Early cognitive and behavioral problems in children with nodular heterotopia

Abstract

Adults with periventricular nodular heterotopia (PNH) suffer from epilepsy and dyslexia but most have normal intelligence. It is not known whether PNH-related reading difficulty can be detected earlier in childhood, or whether associated behavioral problems are present. We studied 10 children with PNH, three of whom did not have seizures, and 10 matched controls with neuropsychological testing and parental rating instruments at two timepoints separated by about one year. Children with PNH performed significantly worse than controls on three tasks related to reading fluency. In addition, those with PNH showed significantly worse adaptive skills, and a measure of conduct problems significantly worsened over time. Mood and behavioral problems were reported more commonly, though not significantly so, in children with PNH. These findings demonstrate that reading dysfluency can be evident in children with nodular heterotopia, even in the absence of epilepsy, but also highlight difficulties with behavior in this population.

Mechanisms Responsible for Cognitive Impairment in Epilepsy

“…In the school setting, 45% of children with epilepsy and an IQ of at least 80 require special education services, and 16% of these children repeat a year of education (Aldenkamp et al 1990;). There are also more specific abnormalities identified in both reading skills (including single-word, phonological awareness, comprehension, and speed or fluency deficits) and math skills (Croona et al 1999;Chaix et al 2006;Pinton et al 2006;Canavese et al 2007;Clarke et al 2007;Felker et al 2011;Verrotti et al 2011). Often, several educational areas are affected in individuals.…”

Prenatal diagnosis of periventricular nodular heterotopia in borderline ventriculomegaly using sonography and magnetic resonance imaging

“…The migration of neuroblasts from the periventricular germinal centers has been demonstrated as early as at the seventh gestational week, continuing for several months postnatally . An arrest of migration, which appears either as a disorder of cortical lamination and gyration (macrogyria, polymicrogyria) or as collections of neurons in abnormal locations (heterotopia of gray matter) has been defined as a defect in the radial glial fibers . Heterotopic brain tissue is usually located between the periventricular region and the overlying cerebral cortex .…”

“…Heterotopic brain tissue is usually located between the periventricular region and the overlying cerebral cortex . PNH, as the most common type of heterotopia, consists of collections of disorganized neurons and glial cells that are located along the walls of the lateral ventricles . The exact prevalence of PNH in the general population is unknown, but it has been reported as an associated finding in 11–20% of epileptic patients with cortical malformations …”

“…Epileptic encephalopathy with infantile spasms and tonic seizures has been reported in 72% of bilateral PNH. Severe mental retardation, seizures, developmental delay, syndactyly, nephrosis, and persistent temporal lobe epilepsy (refractory to temporal lobectomy) were reported in PNH cases …”

“…The onset and severity of clinical symptoms are variable . Epilepsy and dyslexia are common features in adults with PNH, but most have normal intelligence.…”