Viral meningitis
The content of the article:
- Causes and risk factors
- Forms of the disease
- Symptoms of viral meningitis
- Features of the course of viral meningitis in children
- Features of the course of viral meningitis in the elderly
- Diagnostics
- Treatment for viral meningitis
- Possible complications and consequences
- Forecast
- Prevention
Viral meningitis is an inflammatory disease of the meninges, in which viruses act as an infectious agent. The membranes of the brain become inflamed more often.
Infected meninges with viral meningitis
The brain and spinal cord have three membranes: hard, arachnoid, and soft. The dura mater is a tough connective tissue structure located closest to the skull (brain) or spine (spinal cord). Next to it - arachnoid (arachnoid), is separated from the pia mater by the subarachnoid (subarachnoid) space, which fills 120-140 ml of cerebrospinal fluid. The subarachnoid space contains blood vessels, as well as the roots of the spinal nerves. The pia mater is composed of loose connective tissue and adheres tightly to the surface of the brain. In the thickness of the pia mater are the blood vessels that feed the brain.
The serous inflammatory process, characteristic of viral meningitis, is accompanied by the formation of serous, i.e., liquid effusion that permeates the meninges, which leads to their thickening. Edema of the meninges of the brain causes a violation of the outflow of cerebrospinal fluid with a further increase in intracranial pressure. The roots of the cranial and spinal nerves, blood vessels of the brain, etc. can be involved in the pathological process.
Most often, viral meningitis is recorded in children, adolescents and young people, as well as in elderly patients, especially if they have immunodeficiency states and chronic diseases. Viral meningitis is characterized by seasonality, which is determined by the type of virus. One of the incidence peaks occurs in the summer, the second, caused by the mumps virus, in winter and early spring.
Causes and risk factors
The causative agents of viral meningitis are usually enteroviruses (Coxsackie virus types A and B, ECHO viruses), arenaviruses, cytomegalovirus, Epstein-Barr virus, paramyxoviruses, influenza viruses. In 75-80% of patients, enterovirus infection becomes the cause of viral meningitis. In addition, HIV can cause viral meningitis.
Enteroviruses are often the causative agents of viral meningitis
The infectious agent enters the human body by airborne droplets or fecal-oral route, and into the meninges - with the flow of blood (hematogenous route), lymph (lymphogenous) or perineurally.
Forms of the disease
By the nature of the inflammatory process, all meningitis are classified into:
- serous - the cerebrospinal fluid is transparent, contains a large number of lymphocytes (this type includes viral meningitis);
- purulent - the cerebrospinal fluid is viscous, cloudy, contains a large number of neutrophils (when a bacterial infection is attached, viral meningitis can take on a purulent character).
Depending on the etiology, meningitis is divided into:
- viral;
- bacterial;
- mycotic;
- protozoal.
Depending on the pathogenesis:
- primary - primary inflammation has developed in the meninges;
- secondary - developed as a complication of the inflammatory process, originally localized elsewhere.
By the prevalence of the pathological process:
- generalized;
- limited.
According to the rate of the disease, meningitis is of the following forms:
- lightning fast;
- sharp;
- subacute;
- chronic.
Depending on the severity, the disease can be mild, moderate, severe, or extremely severe.
Symptoms of viral meningitis
The incubation period for viral meningitis is usually 2–4 days. The disease usually begins acutely or subacutely. The body temperature rises - at first to subfebrile, later to high numbers, there is a headache, nausea, vomiting, neck muscle tension. The headache is intense, bursting, excruciating, aggravated by head movements, loud sounds, bright light, not eliminated by conventional analgesics. Nausea and vomiting are not associated with food intake, but with increased headache, can occur when changing body position. Along with fever, there are other signs of intoxication, which, however, are usually not very pronounced: pain in muscles and joints, lack of appetite, abdominal pain, diarrhea. Patients often complain of drowsiness and drowsiness. In some cases, on the contrary,there is anxiety and agitation of the patient. More severe disorders, such as confusion, coma, stupor, are not typical for viral meningitis and require further examination of the patient. No changes in peripheral blood were observed.
Specific symptoms of meningitis, including viral
In the early days of the disease, meningeal symptoms appear:
- severe headache, poorly supervised or not relieved by analgesic drugs;
- repeated vomiting, not associated with food intake;
- stiff neck muscles;
- positive symptoms of Kernig and Brudzinsky;
- photophobia;
- increased sensitivity to sounds.
Liquid nasal discharge, cough, sore throat and abdominal pain may occur.
At the onset of the disease, an increase in tendon reflexes is usually observed, but with the progression of the pathological process, they decrease or disappear altogether.
Other symptoms of viral meningitis include: increased skin sensitivity (hyperesthesia), increased sensitivity to stimuli, hypertensive syndrome. Also, in patients with viral meningitis, there is an increase in breathing, a violation of the respiratory rhythm, a change in the heart rate (at the beginning of the disease - tachycardia, later bradycardia develops). Skull percussion is painful.
Body temperature, as a rule, returns to normal within 3-5 days. In some cases, another wave of fever is noted.
In the general structure of viral meningitis, a form stands out that develops against the background of mumps (in about 0.1% of cases). In this case, the neurological syndrome manifests itself 3–6 days after the onset of the disease. This type of viral meningitis is often severe and has a high probability of damage to the auditory nerve, pancreas and gonads, as well as the development of polyneuropathy.
In severe cases of the disease, patients develop strabismus, dilated pupils, diplopia (visual impairment, which consists in the bifurcation of objects visible to a person), control over the pelvic organs may be lost.
Features of the course of viral meningitis in children
Viral meningitis in children can start with the appearance of skin rashes. Children become capricious, whiny, refuse to eat. Against the background of a not too strong rise in temperature, convulsions may occur. The clinical picture of viral meningitis in young children often resembles the symptoms of ARVI - a cough appears, breathing becomes difficult. In infants, there is tension or bulging of the fontanelle.
In children, viral meningitis can begin with skin rashes.
In adolescents and young people with viral meningitis, the cycle of wakefulness and sleep is often disrupted.
Features of the course of viral meningitis in the elderly
Viral meningitis in old and senile age is often atypical, with a blurred clinical picture. Such patients are characterized by headaches of low intensity, in some cases there is no headache at all, but tremors of the limbs and head develop, and mental disorders can be observed.
Diagnostics
Meningitis is suggested by the presence of an intense headache and meningeal symptoms. The primary diagnosis is based on the data obtained during the collection of complaints and anamnesis.
To confirm the diagnosis, identify the pathogen, and also for the purpose of differential diagnosis, a lumbar puncture is performed, followed by laboratory examination of the cerebrospinal fluid. In the cerebrospinal fluid, lymphocytic pleocytosis and a slight increase in the level of protein with glucose levels within the normal range are found. In the first two days after the onset of the disease, especially in the case of infection with enteroviruses or the virus of eastern equine encephalomyelitis, the cytosis of the cerebrospinal fluid is predominantly neutrophilic. In this case, it is advisable to repeat the study after 8-12 hours in order to detect a probable lymphocytic shift. An indirect sign of viral etiology is the absence of an infectious agent during microscopy of preparations of cerebrospinal fluid for any type of staining. To identify the pathogen, they resort to the polymerase chain reaction method.
A reliable method for diagnosing viral meningitis is lumbar puncture
A general and biochemical blood test (glucose, liver function tests, electrolytes, creatinine, amylase) is also performed.
Magnetic resonance imaging is used to determine the location and nature of the pathological process. With an atypical course of viral meningitis, it may be necessary to conduct computed tomography, electromyography, and electroencephalography.
Treatment for viral meningitis
The main objectives of the treatment of viral meningitis:
- decrease in intracranial pressure;
- detoxification therapy;
- elimination of the pathogen.
In the case of a standard uncomplicated course of the disease, viral meningitis is treated at home. In severe cases, as well as with meningitis in newborns, immunocompromised individuals, hospitalization is required. Viral meningitis usually takes 1–2 weeks to cure.
Treatment for viral meningitis is symptomatic and usually takes 1 to 2 weeks
Patients with viral meningitis are shown bed rest, patients should be provided with a dark, quiet room. Treatment is mostly symptomatic. In some cases, the headache subsides after the diagnostic lumbar puncture is performed (as a result of its implementation, the increased intracranial pressure decreases, which is the cause of the headache).
In severe cases, corticosteroids and diuretics are prescribed.
Possible complications and consequences
The consequences of viral meningitis can be seizures, deafness, minor temporary disorders of the intellectual sphere (decreased concentration, memory impairment) and other neurological disorders.
In infants who have had severe viral meningitis, mental and intellectual development may be delayed, and persistent hearing loss may appear.
Forecast
With timely diagnosis and correct therapy, viral meningitis in adult patients, as a rule, ends in full recovery. In about 10% of patients, general weakness and rapid fatigue, impaired coordination of movements, and headache persist for several weeks or months after the illness. With viral meningitis in newborns and young children, the prognosis worsens.
Prevention
In order to prevent viral meningitis, it is recommended:
- isolation of a sick person, it is especially important to avoid contact with small children;
- prevention, and, if necessary, timely treatment of viral diseases, the complication of which can be viral meningitis (ARVI, endemic viral parotitis, etc.);
- strengthening of the body's defenses (proper nutrition, measured daily routine, sufficient physical activity, stay in the fresh air, etc.).
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Anna Aksenova Medical journalist About the author
Education: 2004-2007 "First Kiev Medical College" specialty "Laboratory Diagnostics".
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
