[Gamma-aminobutyric acid concentrations in the plasma in unconscious patients with severe craniocerebral trauma or nontraumatic intracranial hemorrhage].

The detection of cerebral lesions by chemical laboratory studies has not as yet been possible. Tests were carried out to determine whether there was an increase in plasma concentration of the neurotransmitter gamma-aminobutyric acid (GABA) in 12 unconscious patients: 6 with severe craniocerebral trauma (CCT) and 6 with spontaneous intracranial hemorrhage. Normal plasma concentrations were detected in the central venous blood of patients with severe CCT (normal range 366 +/- 123 pmol/ml); in patients with intracranial hemorrhage the values were partially elevated. Maximal values in arterial blood were around 613 pmol/ml (patients with CCT) and 1723 pmol/ml (patients with spontaneous intracranial hemorrhage). The influence of fluid turnover on plasma GABA concentrations is discussed.