acyclovir responsive herpes simplex encephalitis definition of its radiological features; correlation with the clinical picture and CSF analysis

ABSTRACT

In the present study 13 patient with the clinico- radiological diagnosis of herpes simplex encephalitis [HSE] are included. All patients were subjected to [1] full clinical examination [2] CSF analysis that included CSF chemistry [protein, glucose and chloride], cells, latex test for bacterial antigens, CSF culture of pyogenic bacteria and TB and PCR [polymerase chain reaction] for detection of both type I and type II herpes simplex virus [HSV] DNA [3] Both MRI and CT scan of the brain with and without contrast were done to all patients. CSF analysis showed moderate rise of proteins [average 860 mg/dl, normal values up to 450 mg/dl] with normal sugar and glucose and with a predominately lymphocytic pleocytosis in all patients. Latex test was negative for all patients. Both CSF bacterial and TB cultures were eventually negative. HSV type I DNA was detected in the CSF by the PCR test in all patients, type II HSV DNA was not detected in the CSF of any of the patients examined. Involvement of the temporal lobes unilaterally or bilaterally were the cardinal radiological feature demonstrated in all patients. Other areas of the brain, such as the orbital frontal region, the paraventricular region, the basal ganglia or the brain stem, are involved but less frequently. The significance of these findings for the early diagnosis of herpes encephalitis are discussed. Also the clinical course of the patients and their response to treatment will be presented and discussed