OBJECTIVE: We comprehensively characterized a large pediatric cohort with focal cortical dysplasia (FCD) type 1 to expand the phenotypic spectrum and to identify predictors of postsurgical outcomes. METHODS: We included pediatric patients with histopathological diagnosis of isolated FCD type 1 and at least 1 year of postsurgical follow-up. We systematically reanalyzed clinical, electrophysiological, and radiological features. The results of this reanalysis served as independent variables for subsequent statistical analyses of outcome predictors. RESULTS: All children (N = 31) had drug-resistant epilepsy with varying impacts on neurodevelopment and cognition (presurgical intelligence quotient [IQ]/developmental quotient scores = 32-106). Low presurgical IQ was associated with abnormal slow background electroencephalographic (EEG) activity and disrupted sleep architecture. Scalp EEG showed predominantly multiregional and often bilateral epileptiform activity. Advanced epilepsy magnetic resonance imaging (MRI) protocols identified FCD-specific features in 74.2% of patients (23/31), 17 of whom were initially evaluated as MRI-negative. In six of eight MRI-negative cases, fluorodeoxyglucose-positron emission tomography (PET) and subtraction ictal single photon emission computed tomography coregistered to MRI helped localize the dysplastic cortex. Sixteen patients (51.6%) underwent invasive EEG. By the last follow-up (median = 5 years, interquartile range = 3.3-9 years), seizure freedom was achieved in 71% of patients (22/31), including seven of eight MRI-negative patients. Antiseizure medications were reduced in 21 patients, with complete withdrawal in six. Seizure outcome was predicted by a combination of the following descriptors: age at epilepsy onset, epilepsy duration, long-term invasive EEG, and specific MRI and PET findings. SIGNIFICANCE: This study highlights the broad phenotypic spectrum of FCD type 1, which spans far beyond the narrow descriptions of previous studies. The applied multilayered presurgical approach helped localize the epileptogenic zone in many previously nonlesional cases, resulting in improved postsurgical seizure outcomes, which are more favorable than previously reported for FCD type 1 patients.

• Keywords
• drug‐resistant epilepsy, epilepsy surgery, focal cortical dysplasia type 1, multilayered diagnostic protocol, pediatric patients,
• MeSH
• Child MeSH
• Electroencephalography MeSH
• Focal Cortical Dysplasia MeSH
• Cohort Studies MeSH
• Infant MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Malformations of Cortical Development, Group I * complications   surgery   physiopathology   diagnostic imaging   MeSH
• Adolescent MeSH
• Follow-Up Studies MeSH
• Positron-Emission Tomography MeSH
• Child, Preschool MeSH
• Drug Resistant Epilepsy * surgery   diagnostic imaging   physiopathology   etiology   MeSH
• Treatment Outcome MeSH
• Check Tag
• Child MeSH
• Infant MeSH
• Humans MeSH
• Adolescent MeSH
• Male MeSH
• Child, Preschool MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Fetal intracranial hemorrhage represents a rare event with an estimated prevalence of 1:10 000 pregnancies. We report a patient diagnosed prenatally with intracranial hemorrhage and ventriculomegaly carrying a novel, previously unreported, likely pathogenic variant in COL4A1. At the gestational age of 27 weeks, dilation of lateral ventricles was detected during a routine prenatal ultrasound scan, confirmed by prenatal MRI at 30 + 3 weeks of gestation. Prenatal examinations included amniocentesis with conventional G-band karyotyping and arrayCGH, and maternal testing for TORCH and parvovirus B19 infections. Virtual gene panel based on whole-exome sequencing data was performed postnatally. At the age of 2.5 months, the patient manifested epileptic seizures that remain difficult to control. Postnatal MRI showed partial thalamic fusion and polymicrogyria, in addition to severe enlargement of lateral ventricles, multiple deposits of hemosiderin in cerebral and cerebellar hemispheres, and thin optic nerve and chiasma. Virtual gene panel based on whole-exome sequencing data led to a detection of a de novo previously unreported in-frame deletion NM_001845.5:c.4688_4711del in COL4A1 located in the highly conserved NC1 domain initiating collagen helix assembly. The presented case lies one a more severe end of the COL4A1 mutation-related disease spectrum, manifesting as fetal intracranial bleeding, malformation of cortical development, drug-resistant epilepsy, and developmental delay.

• Keywords
• COL4A1, COL4A1 mutation-related disorders, intracranial hemorrhage, malformation of cortical development, polymicrogyria,
• MeSH
• Hydrocephalus * MeSH
• Intracranial Hemorrhages MeSH
• Infant MeSH
• Collagen Type IV genetics   MeSH
• Humans MeSH
• Mutation MeSH
• Fetus MeSH
• Polymicrogyria * genetics   MeSH
• Pregnancy MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Case Reports MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• COL4A1 protein, human MeSH Browser
• Collagen Type IV MeSH