Neuropsychologic Effects of Frontal Lobe Epilepsy in Children

Abstract

Most published neuropsychologic studies on frontal lobe epilepsy have been performed on mixed groups of adults and adolescents with epilepsies of varying etiology. The cognitive profile of frontal lobe epilepsy in children has not been defined. The purpose of this study was to assess neuropsychologic performance in children with frontal lobe epilepsy. Intelligence and executive functions were examined in eight children (age 6 7/12 years to 13 11/12 years) with frontal lobe epilepsy. Performance was related to the focus side, seizure frequency, and age of epilepsy onset. Frontal lobe epilepsy was associated with a range of frontal dysfunctions, but IQ was generally spared. Left focus was associated with deficits in categorization, verbal long-term memory, and detailed visuospatial analysis. Frequent seizures correlated with attention difficulties and inability to inhibit impulsive responses. Children whose epilepsy appeared before age 6 years had reduced ability to change behavioral strategies. Frontal epileptic activity alone can cause selective frontal deficits, the severity and nature of which are related to side, seizure frequency, and age of epilepsy onset. These findings require confirmation on larger series of selected children.

Frontal Lobe Epilepsies: Neuropsychological and Behavioral Consequences in Children

“…These results are consistent with previous findings from neuroimaging studies on dyslexic individuals, which revealed activation anomalies in the frontal lobes (Pugh et al, 1996). Finally, taking a look at fine unimanual and bimanual coordination and the planning and execution of sequences of single motor actions, there are reports of FLE children being slow and having a reduced manual dexterity, with sluggish and stiff or, conversely, over-hasty movements (Hernandez et al, 2002;Riva et al, 2002Riva et al, , 2005. They appear to find it difficult to maintain a fluid sequence of movements and tend to use spatial or verbal strategies to orient their movements, particularly during the performance of Luria's Motor Sequences task, which involves mutual and asymmetrical gestures with both hands, in which FLE children make far more mistakes in the motor sequence, rarely getting the sequences completely right, with a greater impairment in the intermanual tests and when using the non-dominant hand -a finding interpreted as relating to this hand being less well trained and consequently less able to perform new motor tasks.…”

“…The mean results indicated a lower number of matching criteria and a higher number of perseverative errors by comparison with 19 children with TLE, with and without structural lesions, and 30 controls. Riva et al (2002) reported an impaired performance with more perseverative responses and numerous non-perseverative errors, but these results were not confirmed in a subsequent study on a larger sample (Riva et al, 2005). Hernandez et al (2002) found no differences in performance using the WCST when FLE and TLE children were compared with cases of GEA, although the FLE children tended to perform qualitatively more impulsively (e.g.…”

“…Several studies have used the California Verbal Learning Test, which involves learning a list of semantically correlated words and then investigating its recall after presenting an interfering list (immediate recall), and again after a 20 minute interval (delayed recall). FLE children have a normal capacity for immediate and delayed recall (Culhane-Shelburne et al, 2002;Hernandez et al, 2003;Riva et al, 2002) but learning slope showed that the FLE children tended to decline in the last of the five trials, while children with temporal or generalized epilepsy showed a marked increase in the number of items they recalled. This difference was not statistically significant, but suggests a limited capacity of FLE children to sustain adequate attentional levels over time.…”

“…FLE children share many of the features of frontal lobe dysfunctions in adult patients, but the differences in the neuropsychological tests used and, more importantly, the late development of the frontal lobe and the functions it serves mean that findings in adults cannot be extended to patients of developmental age. Most studies on children with FLE reported cognitive capacities in the normal range (Culhane-Shelburne et al, 2002;Hernandez et al, 2002Hernandez et al, , 2003Luton et al, 2010;Riva et al, 2002Riva et al, , 2005, whatever the features of their seizures. Prevost et al (2006), on the other hand, conducted a retrospective study on 21 children with FLE with a mean age of 6 years (though the age range was very wide, from less than 1 to more than 13 years of age), and found that only 52% had a normal IQ, as measured with the Wechsler scales (WPPSI-R and WISC-III); more detailed results are not provided, however.…”

“…Riva et al (2005) also found a limited efficiency in terms of verbal fluency, with significantly lower results for phonemic fluency, while semantic fluency was within normal range in 17 FLE children 6-14 years of age. A limited output was recorded in a design fluency task too, with a significantly higher number of perseverative than non-perseverative errors (Riva et al, 2002(Riva et al, , 2005. The test involved the child first having to draw as many different abstract shapes as possible (free form); then, in the second part of the test, a set number of lines was specified for each shape (fixed form).…”