Viral meningitis — the defeat of covers of a brain proceeding as serous inflammatory process and caused by a viral infection. Like meningitis of other etiology viral meningitis is shown by a headache, nausea, repeated vomitings, existence of meningealny symptoms. Its distinctive features are the sharp beginning, easy extent of violation of consciousness, a short current and a favorable outcome. Viral meningitis is diagnosed on the basis of clinical yielded, results of the analysis of tserebrospinalny liquid and its PTsR-research. Treatment of patients with viral meningitis consists in performing symptomatic therapy (febrifugal, analgetics), according to indications antiviral therapy is carried out.
Viral meningitis represents the inflammation of covers of a brain (meningitis) caused by penetration of viruses into them. Unlike the purulent meningitis caused by bacterial flora, viral meningitis is followed by serous inflammatory process. Formation of a serous exudate which impregnates brain covers is characteristic of a serous inflammation, leading to their thickening. Hypostasis of brain covers at viral meningitis causes violation of outflow of tserebrospinalny liquid and leads to increase in intra cranial pressure. However the serous type of an inflammation is not followed by a mass ekssudation of neutrophils and death of cellular elements therefore viral meningitis has more favorable current, than bacterial.
Causes of viral meningitis
Viral meningitis is an infectious disease. Various viruses which get to brain covers in the hematogenic, limfogenny or perinevralny way can act as its activators. Depending on virus type viral meningitis can arise at contact or airborne infection. Getting to an organism, viruses get into subweb space and infect web and soft brain covers. Spread of viruses to brain substance with development of encephalitis is observed in extremely exceptional cases.
In 75-80% of cases viral meningitis is caused by an enteroviral infection (Koksaki's viruses and ESNO). The virus of epidemic parotitis, Epstein-Barre's virus (the activator of an infectious mononukleoz), arenavirusa, a cytomegalovirus, a herpetic infection, adenoviruses becomes more rare the reason of viral meningitis. HIV infection can also lead to development of viral meningitis. However more often at it only changes in tserebrospinalny liquid are noted, and viral meningitis has an asymptomatic current. Viral meningitis has the seasonal incidence depending on a type of the activator. The majority of cases fall on summertime, the peak of incidence of winter and is characteristic of a virus of epidemic parotitis in the spring.
Symptoms of viral meningitis
As a rule, the incubatory period of viral meningitis takes from 2 to 4 days. The sharp beginning from rise in body temperature to high figures, a general malaise and an intoksikatsionny syndrome is characteristic. Muscle pains, nausea and vomiting, anorexia, a diarrhea and belly-aches can be observed. The patient can complain of cold, a sore throat and/or cough. At babies tension or a vybukhaniye of a fontanel is observed. At viral meningitis easy violations of consciousness are quite often noted: drowsiness or oglushennost. In certain cases the concern and excitement of the patient is on the contrary possible. At emergence of heavier disorders of consciousness (a sopor, a coma) carrying out repeated inspection of the patient and revision of the diagnosis is necessary.
Viral meningitis is followed by a pronounced meningealny syndrome which can be shown from the first day of a disease or demonstrate on second day. It is characterized by the constant painful headache which is badly removed by reception of analgetics, repeated vomitings, hypersensibility of skin (giperesteziy) and painful perception of external irritants (noise, sharp sounds, bright light, etc.). Position of the patient in a bed is characteristic: lying on one side, the head is thrown back back, knees are given to a stomach, hands are pressed to a breast.
At survey of the patient having viral meningitis the excess tension (rigidnost) of razgibatelny group of muscles of a neck complicating reduction of a chin to a breast is noted; positive meningealny symptoms. Brudzinsky's symptoms: top — at passive bending of the head occurs involuntary bending of legs; lower — extension of the leg bent at right angle leads to bending of the second leg. A symptom of Kerniga — difficulty of passive extension of the leg bent at right angle. At children of chest age Le Sage's symptom (a suspension symptom) is indicative: if to lift the child, holding under mice, then bending of legs and their pulling up to a stomach is observed.
Viral meningitis differs in rather short current. For 3-5 days body temperature falls to normal figures though the second wave of fever is in certain cases observed. The entire period of a disease lasts from 7 to 14 days, on average about 10 days.
Diagnosis of viral meningitis
Characteristic complaints of the patient, the sharp beginning of a disease and existence of meningealny symptoms allow to suspect meningitis to the neurologist. For establishment of virus character of an inflammation of brain covers carry out a lyumbalny puncture with a research of tserebrospinalny liquid, the PTsR-research and allocation of the activator.
The analysis of tserebrospinalny liquid at viral meningitis shows insignificant increase in protein, normal content of glucose and . In the first 1-2 days viral meningitis can be followed by a neytrofilny leykotsitoz of a likvor that is more characteristic of a bacterial inflammation. However lack of the activator at microscopy of variously painted dabs of tserebrospinalny liquid testifies in favor of a virus etiology of a disease. Its confirmation requires a repeated research of a likvor later 12 h at which in case of viral meningitis reduction of number of neutrophils and increase of quantity of lymphocytes is observed.
The analysis of tserebrospinalny liquid allows to differentiate viral meningitis from other types of an inflammation of brain covers. So, at a leptospirozny and tubercular etiology of meningitis, and also at its tumoral character, observed in tserebrospinalny liquid it is combined with decrease in level of glucose.
Allocation of a virus is very complex challenge as in tserebrospinalny liquid it contains in a small amount, and (blood, urine, kcal, dab from a nasopharynx) can be in other sources at a carriage or after the postponed infection without development of viral meningitis. Therefore the main modern method of diagnostics of the activator at viral meningitis is PTsR-a research of tserebrospinalny liquid. Serological reactions for diagnosis of viral meningitis are indicative only in case of comparison of their results at the beginning of a disease and 2-3 weeks later. Because of the big duration of such diagnostics it can have only retrospective character.
To the patients having viral meningitis carry in addition out clinical blood test, biochemical tests of a liver, definition of electrolytic composition of blood, content in it of glucose, creatinine, a lipase and amylase. At the atypical course of viral meningitis and doubts at its diagnostics carrying out an electromyography, brain EEG, MRT and KT is possible.
Treatment of viral meningitis
Concerning viral meningitis symptomatic therapy is in most cases carried out. Rest, a bed rest, stay in the darkened room is recommended to the patient. For knocking over of a headache appoint analgetics. But often it considerably decreases after decrease in intra cranial pressure as a result of a diagnostic lyumbalny puncture. Body temperature is above 38 °C is the indication to reception of febrifugal medicines (paracetamol, an ibuprofen, etc.).
Specific and nonspecific antiviral therapy of viral meningitis is necessary at patients with the weakened condition of immune system and at babies. In such cases intravenous administration of immunoglobulin is carried out. If viral meningitis is caused by a virus of herpes or a virus Epstein-Barre, then application of an acyclovir is possible.
Forecast of viral meningitis
At adults viral meningitis in most cases comes to an end with an absolute recovery. Approximately in 10% of cases the residual phenomena in the form of an adynamy, a headache, small disorders of coordination, easy violations of the intellectual sphere are noted (memory impairment, difficulty of ability to concentration, some carelessness and so forth). However and they pass several weeks later, is more rare — months.