ABSTRACT
The current study was carried out on 182 patients with viral encephalitis or meningoencephalitis being selected according to certain clinical as well as C.S.F. criteria in which the viral etiology could be confirmed in 118 cases of them through various virus identification techniques. The aim of the study was to evaluate from the diagnostic as well as prognostic point of view various pH and gases changes in the CSF as well as arterial blood in those patients and in addition to assess the intrathecal IgG production which was reported to increase in those patients. In order to get reliable data, the study included 20 healthy subjects as a control group who were subjected to all lab tests as the patient's group including: CSF and blood pH PO[2] PCo[2] and also a simple equation for determining IgG index as an indicative for intrathecal IgG production. The results showed highly significant reduction in blood PCO2, PO[2] and CSF pH, PO[2], associated with a highly significant elevation in blood pH and CSF PCO[2] in patients compared to control group. Prognostically speaking, the changes in the above mentioned variables, with the exception of blood pH and CSF PO[2] could reflect the clinical severity with an intimate relation to the final outcome. However, no statistical relationship; could be found between these variables and the various etiological viruses. Regarding the IgG index, elevated figures, i.e. > 0.7 were reported in most of the patients [around 84 percent] while all individuals within the control group showed values less than 0.7. However, local IgG production was unreliable test for predicting the outcome, din cal severity and viral etiology where the difference between IgG index values among different outcomes, clinical severity and virals etiology parameters were statistically insignificant