Neuropsychological profile of children with subcortical band heterotopia
Megan Spencer-Smith1, Richard Leventer, Rani Jacobs
1Murdoch Childrens Research Institute, Melbourne, Australia. megan.spencer-smith@mcri.edu.au
Insights
Children with subcortical band heterotopia (SBH) experience significant cognitive, academic, and social challenges. Processing speed and complex cognitive skills are particularly affected in these patients.
Area of Science:
- Neuroscience
- Developmental Biology
- Clinical Neurology
Background:
- Subcortical band heterotopia (SBH), also known as 'double cortex,' is a neuronal migration disorder.
- Previous research primarily focused on neurological, neuroimaging, and genetic aspects of SBH.
- Emerging evidence suggests neuropsychological dysfunction in SBH patients.
Purpose of the Study:
- To further characterize the phenotype of SBH by detailing the neuropsychological profiles of affected children.
- To assess cognitive functioning, including intellectual ability, processing speed, attention, and working memory.
- To evaluate academic achievement, social skills, and behavioral issues in children with SBH.
Main Methods:
- Neuropsychological assessments were conducted on seven children (ages 4-15) with SBH.
- Cognitive abilities and academic achievements (reading, spelling, arithmetic) were evaluated.
- Parental questionnaires addressed social skills and problem behaviors; MRI scans and medical records provided clinical and genetic data.
Main Results:
- Neuropsychological impairments were present across all assessed domains.
- Intellectual ability ranged from 'extremely low' to low (Full-Scale IQ 44-74).
- Severe impairments were noted in processing speed, working memory, and arithmetic; academic, social, and behavioral deficits were less pervasive. No clear neuroimaging-neuropsychological correlation was found.
Conclusions:
- Children with SBH exhibit widespread cognitive, academic, social, and behavioral difficulties.
- The most significant challenges are observed in processing speed and complex cognitive functions.
- These findings highlight the critical need for comprehensive neuropsychological support for children with SBH.
Aim:
Subcortical band heterotopia (SBH) or 'double cortex' is a malformation of cortical development resulting from impaired neuronal migration. So far, research has focused on the neurological, neuroimaging, and genetic correlates of SBH. More recently, clinical reports and small sample studies have documented neuropsychological dysfunction in patients with this malformation. This study aimed to characterize further the phenotype of patients with SBH by describing the neuropsychological profiles of children.
Method:
Seven children (six females) aged 4 to 15 years were assessed for cognitive functioning (intellectual ability, processing speed, attention, working memory) and academic achievement (reading, spelling, arithmetic). Parents completed questionnaires examining their child's social skills and problem behaviours. Magnetic resonance images (MRI) conducted for routine clinical follow-up were coded by a paediatric neurologist. Genetic and seizure history were obtained from medical records.
Results:
There was variation in the neurological, neuroimaging, and genetic presentation of children in the sample. Impairments were observed in all areas of neuropsychological functioning examined. Intellectual ability was generally within the 'extremely low' range (full-scale IQ 44-74; performance IQ 45-72; verbal IQ 57-80). Generalized impairments in cognitive skills were typical, with severe impairments (scores greater than 2SD below the test mean) reported in processing speed, working memory, and arithmetic. Impairments in academic, social, and behavioural functioning were less generalized. No clear relationship between neuroimaging and neuropsychological impairments was found.
Interpretation:
Children with SBH demonstrate cognitive, academic, social, and behavioural problems, with the greatest difficulties in processing speed and complex cognitive skills.
