Executive dysfunction in an Egyptian sample of adult participants with epilepsy: a case–control study

Tarek Desoky; Romany H Gabra

doi:10.4103/ejpsy.ejpsy_33_18

ORIGINAL ARTICLE

Year : 2019 | Volume : 40 | Issue : 1 | Page : 31-34

Executive dysfunction in an Egyptian sample of adult participants with epilepsy: a case–control study

Tarek Desoky¹, Romany H Gabra²
¹ Department of Neuropsychiatry, Faculty of Medicine, South Valley University, Qena, Egypt
² Department of Neuropsychiatry, Faculty of Medicine, Assiut University, Assiut, Egypt

Date of Submission	08-Nov-2018
Date of Acceptance	02-Dec-2018
Date of Web Publication	9-May-2019

Correspondence Address:
Tarek Desoky
lecturer of psychiatry, Department of Neuropsychiatry, Faculty of Medicine, South Valley University, Qena, 83511
Egypt

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ejpsy.ejpsy_33_18

Abstract

Objective The present study aimed to detect the executive function deficits that may affect patients with idiopathic epilepsy and the factors that influence such affection.
Study design A case–control study was conducted.
Materials and methods A total of 40 adult patients aged from 20 to 50 years, with idiopathic epilepsy recruited from the outpatient clinic of South Valley and Assiut University hospital and a similar number of age-matched and sex-matched controls were included. Participants completed Wechsler Intelligence Scale and neuropsychological tests including Wisconsin card sorting test, trail making test (trails A and B), Conners’ continuous performance test, and digit span tests.
Results Relative to the control group, patients poorly performed on most of executive functions, with the longer duration of illness and the higher frequency of seizures being the most evident factors that showed a positive correlation with the executive dysfunction. However, age at onset, type of seizures, and family history of epilepsy had no significant correlation on neuropsychological test performance.
Conclusion One of the main domains of evaluation of the patients with chronic epilepsy should be the cognitive domain. A large number of studies shed light on such hypothesis. Executive dysfunction in patients with epilepsy may share negatively in their quality of life, so it should be a target of diagnosis and therapy.

Keywords: executive function, idiopathic epilepsy, neuropsychological tests

How to cite this article:
Desoky T, Gabra RH. Executive dysfunction in an Egyptian sample of adult participants with epilepsy: a case–control study. Egypt J Psychiatr 2019;40:31-4

How to cite this URL:
Desoky T, Gabra RH. Executive dysfunction in an Egyptian sample of adult participants with epilepsy: a case–control study. Egypt J Psychiatr [serial online] 2019 [cited 2023 Sep 21];40:31-4. Available from: https://new.ejpsy.eg.net//text.asp?2019/40/1/31/257849

Introduction

Executive functions are a group of cognitive processes that are necessary for guiding one’s thoughts and actions (Jurado and Rosselli, 2007). They include planning, sequencing, decision making, purposive action, and ability to monitor, self-correct, and regulate performance (Lezak et al., 2012).

Chronic epilepsy is commonly associated with neuropsychological impairment (Thompson and Duncan, 2005), with mental slowing, memory deficit, and attention deficits are most often seen (Aldenkamp and Arends, 2001).

A set of interrelated factors makes the evaluation of cognitive functions in patients with epilepsy a complex task. They include the underlying etiology of epilepsy; type, severity, and degree of control of seizures; age at onset; anticonvulsant drugs; occurrence of interictal discharge; and psychosocial factors related to the illness (Motamedi and Meador, 2003).

Aim

Executive dysfunction (ED) was frequently studied in epilepsy. However, pediatric population was commonly targeted, and restricted cognitive batteries were employed in previous studies. In this study, we targeted adult population and aimed to assess executive and attention functions using a comprehensive battery including multiple different cognitive tasks.

Materials and methods

Study population

Patients

We evaluated, in a case–control study, 40 adult patients with a diagnosis of idiopathic epilepsy, according to the classification of the International League Against Epilepsy (ILAE 2010), aged from 20 to 50, recruited from the outpatient clinics of South Valley and Assiut University Hospitals during the duration from November 2016 to May 2017. All patients should have been seizure free for the past 48 h before neuropsychological assessment.

The exclusion criteria for the patients included the following: an estimated intelligence quotient (IQ) below 80, any medical condition leading to cognitive impairment, diagnosis of a psychiatric disorder, alcohol or drug abuse, or any brain-related surgical intervention.

Controls

Age-matched and sex-matched healthy controls were evaluated by a psychiatrist and a neurologist to exclude psychiatric and neurological disorders.

An informed written consent was given by all participants, and the study was approved by the ethics committee of South Valley and Assiut Universities. All data of the study were confidential.

Methods

Neuropsychological tests used were as follows:
1. Wisconsin card sorting test (WCST) (Heatonet al., 1981), which evaluates concept building, mental flexibility, and goal maintenance.
2. Trail making test (TMT) (Spreen and Strauss, 1991), which measures visuospatial orientation, sustained attention, and divided attention.
3. Conners’ continuous performance test (Conners and Staff, 2000), which measures a person’s sustained, selective attention and impulsivity.
4. Digit span forward and digit span backward tests (Wechsler, 1999), which measures attention span and verbal working memory.
Wechsler intelligence scale: the IQ of each participant was estimated with the Wechsler intelligence scale for adult, Arabic version (Ismail and Melika, 1999).
Clinical data.

Patients with epilepsy were evaluated for age at onset of epilepsy, duration of illness, frequency of seizures, and family history of epilepsy. Full neurological examination, electroencephalography (EEG), and Brain imaging (computed tomography brain or MRI brain) were done.

Statistical analysis

Statistical analyses were done by the statistical package for social sciences (SPSS; SPSS Inc., Chicago, Illinois, USA), version 16. Means and SD were calculated for each demographic and clinical variable. For studying correlation between variables, we used Spearman’s and Pearson’s correlation coefficients as appropriate to the type of the variable. P value was considered significant if less than 0.05.

Results

Demographic and clinical data

In this study, we have two groups of participants: 40 patients and similar number of age-matched and sex-matched controls. The average mean age for the two groups was ∼25 years, with male to female ratio being about twofolds for both groups. The mean IQ was above 95% for both groups. The mean age of onset of the disease was 22 years, and the mean frequency of seizures was ∼20 during the past year. Most cases (65%) have no family history and negative consanguinity. Most cases (75%) had generalized tonic clonic (GTC) type of seizures. EEG showed definite epileptiform discharge in 85% of patients and approximately two-thirds of patients were under monotherapy antiepileptic treatment ([Table 1],[Table 2],[Table 3]).

Table 1 Sociodemographic characteristics

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Table 2 Clinical characteristics of the patient group

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Table 3 Seizures data of the study groups

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Neuropsychological performance among patients and control groups

Relative to the control group, patients poorly performed on WCST, digit forward, digit backward, Conners’ continuous performance, and TMTs, as shown in [Table 4].

Table 4 Comparing patients with epilepsy and controls on neuropsychological tests

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Correlation of clinical variables to executive dysfunction

Longer duration of illness was significantly correlated with the poorer performance on WCST and TMT, whereas higher frequency of seizures was significantly correlated with the poorer performance on DSF, DSB, and TMT. However, age at onset, type of seizures, and family history of epilepsy had no significant correlation on neuropsychological test performance ([Table 5]).

Table 5 Clinical variables correlation to executive and attention deficits

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Discussion

Fisher et al. (2000), reported cognitive problems as one of the most rated problems among patients with epilepsy. Vlooswijk et al. (2012), attributed such cognitive dysfunction to recurrence of seizures, the effect of drugs, and to the underlying illness. ED makes the patient unable to complete productive activities or socially adjust (Muscara and Catroppa, 2008).

In the present study, we used an extensive cognitive buttery that tests most of the executive and attention functioning such as concept building, goal maintenance, working memory, visuospatial memory, mental flexibility, attention span, and sustained and divided attention. Unlike most of the previous studies that examined executive functions in the pediatric population, we aimed to study executive functions in adult patients with idiopathic epilepsy.

In this study, in most of cognitive domains, patients performed poorly on neuropsychological tests relative to controls. Similarly, Sonmez et al. (2004) and Pascalicchio et al. (2005) found ED in patients with juvenile myoclonic epilepsy. Horner et al. (1996), reported that 5% of patients with temporal lobe epilepsy exhibited ED detected by increased perseverative responses on WCST. Furthermore, Hermann et al. (1991), reported that 44% of patients with epilepsy showed clinically relevant ED.

Moreover, the time needed to complete the TMT was significantly longer in the patients group, and this was matched with the results of some of the previous meta-analyses studies (Lezak, 2004; Sylvie and Kette, 2012).

In continuous performance test, which evaluates selective and sustained attention, the patients performed more poorly than did the group of controls, and this was in agreement with the results of previous studies, which attributed such attention deficit to the nocturnal continuous epileptic discharge, which could not be verified in our study because we did not target this EEG-proved feature in our patients (Sanchez-Carpintero and Neville, 2003; Borgatti et al., 2004).

In digit span test, which evaluates attention span, working memory, and mental control with auditory–verbal stimuli, in consistent with previous studies (Motamedi and Meador, 2003; Austin et al., 2004; Ghaydaa et al., 2009), patients performed more poorly than did the controls.However, among patients, there was a variable degree of affection related to different clinical variables. Longer duration of illness and the higher frequency of seizures were associated with more poor performance on neuropsychological tests. Longer duration of epilepsy was considered as an important factor in cognitive dysfunction in epilepsy in many previous studies (Koepp, 2005; Sylvie and Kette, 2012).

Like many previous studies (Mandelbaum and Burack, 1997; McDonald et al., 2005; Luton et al., 2010), this study reported that the higher frequency of seizures was associated with more ED in patients with idiopathic epilepsy which may be attributed to the structurally damaging effect of the long-lasting frequent uncontrolled seizure disorders.

Conclusion

Chronic epilepsy frequently showed ED which ranged between subtle and profound. It was well approved that cognitive impairment is an important area of study in patients with epilepsy. Our study was in consistence with a large number of previous studies that proved such hypothesis. Patients with chronic epilepsy had performed worse on neuropsychological tests. Duration of illness and frequency of seizures were the most affecting factors with positive correlation with such cognitive dysfunction.[26]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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