Increased levels of amino acids in human lumbar and central cerebrospinal fluid after subarachnoid haemorrhage.

Twenty amino acids were determined chromatographically in cerebrospinal fluid (CSF) from 26 patients and in plasma from 13 of the patients with subarachnoid haemorrhage (SAH). In the first group of 13 patients, from which lumbar CSF and plasma were collected on days three, six and nine after SAH, there was a significantly increased CSF concentration from day three to six and/or nine in all amino acids except for taurine which was within the normal range. In the second group of 13 patients, from which CSF was collected during preoperative clipping of aneurysms, there was an increased concentration in lumbar and central CSF in all amino acids except for taurine compared to controls. There was no correlation between any of the amino acids and cerebral vascular diameter as assessed by angiography. It is suggested that the increased levels in lumbar and central CSF amino acids result from proteolysis due to catabolic processes and from impaired clearance of the amino acids from CSF after SAH.