EEG of tropical encephalopathies

In addition to encountering most of the conditions treated by clinicians in the West, clinicians in the tropics are faced with unique tropical encephalopathies. These are largely but not entirely infectious in nature. Despite the relatively low cost of EEG technology, it remains unavailable in many low-income tropical settings even at the tertiary care level. Where available, the EEG recordings and interpretation are often of unacceptable quality. Nonetheless, there are existing data on the EEG patterns seen in malaria and a number of tropical viral, bacterial, and parasitic infestations.

Epilepsy: Indian perspective

There are 50 million people living with epilepsy worldwide, and most of them reside in developing countries. About 10 million persons with epilepsy are there in India. Many people with active epilepsy do not receive appropriate treatment for their condition, leading to large treatment gap. The lack of knowledge of antiepileptic drugs, poverty, cultural beliefs, stigma, poor health infrastructure, and shortage of trained professionals contribute for the treatment gap. Infectious diseases play an important role in seizures and long-term burden causing both new-onset epilepsy and status epilepticus. Proper education and appropriate health care services can make tremendous change in a country like India. There have been many original researches in various aspects of epilepsy across India. Some of the geographically specific epilepsies occur only in certain regions of our country which have been highlighted by authors. Even the pre-surgical evaluation and epilepsy surgery in patients with drug-resistant epilepsy is available in many centers in our country. This article attempts to provide a complete preview of epilepsy in India.

Prevalence and risk factors for active convulsive epilepsy in rural northeast South Africa

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Epilepsy is prevalent in rural South Africa, but less than other parts of Africa.

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Most epilepsy starts in childhood.

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Poor obstetric history and snoring were associated with active convulsive epilepsy.

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HIV and parasitic infection were not associated with active convulsive epilepsy.

Rationale

Epilepsy is among the most common neurological disorders worldwide. However, there are few large, population-based studies of the prevalence and risk factors for epilepsy in southern Africa.

Methods

From August 2008 to February 2009, as part of a multi-site study, we undertook a three-stage, population-based study, embedded within the Agincourt health and socio-demographic surveillance system, to estimate the prevalence and identify risk factors of active convulsive epilepsy (ACE) in a rural South African population.

Results

The crude prevalence of ACE, after adjusting for non-response and the sensitivity of the screening method, was 7.0/1,000 individuals (95%CI 6.4–7.6) with significant geographic heterogeneity across the study area. Being male (OR = 2.3; 95%CI 1.6–3.2), family history of seizures (OR = 4.0; 95%CI 2.0–8.1), a sibling with seizures (OR = 7.0; 95%CI 1.6–31.7), problems after delivery (OR = 5.9; 95%CI 1.2–24.6), and history of snoring (OR = 6.5; 95%CI 4.5–9.5) were significantly associated with ACE. For children, their mother's exposure to some formal schooling was protective (OR = 0.30; 95%CI 0.11–0.84) after controlling for age and sex. Human immunodeficiency virus was not found to be associated with ACE.

Conclusions

ACE is less frequent in this part of rural South Africa than other parts of sub-Saharan Africa. Improving obstetric services could prevent epilepsy. The relationship between snoring and ACE requires further investigation, as does the relative contribution of genetic and environmental factors to examine the increased risk in those with a family history of epilepsy.

Prevalence of active convulsive epilepsy in sub-Saharan Africa and associated risk factors: cross-sectional and case-control studies

BACKGROUND

The prevalence of epilepsy in sub-Saharan Africa seems to be higher than in other parts of the world, but estimates vary substantially for unknown reasons. We assessed the prevalence and risk factors of active convulsive epilepsy across five centres in this region.

METHODS

We did large population-based cross-sectional and case-control studies in five Health and Demographic Surveillance System centres: Kilifi, Kenya (Dec 3, 2007-July 31, 2008); Agincourt, South Africa (Aug 4, 2008-Feb 27, 2009); Iganga-Mayuge, Uganda (Feb 2, 2009-Oct 30, 2009); Ifakara, Tanzania (May 4, 2009-Dec 31, 2009); and Kintampo, Ghana (Aug 2, 2010-April 29, 2011). We used a three-stage screening process to identify people with active convulsive epilepsy. Prevalence was estimated as the ratio of confirmed cases to the population screened and was adjusted for sensitivity and attrition between stages. For each case, an age-matched control individual was randomly selected from the relevant centre's census database. Fieldworkers masked to the status of the person they were interviewing administered questionnaires to individuals with active convulsive epilepsy and control individuals to assess sociodemographic variables and historical risk factors (perinatal events, head injuries, and diet). Blood samples were taken from a randomly selected subgroup of 300 participants with epilepsy and 300 control individuals from each centre and were screened for antibodies to Toxocara canis, Toxoplasma gondii, Onchocerca volvulus, Plasmodium falciparum, Taenia solium, and HIV. We estimated odds ratios (ORs) with logistic regression, adjusted for age, sex, education, employment, and marital status.

RESULTS

586,607 residents in the study areas were screened in stage one, of whom 1711 were diagnosed as having active convulsive epilepsy. Prevalence adjusted for attrition and sensitivity varied between sites: 7·8 per 1000 people (95% CI 7·5-8·2) in Kilifi, 7·0 (6·2-7·4) in Agincourt, 10·3 (9·5-11·1) in Iganga-Mayuge, 14·8 (13·8-15·4) in Ifakara, and 10·1 (9·5-10·7) in Kintampo. The 1711 individuals with the disorder and 2032 control individuals were given questionnaires. In children (aged <18 years), the greatest relative increases in prevalence were associated with difficulties feeding, crying, or breathing after birth (OR 10·23, 95% CI 5·85-17·88; p<0·0001); abnormal antenatal periods (2·15, 1·53-3·02; p<0·0001); and head injury (1·97, 1·28-3·03; p=0·002). In adults (aged ≥18 years), the disorder was significantly associated with admission to hospital with malaria or fever (2·28, 1·06-4·92; p=0·036), exposure to T canis (1·74, 1·27-2·40; p=0·0006), exposure to T gondii (1·39, 1·05-1·84; p=0·021), and exposure to O volvulus (2·23, 1·56-3·19; p<0·0001). Hypertension (2·13, 1·08-4·20; p=0·029) and exposure to T solium (7·03, 2·06-24·00; p=0·002) were risk factors for adult-onset disease.

INTERPRETATION

The prevalence of active convulsive epilepsy varies in sub-Saharan Africa and that the variation is probably a result of differences in risk factors. Programmes to control parasitic diseases and interventions to improve antenatal and perinatal care could substantially reduce the prevalence of epilepsy in this region.

Neurotropic viral infections leading to epilepsy: focus on Theiler's murine encephalomyelitis virus

Neurotropic viruses cause viral encephalitis and are associated with the development of seizures/epilepsy. The first infection-driven animal model for epilepsy, the Theiler's murine encephalomyelitis virus-induced seizure model is described herein. Intracerebral infection of C57BL/6 mice with Theiler's murine encephalomyelitis virus induces acute seizures from which the animals recover. However, once the virus is cleared, a significant portion of the animals that experienced acute seizures later develop epilepsy. Components of the innate immune response to viral infection, including IL-6 and complement component 3, have been implicated in the development of acute seizures. Multiple mechanisms, including neuronal cell destruction and cytokine activation, play a role in the development of acute seizures. Future studies targeting the innate immune response will lead to new therapies for seizures/epilepsy.

Relevance of neuroimaging in the diagnosis and management of tropical neurologic disorders

The development in neuroimaging techniques has revolutionized the way neurology is practiced, including neurologic disorders in tropics. Some diseases occur exclusively, whereas some are more common in tropical regions. However, some are becoming increasingly prevalent in the developed world too, as a result of patterns of human migration and globalization. It is imperative to learn about the role of imaging in tropical neurology, which might assist early diagnosis and treatment and also add to the existing knowledge. Infections are more common in the tropics and require special attention in view of their potential treatability.

Infectious causes of seizures and epilepsy in the developing world

Central nervous system (CNS) infections are the main cause of seizures and acquired epilepsy in the developing world. Geographical variations determine the common causes in a particular region. Acute seizures are common in severe meningitis, viral encephalitis, malaria, and neurocysticercosis, and in most cases are associated with increased mortality and morbidity, including subsequent epilepsy. Neuronal excitability secondary to proinflammatory signals induced by CNS infections are an important common mechanism for the generation of seizures, in addition to various other specific mechanisms. Newer insights into the neurobiology of these infections and the associated epilepsy could help in developing neuroprotective interventions. Management issues include prompt treatment of acute seizures and the underlying CNS infection, correction of associated predisposing factors, and decisions regarding the appropriate choice and duration of antiepileptic therapy. Strategies for the prevention of epilepsy in CNS infections such as early anti-infective and anti-inflammatory therapy need scientific exploration. Prevention of CNS infections is the only definitive way forward to reduce the burden of epilepsy in developing countries.

Effects of S100B on Serotonergic Plasticity and Neuroinflammation in the Hippocampus in Down Syndrome and Alzheimer's Disease: Studies in an S100B Overexpressing Mouse Model

S100B promotes development and maturation in the mammalian brain. However, prolonged or extensive exposure can lead to neurodegeneration. Two important functions of S100B in this regard, are its role in the development and plasticity of the serotonergic neurotransmitter system, and its role in the cascade of glial changes associated with neuroinflammation. Both of these processes are therefore accelerated towards degeneration in disease processes wherein S100B is increased, notably, Alzheimer's disease (AD) and Down syndrome (DS). In order to study the role of S100B in this context, we have examined S100B overexpressing transgenic mice. Similar to AD and DS, the transgenic animals show a profound change in serotonin innervation. By 28 weeks of age, there is a significant loss of terminals in the hippocampus. Similarly, the transgenic animals show neuroinflammatory changes analogous with AD and DS. These include decreased numbers of mature, stable astroglial cells, increased numbers of activated microglial cells and increased microglial expression of the cell surface receptor RAGE. Eventually, the S100B transgenic animals show neurodegeneration and the appearance of hyperphosphorylated tau structures, as seen in late stage DS and AD. The role of S100B in these conditions is discussed.

Antiepileptic drugs and other medications: what interactions may arise?

Many patients with epilepsy are on lifelong therapy with antiepileptic drugs (AEDs), and AEDs are used for other conditions such as mood stabilization and headache prophylaxis. These drugs have high potential for clinically significant interaction with nonepilepsy drugs. Interactions occur largely through altered pharmacokinetics. One drug may increase the hepatic clearance of another, leading to attenuated efficacy of the affected drug. Alternatively, inhibition of liver metabolism by one drug can cause acute toxicity by reducing clearance of another drug. To identify potential drug interactions before they lead to toxicity or therapy failure, the treating clinician should combine knowledge of the patient's overall history with a general knowledge of comorbid conditions in which significant interactions involving AEDs are most likely to occur. Treatments susceptible to interactions include anticoagulants, antiarrhythmics, antibiotics, antiretroviral drugs, immunosuppressives, antineoplastics, and contraceptives. Therefore, it is important to obtain periodically a thorough history of medical problems, use of medications or herbal remedies, and adverse effects of medications. Physicians managing epilepsy patients should also strive to avoid potential drug interactions by favoring low-interaction AEDs in patients taking many other types of drugs. There is quite a large degree of patient heterogeneity in the extent of any given interaction between an AED and another drug. Indeed, some groups of patients may have different susceptibilities to such interactions because of genetic and environmental influences on drug metabolism. Effective treatment with AEDs should include attention to drug interactions.