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.
Keywords
nonketotic hyperglycinemia - NMDA receptor - perampanel - ketogenic diet - West's
syndrome
