Periventricular nodular heterotopia (PNH) is a brain malformation clinically characterized by the triad of epilepsy, normal intelligence, and dyslexia. We investigated the structure-function relationship between cerebral volumes and cognitive ability in this disorder by studying 12 subjects with PNH and 6 controls using volumetric analysis of high-resolution anatomical MRI and neuropsychological testing. Total cerebral volumes and specific brain compartment volumes (gray matter, white matter, and cerebrospinal fluid) in subjects with PNH were comparable to those in controls. There was a negative correlation between heterotopic gray matter volume and cortical gray matter volume. Cerebral and cortical volumes in PNH did not correlate with Full Scale IQ, unlike in normal individuals. Our findings support the idea that heterotopic nodules contain misplaced neurons that would normally have migrated to the cortex, and suggest that structural correlates of normal cognitive ability may be different in the setting of neuronal migration failure.
Bibliographical noteFunding Information:
We thank all of our subjects for participating in this study; without them this research would not have been possible. B.S.C. was supported by the National Institute of Neurological Disorders and Stroke (Grant K23 NS049159). B.S.C. and T.K. were supported by the Mind–Brain–Behavior Initiative of Harvard University.
- Malformation of cortical development
- Periventricular nodular heterotopia
- Volumetric magnetic resonance imaging
ASJC Scopus subject areas
- Clinical Neurology
- Behavioral Neuroscience