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Published on: March 11, 2013
Dissecting the neurological phenotype in children with callosal agenesis, interhemispheric cysts and malformations of
Sara Uccella1, Andrea Accogli2, Domenico Tortora3
1Pediatric Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Genoa, Italy.
Insights
Children with prenatal agenesis of corpus callosum (ACC) and interhemispheric cysts often have mild neurological issues. Epilepsy is infrequent and manageable, especially when Aicardi syndrome is excluded.
Area of Science:
- Neurology
- Developmental Neuroscience
- Medical Imaging
Background:
- Agenesis of the corpus callosum (ACC) and interhemispheric cysts are congenital brain malformations.
- Malformations of cortical development (MCD) can co-occur, influencing neurological outcomes.
- Understanding the neurological phenotype is crucial for patient management.
Purpose of the Study:
- To delineate the neurological phenotype in children with prenatally diagnosed ACC and interhemispheric cysts.
- To correlate specific cyst types and MCD with neurological and cognitive outcomes.
- To assess the prevalence and characteristics of epilepsy in this cohort.
Main Methods:
- Retrospective review of neuroimaging, neurological, EEG, and genetic data from 36 patients.
- Classification of interhemispheric cysts using the 2001 Barkovich criteria.
- Statistical analysis (Chi-squared, Fisher exact tests) to identify associations.
Main Results:
- Cyst types included 1c, 2a, 2b (frequently with Aicardi syndrome), and 2c.
- Epileptic activity observed in 75% of patients; epilepsy diagnosed in 44.4%.
- Cognitive impairment associated with epilepsy (p=0.032); severe deficits linked to type 2b cysts (Aicardi syndrome) and extensive MCD.
Conclusions:
- Excluding Aicardi syndrome, most patients exhibit mild phenotypes with normal/borderline cognition and minor neurological signs.
- Epilepsy is uncommon and generally responsive to treatment, despite frequent EEG abnormalities.
- Multilobar/bilateral MCD correlate with severe neurological and epileptic outcomes.
Objectives:
To describe the neurological phenotype of children with prenatal diagnosis of agenesis of corpus callosum (ACC) and interhemispheric cysts associated with malformations of cortical development (MCD).
Methods:
We reviewed the neuroimaging, neurologic, EEG, and genetic data of 36 patients (21 males, mean age 7 years) with ACC and interhemispheric cysts. Associations were tested with Chi-squared and Fisher exact tests.
Results:
According to the 2001 Barkovich classification, we found 4 type 1c (11.1%), 6 type 2a (16.6%), 18 type 2b (50%, 6/18 girls with Aicardi syndrome), and 9 type 2c cysts (22.2%). EEG showed specific epileptic activity in 27/36 patients (75%). Epilepsy was diagnosed in 16 subjects (16/36, 44.4%), including all Aicardi patients, and was associated with cognitive impairment (p = 0.032). Severe intellectual disability and epilepsy were associated with type 2b cysts, always due to Aicardi patients (p < 0.05). After excluding Aicardi patients, all subjects with type 2b cysts had mild neurological phenotype. Patients with 2a and 2c cysts more frequently had normal cognition (83.3% and 62.5% of cases, respectively). Patients with type 1c cyst mostly had mild/moderate cognitive impairment. Severe neurologic deficits were associated with 1c cysts and 2b cysts with Aicardi syndrome (p < 0.05). Multilobar and/or bilateral MCD were associated with severe neurological and epileptic phenotypes (p < 0.05).
Conclusion:
Once excluded Aicardi syndrome, most patients with ACC and interhemispheric cysts have a mild clinical phenotype characterized by borderline/normal cognition and minor neurological signs. Despite the high prevalence of EEG epileptic abnormalities, epilepsy in these cases is infrequent and usually responsive to antiepileptic drugs.
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