The widening spectrum of infectious neurological disease.

Abstract

EditorialThe widening spectrum of infectious neurological disease* Three important areas of study reflect the widening range of neurological infections. These are (a) new technologies for pathogenetic studies and diagnosis, (b) the increasing range of neural pathogens and (c) new therapeutic tools.

Diagnosis and treatment of viral encephalitis

“…22 There are several problems with the interpretations of serum and cerebrospinal fluid viral antibodies. 23 These tests take time to perform and a clinician would be best advised not to wait for these results before initiating treatment. Rises in antiviral antibody titres may be non-specific and indicate polyclonal activation due to the infection.…”

Herpes simplex encephalitis

“…Despite their eventual diagnostic usefulness, antiviral antibody titres may also be difficult to interpret for a number of reasons. 20 Recently, it has been possible to perform quantitative PCR assays for HSV 21 and this should be of use both diagnostically and in neuropathogenetic studies.…”

Neurovirological methods and their applications

“…Potential problems with interpretation of virus isolation results include the possibility that they may represent an irrelevant or coexisting virus infection, the presence of asymptomatic virus secretion by the patient, accidental viral contamination, or the presence of a viral reactivation rather than a primary infection. 13 Numerous different viruses have been isolated over the course of many years from the tissues of patients with multiple sclerosis. 14 However, while this disease may well have a viral aetiology, such reports have generally been viewed with scepticism and there is no hard evidence to date for a direct viral cause.…”

“…The techniques used include enzyme linked immunosorbent assays (ELISA), western blotting for viral proteins, immunofluorescence, and immunocytochemistry. 13 Some of these techniques have been used, for example, for the diagnosis of HIV and herpes simplex virus infections, and also in viral pathogenic studies. 13 19 20 Double label immunofluorescence or immunocytochemistry are techniques whereby two viral antigens can be colocalised within the same tissue region or cell, or where a viral antigen can be visualised within a neural cell type identified by an antigenic marker-for example, a herpes simplex virus antigen within a human astrocyte during natural or experimental viral infection.…”

“…13 Some of these techniques have been used, for example, for the diagnosis of HIV and herpes simplex virus infections, and also in viral pathogenic studies. 13 19 20 Double label immunofluorescence or immunocytochemistry are techniques whereby two viral antigens can be colocalised within the same tissue region or cell, or where a viral antigen can be visualised within a neural cell type identified by an antigenic marker-for example, a herpes simplex virus antigen within a human astrocyte during natural or experimental viral infection. 9 Evidence of viral protein expression is critical in assessing the nature of the infection, such as whether it is a latent infection (with no or restricted protein expression) or a productive infection.…”