Infections of the central nervous system of suspected viral origin: A collaborative study from Finland

Abstract

We studied 3231 patients with acute central nervous system (CNS) symptoms of suspected viral origin to elucidate the current etiologic spectrum. In 46% of the cases, a viral finding was observed. Varicella-zoster virus (VZV) was the main agent associated with encephalitis, as well as meningitis and myelitis. VZV comprised 29% of all confirmed or probable etiologic agents. Herpes simplex virus (HSV) and enteroviruses accounted 11% each, and influenza A virus 7%. VZV seems to have achieved a major role in viral infections of CNS. In encephalitis in our population, VZV is clearly more commonly associated with these neurological diseases than HSV. The increase in VZV findings may in part be a pseudophenomenon due to improved diagnostic methods, however, a true increase may have occurred and the pathogenetic mechanisms behind this should be elucidated.

Viral encephalitis after allogeneic stem cell transplantation: a rare complication with distinct characteristics of different causative agents

“…Thus the spectrum of causative viruses associated with encephalitis after allo-SCT differs markedly from that seen in non-immunocompromised hosts (mainly HSV and VZV) and also from that found in other immunosuppressive conditions like acquired immunodeficiency syndrome, where several groups reported a preponderance of CMV, followed by PML, EBV, VZV, HSV and finally HHV-6. 7,9,[27][28][29] The earliest onset of encephalitis after allo-SCT was found for patients with HHV-6 (62 days median). It coincided approximately with the median onset of 60 days recently reported in a series of HHV-6 encephalitis patients but was later than in another HHV-6 encephalitis study reporting a median onset of 22 days after allo-SCT.…”

“…[4][5][6] Viral CNS infections have less frequently been reported in patients after allo-SCT even though they are the most common type of acute encephalitis in nonimmunocompromised hosts in Western countries. [7][8][9][10][11] The largest series published to date on viral encephalitis after allo-SCT reported on 23 human herpesvirus-6 (HHV-6) encephalitis patients. 8 The diagnosis of viral encephalitis still remains an immense challenge and can often only be established by autopsy.…”

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

“…This article presents the 3 types of encephalitis that are prevalent among immunocompetent patients -i.e., herpes simplex encephalitis (HSE), tickborne encephalitis (TBE) and herpes zoster encephalitis (HZE) [1,11]. The aim of this review is also to show the significance of thorough diagnostics and a multidisciplinary approach to patients with viral CNS infections.…”

Viral encephalitis

“…They are the most common cause of viral meningitis worldwide, and it is estimated that 3% of these patients develop encephalitis during the infection. Furthermore, isolated EV encephalitis occurs in 2% to 25% of confirmed viral encephalitis cases, especially in immunodeficient patients with hypogammaglobulinemia and in neonates 4,15 . EV are transmitted via a fecal-oral route and certain serotypes predominate in a particular geographical area, causing cyclical outbreaks when there are sufficient non-immunized individuals present, mainly young children.…”