Progressive rubella panencephalitis is a rare slow viral infection of the central nervous system caused by the rubella virus. Manifests in the period from 8 to 19 years. It is manifested by progressive mental decline, cerebellar syndrome, spastic tetraparesis, visual impairment, epileptic paroxysms. It is diagnosed on the basis of anamnestic and clinical data, the picture of cerebral MRI / CT, the results of the analysis of cerebrospinal fluid. Treatment is carried out by symptomatic means, has little effectiveness. The disease is prone to steady progression.
General information
Progressive rubella panencephalitis (PRP), along with Rasmussen’s encephalitis, subacute sclerosing panencephalitis, Creutzfeldt-Jakob disease, is included in the group of slow CNS infections. A common feature of these diseases is a long latency period that takes decades. Progressive panencephalitis of rubella etiology was first described in 1974, when it was possible to isolate the virus from the cerebral tissues of the patient. PRP is a rare pathology, by now several dozen cases have been described in the literature on neurology. Men are susceptible to the disease, the characteristic age of manifestation of symptoms is 8-19 years.
Causes
The etiofactor of the disease is the rubella virus. A slow infection develops when infected as a result of:
- Intrauterine infection. Rubella during pregnancy in a woman can be asymptomatic. Intrauterine infection of the fetus in the first trimester leads to multiple malformations, then the probability of abnormalities decreases. Signs of congenital rubella (early rubella encephalitis) are usually observed in the immediate period after childbirth. Progressive rubella panencephalitis develops if the virus does not manifest immediately, but remains in a latent state.
- Rubella suffered in childhood. In exceptional cases, after an infection, the virus does not completely eliminate, it persists in the body in a latent form.
The risk group for measles infection during pregnancy includes women with a low concentration of specific measles immunoglobulins (10-25 IU/ ml) that protect the body from the rubella virus.
Pathogenesis
The entry of the rubella virus into the body usually occurs in utero or in early childhood. Due to unknown circumstances, the virus passes into an inactive form, in which it can exist for up to two decades. The reasons for the activation of the latent rubella virus have not been established. The small number of clinical observations makes it impossible to study the pathogenesis of PRP in detail. Morphologically, the formation of perivascular lymphocytic infiltrates and small glial foci in the cerebral cortex, astrocytosis with a predominant lesion of the white cerebral substance is noted. The changes are diffuse in nature, they capture various parts of the brain, for which rubella encephalitis is called “panencephalitis”.
Symptoms
Progressive rubella panencephalitis debuts with nonspecific symptoms. Relatives begin to notice mood swings, changes in character, behavior of the patient. The child learns worse at school, there are problems with concentration, memorization, assimilation of new material. Over time, moderate cognitive impairment develops into a progressive intellectual deficit with the outcome of dementia. A distinctive feature of the PRP is severe cerebellar ataxia, including shakiness in the standing position, instability during walking, disproportionate large-scale movements, overshooting when performing purposeful actions.
The advanced stage of the disease is characterized by epileptic paroxysms, the addition of focal neurological deficit. There is pronounced ataxia (discoordination, shakiness), visual disorders, paresis of the facial nerve. Typical pyramidal symptoms are: muscle weakness, spastic increase in muscle tone, increased tendon reflexes, the appearance of pathological stop signs. Motor disorders spread to all limbs, tetraparesis develops. In some cases, myoclonia is observed — involuntary contractions of individual muscle groups. Sensorimotor aphasia occurs — speech becomes slow, simplified, incomprehensible due to the rearrangement of syllables, the understanding of the speech heard is disrupted.
In the terminal stage, spastic tetraparesis binds patients to bed, there is no arbitrary control of the pelvic organs. There is marked dementia, complete absence of speech (mutism), disorder of eyeball movements (ophthalmoplegia). Coma often occurs. The disease ends in a fatal outcome due to total brain damage.
Diagnostics
The rare occurrence of pathology causes difficulties in the diagnosis of “rubella panencephalitis”. An important role is played by the identification in the patient’s anamnesis of data on rubella suffered in utero or in early childhood. The list of diagnostic measures includes:
- Neurological examination. During the examination, the neurologist determines the presence of facial paresis, pyramidal symptoms, cerebellar syndrome, pronounced cognitive decline, sensorimotor aphasia.
- Lumbar puncture. The procedure allows you to obtain a sample of cerebrospinal fluid and analyze it. A moderate increase in lymphocytes (40 cl / ml), protein (1.5-1.5 g / l) with a predominance of gammaglobulin is characteristic. The concentration of specific anti-redness antibodies is sharply increased, which indicates their production in the tissues of the central nervous system.
- Electroencephalography. Does not detect specific deviations. Typically diffuse slowing of the main rhythm.
- Tomography. MRI, MSCT and CT scans of the brain reveal hydrocephalus, generalized atrophy of cerebral tissues, expansion of the furrows of the cerebral cortex. The cerebellum is particularly grossly atrophied.
- Blood test for anti-redness antibodies. It is carried out by the enzyme immunoassay (ELISA). The antibody titer is increased, but not as significantly as in the cerebrospinal fluid.
As a rule, it is not possible to isolate the rubella virus from the cerebral tissues obtained by biopsy. It is necessary to differentiate progressive panencephalitis of rubella etiology from other slow infections, viral encephalitis, and multiple encephalomyelitis. Differential diagnosis is carried out with subacute sclerosing panencephalitis, characterized by a normal picture of cerebrospinal fluid with an increase in the titer of anticorrheal antibodies.
Treatment
Specific therapy has not been developed. Attempts at treatment with antiviral drugs (amantadine), metabolic agents (inosine) were unsuccessful. Symptomatic therapy (anticonvulsants, antihypoxants, decongestants) is carried out, but it is not able to stop the progression of symptoms.
Prognosis and prevention
Progressive rubella panencephalitis ends fatally. The duration of the disease from the moment of manifestation of symptoms does not exceed 3 years. Due to the lack of effective therapy, great importance is attached to the prevention of rubella infection in pregnant women and children. Specific prevention is carried out by vaccination against rubella in children aged 1 year, followed by revaccination at 6 years. 13-year-old girls who have not been vaccinated before and have not had rubella are recommended a single injection of the vaccine. Women planning pregnancy with a low titer of anti-redness antibodies are vaccinated according to individual indications. Pregnancy management in women at risk should be carried out with the control of the titer of specific antibodies in the blood.
