[P1-80] Epilepsy characteristics and clinical outcome in a patient with megalencephaly, polymicrogyria and ribbon-like band heterotopia
[Introduction] Megalencephaly-related migration disorders include megalencephaly-capillary malformation and megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndromes. Recent genetic studies have identified that genes in the PI3K-AKT pathway are involved in the pathogenesis of these disorders. More recently, we reported a characteristic megalencephaly-related patient who showed megalencephaly, polymicrogyria and ribbon-like band heterotopia. In this study, we report epilepsy characteristics and clinical outcome of this patient with unique migration anomaly.
[Patient description] A female patient was born at term after a normal pregnancy and delivery. Macrocephaly was noted at 1 month of age. At 7 months of age, she was referred for global developmental delay and enlargement of head circumference (49.0 cm, +3.5 SD). MRI revealed bilateral symmetrical polymicrogyria prominently in perisylvian to posterior regions and extensive symmetrical ribbon-like band heterotopia in periventricular region with posterior-temporal dominance. She developed intractable focal seizures at 9 months of age, and subsequently they evolved to epileptic spasms. Interictal EEG showed high-amplitude spike-waves and multifocal spikes. Adrenocorticotropic hormone was temporarily effective. Total callostomy at 22 months of age reduced drop attacks including atonic seizures or spasms. However, she showed profound developmental delay and she still had daily tonic seizures, spasms and focal seizures 1.5 years after callostomy. No genetic abnormality was identified through whole exome sequencing.
[Conclusions] The neuroimaging findings of this patient may represent a novel cortical malformation. Various types of seizures were observed in this patient. Total callostomy was effective at reducing injurious seizure frequency but did not improved developmental outcome.
[Patient description] A female patient was born at term after a normal pregnancy and delivery. Macrocephaly was noted at 1 month of age. At 7 months of age, she was referred for global developmental delay and enlargement of head circumference (49.0 cm, +3.5 SD). MRI revealed bilateral symmetrical polymicrogyria prominently in perisylvian to posterior regions and extensive symmetrical ribbon-like band heterotopia in periventricular region with posterior-temporal dominance. She developed intractable focal seizures at 9 months of age, and subsequently they evolved to epileptic spasms. Interictal EEG showed high-amplitude spike-waves and multifocal spikes. Adrenocorticotropic hormone was temporarily effective. Total callostomy at 22 months of age reduced drop attacks including atonic seizures or spasms. However, she showed profound developmental delay and she still had daily tonic seizures, spasms and focal seizures 1.5 years after callostomy. No genetic abnormality was identified through whole exome sequencing.
[Conclusions] The neuroimaging findings of this patient may represent a novel cortical malformation. Various types of seizures were observed in this patient. Total callostomy was effective at reducing injurious seizure frequency but did not improved developmental outcome.