Neurologic Alterations Due to Respiratory Virus Infections

Bohmwald, Karen; Gálvez, Nicolás M. S.; Ríos, Mariana; Kalergis, Alexis M.

The knowledge not only came from epidemic IAV, as these neurological signs also have been described for seasonal IAV. The H3N2 and H1N1 seasonal IAV have also been associated with neurological manifestations. According to this, a study described in 21 patients of a wide range of age with neurological alterations showed that the primary clinical sign was encephalitis and about 50% of the patients have sequelae (Steininger et al., 2003) . Moreover, although in this study the detection methodology for IV genetic material detection in CSF was improved, only one sample was positive (Steininger et al., 2003; Figure 2 ). In another approximation to understand the etiologic agent causing myelopathy post-influenza-like syndrome, CSF obtained from a patient with this disease was inoculated in several cell lines, previously reported to be permissive for the growth FIGURE 2 | Influenza virus (IV) spreads from the lungs to the CNS through the vagus nerve promoting an inflammatory state. Upon infection of IV, the virus reaches the lungs and, from there, it can spread into the CNS by transneural route, through the vagus nerve. Once set on the brain, it induces the secretion of several pro-inflammatory cytokines such as IL-1, IL-6, IL-8 and G-CSF. Viral RNA has been detected in CSF of infected patients, and also microglial apoptosis has been described.