Infectious diseases of the nervous system are among the most common forms of neurological disorders, their percentage in the structure of general pathology of the nervous system is about 40%. In recent years capabilities of the diagnostics of neuroinfections have greatly improved. There are acute (meningitis, encephalitis), subacute and chronic lingering (arachnoiditis, arahnoentsefality) infections of the central nervous system. According to the etiological factor (cause illness) we distinguish viral, bacterial, fungal, and protozoal (eg Toxoplasmosis) brain damage. All acute infections of the central nervous system (meningitis, encephalitis) are urgent and the sick must be immediately taken to hospital. That’s why if a patient has a set of disturbing symptoms such as suddenly emerged fever, headache, vomiting, photophobia, seizures, and especially if the day before he suffered from severe cold or other infections, this is a reason to consult a doctor immediately or to call the team of "first aid ". In the hospital, the patient usually undergoes lumbar puncture so that doctors could study the CSF (cerebrospinal fluid) for inflammatory changes and determination of viral and bacterial agents, and MRI of the brain. From the results of the study a doctor determines the tactic of treatment of the patient. The chronic lingering neuroinfection flows most often in the form of arachnoiditis or arahnoentsefalita, and often has a viral etiology. They manifest themselves in persistent headache, subfebrile temperature, severe sweating and general weakness, chronic fatigue, double vision, unsteadiness when walking, nausea and vomiting in the morning. Infection of the central nervous system is necessarily confirmed by the occurrence on MRI detection of inflammatory changes in the brain or the membranes, signs of intracranial hypertension in the fundus, as well as specific immunological parameters of blood. A very important is the identification of the causative agent of infectious diseases of the brain. For this purpose, the study of blood content of immunoglobulins (antibodies) to the main pathogens neuroinfections is applied: virus of herpes simplex of types 1 and 2, cytomegalovirus, varicella zoster, Epstein-Barr virus, toxoplasma, and so on. (So-called TORCH infections group). Due to the development and introduction into clinical practice of powerful antiviral and antibacterial drugs and immunoglobulins the quality of care of patients with inflammatory diseases of the central nervous system significantly improved. The neurologist of the ambulatory practice often deals with chronic indolent viral neuroinfections and effects of the previously acute neuroinfections. Residual phenomena of neuroinfections often manifest themselves in hypertension syndrome varying in degrees of severity (increased intracranial pressure), as well as in asthenic-vegetative syndrome, which greatly reduces the ability to work and quality of life. The presence of prolonged subfebrile temperatures combined with persistent headaches and nausea, seizures of unknown origin is a reason to address the neurologist and examine yourself on neuroinfection.