The Most Common Lesions Detected by Neuroimaging as Causes of Epilepsy

Neurocysticercosis Prevalence and Characteristics in Communities of Sinda District in Zambia: A Cross-Sectional Study

BACKGROUND

This study aimed at describing the epidemiology of (neuro)cysticercosis as well as its clinical and radiological characteristics in a Taenia solium endemic district of Zambia.

METHODS

This was part of a cross-sectional community-based study conducted in Sinda district to evaluate an antibody-detecting T. solium point-of-care (TS POC) test for taeniosis and (neuro)cysticercosis. All TS POC cysticercosis positive (CC+) participants and a subset of the TS POC cysticercosis negative (CC-) received a clinical evaluation and cerebral computed tomography (CT) examination for neurocysticercosis (NCC) diagnosis and staging.

RESULTS

Of the 1249 participants with a valid TS POC test result, 177 (14%) were TS POC CC+ . Cysticercosis sero-prevalence was estimated to be 20.1% (95% confidence intervals [CI] 14.6-27.0%). In total, 233 participants received a CT examination (151 TS POC CC+ , 82 TS POC CC-). Typical NCC lesions were present in 35/151 (23%) TS POC CC+ , and in 10/82 (12%) TS POC CC- participants. NCC prevalence was 13.5% (95% CI 8.4-21.1%) in the study population and 38.0% (95% CI 5.2-87.4%) among people reporting epileptic seizures. Participants with NCC were more likely to experience epileptic seizures (OR = 3.98, 95% CI 1.34-11.78, p = 0.01) than those without NCC, although only 7/45 (16%) people with NCC ever experienced epileptic seizures. The number of lesions did not differ by TS POC CC status (median: 3 [IQR 1-6] versus 2.5 [IQR 1-5.3], p = 0.64). Eight (23%) of the 35 TS POC CC+ participants with NCC had active stage lesions; in contrast none of the TS POC CC- participants was diagnosed with active NCC.

CONCLUSION

NCC is common in communities in the Eastern province of Zambia, but a large proportion of people remain asymptomatic.

Vulnerability of the Hippocampus to Insults: Links to Blood-Brain Barrier Dysfunction

The hippocampus is a critical brain substrate for learning and memory; events that harm the hippocampus can seriously impair mental and behavioral functioning. Hippocampal pathophysiologies have been identified as potential causes and effects of a remarkably diverse array of medical diseases, psychological disorders, and environmental sources of damage. It may be that the hippocampus is more vulnerable than other brain areas to insults that are related to these conditions. One purpose of this review is to assess the vulnerability of the hippocampus to the most prevalent types of insults in multiple biomedical domains (i.e., neuroactive pathogens, neurotoxins, neurological conditions, trauma, aging, neurodegenerative disease, acquired brain injury, mental health conditions, endocrine disorders, developmental disabilities, nutrition) and to evaluate whether these insults affect the hippocampus first and more prominently compared to other brain loci. A second purpose is to consider the role of hippocampal blood-brain barrier (BBB) breakdown in either causing or worsening the harmful effects of each insult. Recent research suggests that the hippocampal BBB is more fragile compared to other brain areas and may also be more prone to the disruption of the transport mechanisms that act to maintain the internal milieu. Moreover, a compromised BBB could be a factor that is common to many different types of insults. Our analysis indicates that the hippocampus is more vulnerable to insults compared to other parts of the brain, and that developing interventions that protect the hippocampal BBB may help to prevent or ameliorate the harmful effects of many insults on memory and cognition.

Quantitative susceptibility mapping identifies hippocampal and other subcortical grey matter tissue composition changes in temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is associated with widespread brain alterations. Using quantitative susceptibility mapping (QSM) alongside transverse relaxation rate (R 2 * ), we investigated regional brain susceptibility changes in 36 patients with left-sided (LTLE) or right-sided TLE (RTLE) secondary to hippocampal sclerosis, and 27 healthy controls (HC). We compared three susceptibility calculation methods to ensure image quality. Correlations of susceptibility andR 2 * with age of epilepsy onset, frequency of focal-to-bilateral tonic-clonic seizures (FBTCS), and neuropsychological test scores were examined. Weak-harmonic QSM (WH-QSM) successfully reduced noise and removed residual background field artefacts. Significant susceptibility increases were identified in the left putamen in the RTLE group compared to the LTLE group, the right putamen and right thalamus in the RTLE group compared to HC, and a significant susceptibility decrease in the left hippocampus in LTLE versus HC. LTLE patients who underwent epilepsy surgery showed significantly lower left-versus-right hippocampal susceptibility. SignificantR 2 * changes were found between TLE and HC groups in the amygdala, putamen, thalamus, and in the hippocampus. Specifically, decreased R2 * was found in the left and right hippocampus in LTLE and RTLE, respectively, compared to HC. Susceptibility andR 2 * were significantly correlated with cognitive test scores in the hippocampus, globus pallidus, and thalamus. FBTCS frequency correlated positively with ipsilateral thalamic and contralateral putamen susceptibility and withR 2 * in bilateral globi pallidi. Age of onset was correlated with susceptibility in the hippocampus and putamen, and withR 2 * in the caudate. Susceptibility andR 2 * changes observed in TLE groups suggest selective loss of low-myelinated neurons alongside iron redistribution in the hippocampi, predominantly ipsilaterally, indicating QSM's sensitivity to local pathology. Increased susceptibility andR 2 * in the thalamus and putamen suggest increased iron content and reflect disease severity.

A tract-based spatial statistics study of white matter integrity in epilepsy

OBJECTIVE

To explore the changes of cerebral white matter diffusion tensor in epilepsy.

METHODS

This study was a retrospective study based on diffusion tensor imaging (DTI). Twenty-six epileptic patients and 42 normal controls matched for sex, age and handedness were enrolled in our research. Based on the method of tract-based spatial statistics (TBSS), we analyzed the changes of each relevant parameter index of DTI in white matter of the brain in all subjects, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD).

RESULTS

In comparison with the control group, epileptic patients had decreased FA and elevated MD, AD, and RD in the anterior thalamic radiation, corticospinal tract, forceps major, forceps minor, cingulum, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, superior longitudinal fasciculus and uncinate fasciculus (P < 0.05).

CONCLUSION

Widespread white matter integrity was observed in epileptic patients, which may be the structural basis for the development of affective disorders, impaired cognition, and motor abnormalities.

Integrating Network Neuroscience Into Epilepsy Care: Progress, Barriers, and Next Steps

Drug resistant epilepsy is a disorder involving widespread brain network alterations. Recently, many groups have reported neuroimaging and electrophysiology network analysis techniques to aid medical management, support presurgical planning, and understand postsurgical seizure persistence. While these approaches may supplement standard tests to improve care, they are not yet used clinically or influencing medical or surgical decisions. When will this change? Which approaches have shown the most promise? What are the barriers to translating them into clinical use? How do we facilitate this transition? In this review, we will discuss progress, barriers, and next steps regarding the integration of brain network analysis into the medical and presurgical pipeline.

Gri Cevher Heterotopisi Bulunan Pediatrik Hastaların Manyetik Rezonans Görüntüleme Bulguları ve Eşlik Eden Malformasyonların Değerlendirilmesi

Objective: The aim of the present study is to classify gray matter heterotopias according to magnetic resonance imaging findings and to define the accompanying malformations. Methods: Images of all pediatric patients who were detected to have heterotopia in brain magnetic resonance imaging between January 2012 and June 2020 were retrospectively evaluated. The type, location of heterotopia, and accompanying cerebral anomalies were analyzed. Results: A total of 42 patients, 22 male, and 20 female, with a mean age of 7.80 ± 4.53 years (2-16 years) with gray matter heterotopia were included in the study. Of the patients, 33 (78.6%) had subependymal, 7 (16.7%) had subcortical, and 2 (4.7%) had band heterotopia. Twenty-four patients had epilepsy. Conclusion: The sub ependymal heterotopias were frequently located in the trigon region of the lateral ventricles. All subcortical heterotopias were in the frontal and unifocal locations. Band heterotopias were located bilaterally and subcortically in a symmetrical fashion in the cerebral hemisphere. The main accompanying anomalies were ventriculomegaly, Arnold-Chiari malformation, and corpus callosum agenesis. Considering the neurological developments of pediatric patients, it is important to identify the type of heterotopia and accompanying anomalies for patient management.

Social cognition in children and adolescents with epilepsy: A meta-analysis

Many studies have investigated impairments in two key domains of social cognition (theory of mind [ToM] and facial emotion recognition [FER]) in children and adolescents with epilepsy. However, inconsistent conclusions were found. Our objective was to characterize social cognition performance of children and adolescents with epilepsy. A literature search was conducted using Web of Science, PubMed, and Embase databases. The article retrieval, screening, quality assessment (Newcastle-Ottawa-Scale), and data extraction were performed independently by two investigators. A random-effects model was used to examine estimates. The meta-analysis included 19 studies, with a combined sample of 623 children and adolescents with epilepsy (mean [SD] age, 12.13 [2.62] years; 46.1% female) and 677 healthy controls [HCs]) (mean [SD] age, 11.48 [2.71] years; 50.7% female). The results revealed that relative to HCs, children and adolescents with epilepsy exhibited deficits in ToM (g = -1.08, 95% CI [-1.38, -0.78], p < 0.001, the number of studies [k] = 13), FER (g = -0.98, 95% CI [-1.33, -0.64], p < 0.001, k = 12), and ToM subcomponents (cognitive ToM: g = -1.04, 95% CI [-1.35, -0.72], p < 0.001, k = 12] and affective ToM: g = -0.73, 95% CI [-1.12, -0.34], p < 0.001, k = 8). In addition, there were no statistically significant differences in social cognition deficits between children and adolescents with focal epilepsy and generalized epilepsy. Meta-regressions confirmed the robustness of the results. These quantitative results further deepen our understanding of the two core domains of social cognition in children and adolescents with epilepsy and may assist in the development of cognitive interventions for this patient population. Systematic review registration: https://inplasy.com/inplasy-2022-3-0011/, identifier INPLASY202230011.

Theory of Mind and Empathy in Adults With Epilepsy: A Meta-Analysis

Mounting evidence suggests that social cognitive abilities [including theory of mind (ToM) and empathy] are impaired in adult patients with epilepsy. Although the deficits in overall ToM in epilepsy have been documented well, the effects of epilepsy on empathic ability and specific subcomponents of ToM remain unclear. The primary aim of this study was to provide the first meta-analytic integration of ToM and empathy in adult patients with epilepsy, and to decompose these constructs to clearly differentiate their distinct (cognitive ToM and affective empathy) and overlapping (affective ToM/cognitive empathy) components. This meta-analysis included 28 studies. Adult patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE) showed impairments in cognitive ToM and affective ToM/cognitive empathy compared to the healthy controls (HCs); no group differences were identified for affective empathy. Besides, cognitive ToM was impaired in adult patients with idiopathic generalized epilepsy (IGE) and focal seizures (caused by epileptogenic foci) outside the temporal and frontal lobes (extra-TLE/FLE) and no group differences were evident for affective ToM/cognitive empathy compared to the HCs. Moreover, relative to the HCs, no group differences were identified for affective empathy in adult patients with IGE. Additionally, no (statistically) significant difference was observed between the magnitude of ToM/empathy impairment in adult patients who underwent and those who did not undergo epilepsy surgery. These quantitative findings suggest differential impairment of the core aspects of social cognitive processing in adult patients with epilepsy, which may contribute to the development of structured cognitive interventions (i.e., social cognitive training) for adult patients with epilepsy.