Current Literature In Clinical Science
Not Necessarily Benign: Rolandic Epilepsy
A Meta-Analysis Of Literacy And Language In Children With Rolandic Epilepsy. Smith AB, Bajomo O, Pal DK. Dev Med Child Neurol 2015;57:1019–1026.
AIM: Rolandic epilepsy is the most common childhood epilepsy, often presenting with neuropsychological impairments. The aim of the study was to formally assimilate the findings of existing studies varying widely in methodology, thereby confirming the nature and prevalence of impairments in literacy and language. METHODS: Using meta-analytical techniques, we evaluated 22 studies of literacy and/or language skills in children with rolandic epilepsy, published after 2000, among participants with IQs>70 and in which effect sizes could be acquired. Diagnosis required the presence of classical centrotemporal spikes arising from a normal background on electroencephalograms; a clinical history including at least one seizure; and no additional neurological condition. Overall effect size and heterogeneity were measured for single-word reading, phonological processing, and expressive and receptive language. RESULTS: Mean effect sizes (Cohen’s d) ranged from 0.50 (95% confidence interval [CI] 0.23-0.78) for phonological processing, through 0.71 (95% CI 0.52-0.90) for word reading and 0.72 (95% CI 0.34-1.1) for receptive language, to 0.75 (95% CI 0.45-1.05) for expressive language. While group differences for reading measures were consistent, those for language were heterogeneous and varied across studies explained by age and IQ of samples.
Commentary Appreciating the cognitive outcome of benign rolandic epilepsy (BRE) is an important endeavor, not only because it is the most common form of childhood epilepsy, but because BRE may provide a window from which to view the broader developmental consequences of epileptic activity in childhood or the presumed, yet unknown, consequences of interictal epileptic discharges (IEDs). Given typical early development and onset of seizures at approximately ages 5 to 7 years along with few clinical seizures, no structural abnormalities, few medications prescribed, and abundant focal IEDs, the study of children with BRE provides an opportunity to understand the concept of epileptic encephalopathy in a relatively mild form. This meta-analysis of literacy and language in children with rolandic epilepsy is illuminating and also consistent with the experiences of those of us who work clinically with children with BRE and conduct research with this population. Aggregating multiple small sample studies of BRE patients, it is clear that reading difficulties, along with phonological processing weaknesses, are present in children with BRE as a group, relative to healthy controls. Moreover, expressive and receptive language function are vulnerable in the population relative to healthy controls, and interestingly, this effect appears to be greater in older children than younger despite the fact that children with BRE are known to outgrow the syndrome in early to midadolescence (1). Epilepsy Currents, Vol. 16, No. 4 (July/August) 2016 pp. 254–255 © American Epilepsy Society
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There is debate in this field about how benign BRE really is in terms of cognitive morbidity and to what degree this group of patients “out-grows” deficits over time. It is quite unlikely that seizures themselves contribute to cognitive limitations given the few clinical seizures observed in the typical BRE syndrome relative to reported learning and cognitive processing symptoms. Associations between cognitive function and IEDs have been variable across studies, as noted in the background section of the meta-analysis that is the target of this commentary. While the specific role of IEDs may not be elucidated as of yet, it is plausible that abnormal electrical activity is a signal of neurological dysfunction that has the potential to disrupt neural network function and development. With this in mind, the laterality, frequency, and age of onset of this abnormal pattern, theoretically, would all have the potential to contribute to cognitive dysfunction both during the active phase of the syndrome and over time due to developmental disruption by IEDs. Should evidence eventually identify a developmental cost associated with IEDs, such as verbal learning limitations as discussed here, then clear implications for treatment paradigms to suppress IEDs and support developmental progression would warrant a call for placebo controlled antiepileptic drug trials for BRE with cognitive outcome and IED suppression as the primary outcomes. However, the potential cost of negative neurodevelopmental effects of long-term AED use during the developmental period would need to be weighed against the potential benefit of IED suppression. Considering the developmental timing of the onset of the BRE syndrome is important. In this meta-analysis the average
Benign Rolandic Epilepsy
age of onset was approximately 5 to 7 years and certainly typical for this syndrome. During this time of life, children have fairly well developed behavioral and emotional regulation; they have acquired language and have established basic social communication skills. Proximal development at this stage takes place in the context of early elementary education and involves establishment of fundamental academic skills, such as reading and number concepts. In fact, most children actively build the neurological connections necessary to develop reading skills in the early elementary years, at precisely the time of BRE onset. As such, it comes as no surprise to neuropsychologists trained in a developmental systems approach to neuropsychology (2) that reading and phonological processing limitations are consistently observed across studies of children with BRE. It remains to be fully understood whether the morbidity associated with BRE is reversible later in adolescence after seizures and IEDs have abated. Camfield and Camfield (3) have documented long-term adjustment of patients with childhood onset epilepsy and report that adults who had recovered from BRE do not, as a group, generally have negative adaptive outcomes in terms of employment, education, and general citizenship. There are not sufficient longitudinal studies of cognition in the BRE patient population from which to derive appropriate conclusions regarding resolution or continuation of neuropsychological deficits over time among the patients who demonstrate vulnerability in childhood.
The findings of this meta-analysis reveal that older BRE patients were more likely to demonstrate language problems than younger ones, which, interestingly, runs counter to the idea that this group of individuals outgrows cognitive deficits along with the BRE syndrome itself. Long-term follow-up of adolescents who have recovered from BRE is an important endeavor to pursue. Because children in the active phase of BRE are vulnerable to relatively mild cognitive difficulties in the setting of normal intellectual function, assessment with a high degree of sensitivity will be important to detect continued dysfunction during the recovery phase. Better prediction of long-term outcome with and without treatment intervention is essential for improving clinical counseling and management of this sizable pediatric epilepsy population. by Katrina Boyer, PhD References 1. Bauma PA, Bovenkerk AC, Westendorp RG, Brouweer OF. The course of benign partial epilepsy of childhood with centrotemporal spikes: a meta-analysis. Neurology 1997:48:430–437. 2. Bernstein JH. Developmental neuropsychological assessment. In: Pediatric Neuropsychology. Research, Theory, and Practice. (Yeates KO, Taylor HG, Ris MD, eds.) New York: The Guilford Press, 2000:405-438. 3. Camfield CS, Camfield PR. Rolandic epilepsy has little effect on adult life 30 years later: a population-based study. Neurology 2014 1;82:1162–1166.
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Not Necessarily Benign: Rolandic Epilepsy
A Meta-Analysis Of Literacy And Language In Children With Rolandic Epilepsy. Smith AB, Bajomo O, Pal DK. Dev Med Child Neurol 2015;57:1019–1026.
AIM: Rolandic epilepsy is the most common childhood epilepsy, often presenting with neuropsychological impairments. The aim of the study was to formally assimilate the findings of existing studies varying widely in methodology, thereby confirming the nature and prevalence of impairments in literacy and language. METHODS: Using meta-analytical techniques, we evaluated 22 studies of literacy and/or language skills in children with rolandic epilepsy, published after 2000, among participants with IQs>70 and in which effect sizes could be acquired. Diagnosis required the presence of classical centrotemporal spikes arising from a normal background on electroencephalograms; a clinical history including at least one seizure; and no additional neurological condition. Overall effect size and heterogeneity were measured for single-word reading, phonological processing, and expressive and receptive language. RESULTS: Mean effect sizes (Cohen’s d) ranged from 0.50 (95% confidence interval [CI] 0.23-0.78) for phonological processing, through 0.71 (95% CI 0.52-0.90) for word reading and 0.72 (95% CI 0.34-1.1) for receptive language, to 0.75 (95% CI 0.45-1.05) for expressive language. While group differences for reading measures were consistent, those for language were heterogeneous and varied across studies explained by age and IQ of samples.
Commentary Appreciating the cognitive outcome of benign rolandic epilepsy (BRE) is an important endeavor, not only because it is the most common form of childhood epilepsy, but because BRE may provide a window from which to view the broader developmental consequences of epileptic activity in childhood or the presumed, yet unknown, consequences of interictal epileptic discharges (IEDs). Given typical early development and onset of seizures at approximately ages 5 to 7 years along with few clinical seizures, no structural abnormalities, few medications prescribed, and abundant focal IEDs, the study of children with BRE provides an opportunity to understand the concept of epileptic encephalopathy in a relatively mild form. This meta-analysis of literacy and language in children with rolandic epilepsy is illuminating and also consistent with the experiences of those of us who work clinically with children with BRE and conduct research with this population. Aggregating multiple small sample studies of BRE patients, it is clear that reading difficulties, along with phonological processing weaknesses, are present in children with BRE as a group, relative to healthy controls. Moreover, expressive and receptive language function are vulnerable in the population relative to healthy controls, and interestingly, this effect appears to be greater in older children than younger despite the fact that children with BRE are known to outgrow the syndrome in early to midadolescence (1). Epilepsy Currents, Vol. 16, No. 4 (July/August) 2016 pp. 254–255 © American Epilepsy Society
254
There is debate in this field about how benign BRE really is in terms of cognitive morbidity and to what degree this group of patients “out-grows” deficits over time. It is quite unlikely that seizures themselves contribute to cognitive limitations given the few clinical seizures observed in the typical BRE syndrome relative to reported learning and cognitive processing symptoms. Associations between cognitive function and IEDs have been variable across studies, as noted in the background section of the meta-analysis that is the target of this commentary. While the specific role of IEDs may not be elucidated as of yet, it is plausible that abnormal electrical activity is a signal of neurological dysfunction that has the potential to disrupt neural network function and development. With this in mind, the laterality, frequency, and age of onset of this abnormal pattern, theoretically, would all have the potential to contribute to cognitive dysfunction both during the active phase of the syndrome and over time due to developmental disruption by IEDs. Should evidence eventually identify a developmental cost associated with IEDs, such as verbal learning limitations as discussed here, then clear implications for treatment paradigms to suppress IEDs and support developmental progression would warrant a call for placebo controlled antiepileptic drug trials for BRE with cognitive outcome and IED suppression as the primary outcomes. However, the potential cost of negative neurodevelopmental effects of long-term AED use during the developmental period would need to be weighed against the potential benefit of IED suppression. Considering the developmental timing of the onset of the BRE syndrome is important. In this meta-analysis the average
Benign Rolandic Epilepsy
age of onset was approximately 5 to 7 years and certainly typical for this syndrome. During this time of life, children have fairly well developed behavioral and emotional regulation; they have acquired language and have established basic social communication skills. Proximal development at this stage takes place in the context of early elementary education and involves establishment of fundamental academic skills, such as reading and number concepts. In fact, most children actively build the neurological connections necessary to develop reading skills in the early elementary years, at precisely the time of BRE onset. As such, it comes as no surprise to neuropsychologists trained in a developmental systems approach to neuropsychology (2) that reading and phonological processing limitations are consistently observed across studies of children with BRE. It remains to be fully understood whether the morbidity associated with BRE is reversible later in adolescence after seizures and IEDs have abated. Camfield and Camfield (3) have documented long-term adjustment of patients with childhood onset epilepsy and report that adults who had recovered from BRE do not, as a group, generally have negative adaptive outcomes in terms of employment, education, and general citizenship. There are not sufficient longitudinal studies of cognition in the BRE patient population from which to derive appropriate conclusions regarding resolution or continuation of neuropsychological deficits over time among the patients who demonstrate vulnerability in childhood.
The findings of this meta-analysis reveal that older BRE patients were more likely to demonstrate language problems than younger ones, which, interestingly, runs counter to the idea that this group of individuals outgrows cognitive deficits along with the BRE syndrome itself. Long-term follow-up of adolescents who have recovered from BRE is an important endeavor to pursue. Because children in the active phase of BRE are vulnerable to relatively mild cognitive difficulties in the setting of normal intellectual function, assessment with a high degree of sensitivity will be important to detect continued dysfunction during the recovery phase. Better prediction of long-term outcome with and without treatment intervention is essential for improving clinical counseling and management of this sizable pediatric epilepsy population. by Katrina Boyer, PhD References 1. Bauma PA, Bovenkerk AC, Westendorp RG, Brouweer OF. The course of benign partial epilepsy of childhood with centrotemporal spikes: a meta-analysis. Neurology 1997:48:430–437. 2. Bernstein JH. Developmental neuropsychological assessment. In: Pediatric Neuropsychology. Research, Theory, and Practice. (Yeates KO, Taylor HG, Ris MD, eds.) New York: The Guilford Press, 2000:405-438. 3. Camfield CS, Camfield PR. Rolandic epilepsy has little effect on adult life 30 years later: a population-based study. Neurology 2014 1;82:1162–1166.
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