What is Herpetic Meningitis?
Herpetic meningitis is caused by the herpes simplex virus type 1 and 2.
Causes of Herpetic Meningitis
The causative agent of herpes meningitis can be type 2 herpes simplex virus (HSV-2) and varicella-zoster virus and shingles.
HSV-2 is primarily a causative agent of genital herpes. Aseptic meningitis occurs in 16% of patients against the background of the first exacerbation of genital herpes. Less commonly, meningitis occurs with repeated exacerbations of genital herpes. Diagnosis of meningitis caused by HSV-2 is facilitated by the detection of vesicular lesions in the genital area, as well as if there are complaints of difficulty in painful urination, lumbosacral radicular pain, paresthesia, and anesthesia in the anogenital zone.
Pathogenesis During Herpetic Meningitis
The pathogen penetrates into the human body mainly by airborne droplets. In the future, the pathogen persists for life in various nerve ganglia with periodic reactivation of the infectious process in individuals with immunodeficiency.
Herpetic meningitis is often observed against a background of primary genital infection – in 36% of women and 13% of men. In most patients, herpes sores on average per week precede the signs of meningitis. Herpetic meningitis can cause complications in the form of sensitivity disorders, root pain, etc. In 18–30% of cases, relapses of the disease are described.
Thus, the most characteristic neurological manifestation of the infection caused by HSV-2 is the combination of recurrent meningitis and sciatica.
Symptoms of Herpetic Meningitis
Herpetic serous meningitis (0.5–3% of all serous meningitis) develops more often than streets with primary genital herpes. The body temperature rises, a headache, photophobia, meningeal symptoms appear, in the cerebrospinal fluid there is moderate cytosis with a predominance of lymphocytes.
Headache growing, persistent, diffuse, or localized in the fronto-temporal region. Vomiting is repeated, not associated with food intake. At the onset of the disease, meningeal symptoms (stiff neck, Kernig and Brudzinsky symptoms) are detected. Often, the first manifestations of meningitis are preceded by signs of SARS, vesicular eruptions on the skin and mucous membranes. However, more often the disease occurs in the form of meningoencephalitis. On the 2nd 4th day, symptoms of cerebral edema appear: impairment of consciousness in the form of confusion, lack of orientation in time and space. Patients often become aggressive. Visual, auditory hallucinations, local or generalized convulsions appear; focal symptoms in the form of mono- or hemiparesis, movement coordination disorders, static ataxia.
The course of meningitis is acute. Body temperature returns to normal within a week, headaches and meningeal symptoms disappear. With extremely severe forms of meningitis and meningoencephalitis, death is possible.
Herpetic meningitis caused by the shingles virus is manifested by fever, headache and very mild meningeal symptoms. The onset of the disease is acute, the body temperature sometimes reaches 38-39 ° C. Confusion, sopor, coma are extremely rare.
Diagnosing Herpetic Meningitis
In the study of CSF, lymphocytic pleocytosis (300–400 cells in 1 μl), an increase in the protein level is usually found. Glucose may be normal or reduced.
To confirm meningitis, the herpes virus should be isolated from the cerebrospinal fluid and blood. Express methods allow you to quickly and early determine the presence of HSV antigen in the cerebrospinal fluid and blood (ELISA) or virus DNA (PCR). For the purpose of determining specific antibodies in the blood and cerebrospinal fluid, PH, CSCs are used over time. Antibodies appear during primary infection at week 2 and reach a maximum at week 3. In the future, they can persist throughout life.
Liquor syndrome in herpetic meningitis caused by shingles occurs very rarely. Liquor syndrome is characterized mainly by lymphocytic pleocytosis (from 25 to 150 cells in 1 μl). Pleocytosis decreases from the first days to the 6th week of the disease. Compared with other serous meningitis, herpes sores are characterized by longer periods of rehabilitation of CSF. Lymphocytic pleocytosis occurs in 40-80% of cases of manifest infection caused by shingles virus.
Treatment of Herpetic Meningitis
With meningitis caused by HSV-2 and shingles virus, the appointment of acyclovir is indicated (5 mg / kg intravenous drip 3 times a day for 5 days).