Epilepsy, as a chronic disorder, involves patients in different ways, i.e., physically and socially [42]. Psychiatric–behavioral problems are common in CWE and can have a major influence on their QOL and families. In many cases, these problems are more challenging than epilepsy itself [43]. This study examined cognitive functions, socio-economic levels, and the QOL of ADHD and epilepsy patients.
Although the proportion of males was higher in all groups, except for the group of ADHD with epilepsy, they were almost equal when compared with the controls. Similarly, other studies have reported a prevalence of males with ADHD up to 3–7 times greater than females. Meanwhile, ADHD and epilepsy children often have the same gender ratios [44,45,46].
In the present study, the relation among epilepsy-related variables showed no significant difference regarding age at the onset of seizure, the duration of epilepsy, and time since the last seizure in CWE-ADHD and those with epilepsy, while the type of seizure was significantly different between the two groups.
Hermann et al. observed no correlation between younger age at the onset of seizure and the presence of ADHD in the cohort study with a newly diagnosed epilepsy [44], and the same result was found by [47] in a retrospective cohort study on CWE. Contrarily, some studies have demonstrated a significantly high prevalence of ADHD in patients with an earlier epilepsy onset as confirmed by [48]. Moreover, [49] observed that earlier epilepsy onset in younger children was associated with more attention deficit, especially in childhood epilepsy with centrotemporal spikes. ILAE has concluded that the relationship between early seizure onset and ADHD development is still uncertain [50].
Regarding the type of seizures, the higher proportion had a generalized type of epilepsy in both groups. Considerable research has examined whether distinct seizure types were associated with a higher risk of ADHD and epilepsy and has found no association [31, 51, 52]. ILAE has also concluded that specific seizure types are not anticipated higher risk of ADHD in epilepsy [44, 45, 50, 53].
In the current study, the comparison of EEG changes among the three groups, namely, the group of epilepsy, the group of ADHD with epilepsy, and the group of ADHD with EEG changes, showed significant differences for unprovoked generalized paroxysmal changes, which could be attributed to the generalized type of seizures observed in most of the cases.
Additionally, the E-Chess scores in the group of ADHD with epilepsy and the group of epilepsy were significantly different in the number of the anticonvulsants used and the total E-Chess severity score. Regarding the number of the anticonvulsant drugs used, multiple studies have been conducted to clarify the effect of antiepileptic drugs (AEDs) on ADHD comorbidity, but the variety of the anticonvulsant drugs involved restricted the comparison among studies due to their poor consistency. Polytherapy was typically associated with a higher level of behavioral issues according to ILAE [50, 54].
In contrast, several studies from divergent settings have found no correlation between the numbers of anticonvulsant drugs and psychiatric problems [50, 55]. Furthermore, Hermann et al. found no differences between the group of epilepsy and the group of ADHD with epilepsy in terms of the number of anticonvulsant drugs [44]. Regarding seizure frequency, many previous studies have found no correlation of seizure frequency in the studied groups [31, 51, 52].
Regarding the CPRS, a combined subtype of ADHD predominated in the group of ADHD with EEG changes and the group of ADHD with epilepsy, while the hyperactivity subtype predominated in the group of ADHD without EEG changes. Other studies have presented similar results, in which the combined subtype of ADHD was more prevalent than the inattentiveness subtype in ADHD with epilepsy patients [31, 56,57,58].
Some studies have corroborated that the combined subtype was more common in patients with ADHD [31, 59]. Meanwhile, other studies have asserted that hyperactivity and impulsivity subtypes were more common [60, 61].
According to EEG, our study categorized ADHD into two subgroups. The group of ADHD with EEG changes showed a predominance of the combined subtype of ADHD similar to ADHD with epilepsy, while the group of ADHD without EEG changes was different from other groups. That was further confirmed by the CPRS subscales, as the group of ADHD with EEG changes similar to the group of ADHD with epilepsy had a highly elevated clinical rating response in all subscales relative to the group of ADHD without EEG changes. These variations in ADHD subtypes could be attributed to the characteristics of the methodology of different studies [51].
In our study, the assessment of cognitive functions by WISC-III questionnaires showed no significant difference in IQ classification among all groups. This is similar to studies that have validated that ADHD patients with and without epilepsy did not vary with respect to IQ (p = 0.48), thereby promoting a correlation between epilepsy and ADHD, irrespective of lower IQ scores [57]. Nevertheless, the ADHD and epilepsy groups had lower scores on the measurement of the IQ subscales (verbal, output, and overall IQs) than other groups including the controls with a significant difference in performance IQ.
This was explained by Hermann et al., who argued that motor/psychomotor speed and executive functioning tended to severely affect epilepsy-ADHD children with neuropsychological problems. This was marked by response inhibition impairment, concept formation, mental flexibility/working memory, and passive inattention [44, 56, 62, 63].
According to the socioeconomic scale score, most of the children in the group of ADHD with epilepsy and the group of epilepsy were in low socioeconomic classes with low mean values of social scores in comparison with the other studied groups. This could be explained as epilepsy might be responsible for the decrease of socioeconomic levels.
In a systematic review, there has been growing evidence of the correlation between socio-economic disadvantages and ADHD, indicating that socio-economic disadvantages may lie on the causal pathway between, or may be triggered by, ADHD genotype and phenotype [64].
Several studies reported that low socioeconomic status is a risk factor for the development of epilepsy [65, 66], as low socioeconomic status is associated with social and economic deprivation, unemployment, and low income, which in turn are associated with risk factors as birth defects, trauma, infection, and poor nutrition that may cause epilepsy [67,68,69].
Another study has revealed that epilepsy prevalence is closely linked to specific socio-economic deprivation measures. When epilepsy is found in areas of greater socioeconomic deprivation, the existing major consequence of epilepsy on employment and higher education may be substantial [70].
Regarding PedsQL, significant differences were detected between groups, while the group of ADHD with epilepsy had the poorest PedsQL scores. The total score and certain subscores of PedsQL (psychological summary score) were the lowest in the group of ADHD with epilepsy. Our findings indicate that the relationship between ADHD and epilepsy co-occurrence with poor PedsQL is greater than that between isolated ADHD or epilepsy and poor PedsQL.
A poor PedsQL may be related to epilepsy, chronic course, social stigma, learning challenges, and seizure fear [71]. Additionally, persistent inattentiveness, hyperactivity, and impulsive ADHD symptoms usually have severe adverse effects on the academic, family, and social life of the children affected [72]. The co-existence of these two conditions may increase the risk of psychosocial and cognitive difficulties and impairment in the QOL.
In the present study, the correlation between the total IQ score with the total socioeconomic scale score and the subscales of PedsQL scores among the studied groups showed that physical summary, psychological summary, and total QOL scores had a significant positive correlation with the total IQ score in the group of ADHD with epilepsy, whereas no significant correlations were detected in other groups.
Similarly, Abd El Naby et al. verified that there was a strong significant correlation between PedsQL scores with IQs (p value = 0.001) [17]. Other studies have confirmed that ADHD with epilepsy is inversely correlated with the QOL and that treating ADHD significantly improves the QOL of CWE [73, 74].
In our study, the correlation between the total socioeconomic scale, total IQ, subscales of PedsQL scores with the clinical variables of epilepsy and the E-Chess total severity score in the group of epilepsy and the group of ADHD with epilepsy showed a significant correlation between the age at the onset of seizure and the total IQ score in the group of epilepsy. Meanwhile, other scores have not affirmed a significant correlation. In a similar study, young age at the onset of seizure was strongly associated with cognitive impairment in most childhood epilepsies [75].
In contrast, some research has suggested that cognitive dysfunction at the onset of epilepsy does not lead to the increase of intensity over time but keeps on a trajectory [76, 77].
Several factors may have a severe effect on cognitive function in epilepsy, such as underlying structural lesions and epilepsy-related disorders, alternation in neurogenesis and synaptogenesis and change of excitatory/inhibitory balance, and network connectivity. Other factors such as epileptic activity severity, psychosocial aspects, and surgical or pharmacological treatment of seizures may contribute to increased cognitive impairment in epilepsy [78, 79].
Moreover, no significant correlation emerged between the total E-Chess severity scores with PedsQL, which can be explained as the majority of patients in epilepsy groups had low severity of epilepsy.
Some studies have revealed a positive correlation between higher severity of epilepsy and lower QOL. This could be attributed to the stigma of epilepsy, worries about having seizures in school, cognitive impairment, impaired memory, and inability to pay attention which may be associated with some epilepsy syndromes [80, 81].
Additionally, we found that no significant correlation exists between PedsQL and socioeconomic scale scores with the age at the onset of seizure and the duration of epilepsy. This may be suggested by the prolonged duration of illness that is associated with the adaptation of the child and parents to illness, the acceptance of its stigma with decreased anxiety and depression, and the risk of psychiatric comorbidities that cause the impairment of the QOL.
This study has some limitations. First, our sample size was sufficient for the present study but not large, potentially raising the risk of sample-specific findings and potentially restricting their generalizability to more diverse populations. Second, most of the participants were on medications that had several side effects that should be investigated.
We recommend that all CWE be evaluated for ADHD and given appropriate treatment for them to improve their QOL and protect them against cognitive impairments. Also, further research on a larger group of patients will help support our results.