Epilepsy of infancy with migrating focal seizures in a patient with nonketotic hyperglycinemia

• Main Authors: Anuar, Muhamad Azamin, Syed Ahmad Shihabuddin Abdurrahman Alsagoff, Sharifah Aishah, Mohamed, Ahmad Rithauddin, Murugesu, Sumitha
• Format: Article
• Language: English
• Published: Korean Child Neurology Society 2022
• Subjects: RJ Pediatrics; RJ370 Disease of children; RJ58 Clinical cases
• Online Access: http://irep.iium.edu.my/104286/2/104286_Epilepsy%20of%20Infancy%20with%20Migrating%20Focal%20Seizures.pdf; http://irep.iium.edu.my/104286/; https://www.annchildneurol.org/journal/view.php?doi=10.26815/acn.2022.00346

Nonketotic hyperglycinemia (NKH) is an inborn error of glycine metabolism leading to refractory epilepsy and severe developmental delays. It is caused by autosomal recessive inheritance of a defect in the glycine cleavage system in the mitochondrial enzymatic complex pathway [1]. This defect leads to overstimulation of the N-methyl-D-aspartate receptor and neurological damage due to glycine accumulation in all body compartments. The typical presentation of NKH is progressive encephalopathy, apnea, and seizures during the neonatal period [2]. Those who survive the neonatal period progress into refractory seizures with moderate to severe cognitive impairment. Apart from antiseizure medications, sodium benzoate, dextromethorphan, and a ketogenic diet, no known therapy is effective in treating this condition [3]. Electroencephalography (EEG) is used to assess brain and seizure activity in NKH. The usual patterns seen are burst-suppression, hypsarrhythmia, and multifocal epileptiform activity [4,5]. Epilepsy of infancy with migrating focal seizures (EIMFS) in NKH has never been described in the literature. We report a case of a severe form of NKH presenting during the neonatal period that showed a burst-suppression EEG pattern and evolved into EIMFS