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Archived Comments for: Herpes simplex 1 encephalitis presenting as a brain haemorrhage with normal cerebrospinal fluid analysis: a case report

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  1. Uncertainity of the diagnosis

    Szatmar Horvath, Vanderbilt University

    5 January 2009

    The diagnosis of viral CNS infections are undoubtedly one of the clinical challenges. However, there are well defined steps and clinical protocols that everyone who is involved in clinical practice should keep in mind (1). <br>Based on a single PCR result and an MRI scan Gkrania-Klotsas & Lever claim that the presented case is a HSE, but have neither screened for other, clinically relevant neurotropic viruses (e.g. EBV, HIV), nor performed EEG for HSE specific brain activity. <br>Now, however, it is clear the relatively high frequency of false positive and the large number of false-negative results stress the need for improvement in the quality of HSV nucleic acid amplification tests and for external quality control programmes(2, 3). Hence, we propose that PCR should never stand alone (without a concomitant ELISA) in the diagnosis of herpesviral encephalitis, as described in our recent EBV case (4).<br><br>Altogether, I am not convinced the case being a real HSE case and this paper sets the course and standards for encephalitis diagnosis.<br><br><br>1. Steiner I, Budka H, Chaudhuri A, Koskiniemi M, Sainio K, Salonen O, Kennedy PG.Eur J Neurol. 2005 May;12(5):331-43. <br><br>2.Schloss L, van Loon AM, Cinque P, Cleator G, Echevarria JM, Falk KI, Klapper P, Schirm J, Vestergaard BF, Niesters H, Popow-Kraupp T, Quint W, Linde A. J Clin Virol. 2003 Oct;28(2):175-85.<br><br>3. Schultze D, Weder B, Cassinotti P, Vitek L, Krausse K, Fierz W. Swiss Med Wkly. 2004 Nov 27; 134(47-48):700-4. <br><br>4. Chadaide Z, Voros E, Horvath S. J Med Virol. 2008 Nov;80(11):1930-2. <br>

    Competing interests


  2. The authors reply to Dr Horvarth

    Effrossyni Gkrania-Klotsas, Addenbrooke's Hospital, Cambridge

    5 January 2009

    We thank Dr Horvarth for his comments. HSE remains a difficult diagnosis. We feel that this patient's clinical history, clinical presentation and outcome strongly suggest it as well. Our original screen for other viruses included, by local protocols, a PCR for VZV and a PCR for enterovirus, both from CSF specimens, which were both negative. The lack of any relevant exposure history, paired with a negative HIV test from the peripheral blood by ELISA, made us not pursue further an acute HIV diagnosis, for instance by doing a peripheral viral load. Similarly, the patient had serological evidence of past but not recent EBV infection at the time, so EBV was not considered as a diagnosis. No evidence of immunodeficiency was present at the time or during follow-up. Although an EEG was ordered, it was cancelled in view of the patients favorable clinical response. Overall, the clinical impression remains the most important tool for diagnosis. The overall sensitivity and specificity ranges of PCR in HSE in children and adults are excellent, ranging from 95–100% to 94–99%, respectively.1. Lakeman FD, et al. PCR in the diagnosis of HSE. J Infect Dis. 1995;171:857–863 2. Aurelius E, et al. Rapid diagnosis of herpes simplex encephalitis.... Lancet. 1991;337:189–192.

    Competing interests

    No competing interests