Comparison of decision-making under ambiguity in patients with temporal lobe and frontal lobe epilepsy

Psychiatric comorbid disorders and impulsivity in patients with drug-resistant temporal and extra-temporal focal epilepsies

PURPOSE

To analyze patients with drug-resistant focal epilepsy from temporal (TLE) and extra-temporal origin (ETE) and to compare the prevalence of psychiatric comorbid disorders and impulsivity between them and a control group.

METHODS

Consecutively studied patients with TLE and ETE confirmed with Video-EEG were included. Standardized psychiatric assessment was conducted using the Structured Clinical Interview for Axis I and II diagnosis of DSM-IV (SCID I-II), the Barrat-11 scale for impulsivity, and Beck inventory for depression. Parametric and nonparametric tests were performed.

RESULTS

Seventy-three patients with temporal lobe epilepsy (TLE), 21 extra-temporal epilepsy (ETE) and 58 healthy control subjects were included. Both groups of patients showed a high frequency of Axis I comorbid psychiatric disorders: Depression was the most frequent disorder followed by Anxiety Disorders. Furthermore, Axis II (Personality disorders) were also diagnosed, similarly in both groups of patients (p > 0.05). In addition, both TLE and ETE groups presented higher impulsivity scores compared with the control group (p < 0.01). ETE showed a tendency to a higher impulsivity in the motor factor (p = 0.05). Among patients with TLE, a left laterality of the epileptogenic zone, and the presence of comorbid psychiatric disorders (depression), were found as independent factors associated with higher impulsivity (p < 0.05).

CONCLUSION

Comorbid depression associated with higher impulsivity are important issues to consider in behavioral and clinical evaluation of patients with drug-resistant focal epilepsies, with the aim to set up a prompt treatment.

Inhibitory control deficits in patients with mesial temporal lobe epilepsy: an event-related potential analysis based on Go/NoGo task

Objective

Neuropsychiatric comorbidities are common among patients with mesial temporal lobe epilepsy (MTLE). One of these comorbidities, impulsivity, can significantly impact the quality of life and prognosis. However, there have been few studies of impulsivity in these patients, and the existing findings are inconsistent. The present study investigates impulsivity in MTLE patients from the perspective of inhibitory control and its underlying processes using event-related potentials (ERPs) initiated using a Go/NoGo task.

Methods

A total of 25 MTLE patients and 25 age-, gender-, and education-matched healthy controls (HCs) completed an unequal visual Go/NoGo task. Different waveforms as well as behavioral measures were analyzed between Go and NoGo conditions (N2d and P3d). Impulsivity was also assessed using self -rating scales, and clinical variables that may be related to ERPs were explored.

Results

Compared with HCs, MTLE patients exhibited significantly longer reaction time (RT) (p = 0.002) and lower P3d especially at the frontal electrode sites (p = 0.001). In the MTLE group, the seizure frequency (p = 0.045) and seizure types (p < 0.001) were correlated with the P3d amplitude. A self-rated impulsivity assessment revealed that MTLE patients had higher non-planning (p = 0.017) and total scores (p = 0.019) on the BIS-11 as well as higher DI (p = 0.010) and lower FI (p = 0.007) on the DII.

Conclusion

The findings demonstrate that the presence of inhibitory control deficits in patients with MTLE are characterized by deficits in the late stage of inhibition control, namely the motor inhibition stage. This study improves our understanding of impulsivity in MTLE patients and suggests that ERPs may constitute a sensitive means of detecting this trait.

Decision-making under ambiguity after frontal lobe resection for epilepsy

PURPOSE

Decision-making is crucial to daily life and can impact our society as well as economic conditions. Although the frontal lobes have been identified as important for decision-making, this capacity has only been studied to a limited extent in frontal lobe epilepsy and not at all after frontal lobe resection (FLR) for epilepsy. This study aimed to explore decision-making under ambiguity after FLR for epilepsy.

METHODS

Fourteen patients having undergone FLR for epilepsy completed the Iowa Gambling Task (IGT) which is a widely used tool to measure decision-making under ambiguity. Iowa Gambling Task scores included in the analysis were: total net score, separate scores from five blocks across the test, and a change score (last block of IGT minus first block). A group of healthy controls (n = 30) was used as a comparison. Associations between IGT and standardized neuropsychological methods for assessment of executive functions, self-rating questionnaires of mental health, fatigue, and behavior linked to frontal lobe dysfunction were also investigated.

RESULTS

The patient group performed inferior to controls at the final block of the IGT (p =.001).A group difference in IGT change scores was found (p =.005), reflectingthe absence of a positive change in performance over time for the FLR group compared to the control group. Correlations with tests of executive functions as well as self-rating scales were mainly statistically nonsignificant.

CONCLUSIONS

This study shows that patients having undergone FLR for epilepsy have difficulties with decision-making under ambiguity. The performance illustrated a failure to learn throughout the task. Executive as well as emotional deficits may impact decision-making processes in this patient group and need to be considered in further studies. Prospective studies with larger cohorts are needed.