Possible involvement of a gamma-hydroxybutyric acid receptor in startle disease

Abstract

involvement of a gamma-hydroxybutyric acid receptor in startle disease. Acta Paediatr 1994;83:678-80. Stockholm. ISSN 0803-5253 Startle disease or hyperexplexia is an autosomal dominant neurological disorder, with a neonatal onset, characterized by muscular hypertonia and myoclonic jerks, exaggerated by the slightest stimulus. Low concentrations of free gamma-aminobutyric acid (GABA) have been found in the cerebrospinal fluid of two affected infants. The involvement of GABA or its receptors has been raised and the use of GABA-agonist drugs has been suggested. We report a newborn with startle disease who also had a low concentration of GABA in the cercbrospinal fluid. No clinical improvement was observed with progabide, a GABA agonist. Furthermore, a high dose (100 mg/kg) of gammahydroxybutyrate (GHB) did not improve muscular stiffness and failed to induce gcncral anaesthesia. GHB, currently used as an effective general anaesthetic, is a structural analogue of GABA. It is present naturally at low concentrations in the brain and is regarded as an inhibitory neurotransmitter. Two specific GHB receptors, distinct from the GABA receptors, have been identified in rat brain. Failure to induce general anaesthesia with a high dose of GHB suggests that one of thcsc receptors could be involved in startle disease. a Gamma-hydroxyhutyric acid, neurotransmitter, startle disease