Cognitive impairment and quality of life of people with epilepsy and neurocysticercosis in Zambia

Neurocysticercosis and cognitive impairment among people with epilepsy in Taenia solium endemic regions of rural southern Tanzania: A hospital-based cross-sectional study in mental health clinics of selected sites in Tanzania

BACKGROUND

Epilepsy poses a significant public health problem in many parts of the world. The majority of people with epilepsy (PWE) are from low-income and middle-income countries (LMICs). Taenia solium neurocysticercosis (NCC) is estimated to cause 30% of preventable epilepsy in PWE in areas of T. solium endemicity. This study was conducted to assess the prevalence of NCC in PWE, evaluate the presence of cognitive impairment in PWE and assess potentially contributing factors.

METHODS

PWE were recruited within a mental health clinic-based cross-sectional study in rural Southern Tanzania. PWE underwent a detailed neurological examination, including mental state, and a blood sample was collected for T. solium cysticercosis (CC) serology testing. Patients who were serologically positive for CC and those detected to have prominent neurological deficits apart from epilepsy were invited to receive a cerebral computed tomography (CT) examination.

RESULTS

Out of the 223 people with epilepsy (PWE) recruited, 221 underwent clinical examination. Among these, 26 (11.8 %) had cognitive impairment, and 2 had neurological signs or symptoms without cognitive impairment. Twenty-five of the 223 PWE (11.2 %) tested positive for CC, of which 4 had cognitive impairment. One hundred and ninety-eight (88.8 %) tested negative for CC, of which 22 had cognitive impairment. A total of 36 participants underwent CT scans, with 18 testing positive and 18 testing negative for CC. Of the 36 who had CT scans, 8 (22.2 %) were diagnosed with NCC; 7 were CC positive, and 1 was CC negative; only the latter had cognitive impairment. Multivariate logistic regression confirmed that cognitive impairment in PWE was 8.62 times higher for Kongwa participants than Chunya, with a statistically significant association (95 % CI: 1.75, 156; p = 0.037). Additionally, having and education was associated with a 91 % reduction in the odds of cognitive impairment (OR = 0.09) compared to no education, which was also statistically significant (95 % CI: 0.01, 0.33; p = 0.002). There was no association between cognitive impairment and NCC.

CONCLUSION

Our study found a 22.2 % prevalence of NCC among PWE. Cognitive impairment was present in 11.8 % of PWE but was not significantly associated with NCC. Socioeconomic and educational factors may play a larger role in cognitive impairment among PWE.

Gaps in treatment of epileptic seizures in a Zambian rural area

BACKGROUND

Epilepsy is a multifactorial neurological disorder, including parasitic infections of the brain such as neurocysticercosis (NCC). People with epileptic seizures (PWES) in low and middle-income countries often do not receive appropriate treatment, which besides epileptic seizures, may also lead to reduced quality of life and possibly death. The objective of this study was to describe gaps in treatment of epileptic seizures in a Zambian rural area.

METHODS

A cross-sectional study was conducted in Sinda district of Zambia between August and October 2018. PWES identified from clinic records and with the help of community healthcare workers were recruited. Two questionnaires, one to PWES and the other to local healthcare workers, were administered to describe the treatment gap.

RESULTS

A total of 146 PWES and 43 healthcare workers were interviewed. Of the 146 PWES, 131 had taken anti-seizure medication (ASM) at some point since their seizure onset, of which 49.6% were on current treatment. Only 18.3% were on continuous ASM, an overall treatment gap of 83.6%. Over 55% of healthcare workers did not know the relationship between epilepsy and NCC. The risk factors associated with lack of appropriate treatment were stock-outs of ASMs, lack of diagnostic equipment, poor patient follow-up, and PWES opting for traditional medicine.

CONCLUSION

The treatment gap is substantial in Sinda district. The causes are multifactorial, involving shortcomings at the level of healthcare facilities, communities, and individuals. Directed training of healthcare workers and significant improvements in the supply and dispensing of ASMs will be key in substantially reducing the gap.

Association between Alzheimer's disease and Toxocara infection/exposure: a case-control study

BACKGROUND

Infections may contribute to Alzheimer's disease (AD) risk. Limited evidence suggests Toxocara spp. infection/exposure could influence AD development.

METHODS

We investigated Toxocara seropositivity and AD in Iranian adults using a matched case-control study. Our sample included 90 AD cases and 91 healthy older adults. Anti-Toxocara immunoglobulin G (IgG) antibodies were assessed via enzyme-linked immunosorbent assay. We computed the odds ratios (ORs) and 95% confidence intervals (CIs) through univariable and multivariable analyses, adjusting for potential confounders.

RESULTS

There were 33/90 (36.67% [95% CI 26.75 to 47.48]) anti-Toxocara IgG seropositive individuals identified among the AD cases and 21/91 (23.07% [95% CI 14.89 to 33.09]) among the healthy controls. In univariable analysis, a significant association was identified between anti-Toxocara IgG seropositivity and AD (OR 1.93 [95% CI 1.01 to 3.69], p<0.001). Moreover, the association remained significant (OR 2.18 [95% CI 1.05 to 4.49], p<0.001) in multivariable analysis after adjustment for covariates. There was no association between anti-Toxocara IgG seropositivity and the severity of AD (OR 0.75 [95% CI 0.21 to 2.61], p=0.47).

CONCLUSIONS

Our findings indicated that Toxocara exposure/infection could be a potential risk factor for development of AD. To better understand a real causality between Toxocara exposure/infection and AD and related dementias, follow-up designed and adequately powered studies are needed.

Neurocysticercosis: Isolated Lesion in the Left Middle Frontal Gyrus

OBJECTIVE

Neurocysticercosis (NCC) is one of the most common parasitic infections of the central nervous system. We present a case study of a 21-year-old African man with an isolated NCC lesion to the left middle frontal gyrus, which is also known as the dorsolateral prefrontal cortex (dlPFC).

METHOD

A neuropsychological evaluation was requested by the patient's inpatient psychiatry team regarding worsening attention and depressive symptoms approximately 6 months after NCC diagnosis and treatment.

RESULTS

Neuropsychological findings revealed deficits in the aspects of executive functioning, attention, working memory, and significant depressive symptoms.

CONCLUSION

To our knowledge, this is the first case study of its kind demonstrating deficits in cognitive functioning consistent with the dlPFC lesion location. Sociocultural and linguistic considerations, clinical findings, and limitations are discussed.

The impact of brivaracetam on cognitive processes and anxiety in various experimental models

BACKGROUND

Memory deficits and anxiety symptoms are undesirable effects that occur in epilepsy patients. They may be associated with the pathophysiology of the disease but also with anticonvulsant therapy. Brivaracetam (BRV) is one of the newest antiseizure drugs. It acts as a ligand for synaptic vesicle glycoprotein 2A (SV2A), which may play a significant role in cognitive processes. Although BRV has a favorable safety profile, its central side effects remain unclear. Hence, this study aimed to evaluate the effect of BRV on various types of memory and anxiety in rats.

METHODS

BRV was given to adult male Wistar rats (n = 80) via gastric tube as a single dose (6 mg/kg or 20 mg/kg) or chronically (6 mg/kg). The effect of the drug on spatial memory was evaluated in the Morris water maze (MWM), fear-learning by passive avoidance (PA), and recognition memory with novel object recognition (NOR). The elevated plus maze (EPM) was used to assess anxiety-like behaviors.

RESULTS

The impact of BRV on memory is dose-dependent and mainly high doses may alter retrieval memory and fear-learning. Sub-chronic administration also impaired retrieval and spatial memory in animals. Moreover, chronic BRV may increase anxiety levels in rats but did not affect recognition memory.

CONCLUSIONS

BRV may cause transient memory deficits as well as anxiety disturbances. However, the results are varied and depend on the type of memory, used dose, and duration of administration.

Impaired orienting function detected through eye movements in patients with temporal lobe epilepsy

Objective

Patients with temporal lobe epilepsy (TLE) often exhibit attention function impairment. The orienting network is the subsystem of the attention network that has not been fully studied. In this study, we used eye-tracking technology with an attention network test (ANT)-based task to assess the orienting function of TLE patients, aiming to characterize their eye movement patterns.

Methods

A total of 37 TLE patients and 29 healthy controls (HCs) completed the ANT task based on eye-tracking technology. Orienting function damage was mainly assessed by the ANT orienting effect. Eye movement metrics, such as mean first goal-directed saccade latency (MGSL), total saccades, and saccade amplitudes, were compared between groups.

Results

The TLE patients had a significantly lower ANT orienting effect (HC, 54.05 ± 34.05; TLE, 32.29 ± 39.54) and lower eye-tracking orienting effect (HC, 116.98 ± 56.59; TLE, 86.72 ± 59.10) than those of the HCs. The larger orienting effects indicate that orienting responses are faster when receiving a spatial cue compared with a center cue. In the spatial cue condition, compared with HCs, the TLE group showed a longer first goal-directed saccade latency (HC, 76.77 ± 58.87 ms; TLE, 115.14 ± 59.15 ms), more total saccades (HC, 28.46 ± 12.30; TLE, 36.69 ± 15.13), and larger saccade amplitudes (HC, 0.75° ± 0.60°; TLE, 1.36° ± 0.89°). Furthermore, there was a positive correlation of the orienting-effect score between the ANT task and eye-tracking metrics (r = 0.58, p < 0.05).

Conclusion

We innovatively developed a new detection method using eye-tracking technology in combination with an ANT-based task to detect the orienting function in TLE patients. The current research demonstrated that TLE patients had a significant orienting dysfunction with a specific saccade pattern characterized by a longer first goal-directed saccade latency, more total saccades, and larger saccade amplitudes. These oculomotor metrics are likely to be a better indicator of orienting function and may potentially be used for behavioral-based interventions and long-term cognition monitoring in TLE patients.

Impaired spatial working memory and reduced hippocampal neuronal density in a rat model of neurocysticercosis

Neurocysticercosis (NCC) is the most common parasitic disease affecting the nervous system and is a leading cause of acquired epilepsy worldwide, as well as cognitive impairment, especially affecting memory. The aim of this study was to evaluate the effect of NCC on spatial working memory and its correlation with hippocampal neuronal density, in a rat model of NCC. This experimental study was conducted on female (n = 60) and male (n = 73) Holtzman rats. NCC was induced by intracranial inoculation of T. solium oncospheres in 14 day-old-rats. Spatial working memory was assessed using the T-maze test at 3, 6, 9, and 12 months post-inoculation, and sensorimotor evaluation was performed at 12 months post-inoculation. Hippocampal neuronal density was evaluated by immunostaining of NeuN-positive cells of the CA1 region. Of the rats inoculated with T. solium oncospheres, 87.2% (82/94) developed NCC. The study showed a significant decline in spatial working memory over a 1-year follow-up period in rats experimentally infected with NCC. Males showed an early decline that started at 3 months, while females demonstrated it at 9 months. Additionally, a decrease in neuronal density was observed in the hippocampus of NCC-infected rats, with a more significant reduction in rats with cysts in the hippocampus than in rats with cysts in other brain areas and control rats. This rat model of NCC provides valuable support for the relationship between neurocysticercosis and spatial working memory deficits. Further investigations are required to determine the mechanisms involved in cognitive impairment and establish the basis for future treatments.

Status of epilepsy in the tropics: An overlooked perspective

Epilepsy is one of the most common serious chronic neurological diseases affecting people of all ages globally. It is characterized by recurrent seizures. About 50 million people worldwide have epilepsy. Indubitably, people with epilepsy (PWE) may be without access to appropriate treatment. Many studies have examined the molecular mechanisms and clinical aspects of epilepsy; nonetheless, the treatment gap exists in some special areas. In the tropics, the specific geographical and ecological conditions and a lack of medical resources result in neglect or delay of diagnosis for PWE. Herein, we summarized the epidemiology of epilepsy in the tropics and discussed the disease burden and existing problems, aiming to offer a medical environment for patients in need and highlight the importance of reducing the epileptic disease burden in tropical countries.

Meanings of quality of life among people living with epilepsy in Ghana; a qualitative exploratory study

PURPOSE

The purpose of this study was to explore the meanings of quality of life among people living with epilepsy (PLWE) in Ghana.

METHODS

An exploratory-qualitative study design was adopted. Face-to-face in-depth interviews, using a semi-structured interview guide, were conducted on 15 PLWE who were purposively selected for the study. The interviews were audio recorded and transcribed verbatim. The content analysis approach was then used to analyze the data.

RESULTS

Four themes - "acceptance", "support", "seizure control", and "self-reliance" emerged from the study as meanings of Quality of life (QoL). Quality of life meant unconditional acceptance from family, friends, acquaintances at home, school, and work, and by the public despite epilepsy. Receiving support in the form of protection from injury during a seizure, financial assistance to meet individual and family demands, emotional warmth, and spiritual support through prayers and encouragement, was QoL for PLWE. Achievement of control over seizures and being self-reliant in terms of selfcare and daily activities in addition to having some form of financial independence meant QoL.

CONCLUSION

Meanings of quality of life among PLWE is associated with being accepted and supported by family and friends as well as being in control of seizures and attaining a status of independence.

Health-related quality of life among people with type 2 diabetes mellitus - A multicentre study in Bangladesh

AIMS

This study aimed to explore the health-related quality of life and the various demographics and clinical characteristics associated with it among people with type 2 diabetes mellitus in Bangladesh.

METHODS

A total of 1253 participants with type 2 diabetes were recruited from a cross-sectional and retrospective study conducted in Bangladesh in 2017. Participants were recruited from six rural and urban diabetes hospitals. The health-related quality of life of the participants was assessed using the validated EuroQol-5D-5L scale and EuroQol-VAS score. Information was collected via face-to-face interviews and existing medical records. Data was analysed using univariate and multivariable regression analyses with bootstrap resampling.

RESULTS

The average health-related quality of life was 0.64 (±0.20) for EQ-5D-5L score and 61.69 (±34.98) for EQ-VAS score. Old age, low income, low education level, residing in an urban area, longer duration of diabetes, being physically inactive, the presence of macro- and/or micro-vascular complications, impaired cognitive function, being depressed and having anxiety were related to poor health-related quality of life.

CONCLUSION

The health-related quality of life among people with type 2 diabetes in Bangladesh is low, and various socio-demographic and psychological factors and diabetes-related complications are associated with it. This finding will help reform treatments and enforce lifestyle modifications to ensure that the burden of diabetes on people's quality of life is minimal.

High frequency of Taenia solium antigen positivity in patients admitted for neurological disorders in the Rural Hospital of Mosango, Democratic Republic of Congo

Background

The epidemiology of human cysticercosis and neurocysticercosis, caused by the larval stage of the pork tapeworm Taenia solium, is not well known in the Democratic Republic of Congo (DRC). Within a multicenter etiological and diagnostic study conducted by the NIDIAG consortium (“Better Diagnosis for Neglected Infections”) and investigating several challenging syndromes, we consecutively evaluated from 2012 to 2015 all patients older than 5 years presenting with neurological disorders (neurology cohort) and with fever > 7 days (persistent fever cohort) at the rural hospital of Mosango, province of Kwilu, DRC. In both cohorts, etiological diagnosis relied on a systematic set of reference laboratory assays and on pre-established clinical case definitions. No neuroimaging was available in the study hospital. In this study, we determined the frequency of T. solium infection in both cohorts and explored in the neurology cohort its association with specific neurological presentations and final etiological diagnoses.

Methods

We conducted a post-hoc descriptive and analytic study on cysticercosis in the neurology and persistent fever cohorts, based on the presence in serum samples of circulating T. solium antigen using the B158/B60 enzyme-linked immunosorbent assay (ELISA) and of cysticercosis IgG using the LDBIO Cysticercosis Western Blot IgG assay.

Results

For the neurology cohort, 340 samples (of 351 enrolled patients) were available for analysis (males: 46.8%; mean age: 38.9 years). T. solium antigen positivity was found in 43 participants (12.6%; 95% confidence interval [CI] 9.3–16.7%), including 9 of 60 (15%) patients with epilepsy. Among the 148 samples available from the persistent fever cohort (males: 39.9%; mean age: 19.9 years), 7 were positive in the T. solium antigen ELISA (4.7%; 95% CI 1.9–9.5%; P = 0.009 when compared to the neurology cohort). No significant association was found within the neurology cohort between positivity and clinical presentation or final diagnoses. Of note, the IgG antibody-detecting assay was found positive in only four (1.3%) of the participants of the neurology cohort and in none of the persistent fever cohort.

Conclusions

T. solium antigen positivity was found in at least 10% of patients admitted with neurological disorders in the Kwilu province, DRC, with no specific pattern of presentation. Further neuroimaging studies should be used to confirm whether neurocysticercosis is prevalent in this region.

Peripheral Taenia infection increases immunoglobulins in the central nervous system

Human cysticercosis is a disease caused by larvae of the cestode Taenia solium. It is an important common cause of adult-onset seizures world-wide where it exacts a debilitating toll on the health and well-being of affected communities. It is commonly assumed that the major symptoms associated with cysticercosis are a result of the direct presence of larvae in the brain. As a result, the possible effects of peripherally located larvae on the central nervous system are not well understood. To address this question, we utilised the Taenia crassiceps intra-peritoneal murine model of cysticercosis, where larvae are restricted to the peritoneal cavity. In this model, previous research has observed behavioural changes in rodents but not the development of seizures. Here we used ELISAs, immunoblotting and the Evans Blue test for blood-brain barrier permeability to explore the central effects of peripheral infection of mice with T. crassiceps. We identified high levels of parasite-targeting immunoglobulins in the sera of T. crassiceps-infected mice. We show that the T. crassciceps larvae themselves also contain and release host immunoglobulins over time. Additionally, we describe, for the first known time, significantly increased levels of IgG within the hippocampi of infected mice, which are accompanied by changes in blood-brain barrier permeability. However, these T. crassiceps-induced changes were not accompanied by alterations to the levels of proinflammatory, pro-seizure cytokines in the hippocampus. These findings contribute to the understanding of systemic and neuroimmune responses in the T. crassiceps model of cysticercosis, with implications for the pathogenesis of human cysticercosis.

Alterations Functional Connectivity in Temporal Lobe Epilepsy and Their Relationships With Cognitive Function: A Longitudinal Resting-State fMRI Study

Background: Cognitive impairments in temporal lobe epilepsy (TLE) patients has been described as a chronically progressive feature of the disease. However, how severe recurrent seizures modify neuronal circuits in the human brain and subsequently degrade cognitive function, remains largely unknown. Here, we aimed to investigate longitudinal alterations by functional magnetic resonance imaging (fMRI) in TLE patients and to assess how those alterations are related to cognitive function performance.

Methods: Sixteen TLE patients and 20 normal controls (NCs) were recruited for a study to observe longitudinal alterations in resting-state functional connectivity (FC) and to estimate alertness, orientation, and executive function both at baseline and at a follow-up time ~3 years later.

Results: TLE patients, compared with NCs, showed impaired executive function, intrinsic alertness, and phasic alertness and exhibited lengthened reaction time (RT) in the spatial cue and center cue conditions at baseline. The orienting function of TLE patients was declined at follow-up compared to the baseline. Cross-sectional analysis demonstrated that TLE patients displayed significantly greater positive correlation than NCs between the right dorsolateral prefrontal cortex (DLPFC) and the right inferior parietal lobule (IPL) and right superior frontal gyrus (SFG). Furthermore, among TLE patients, the longitudinal study revealed a decrease in correlation between the right DLPFC and the right SFG compared to the baseline. In addition, there was a significant negative correlation between the longitudinal change in FC and the change in orienting function in TLE subjects.

Conclusions: Abnormal connectivity between the DLPFC and the SFG suggests the potential of longitudinal resting-state fMRI to delineate regions relevant to cognitive dysfunction for disease progression.

Taenia solium Cysticercosis and Its Impact in Neurological Disease

Taenia solium neurocysticercosis (NCC) is endemic in most of the world and contributes significantly to the burden of epilepsy and other neurological morbidity. Also present in developed countries because of immigration and travel, NCC is one of few diseases targeted for eradication. This paper reviews all aspects of its life cycle (taeniasis, porcine cysticercosis, human cysticercosis), with a focus on recent advances in its diagnosis, management, and control. Diagnosis of taeniasis is limited by poor availability of immunological or molecular assays. Diagnosis of NCC rests on neuroimaging findings, supported by serological assays. The treatment of NCC should be approached in the context of the particular type of infection (intra- or extraparenchymal; number, location, and stage of lesions) and has evolved toward combined symptomatic and antiparasitic management, with particular attention to modulating inflammation. Research on NCC and particularly the use of recently available genome data and animal models of infection should help to elucidate mechanisms of brain inflammation, damage, and epileptogenesis.

Control of Taenia solium; A Case for Public and Private Sector Investment

The zoonotic helminth T. solium is one of the leading causes of acquired epilepsy in endemic countries, resulting in a high burden both in human health and social stigma of affected people (1-3). In 2012 T. solium was highlighted as a priority for control in the World Health Assembly resolution 66.12 (4). Despite a call for validated control strategies by 2015 and a "Tool Kit" of control options being available, relatively few examples of successfully implemented and sustainable control programs are available (5-7). A minimal control strategy focusing solely on the porcine host has also been proposed although the cost-effectiveness of such has yet to be explored (8). Although acknowledgment has been made of the need for initiatives to be sustainable, we are yet to see sufficient consideration of the balance between the provision of public and private goods, and the need for engagement of the people and organizations in the pork value chains within T. solium control strategies. We utilized a food chain risk analysis model to determine the incremental cost-effectiveness ratio (ICER) in terms of $/infective meal avoided, of combining a pharmaceutical intervention in pigs with strengthened meat hygiene services. The addition of a vaccination and treatment protocol, at an additional 10.3% cost, was illustrated to have the potential to improve the ICER of improving meat inspection by 74.6%. The vaccination and treatment protocol also had the potential to reduce the losses borne by the pork industry of condemned meat by 66%, highlighting the potential to leverage private sector investment in T. solium control.

The Association between Calcified Neurocysticercosis and Cognitive Performance: A Case-Control Study Nested to a Population-Based Cohort

Mechanisms implicated in the association between neurocysticercosis (NCC) and cognitive impairment remain unknown. Atahualpa residents aged ≥ 40 years with calcified NCC were identified as case patients and paired 1:1 to age- and gender-matched controls. The selection process generated 79 pairs. Cognitive performance was measured by the Montreal Cognitive Assessment (MoCA). A conditional logistic regression model revealed no differences in MoCA scores across case patients and controls, after adjusting for education, epilepsy, depression, and hippocampal atrophy. The single covariate remaining significant was hippocampal atrophy. When participants were stratified according to this covariate, linear models showed lower MoCA scores among case patients (but not controls) with hippocampal atrophy. In a fully adjusted linear regression model, age remained as the single covariate explaining cognitive impairment among NCC patients. This study demonstrates an association between hippocampal atrophy and poor cognitive performance among patients with calcified NCC, most likely attributable to the effect of age.

Associated and predictive factors of quality of life in patients with temporal lobe epilepsy

OBJECTIVE

Identifying the factors that are correlated with and predictive of reduced quality of life (QOL) is essential to optimize the treatment of epilepsy and the management of comorbidities.

METHODS

We analyzed the independent associations between the Quality of Life in Epilepsy-31 (QOLIE-31) inventory and the demographic, clinical, psychiatric, and cognitive variables of 47 consecutive patients with temporal lobe epilepsy (TLE). Predictors of the correlated variables were analyzed by multiple linear regression analysis.

RESULTS

The QOLIE-31 total score was positively correlated with occupational status and Mini-Mental State Examination (MMSE) scores (r = 0.290 and 0.295, respectively; P < 0.05) and negatively correlated with the duration of seizures, adverse effects of antiepileptic drugs (AEDs), and the Pittsburgh Sleep Quality Inventory (PSQI), Self-rating Anxiety Scale (SAS), and Self-rating Depression Scale (SDS) scores (r = -0.357, 0.321, 0.328, -0.672, and -0.565, respectively; P < 0.05; P < 0.01 for the SAS and SDS). In the final multivariate regression model, anxiety, long durations of seizures, adverse effects of AEDs, and depression explained approximately 60.6% (adjusted R² = 0.606, R coefficient = 0.800) of the QOLIE-31 overall score variance.

CONCLUSION

Anxiety, long durations of seizures, adverse effects of AEDs, and depression were significant predictors of QOL, and these variables had relatively high prediction capacities for the overall QOLIE-31 in the regression model. Comorbid anxiety is the most powerful negative determinant of the QOLIE-31.