• Pooled samples of lumbar CSF from nine patients with neurologic disorders were aliquoted and subjected to the differential influence of temperature for four hours. The determination of the γ-aminobutyric acid (GABA) levels in CSF by ion-exchange-fluorometric analysis before and after incubation showed a progressive increase in GABA content of CSF as a function of temperature, reaching a maximum at 50 °C. However, no increases in GABA level were noted in CSF incubated at 80 °C or 100 °C. These in vitro increases in the GABA content of untreated CSF appear to be entirely secondary to enzyme action, subject to individual and temperature variability, and necessitate standardization of clinical CSF protocols.
Theodore A. Hare, James H. Wood, Bala V. Manyam. Clinical Implications of Enzyme-Mediated Alterations of γ-Aminobutyric Acid Content in Human CSF. Arch Neurol. 1981;38(8):491–494. doi:10.1001/archneur.1981.00510080053006