Long-Term Follow-Up in Children With Focal Cortical Dysplasia IIId for Early Brain Injuries, Including Neuropathological Findings.

BACKGROUND: Early cerebral injury has a close relationship with epilepsy and focal cortical dysplasia Ⅲd. We investigated children with focal cortical dysplasia Ⅲd who underwent surgery for epilepsy. METHODS: We selected 49 patients from among 260 pediatric patients who had undergone epilepsy surgery, analyzing their clinical materials and pathology data. The selected patients had been followed for more than two years. RESULTS: The 49 patients were divided into seven groups based on different early brain injuries. There was a significant difference (P < 0.05) between Engel class I ratio of cerebral hemorrhage group (84.6%) and that of central nervous system infection group (42.1%) in two to eight years follow-up. The patients with prior cerebral hemorrhage had a wider scope (P < 0.05) of brain damage than those in the brain infection and febrile convulsion groups. Secondary polymicrogyria commonly existed. Neuron islands were located adjacent to polymicrogyria in cerebral hemorrhage and brain trauma patients, and missing neuronal laminations beside the polymicrogyria was noted in others. CONCLUSIONS: In children with focal cortical dysplasia Ⅲd, individuals with cerebral hemorrhage within the perinatal period exhibited a wider range of brain lesions, while the postoperative follow-up outcome was better. Secondary polymicrogyria existed along with focal cortical dysplasia Ⅲd and is related to the developmental lesion. The processes of secondary polymicrogyria caused by different early brain injuries might be different.

Challenges in managing epilepsy associated with focal cortical dysplasia in children.

Focal cortical dysplasia (FCD) is the most common cause of intractable focal epilepsy in children, in whom seizures are most commonly pharmacoresistant from onset. This review summarizes the current understandings of the epidemiology, natural history, and the proposed mechanisms of epileptogenisis in FCD. Advances in neuroimaging techniques have enhanced the recognition of this pathology, which can be subtle. Illustrative neurophysiology and imaging examples are provided to help the clinicians identify diagnostic evidence of suspected FCD. Given the refractory course to pharmacologic management, alternative options such as ketogenic diet, resective surgery or neuromodulation can be considered. Recognition of FCD pathology in children with early onset epilepsy should prompt timely evaluations for resective surgery, which may render a significant number of patients seizure-free and improve neurocognitive outcome.

Novel surface features for automated detection of focal cortical dysplasias in paediatric epilepsy.

Focal cortical dysplasia is a congenital abnormality of cortical development and the leading cause of surgically remediable drug-resistant epilepsy in children. Post-surgical outcome is improved by presurgical lesion detection on structural MRI. Automated computational techniques have improved detection of focal cortical dysplasias in adults but have not yet been effective when applied to developing brains. There is therefore a need to develop reliable and sensitive methods to address the particular challenges of a paediatric cohort. We developed a classifier using surface-based features to identify focal abnormalities of cortical development in a paediatric cohort. In addition to established measures, such as cortical thickness, grey-white matter blurring, FLAIR signal intensity, sulcal depth and curvature, our novel features included complementary metrics of surface morphology such as local cortical deformation as well as post-processing methods such as the "doughnut" method - which quantifies local variability in cortical morphometry/MRI signal intensity, and per-vertex interhemispheric asymmetry. A neural network classifier was trained using data from 22 patients with focal epilepsy (mean age = 12.1 ± 3.9, 9 females), after intra- and inter-subject normalisation using a population of 28 healthy controls (mean age = 14.6 ± 3.1, 11 females). Leave-one-out cross-validation was used to quantify classifier sensitivity using established features and the combination of established and novel features. Focal cortical dysplasias in our paediatric cohort were correctly identified with a higher sensitivity (73%) when novel features, based on our approach for detecting local cortical changes, were included, when compared to the sensitivity using only established features (59%). These methods may be applicable to aiding identification of subtle lesions in medication-resistant paediatric epilepsy as well as to the structural analysis of both healthy and abnormal cortical development.