P2.265: Unusual presentation of Gray Matter Heterotopia in a pediatric patient: A Case report

Introduction: Brain heterotopia is a group of rare malformations with a heterogeneous phenotype, ranging from asymptomatic to a severe clinical picture (drug-resistant epilepsy, severe developmental delay). The etiology is multifactorial, including both genetic and environmental factors. The development of the cerebral cortex results from complex sequential processes including cell proliferation, cell migration, cortical organization, and formation of neuronal networks. Disruption of these steps yields different types of cortical malformations including gray matter heterotopia, characterized by the ectopic position of neurons along the ventricular walls or in the deep white matter. Cortical malformations are major causes of epilepsy, being responsible for up to 40% of drug-resistant epilepsy, and the cognitive level of affected patients varies from normal to severely impaired.

Case Description: A developmentally appropriate three year old male was brought in by his parents for increasingly frequent, chronic, unilateral headaches above his left ear that lasted less than a minute and occurred once every 2- 3 weeks. There were no associated seizure like activity, nausea, vomiting, ataxia, dizziness or vision changes. His maternal grandmother had a history of migraines. He was born term and had met developmental milestones with no regression. As an infant, he exhibited jerking movements in his sleep which were attributed to myoclonic jerks but did not have them in later life. On physical examination, he was cooperative and friendly without dysmorphic features. There were no neurocutaneous abnormalities. Cranial nerve examination and motor examination showed no abnormalities. Mental status examination, memory, language and intelligence were appropriate for age. A MRI with and without contrast was recommended. Image findings: Sagittal T1-weighted images demonstrated a mega cisterna magna. T1 and T2-weighted images demonstrated irregularity of the contour of the left lateral ventricle, superiorly, with separate ependymal and periventricular signal alteration, isointense to gray matter on T1-weighted images, T2-weighted images and FLAIR images. The findings were consistent with gray matter heterotopia (GMH).

Discussion: GMH is caused by an abnormal migration or interruption in the normal migration of neurons from the periventricular telencephalic germinal matrix to the cerebral cortex. Frequent seizures are the main clinical features of GMH. Studies show that as the size of the gray matter increases, epileptic episodes occur earlier and there is greater damage to the brain tissue with greater neurocognitive dysfunction. Most patients present with epilepsy as the main concern; a smaller presentation is associated with pediatric neurodevelopmental delays and our case here presented with unilateral headache which was diagnosed with MRI.

Conclusion: Gray matter Heterotopia can have unusual presentation besides seizure and developmental delays. A unilateral headache without seizures is a unique presentation of GMH and MRI imaging helps in the correct diagnosis.