title: Amino acid composition of brain cysts: levels of excitatory amino acids in cyst fluid fail to predict seizures.
abstract: A recent study describing two epileptic patients with brain cysts has suggested that elevated concentrations of excitatory amino acids in cysts may play a role in induction and maintenance of epileptogenesis [Epilepsy Res. 28 (1997) 245]. Here, we report that only in 3 out of 22 patients with brain cysts undergoing brain surgery cyst fluids displayed highly increased amounts of the excitatory amino acids aspartate and/or glutamate. Two of these patients experienced epileptic seizures prior to neurosurgical intervention. Thus, highly increased excitatory amino acid levels are present only in a subset of patients with brain cysts. Our observation that one patient with highly increased glutamate and aspartate concentrations in the cyst did not display seizures or typical epileptiform potentials in the EEG questions that these excitatory amino acids in the cyst fluid are directly involved in epileptogenicity. This patient displayed an increased level of adenosine in the cyst fluid, which is known to have anticonvulsant properties and might provide protection from seizures. In summary, there is no evidence for a close correlation between excitatory amino acids in brain cysts and the occurrence of seizures.
authors.affiliation: Department of Neurology, University Hospital, University of Zürich, Frauenklinikstrasse 26, CH-8091 Zürich, Switzerland. hgwepi@neurol.unizh.ch
authors.forename: Heinz-Gregor
authors.initials: HG
authors.lastname: Wieser
authors.forename: Uwe
authors.initials: U
authors.lastname: Rudolph
authors.forename: Nenad
authors.initials: N
authors.lastname: Blau
authors.forename: Detlev
authors.initials: D
authors.lastname: Boison
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Imhof
authors.forename: René
authors.initials: R
authors.lastname: Bernays
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yonekawa
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001224:Aspartic Acid / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000601:surgery; D002648:Child; D003560:Cysts / Q000378:metabolism* / Q000601:surgery; D004569:Electroencephalography; D004827:Epilepsy / Q000188:drug therapy / Q000378:metabolism* / Q000601:surgery; D018846:Excitatory Amino Acids / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D000927:Anticonvulsants; D018846:Excitatory Amino Acids; D001224:Aspartic Acid; D018698:Glutamic Acid; D000241:Adenosine