[Cerebrospinal fluid as informative source of the brain].

The examination of cerebrospinal fluid has provided useful information for diagnosis of CNS infections. The progress of analytical technology has brought the possibility to detect very small amounts of chemical substances. I thought that new information from brain should be obtained by using modern analytical technology for several substances in CSF. Free amino acid pattern, glutamine, homocarnosine, glutamic acid decarboxylase (GAD), neuron specific enolase (NSE) and 2',5'-oligoadenylic acid synthetase (2-5 A) in CSF have been examined for information of brain injury and dysfunctions. The results are as follows. 1) The individual difference and constancy of free amino acid pattern in CSF were found in children without any neurological diseases. 2) The levels of free amino acids in CSF increased in the acute phase of bacterial meningitis. 3) High levels of glutamine in CSF of children with acute bacterial meningitis were normalized during the recovery phase. 4) A marked imbalance of free amino acids in CSF was found in children with Lennox-Gastaut syndrome. 5) A decrease of homocarnosine levels in CSF was related with the degree of unconsciousness in children suffering from neurological diseases. 6) High GAD activities in CSF were observed in the acute phase of aseptic meningitis and after intrathecal injection of methotrexate for the therapy against meningeal leukemia. 7) High NSE activities in CSF were found in the acute phase of bacterial meningitis, intracranial hemorrhage, encephalopathy and encephalitis. 8) High 2-5A activities CSF were measured in the acute phase of mumps meningitis with subsequent decreases during the recovery phase. These results suggest that several substances in CSF are useful as markers of brain injury and dysfunction.