The prognosis and long-term course of viral encephalitis

Outcome and Sequelae of Infectious Encephalitis

Acute infectious encephalitis is a widely studied clinical syndrome. Although identified almost 100 years ago, its immediate and delayed consequences are still neglected despite their high frequency and possible severity. We reviewed the available data on sequelae and persisting symptoms following infectious encephalitis with the aim of characterizing the clinical picture of these patients at months to years after hospitalization. We searched PubMed for case series involving sequelae after infectious encephalitis. We carried out a narrative review of the literature on encephalitis caused by members of the Herpesviridae family (herpes simplex virus, varicella zoster virus, and human herpesvirus-6), members of the Flaviviridae family (West Nile virus, tick-borne encephalitis virus, and Japanese encephalitis virus), alphaviruses, and Nipah virus. We retrieved 41 studies that yielded original data involving 3,072 adult patients evaluated after infectious encephalitis. At least one of the five domains of cognitive outcome, psychiatric disorders, neurological deficits, global functioning, and quality of life was investigated in the reviewed studies. Various tests were used in the 41 studies and the investigation took place at different times after hospital discharge. The results showed that most patients are discharged with impairments, with frequent deficits in cognitive function such as memory loss or attention disorders. Sequelae tend to improve within several years following flavivirus or Nipah virus infection, but long-term data are scarce for other pathogens. Further research is needed to better understand the extent of sequelae after infectious encephalitis, and to propose a standardized assessment method and assess the rehabilitation efficacy in these patients.

Epileptic fits and epilepsy in the elderly: general reflections, specific issues and therapeutic implications

Seizures and epilepsy are commonly encountered in the elderly. Diagnosis is not always straightforward as reliable history is often difficult to obtain and EEG findings can be non-specific. When to treat and how may be difficult choices as adequate studies in elderly are rather scarce. Treatment should be based on careful assessment and comparison of risk/benefit profiles of various anti-epileptic drugs (AEDs) in this specific elderly population. Since most AEDs are effective in terms of seizure control in the elderly, the choice of treatment is often determined by tolerability, pharmacokinetic profile and drug interactions of AEDs. As recently introduced AEDs have a better safety profile compared to older agents it seems logical to initiate treatment in the frail elderly patient with those more modern AEDs. In this review some distinctive clinical features of epilepsy in the elderly are discussed in three sections (general issues, special issues and selected treatment options with special reference to medicinal treatment).

Rare indications of IVIG therapy in neurological diseases based on case reports and small studies

IVIG treatment has been tried in several neurological diseases with presumed immunopathogenesis. Many of the rare neurological diseases seem to benefit from IVIG treatment; however, negative results have been rarely published. Despite the majority of positive results, a general use of IVIG cannot be recommended for these diseases. Beside the lack of controlled studies and the small numbers of reported cases, a publication bias has to be considered since negative study results are usually not reported. Therefore, at this stage treatment with IVIG should be used in conjunction with controlled therapy trials.

Long-term Death Rates, West Nile virus epidemic, Israel, 2000

We studied the 2-year death rate of 246 adults discharged from hospital after experiencing acute West Nile Virus infection in Israel during 2000. The age- and sex-adjusted death rates were significantly higher than in the general population. This excess was greater for men. Significant adverse prognostic factors were age, male sex, diabetes mellitus, and dementia.

Central nervous system immunity associated with clinical outcome in acute encephalitis

To search for useful laboratory measures of central nervous system (CNS) immunity that may provide an accurate prognosis or clues regarding treatment choice, cerebrospinal fluid (CSF) samples were obtained from 14 consecutive patients with acute encephalitis during acute as well as convalescent or chronic stages, and then examined for surface antigen expressions by lymphocytes and the presence of antineuronal tissue antibodies as well as the levels of IgG-related parameters and proinflammatory cytokines, including IL-2, IL-6, IFN-gamma, and tumor necrosis factor-alpha (TNF-alpha). Seven patients with aseptic viral meningitis served as nonencephalitic controls. Eight of the 14 acute encephalitis patients recovered fully, and reductions in the percentages of CD4(+)CD29(+) helper inducer T cells and IL-2 receptor-positive CD4(+) cells were associated with early recovery and favorable outcome, respectively, whereas a low percentage of CD4(+)CD26(+) memory T cells during an acute stage was associated with an unfavorable outcome following adjunctive intravenous corticosteroid treatment. Further, three of the four encephalitis patients who exhibited autoantibodies had a poor prognosis. These findings suggest that CNS immunity status has an effect on prognosis, while flow cytometric analyses of CSF CD4(+) helper T cell subsets may serve as effective means of assessment.

Predictive factors of short-term neurologic outcome in children with encephalitis

When a child is admitted to the hospital with presumed encephalitis, the physician must use clinical criteria to gauge the appropriate level of hospital care and to give a preliminary assessment of outcome to the family because the etiology is unknown. This study attempted to determine which clinical factors gathered on hospital admission would be most helpful to the physician. The records of 106 children (ages 1 month to 20 years), admitted to Rainbow Babies and Childrens Hospital between 1978-1989 who had discharge diagnoses of encephalitis, were reviewed. Seventy-five met the case definition of presumed viral encephalitis, with viral etiology established in 23% of patients. Poor short-term outcome was defined as the presence of an abnormal neurologic examination at hospital discharge, and was present in 32% of patients. Focal signs on neurologic examination (odds risk: 16.30, P < .05) and abnormal neuroimaging studies (odds risk: 5.66, P < .05) were the only 2 factors present at admission that predicted a poor short-term outcome. Glasgow coma scale at admission was predictive of an abnormal neurologic examination at discharge only when profoundly depressed (6 or less); otherwise, this scale was not useful as a prognostic tool. Factors that were not correlated with adverse outcomes included age younger than 1 year, any type of seizure occurrence, status epilepticus, diffuse or focal electroencephalographic abnormalities, or abnormal cerebrospinal fluid findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunoglobulin therapy in neurologic diseases

An overview is given on the use of immunoglobulins in clinical neurology. While 5S-immunoglobulins may be employed in addition to virostatics in viral encephalitis, 7S-immunoglobulins can be used in autoimmune diseases like myasthenia gravis, multiple sclerosis, and the Guillain-Barré syndrome. Refractory childhood epilepsies like the Lennox-Gastaut syndrome responded to 7S-immunoglobulins. Hyperimmunoglobulins are to be given in bacterial infections in which toxins are formed and in viral infections caused by cytomegalovirus and tick-borne encephalitis virus. While some open studies report benefit from the use of immunoglobulins in neurological diseases, controlled evidence for their efficacy is still missing.