The understanding of mental states and the cognitive phenotype of frontal lobe epilepsy

Theory of mind in epilepsy

Epilepsy is characterized by recurrent, chronic, and unprovoked seizures. Epilepsy has a significant negative impact on a patient's quality of life even if seizures are well controlled. In addition to the distress caused by seizures, patients with epilepsy (PwE) may suffer from cognitive impairment with serious social consequences such as poor interpersonal relationships, loss of employment, and reduced social networks. Pathological changes and functional connectivity abnormalities observed in PwE can disrupt the neural network responsible for the theory of mind. Theory of mind is the ability to attribute mental states to other people (intentions, beliefs, and emotions). It is a complex aspect of social cognition and includes cognitive and affective constructs. In recent years, numerous studies have assessed the relationship between social cognition, including the theory of mind, in PwE, and suggested impairment in this domain. Interventions targeting the theory of mind can be potentially helpful in improving the quality of life of PwE.

Frontal lobe epilepsy: an eye tracking study of memory and attention

Objective

To explore the characteristics and mechanisms of working memory impairment in patients with frontal lobe epilepsy (FLE) through a memory game paradigm combined with eye tracking technology.

Method

We included 44 patients with FLE and 50 healthy controls (HC). All participants completed a series of neuropsychological scale assessments and a short-term memory game on an automated computer-based memory evaluation platform with an eye tracker.

Results

Memory scale scores of FLE patients including digit span (U = 747.50, p = 0.007), visual recognition (U = 766.50, p = 0.010), and logical memory (U = 544.00, p < 0.001) were significantly lower than HC. The patients with FLE took longer to complete the four levels of difficulty of the short-term memory game than healthy controls (level 1: U = 2974.50, p = 0.000; level 2: U = 3060.50, p = 0.000; level 3: U = 2465.00, p = 0.000; level 4: U = 2199.00, p = 0.000). During the memory decoding period, first fixation on the targets took significantly longer for FLE patients for all difficulty levels compared to controls (level 1: U = 3407.00, p = 0.008; level 2: U = 3618.00, p = 0.036; level 3: U = 3345.00, p = 0.006; level 4: U = 2781.00, p = 0.000). The average fixation duration per target among patients with FLE was found to be significantly longer compared to HC (level 1: U = 2994.50, p = 0.000; level 2: U = 3101.00, p = 0.000; level 3: U = 2559.50, p = 0.000; level 4: U = 2184.50, p = 0.000). The total fixation duration on AOI/total completion time of FLE patients was significantly lower than those of HC for levels 1 to 3 (level 1: U = 1557.00, p = 0.000; level 2: U = 2333.00, p = 0.000; level 3: U = 2757.00, p = 0.000). Furthermore, the eye tracking data during the memory decoding phase were correlated with neuropsychological scale scores (p < 0.05).

Conclusion

Patients with FLE exhibited short-term memory impairment probably due to deficits in attentional maintenance, especially during the memory decoding phase. Eye tracking technology provided the possibility to help separate and quantify visual attention from memory processing, contributing to exploring underlying mechanisms of memory impairment in FLE.

Hemodynamic correlates of emotion regulation in frontal lobe epilepsy patients and healthy participants

The ability to regulate emotions is indispensable for maintaining psychological health. It heavily relies on frontal lobe functions which are disrupted in frontal lobe epilepsy. Accordingly, emotional dysregulation and use of maladaptive emotion regulation strategies have been reported in frontal lobe epilepsy patients. Therefore, it is of clinical and scientific interest to investigate emotion regulation in frontal lobe epilepsy. We studied neural correlates of upregulating and downregulating emotions toward aversive pictures through reappraisal in 18 frontal lobe epilepsy patients and 17 healthy controls using functional magnetic resonance imaging. Patients tended to report more difficulties with impulse control than controls. On the neural level, patients had diminished activity during upregulation in distributed left-sided regions, including ventrolateral and dorsomedial prefrontal cortex, angular gyrus and anterior temporal gyrus. Patients also showed less activity than controls in the left precuneus for upregulation compared to downregulation. Unlike controls, they displayed no task-related activity changes in the left amygdala, whereas the right amygdala showed task-related modulations in both groups. Upregulation-related activity changes in the left inferior frontal gyrus, insula, orbitofrontal cortex, anterior and posterior cingulate cortex, and precuneus were correlated with questionnaire data on habitual emotion regulation. Our results show that structural or functional impairments in the frontal lobes disrupt neural mechanisms underlying emotion regulation through reappraisal throughout the brain, including posterior regions involved in semantic control. Findings on the amygdala as a major target of emotion regulation are in line with the view that specifically the left amygdala is connected with semantic processing networks.

Morphological brain alterations in dialysis- and non-dialysis-dependent patients with chronic kidney disease

To 1) investigate the morphological brain-tissue changes in patients with dialysis- and non-dialysis-dependent chronic kidney disease (CKD); 2) analyze the effects of CKD on whole-brain cortical thickness, cortical volume, surface area, and surface curvature; and 3) analyze the correlation of these changes with clinical and biochemical indices. This study included normal controls (NCs, n = 34) and patients with CKD who were divided into dialysis (dialysis-dependent chronic kidney disease [DD-CKD], n = 26) and non-dialysis (non-dialysis patients who underwent cranial magnetic resonance imaging scans [NDD-CKD], n = 26) groups. Cortical thickness, volume, surface area, and surface curvature in each group were calculated using FreeSurfer software. Brain morphological indicators with statistical differences were correlated with clinical and biochemical indicators. Patients with CKD exhibited a significant and widespread decrease in cortical thickness and volume compared with NCs. Among the brain regions associated with higher neural activity, patients with CKD exhibited more significant morphological changes in the paracentral gyrus, transverse temporal gyrus, and lateral occipital cortex than in other brain regions. Cortical thickness and volume in patients with CKD correlated with blood pressure, lipid, hemoglobin, creatinine, and urea nitrogen levels. The extent of brain atrophy was further increased in the DD-CKD group compared with that in the NDD-CKD group. Patients with CKD potentially exhibit a certain degree of structural brain-tissue imaging changes, with morphological changes more pronounced in patients with DD-CKD, suggesting that blood urea nitrogen and dialysis may be influential factors in brain morphological changes in patients with CKD.

Toward social neuropsychology of epilepsy: a meta-analysis on social cognition in epilepsy phenotypes and a critical narrative review on assessment methods

Background

The aim of this review is to (a) characterize social cognition impairments in the domains of emotion recognition (ER) and theory of mind (ToM) in patients with epilepsy and (b) to review assessment tools with a focus on their validity and usability in clinical practice.

Methods

An electronic search for clinical studies investigating social cognition in epilepsy populations vs healthy control subjects (HC) yielded 53 studies for the meta-analysis and descriptive review.

Results

Results suggest that (1) social cognition is significantly impaired in patients with temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE) and patients with epilepsy not originating within the temporal or frontal lobes including idiopathic generalized epilepsies (eTLE/eFLE); (2) there is no significant difference between eTLE/eFLE and TLE regarding ER, while TLE and FLE patients perform worse than those with eTLE/eFLE, without significant differences between FLE and TLE regarding ToM ability. A descriptive analysis of the most commonly used assessment tools and stimulus material in this field revealed a lack of ecological validity, usability, and economic viability for everyday clinical practice.

Conclusions

Our meta-analysis shows that patients with epilepsy are at a significantly increased risk of deficits in social cognition. However, the underlying multifactorial mechanisms remain unclear. Future research should therefore specifically address the impairment of processing and methodological problems of testing.

Affective Empathy, Theory of Mind and Social Functioning in Patients With Focal Epilepsy

OBJECTIVE

Social cognition comprises basic and more complex functions, such as theory of mind (ToM) and affective empathy. Although everyday social interactions may be impaired if such higher-order social cognitive functions are compromised, associations between social functioning and social cognition in people with focal epilepsy (PWFE) are still poorly understood. We used a novel, naturalistic approach to investigate ToM in PWFE by applying the Movie for the Assessment of Social Cognition (MASC). Furthermore, we studied affective empathy, the relationship between social cognitive parameters and measures of social functioning, as well as between epilepsy focus and ToM.

METHODS

Thirty patients with either temporal (TLE) or frontal lobe epilepsy (FLE) were compared to 29 healthy control subjects (HC). In addition to the MASC, we applied questionnaire measures assessing empathy and everyday social functioning.

RESULTS

PWFE, especially with FLE, performed significantly worse than HC on the MASC. Perceived social integration and social activities, but not affective empathy, were reduced in PWFE. Regression analyses revealed associations between perceived social integration, clinical group status, affective empathy and ToM.

CONCLUSION

PWFE displayed ToM deficits during a naturalistic task, whereas affective empathy was unimpaired. FLE may be associated with especially compromised ToM performance. Social cognition and social functioning appear to be interrelated in PWFE, whose self-perceived levels of social integration and social activities are lower than those of HC. More research into the association between social cognition and social functioning in PWFE is needed, in order to develop tailored intervention programs for these patients.

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.

Radiomics for the Prediction of Epilepsy in Patients With Frontal Glioma

Objective

This study was conducted in order to investigate the association between radiomics features and frontal glioma-associated epilepsy (GAE) and propose a reliable radiomics-based model to predict frontal GAE.

Methods

This retrospective study consecutively enrolled 166 adult patients with frontal glioma (111 in the training cohort and 55 in the testing cohort). A total 1,130 features were extracted from T2 fluid-attenuated inversion recovery images, including first-order statistics, 3D shape, texture, and wavelet features. Regions of interest, including the entire tumor and peritumoral edema, were drawn manually. Pearson correlation coefficient, 10-fold cross-validation, area under curve (AUC) analysis, and support vector machine were adopted to select the most relevant features to build a clinical model, a radiomics model, and a clinical-radiomics model for GAE. The receiver operating characteristic curve (ROC) and AUC were used to evaluate the classification performance of the models in each cohort, and DeLong's test was used to compare the performance of the models. A two-sided t-test and Fisher's exact test were used to compare the clinical variables. Statistical analysis was performed using SPSS software (version 22.0; IBM, Armonk, New York), and p <0.05 was set as the threshold for significance.

Results

The classification accuracy of seven scout models, except the wavelet first-order model (0.793) and the wavelet texture model (0.784), was <0.75 in cross-validation. The clinical-radiomics model, including 17 magnetic resonance imaging-based features selected among the 1,130 radiomics features and two clinical features (patient age and tumor grade), achieved better discriminative performance for GAE prediction in both the training [AUC = 0.886, 95% confidence interval (CI) = 0.819-0.940] and testing cohorts (AUC = 0.836, 95% CI = 0.707-0.937) than the radiomics model (p = 0.008) with 82.0% and 78.2% accuracy, respectively.

Conclusion

Radiomics analysis can non-invasively predict GAE, thus allowing adequate treatment of frontal glioma. The clinical-radiomics model may enable a more precise prediction of frontal GAE. Furthermore, age and pathology grade are important risk factors for GAE.

Diversified social cognition in temporal lobe epilepsy

OBJECTIVES

In an integrated model of social cognition (SC), the theory of mind (ToM), the recognition of behavior in social situations (RBSS), empathy, and sensitivity to moral and conventional rules (SMCR) cooperate in generating mental representations of the interpersonal relationships. The aim of this study was to extend our knowledge of the SC of temporal lobe epilepsy (TLE) patients by characterizing its various aspects and predictors.

MATERIALS AND METHODS

Fifty adult patients with TLE and 50 healthy controls were assessed using ToM, RBSS and SMCR neuropsychological tests, the Empathy Questionnaire, and the psychopathology Symptoms Check List 90R (SCL90-R).

RESULTS

Patients and controls were similar in terms of occupation, income level, age, sex, marital status and the number of family members. Multivariate analysis of variance with demographic variables as the covariates showed that they were similar in SMCR and empathy. The patients, conversely, had lower ToM and RBSS scores, and higher scores on the SCL90-R psychoticism, depression, paranoid ideation, obsessive-compulsive, somatization and anxiety scales. Impaired RBSS was predicted by psychopathological symptoms, income level, schooling and the duration of epilepsy; ToM related to TLE laterality, seizure frequency and epilepsy duration.

CONCLUSIONS

In adult patients with TLE, SC is simultaneously partially impaired and partially preserved, and the fact this is associated with clinical, demographic and psychological variables suggests that SC depends on the integrity of the temporal lobe and the interconnected brain regions, as well as psychosocial stimuli. This approach may contribute to clarify the neurobehavioural phenotype of TLE.

The contribution of the frontal lobe to creativity. Insights from epilepsy

PURPOSE

This study was aimed to evaluate the impact of frontal (FLE) and temporal lobe epilepsy (TLE) on graphic creativity.

METHODS

A hundred and six patients with FLE (n = 32) or TLE (n = 74) and 38 healthy subjects underwent a design fluency (DF) test constituted by a free and a fixed condition. For each condition, the number of correct designs, as an index of creativity, and unacceptable nonperseveration or perseveration designs were calculated. The participants also underwent a comprehensive neuropsychological battery.

RESULTS

The number of novel correct designs significantly differed between the groups: patients with FLE produced fewer designs than patients with TLE and controls, while epilepsy laterality had no effect. Patients with FLE also produced more unacceptable nonperseveration designs than controls, with no between-group differences in the perseverations. The number of novel designs was predicted by the type of epilepsy, whereas word fluency, comprehension, attention, set shifting, visual matching, and constructive praxis had no influence. This score was a sensitive marker of FLE discriminating FLE cognitive pattern from the pattern of TLE and healthy condition.

CONCLUSIONS

Left or right FLE, but not TLE, can impair graphic creativity. This finding and that DF was unrelated to other cognitive abilities suggest that creativity is a specific domain, sensitive to epilepsy-related frontal lobe dysfunctions. This behavioral approach including test accuracy may have implications in defining FLE cognitive phenotype.