Influenza is an acute infectious disease that affects both the upper and lower respiratory tract, the causative agent of which is the virus.
Brain damage in viral infections, caused mainly by influenza viruses, parainfluenza viruses, and adenoviruses, is more common than primary viral encephalitis.
Influenza can be severe, leading to the development of encephalitis. Neurotoxicosis is accompanied by inflammation of the meninges. In the acute stage of the disease, motor and sensory disturbances, as well as confusion, appear on days 3–7. Confusion can give way to agitation with perceptual delusions, and then to mood swings, dysmnesia, and asthenia.
Nervous system damage in influenza is caused by microcirculation disorders and the effects of toxins on nerve cells. This complication is typical of toxic forms and can complicate the course of the disease at any stage, disrupting the functioning of the central or peripheral nervous system. With meningoencephalitis, depressive, paranoid, and delirious symptoms may develop.
Elderly patients are particularly susceptible to the negative consequences of memory impairment after an illness. Older adults are more likely to suffer from memory and attention disorders because they experience age-related changes in the levels of neurotransmitters responsible for cognitive functions.
