Herpesvirus infections of the central nervous system in immunocompromised patients

Abstract

Human herpesviruses may cause infections of the central nervous system during primary infection or following reactivation from a latent state. Especially in immunosuppressed patients the infection can take a life-threatening course, and therefore early diagnosis of herpesvirus-associated neurological diseases should have high priority. Clinical presentation in these patients is usually without typical features, making diagnosis even more challenging. Therefore general broad testing for different herpesviruses in cerebrospinal fluid samples is highly recommended. In addition, determination of the virus DNA level in the cerebrospinal fluid by quantitative assays seems to be of high importance to determine prognosis. Moreover, it might help to differentiate between specific virus-associated disease and unspecific presence of virus in the cerebrospinal fluid, especially in immunocompromised patients. Polymerase chain reaction analysis of cerebrospinal fluid has revolutionized the diagnosis of nervous system viral infections, particularly those caused by human herpesviruses. This review summarizes the role human herpesviruses play in central nervous system infections in immunocompromised patients, with a focus on the clinical manifestation of encephalitis.

Psychiatric Aspects of Herpes Simplex Encephalitis, Tick-Borne Encephalitis and Herpes Zoster Encephalitis Among Immunocompetent Patients

“…Mononuclear pleocytosis is detectable in 2/3 of CSF samples [36]. As in the diagnostics of HSV encephalitis, CSF-PCR for VZV-DNA remains the method of choice [13]. On the other hand, the detection of CSF antibodies against VZV is, as Nagel et al stated, of more diagnostic value than PCR, which may not be sensitive enough [36,37].…”

“…According to Steiner, HSE is not a feature of a person with a compromised immune system, with the exception of acquired immunodeficiency syndrome (AIDS) and after a bone marrow transplant [12]. Nevertheless, patients in immunosuppression are at risk of a less favorable and atypical course of the infection [13]. On the other hand, typical symptoms of encephalitis, such as headaches or fever, may be absent in patients with AIDS.…”

“…Later on, extensive hypodense areas are visible in the temporal lobes [10,15]. Although the results often exhibit lymphocytic pleocytosis and elevated protein levels, 5-10% of CSF samples do not show abnormalities and the standard examination is considered neither characteristic nor diagnostic [13].…”

“…With regard to the serotypes of HSV, various authors concur that 90% of encephalitis cases in patients with a healthy immune system are caused by HSV1, whereas HSV2 tends to cause aseptic meningitis or encephalitis in immunocompromised people and newborns [3,[13][14][15][16]. There are two peaks of morbidity in terms of the patients' age: one under the age of 20 and the other in the mid-sixties [17].…”

“…The best HSV-PCR assay results are considered to be obtainable 2-10 days from the disease onset [13]. Magnetic resonance remains the most sensitive diagnostic method for the detection of early changes in the course of HSE.…”