Neuropsychological outcome of childhood Epilepsy: A study of cognitive functioning and academic skill development. Running Title: Neuropsychological outcome of Epilepsy
Dr. Smita A. Desai, Ph.D; Eeshani Chakraverty, M Phil
Affiliation: Name: - DRISHTI, A Learning Center Address: 205-206 Midas Chambers, Off New Link Rd, Andheri (W), Mumbai â€“ 400 053, INDIA. Fax: 022-26732494; Tel: 022-26732496/97 e-mail: firstname.lastname@example.org Corresponding Author: Dr. Smita Desai.
Key words: Cognitive functioning, academic skills, epilepsy, learning difficulties.
Neuropsychological outcomes of childhood epilepsy: A study of cognitive functioning and academic skill development
Abstract: The total number of people suffering from Epilepsy in our country is quite large. There is accumulating evidence that epilepsy must be considered as a major risk factor for childhood development and learning difficulties. This study was aimed at comparing the cognitive functions and academic achievement of children having Epilepsy with those not having Epilepsy, with both groups being referred for academic difficulties. The study sample consisted of two groups of children, one with no history of Epilepsy (N=39) and the other with a history of Epilepsy (N=31) in the age range of 8 to 12.11 years. The cognitive and academic functions were assessed using standardized assessment tools. The study showed that there were significant differences between the two groups in specific areas of cognition; however no significant difference was found in information processing skills and academic achievement measures.
Introduction Epilepsy occurs when there are recurrent seizures due to abnormal electrical activity in the brain. Not all fits or seizures are convulsive. A single seizure does not mean epilepsy, although the symptoms are the same. Epilepsy is the name given to seizures that can occur more than once because of an underlying abnormality in the brain (Aldenkamp, 1987). The prevalence rate of epilepsy in India stands at around 5/1000 (Ray, et al., 2002). At this rate, present estimates of people suffering from epilepsy in this country would be more than 5 million!! There is accumulating evidence that epilepsy must be considered a major risk factor for childhood development. (Aldenkamp & Dodson, 1990; Vinayan et al., 2005). Children with epilepsy as a group are at undue risk of developing learning difficulties (Rutter et al., 1970; Thompson, 1987). Learning problems occur in an estimated 550% of children with epilepsy. (Thompson, 1987). Community based studies in the UK (Verity & Ross, 1985) show that 30% of the investigated children with epilepsy underachieve in school and that many are referred to special education. Classroom performance is dependent upon several factors: the childâ€™s personality structure, environmental factors and cognitive functions. The interrelationships between cognitive functioning and epileptic conditions are of exceptional complicity (Aldenkamp & Dodson, 1990; Noeker et al., 2005). Learning, an adaptive process by which behaviour is modified through experience, can be adversely affected by epilepsy, which is characterized by episodic disruption of neural activity. Seizures have an immediate effect on cognitive function. This effect is more distinct if the seizures occur in series, than if they occur as single events. Certain aspects of seizures correlate with intellectual functioning. Early onset of generalized convulsions is associated with lower IQ scores than early onset of partial seizures. (Oâ€™Leary et al, 1983). Primary generalized and secondarily generalized seizures seem to affect neuropsychological results more than partial seizures do (Giordani, et al, 1985). Intellectual impairment is also related to age of onset, a long history and high frequency of seizures. Earlier the age of onset, the extent of intellectual impairment is considered to be greater and with a long-term impact. Diurnal seizures are seen to have direct effects on the processes of alertness, short-term learning, and
abstract reasoning; nocturnal seizures are seen to have detrimental effects on language functions, memory, and alertness (Renier, 1987). There may be learning disabilities brought about through disruption of longer-term processes of storage and retrieval and by prolonged and permanent reduction in the brainâ€™s capacity to react adaptively to incoming information. The effects of epilepsy on learning have been investigated by examination of processes integral to learning, such as attention and memory, and by consideration of the end results, mainly educational attainments. (Bailet & Turk, 2000; Binnie, Channon, & Marston, 1990; Motte, 2001). Most studies are focused on reading achievement. In a study by Rutter et al (1970), children with epilepsy showed a reading retardation by approximately 12 months. Other studies suggest that arithmetic is the academic skill most impaired (Ross & West, 1978). In a comparative study of two groups (one epileptic and the other non-epileptic) of learning disabled, findings revealed specific patterns of cognitive dysfunction in the LD group with epilepsy (Dekker, et al, 1989). These results are similar to another study where the epileptic group was seen to have specific deficits in short term memory, memory span, attention deficits, concept formation, logical thinking, slowing of information processing in complex task configurations and found to be related to underachievement in arithmetic. (Aldenkamp, 1987). Most data based on neuropsychological assessment of children with epilepsy show that academic problems arise from specific cognitive deficiencies rather than generalized cognitive dysfunction. Rutter et al (1970) reported impaired memory functioning and reduced attention capacity. Factor analytical studies performed on several groups of patients with intractable seizures indicate that the most consistent predictor of neuropsychological impairment and show the relative prominence of the factor of distractibility, in which the subtests of coding, digit span and arithmetic are over represented. The study thus concludes that attention factors may be particularly vulnerable to seizure activity (Kupke & Lewis, 1985).
Epilepsy and a concurrence of learning and behaviour difficulties are seen to have long-term, wide ranging outcomes (Oostrom et al., 2003; Sillanpaa, 2004).
Methodology The present study was carried out at Drishti, a tertiary referral center for assessments & therapy in Mumbai. Aims: To explore if there are any differences in the cognitive functioning & academic skills of two samples of students referred for assessment of learning difficulties. One sample of students has a history of epileptic seizures, whereas the other has no history of epilepsy. Research sample: Demographic data and data from standardized evaluations were studied for this total sample of 70 students. Of these, one group of 31 students had a history of epileptic seizures and was currently on Anti-Epileptic Drugâ€™s (AEDâ€™S), or had current occurrence of seizures (Group with Epilepsy-GEp). The other group of 39 students had no occurrence of epileptic seizures (Group with No Epilepsy-GNEp). In the total sample, there were 45 males and 25 females. In the sample group with epilepsy (GEp), there were 19 males and 12 females, while in the group with no history of Epilepsy (GNEp) there were 26 males and 13 females. The age range extended from 8-12.11 years. All the children were from an urban population. These children were referred to the center for assessment by parents or referring agencies i.e. the treating neurologist/ psychiatrist/ pediatrician or the school. Procedure: This study is a retrospective analysis of psycho-educational assessment data. Assessments were individualized to suit the presenting complaint. Assessment tools used were formal and standardized. Selective data from these assessments was analyzed for the study. Assessment areas analyzed for this study were cognitive functioning, information processing, attention and academic skills of reading, written language, and math. Materials: The assessment data analysed was across the areas of cognitive functioning, information processing, attention, and academic achievement. Demographic and developmental data was collected using a case history form filled out by parents. The selective data analysed include the composite scores from the following instruments:
Weschler Intelligence Scale for Children-Indian adaptation (WISC)(Bhatt, M; 1973) : This test measures the verbal as well as non-verbal intelligence of the student using the verbal and performance scales. The sub-test scaled scores range from 0-20 with an average of 10. Composite scores include the Verbal IQ, Performance IQ and the Global IQ. Ross Information Processing Assessment (RIPA) (Swain, D; 1999): The RIPA-P quantifies & describes cognitive-linguistic deficits in individuals between the ages of 5-0 and 12-11 yrs. It can be used to identify specific individual strengths and weaknesses, to develop and guide rehabilitation goals and objectives. Information Processing Quotient (IPQ): The IPQ comprises the standard scores of all eight RIPA-P sub-tests, and gives a comprehensive estimate of a child's overall information processing abilities. Woodcock-Johnson Psycho-educational Battery-Revised (WJ-R )(Woodcock, R & Johnson, M; 1989-1990): The WJ-R is a wide range comprehensive set of individually administered tests for measuring cognitive abilities, scholastic aptitude and achievement. This test yields age equivalent and grade equivalent scores for all the subtests. The sub-tests can be grouped into reading, written language, and Math clusters. None of the sub-tests are timed tests. Derived Standard scores (SS) and Percentile ranks (PR) are peer comparison statements. Analysis: The data was analysed using appropriate statistical tools. Percentages were calculated for the various sample
characteristics (viz. age, sex, speech milestones, and motor milestones) for both the groups. The studentâ€™s t-test for independent samples was used to estimate significant differences between the groups in the areas of cognition (using the VIQ, PIQ, GIQ, IPQ scores) and academic achievement (Reading comprehension, Written expression, Math calculations). The statistical analyses were carried out using Microsoft Excel 2000.
Results & Discussion The purpose of this study was to examine whether there are any significant differences in the cognitive functioning, information processing and academic skills development between two groups of children, with one group suffering from epilepsy (GEp) and the other group with no epilepsy (GNEp). Table 1 provides an overview of the distribution of the demographic variables of age and gender. The age of the 70 children who formed the study sample ranged from 8 years to 12.11 years. In the GNEp, 41.03% children were in the age range of 8 to 8.9 years, 58.97% children were in the age range of 10 to 11.11 years and zero percent (0%) children were in the age range of 12 to 12.11 years. In the GEp 54.84% children were in the age range of 8 to 8.9 years, 65.48% children were in the age range of 10 to 11.11 years and 9.68% children were in the age range of 12 to 12.11 years. There were 66.67% male children and 33.33% female children in the GNEp. The GEp had 61.29% male children and 38.71% female children (Table 1 here). The demographic data collected during the study shows that there were a greater number of males (64.28%) referred for assessment of learning difficulties. This was true across both the groups. A greater number of students in the non-epilepsy group (58.97%) were in the age range of 10-11.11 years, whereas the larger group in the epilepsy group was in the age range of 8-9.11 years. Thus, it can be seen that children with Epilepsy were referred at a relatively younger age for assessment of learning difficulties. Table 2 shows the developmental characteristics of speech development and motor development of the two groups in the study. A study of these developmental milestones of both the groups shows that 45.16% of the GEp had delayed speech development as compared to 30.77 % of those in the GNEp. Similarly, 19.35% of the GEp showed a delay in motor development as compared to 12.82% of the GNEp. (Table 2 here) Cognitive functioning of the sample was studied through the use of two measures: intellectual functioning and information processing. Table 3 shows the difference in cognitive functioning between GNEp and GEp. The
t-test was used to compute the differences. The mean VIQ for the GEp was 87.71 placing it in the borderline range, whereas that of the GNEp was 96.97 placing it in the average range. The mean PIQ for the GEp was 93.74, being in the average range, whereas that for the GNEp group was 106.18 also being in the average range. The mean
full scale IQ of the GEp was 89.58 placing it at the borderline of average range, whereas it was 101.54 for the GNEp placing it in the average range. All the three intelligence quotients were lower for the GEp. The mean IQ scores of the GNEp were higher than the GEp across all the areas of cognition (viz., VIQ, PIQ, GIQ and IPQ) measured in the current study. The ‘t’ values indicated statistically significant differences ( p< 0.05) in the Verbal Intelligence Quotient (VIQ), Performance Intelligence Quotient (PIQ) and Global Intelligence Quotient (GIQ) between the two groups. Scores on the RIPA were taken in its composite form as the Information Processing Quotient (IPQ). With the mean IPQ of the GEp being 81.64 and the GNEp being 83.79, the difference was not found to be statistically significant. (Table 3 here) Table 4 shows the difference between GNEp and GEp in the areas of academic achievement on the WJ-R. The mean scores were higher for the GNEp across all the areas of academic achievement (viz., Reading, Writing and Mathematics). However, a study of the mean scores of the two groups showed that the reading comprehension scores of both the groups fell below the mean. However, the reading scores of the GNEp was 81, SD 13.71, falling in the range of ‘low average’ classification, whereas the scores of the GEp being 74.42, SD=20.43, fell in the ‘well below average’ classification. Mean standard score in the area of written expression for the GNEp was 85, SD=18.34, placing performance in the low average range, whereas that for the GEp was 76.29, SD= 23.89, thus placing it in the range of well below average functioning. Mean SS in the area of Math calculations for the GNEp was 96.38, SD= 19.98, placing it in the range of average functioning and that for the GEp was 91.71, SD= 23.28 placing it also in the range of average functioning. The t-test was used to compute the differences. No significant difference was found between the two groups across the different areas of academic achievement (viz., Reading, Writing and Mathematics) measured in this study. (Table 4 here) The relationship between cognitive functioning and epilepsy is seen to be complex. Studies have shown (Bourgeois, 1998; Noeker, et al., 2005) that children with epilepsy are seen to have poorer cognitive functioning and attention skills than their peers. However, different studies indicate these cognitive dysfunctions to be specific rather than global (Germano, et al., 2005). These deficits were seen to be in verbal processing, language tasks,
visual perception and memory. This also supports the findings of this study where the mean VIQ of the GEp is seen to be on the borderline of average range and significantly lower than that of the GNEp. Related literature also indicates the presence of non-verbal intellectual difficulties, with children with epilepsy being over represented in the lowest tenth percentile (Giordani, 1985; Hoie, B et al., 2005). However, results from this sample indicate adequate functioning in the area of non-verbal intelligence (PIQ), although there are significant differences between the two groups. Germano et al. (2005) and Carlsson et al. (2000) report that none of their subjects affected by epilepsy showed any global intellectual deficit (as measured by full scale IQ on the WISC_R). This is also seen in the analysis of the current study. Reports of impaired memory, abstract reasoning, and visual-spatial orientation are also present (Rugland, 1990; Stores, 1981). However; some studies find these cognitive deficits to be transient (Saint-Martin et al., 2001). As found with the sample of the present study, Schouten et al (2002) also report that their sample of children with and without epilepsy performed similarly on tasks of recall and retention. Although children with epilepsy tend to exhibit more reading difficulties than their classmates, very few studies have systematically investigated the relationship between these two factors. A study by Vanasse, et al, (2005) indicates that although the reading achievement of their epilepsy group was close to 2 years lower than expectations, these children did not differ from the non-epilepsy group on the phonological processing tasks. Results of the current study also indicated that although reading difficulties were present in the epilepsy group, they did not differ significantly in achievement from the non-epilepsy group, which was also referred for academic difficulties. Results of studies by Papavasiliou et al. (2005) and Yung, et al. (2000) indicate that greater difficulties were seen in the epilepsy group on written language skills when compared with the control group. Results of the present study show deficits in the area of written language achievement of the group with Epilepsy, but no significant difference between the two groups. Studies have also reported arithmetic as being the academic skills most impaired (Aldenkamp, 1983, 1987; Ross & West, 1978). However, in the present study, performance of the GEp on the math calculation subtest was adequate and comparable to the GNEp.
Carlsson et al (2000) also investigated as to whether there was an association between dyslexia and epilepsy. Two groups, both identified with dyslexia, but one with epilepsy and the other without, were compared. Results indicated no significant differences on neuropsychological variables or spelling ability. However, those with epilepsy did show more reading errors. The results of this study and sparse literature in this area reflect upon the need to explore further into the possible similarities in neuropsychological processes for those suffering from epilepsy and those with dyslexia without the presence of epilepsy. Studies need to be conducted on larger samples (small ample size was one of the limitations of the current study). Also, these studies need to then differentiate between different types of epilepsy, which this study did not do.
In order to help out the children with epilepsy, recommendations are mainly in the areas of drug therapy, parent counseling, school-teacher education and improving the Quality of life of the individual ( Bourgeois, 1999; Galletti, 2004; Malhi & Singhi, 2005).
References Aldenkamp, A.K. (1987). Learning disabilities and epilepsy. In Aldenkamp,A.P., Alpherts, W., Meinardi ,H., & Stores G. (Eds.) Education and Epilepsy. Lisse/Berwyn: Swets & Zeitlinger Aldenkamp, A.P., et al. (1990). Test-retest variability in children with epilepsy. Epilepsy research, 2,165-72. Bailet, L.L., & Turk, W.R.(2000). The impact of childhood epilepsy on neurocognitive and behavioral performance: a prospective longitudinal study. Epilepsia, 41(4), 426-31. Berg, A.T., et al. (2005). Special education needs of children with newly diagnosed epilepsy. Developmental Medicine & Child Neurology; 47(11),749-53. Carlsson, G., et al. (2000). Neuropsychological long-term outcome of rolandic EEG traits. Epileptic Disorders, 2 Supplement 1, S63-66. Dekker, R., et al. (1989). Subtypes of learning disabilities in epilepsy. Abstracts, 18 th International Epilepsy Congress. New Delhi
Galletti, F. & Sturniolo, M.G. (2004). Counseling children and parents about epilepsy. Patient Education Counseling; 55(3), 422-25. Germano, E., et al. (2005). Benign childhood epilepsy with occipital paroxysms: neuropsychological findings. Epilepsy Research, 64(3), 137-50. Hoie, B., et al. (2005). Seizure-related factors and non-verbal intelligence in children with epilepsy. A populationbased study from Western Norway. Seizure : The Journal Of The British Epilepsy Association, 14(4), 223-31. Kupke ,T., &Lewis, R.( 1985). WAIS and neuropsychological tests: common and unique variance within an epileptic population. Journal of Clinical Experimental Neuropsychology,7, 353-66. Malhi, P., & Singhi, P. (2005). Correlates of quality of life with epilepsy. Indian Journal of Pediatrics, 72(2), 131-135. Motte, J. ( 2001). Epilepsy and childhood learning disabilities. Epileptic Disorders, 3, spec No 2, SI47-9. Noekar, M., et al. (2005). Development of mental health dysfunction in childhood epilepsy. Brain & Development; 27(1), 5-16. Oostrom, K.J., et al. (2003). Behavioral problems in children with newly diagnosed idiopathic or cryptogenic epilepsy attending normal schools are in majority not persistent. Epilepsia, 44(1), 97-106. Papavasiliou, A., et al. (2005). Written language skills in children with benign childhood epilepsy with centrotemporal spikes. Epilepsy and Behaviour., 6(1), 50-8 Renier, W.O. (1987). Restrictive factors in the education of children with epilepsy from a medical point of view. In Aldenkamp, A.P. et.al (Ed.) Education and Epilepsy. Lisse/Berwyn:Swets & Zeitlinger Ross, E.M., & West, P.B. (1978). Achievement and problems of British eleven year olds with epilepsy. In: Rowan, A.J, & Meinardi, H.(Eds.) Advances in epileptology: psychology, pharmacotherapy and new diagnostic approaches. Lisse/Berwyn:Swets&Zeitlinger,. Rutter, M., Graham, P., & Yule, W. ( 1970). A neuropsychiatric study in childhood. Clinics in Developmental Medicine. London: Heinemann. Rugland,A.L. (1990). Neuropsychological Assessment of Cognitive Functioning in Children with Epilepsy. Epilepsia, 31 (suppl.4), S41-S44.
Saint-Martin, A.D., et al. (2001). Cognitive consequences of Rolandic Epilepsy. Epileptic Disorders, 3, Spec No 2, SI59-65. Schouten, A., et al. (2002). Learning and memory of school children with epilepsy: a prospective controlled longitudinal study. Developmental Medicine & Child Neurology; 44(12), 803-11. Sillanpaa, M. (2004). Learning disability: occurrence and long-term consequences in childhood-onset epilepsy. Epilepsy And Behaviour; 5(6), 937-44. Thomson, P.J. (1987). Educational attainment in children and young people with epilepsy. In Oxley J, Stores G. (Eds.) Epilepsy And Education. London: The Medical Tribune Group. Vanasse, C.M., et al. (2005). Impact of childhood epilepsy on reading and phonological processing abilities. Epilepsy and behaviour, 7(2), 288-96. Verity, C. M., & Ross, E.M. (1985). Longitudinal studies of childrenâ€™s epilepsy. In Ross, E., & Reynolds, E. Chichester (Eds.) Paediatric perspectives on epilepsy.: John Wiley & Sons Ltd. Vinayan, K. P., et al. (2005). Educational problems with underlying neuropsychological impairment are common in children with Benign Epilepsy of Childhood with Centrotemporal Spikes (BECTS). Seizure : The Journal Of The British Epilepsy Association, 14(3), 207-12. Yung, A.W., et al. (2000). Cognitive and behavioral problems in children with centrotemporal spikes. Paediatric Neurology, 23(5), 391-5.
Table 1: Sample characteristics-demographic variables of age & gender.
Variables Male SEX Female 8-9.11 10-11.11 AGE 12-12.11
Non Epilepsy 67% 33% 41.03% 58.97% 0%
Epilepsy 61.29% 38.71% 54.84% 35.48% 9.68%
Total 64% 35.71% 47.14% 48.57% 4.29%
Table 2: Sample characteristics: developmental delays. Variables Speech
Table 3: Differences between GNEp and GEp in cognitive functioning.
(Mean ± SD)
(Mean ± SD)
96.97 ± 15.58
87.71 ± 17.77
106.18 ± 17.65
93.74 ± 16.75
101.54 ± 16.34
89.58 ± 16.94
83.79 ± 27.55
81.64 ± 20.09
(df = 68)
VIQ = Verbal Intelligence Quotient PIQ = Performance Intelligence Quotient GIQ = Global Intelligence Quotient IPQ = Information Processing Quotient
Table 4: Difference between GNEp and GEp in academic achievement.
(Mean ± SD)
(Mean ± SD)
81.00 ± 13.71
74.42 ± 20.43
85.00 ± 18.34
76.29 ± 23.89
96.38 ± 19.98
91.71 ± 23.28
(df = 68) Reading (Comprehension) Writing (Expression) Mathematics (Calculation)
*p<0.05 NS: Not Significant
Published on Dec 31, 2008
Neuropsychological outcome of childhood epilepsy: A study of cognitive functioning and academic skill development. Disabilities and Impairme...