Retrospective Study of Patients with Herpes Simplex Encephalitis and Positive CSF PCR
Polchai Pleumpanupat MD*, Nasuda Danchaivijitr MD**, Chotipat Danchaivijitr MD, MRCP(UK)*
Affiliation : * Division of Neurology, Department of Medicine, Siriraj Hospital Mahidol University, Bangkok, Thailand **Department of Radiology, Siriraj Hospital Mahidol University, Bangkok, Thailand
Objective : To determine the clinical presentations, laboratory and imaging findings of patients with HSE and
positive CSF PCR then compare these with information from other viral encephalitis patients in order to find
clinical clues that might help clinicians in early diagnosis and treatment of HSE while awaiting for the CSF
PCR result.
Material and Method: A patient group with both HSE and positive CSF PCR and a control group of patients
with other viral encephalitis were identified from Siriraj Hospital database within the period of 1997-2006.
Medical notes of these patients were reviewed and relevant information, including clinical, laboratory and
imaging study, were extracted. Then, descriptive statistics, unpaired t-test and Fisher’s exact test were
performed with the purpose to determine any clinical or laboratory clues that are significantly different
between these two groups, which might help clinicians in making an early diagnosis of HSE.
Results : Seven HSE cases and 22 cases in control group were included. Fever, headache, alteration of
consciousness, behavioral change, neck stiffness are the most commonly found clinical presentations in HSE
patients with CSF PCR positive. CSF examination show CSF leukocytosis with lymphocyte predominate,
decreased CSF:blood glucose ratio and elevated CSF protein in all cases. However, no single clinical or
laboratory finding helps in differentiating HSE with positive CSF PCR from other viral encephalitides, except
radiological abnormalities of temporal lobe, which yields a positive predictive value of 0.5 and a negative
predictive value of 0.93.
Conclusion : Our study showed that HSE shares common clinical and laboratory findings with other viral
encephalitides, except for temporal lobe involvement. Early diagnosis is important and empirical acyclovir
should be commenced early in patients with viral encephalitis, especially for those with radiological
abnormalities on the temporal lobe.
Keywords : Cerebrospinal fluid, Encephalitis, Herpes simplex, Encephalitis viral, Polymerase chain reaction
