Use of perampanel and a ketogenic diet in nonketotic hyperglycinemia

Daida A, Hamano SI, Ikemoto S, Hirata Y, Matsuura R, Koichihara R, Oba D, Ohashi H. Use of Perampanel and a Ketogenic Diet in Nonketotic Hyperglycinemia: A Case Report. Neuropediatrics. 2020 Mar 16. doi: 10.1055/s-0040-1708536. [Epub ahead of print]

Abstract

BACKGROUND:

 Nonketotic hyperglycinemia is a severe form of early onset epileptic encephalopathy caused by disturbances in the glycine cleavage system; the neurological damage is mainly attributed to overstimulation of the N-methyl-D-aspartate receptor.

CASE:

 The patient presented with a severe form of nonketotic hyperglycinemia and experienced frequent epileptic spasms and focal seizures, which were resistant to vigabatrin, adrenocorticotropic hormone therapy, and combined dextromethorphan and sodium benzoate treatments. By 9 months of age, perampanel reduced epileptic spasms by >50%. At 14 months of age, the ketogenic diet markedly reduced focal seizures and glycine levels in the cerebrospinal fluid.

CONCLUSION:

 Perampanel reduced fast excitatory neuronal activity, which was induced by an α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor, followed by prolonged electrical depolarizations due to an N-methyl-D-aspartate receptor. Furthermore, the ketogenic diet may have modulated the excessive neurotoxic cascade through the N-methyl-D-aspartate receptor. Perampanel and ketogenic diet were effective for seizure control in our patient.