strychnine and Spasms--Infantile

Non-ketotic hyperglycinaemia (NKH) is a severe seizure disorder associated with high glycine levels. Glycine is a major inhibitory neurotransmitter in the CNS, but has also modulating effects at one of the glutamate receptors, the N-methyl-D-aspartate-(NMDA) receptor. Based on this knowledge we treated a female newborn suffering from severe NKH with the NMDA receptor blocker ketamine in association with strychnine and magnesium supplementation. This treatment led to cessation of seizures, reappearance of swallowing and sucking and improved the neurological status. Some pharmacokinetic data of strychnine and ketamine in the infant are given.. Ketamine in combination with strychnine may be beneficial in non-ketotic hyperglycinaemia.

Topics: Amino Acid Metabolism, Inborn Errors; Chromosome Aberrations; Chromosome Disorders; Drug Therapy, Combination; Excitatory Amino Acid Antagonists; Female; Genes, Recessive; Glycine; Glycine Agents; Humans; Infant, Newborn; Ketamine; Neurologic Examination; Receptors, N-Methyl-D-Aspartate; Spasms, Infantile; Strychnine

Nonketotic hyperglycinemia is an inborn error of metabolism resulting from a defect in the glycine cleavage enzyme system. It is characterized biochemically by elevated concentrations of glycine in blood, spinal fluid, and urine. Previous therapies which have been directed toward reducing the glycine concentration in plasma and CSF have not been successful in preventing neurological deterioration, which may be the result of the role of glycine as an inhibitory neurotransmitter. Strychnine treatment was initiated because it is a specific antagonist of glycine at postsynaptic membranes. The patient reported here has shown clinical and EEG improvement while taking strychnine in conjunction with sodium benzoate.

Topics: Benzoates; Clonazepam; Drug Therapy, Combination; Electroencephalography; Enzymes; Female; Glycine; Humans; Infant; Intellectual Disability; Liver; Spasms, Infantile; Strychnine