Subacute sclerosing panencephalitis

Description:

Subacute sclerosing encephalitis (demyelinating leucio-and panencephalites)  - peculiar forms of chronic and subacute encephalitis with the progressing heavy current (encephalitis with Dauson's inclusions, a subacute sclerosing leukoencephalitis of Van-Bogart, a nodular panencephalitis to Petya-Deringa, a subacute sclerosing panencephalitis of Tarishki). As distinctions between them in a clinical picture and morphology are relative and insignificant, now treat them as one disease, most often under the name "subacute sclerosing panencephalitis". This group of diseases includes also periaksialny encephalitis of Shilder (a diffusion periaksialny sclerosis) which, however, has some rather outlined clinical and pathomorphologic features.

The subacute sclerosing panencephalitis meets at the children who had measles to two-year age more often. The subacute sclerosing panencephalitis develops in several years after measles and usually for several months leads to dementia. Very high caption of protivokorevy antibodies in serum and cerebrospinal fluid is characteristic of it. Apparently, this disease is result of reaction of a macroorganism to the broken replication of a virus of measles in a brain.

In the USA less than 10 cases of this rare disease annually are registered. Incidence sharply decreased after introduction of protivokorevy vaccination. The anamnesis is in most cases typical: measles in the early childhood (up to 2 years), stage of latency within 6-8 years, then the accruing neurologic frustration; in 85% of cases the diagnosis is made at the age of 5-15 years.

Reasons of a subacute sclerosing panencephalitis:

In an etiology of subacute sclerosing encephalitis the large role is played by a persistent viral infection, apparently, clumsy. Very high credits of clumsy antibodies (which are not noted even at patients with an acute clumsy infection) are found in patients with a subacute sclerosing panencephalitis in blood and cerebrospinal liquid. The immunoglobulin inherent to the current clumsy infection is revealed also specific clumsy. The measles virus in a brain is in a supressirovanny state. Some researchers managed to allocate a measles virus from tissue of a brain of the died patients. In a pathogeny of a disease autoimmune mechanisms, and also the acquired or inborn defect of immune system play a role.

Pathogeny:

In a pathogeny of a subacute sclerosing panencephalitis two major factors - a virus persistention in TsNS and disturbances of an immune responsiveness matter.

Microscopically are found the expressed diffusion demyelination and a gliosis of white matter of hemicerebrums. In some cases there is a set of gliozny small knots. In other cases oxyphilic inclusions in kernels of neurons of bark, a subcortex, a brainstem against the background of their dystrophic changes are found. Axial cylinders at first remain rather intact, then perish. Moderately expressed perivascular infiltration lymphoid and plasmocytes is noted. Growth of a glia with the sclerosis centers is characteristic of Shilder's leukoencephalitis.

Symptoms of a subacute sclerosing panencephalitis:

Children and teenagers aged from 2 up to 15 years are subject to a disease generally, however sometimes the disease meets also at mature age. Beginning of a disease subacute, imperceptible. There are symptoms regarded as neurotic: absent-mindedness, irritability, fatigue, tearfulness. Then signs of change of the personality, a deviation in behavior are found. Patients become indifferent, lose feeling of a distance, friendship, a debt, correctness of relationship, disciplines. Primitive inclinations begin to dominate: greed, selfishness, cruelty. At the same time appear slowly disturbances of the highest brain functions (agraphia, aphasia, aleksiy, apraxia), space orientation, frustration of a body scheme accrue. In 2-3 months from the beginning of a disease in the neurologic status hyperkinesias in the form of myoclonias, the torsion spasm, a hemiballism come to light. In the same time there are convulsive epileptic seizures, small epileptic seizures, constant partial convulsive attacks like kozhevnikovsky epilepsy. Further in process of progressing of a disease hyperkinesias weaken, however the phenomena of parkinsonism and dystonic disturbances begin to accrue up to a cerebrate rigidity. Extrapyramidal frustration are usually combined by the expressed vegetative disturbances - greasiness of the person, hypersalivation, a hyperhidrosis, vasculomotor lability, tachycardia, a tachypnea. Often observe involuntary laughter and crying, sudden screaming ("shout of a seagull"). A frequent symptom is the static locomotory ataxy of a frontal origin (the patient does not hold a body in vertical position).

In a late stage of a disease arise mono - gemi-and tetraparesis of spastic character which is as if imposed on extrapyramidal and frontal and cerebellar motive disturbances. Touch and motor aphasia, acoustical and visual agnosia come to light. The cachexia progresses.

Current and forecast
During subacute sclerosing encephalitis allocate four stages.

- In the 1st stage the leading symptoms are changes of the personality, a deviation in behavior, the increasing defects of the highest brain functions, various hyperkinesias, convulsive and not convulsive attacks. This I stage (psychotic) lasts from 1 to 12 month.

- In the 2nd stage extrapyramidal disturbances of a tone and disorder of vegetative central regulation accrue; Disturbances of a muscle tone quite often have the mixed spastiko-rigid character, hyperkinesias (an athetosis, myoclonias, trembling) are often noted. Subcrustal disturbances in an initial stage develop on mono - or to a gemitip, but further extend to both hands and legs. Symptoms of defeat of pyramidal ways at a panencephalitis appear against the background of already developed disease picture. Treat often found symptoms also static and locomotory ataxy (owing to damage of a cerebellum or a frontal lobe of bark). Epileptic seizures in the form of generalized spasms, simple and difficult absentias epileptica, twilight states and avtomatizm belong to typical and constant symptoms of a disease. This stage usually proceeds from 6 months to 1 year.

- the 3rd stage is characterized by sharp increase of muscular rigidity, emergence of the torsion spasms, myogenetic contractures. At patients long tonic spasms of detserebratsionny type are noted, weak-mindedness accrues. Due to strengthening of rigidity clonic spasms and hyperkinesias weaken. Duration of the III stage - several months.

- Full loss of mental functions, a resistant cerebrate rigidity, hyper thermal crises with fever of gektichesky type, a cachexia are characteristic of the last (coma) stage of subacute sclerosing encephalitis. The lethal outcome comes at development of a circulator collapse or intercurrent disease.

The course of sclerosing encephalitis which is steadily progressing also always comes to an end letalno. Disease duration usually from 6 months to 2-3 years. The forms proceeding chronically with periodically occurring remissions meet. Death comes in a condition of a full obezdvizhennost, a cachexia, marasmus, most often in the epileptic status or owing to pneumonia.

The clinical picture of a leukoencephalitis of Shilder has some features: the pyramidal symptoms dominating over extrapyramidal are more expressed, big epileptic seizures are more often noted. In initial stages mental disturbances prevail. The current in the form of a pseudo-tumorous form with signs of increase of the one-focal polusharny symptoms which are followed by intracranial hypertensia is possible. Damage of cranial nerves, especially II and VIII couples is characteristic. The amblyopia up to an amaurosis is possible. On an eyeground the atrophy of disks of optic nerves is found. In certain cases at an amaurosis there are safe pupillary tests on light that is caused by the central character (due to defeat of an occipital share) an amaurosis. In cerebrospinal liquid the moderate pleocytosis, increase in protein content and level of gamma-globulin are found. Colloid reaction of Lange gives a paralytic curve at subacute sclerosing encephalitis, inflammatory and mixed - at Shilder's leukoencephalitis. Pathological changes of reaction of Lange and a gipergammaglobulinorrakhiya are precursory symptoms leucio-and a panencephalitis. Increase in level of oligoklonalny liquor is found. In blood serum and cerebrospinal liquid are defined extremely high (especially at subacute sclerosing encephalitis) credits of clumsy antibodies. On EEG periodic stereotypic regular bilateral and synchronous high-amplitude categories of electric activity (Rademekker's complexes) are registered. At the ekhoentsefaloskopiya which is carried out in cases with a pseudo-tumorous current of a leukoencephalitis, the shift of median structures is not found. The computer axial tomography is most informative.

Diagnosis:

Some difficulties in an early stage when the neurasthenia, hysteria, schizophrenia are often diagnosed meet. Further the differential diagnosis is carried out with a brain tumor. In diagnosis it is necessary to rely on diffusion, but not on defeat "odnoochagovost", absence of intracranial hypertensia, shift of median structures of a brain at an ekhoentsefalografiya, MRT, pathognomonic picture EEG.

At EEG characteristic changes are registered: periodic (everyone 3-8 c) the categories of high-amplitude sharp-pointed slow waves alternating with the activity suppression periods. A characteristic picture of cerebrospinal fluid - lack of cells, the normal or slightly increased concentration of protein and very high relative concentration of gamma-globulins (more than 20% of all protein of cerebrospinal fluid). The caption of protivokorevy antibodies in cerebrospinal fluid is permanently raised, often there are specific oligoklonalny immunoglobulins.

At KT and MPT the multiple centers of defeat of white matter, an atrophy of bark and not obstructive hydrocephaly are visible.

It is possible to allocate with special methods a measles virus from culture of tissue of brain. Viral antigens reveal immunocytochemistry, and virus RNA - methods of fluorescent hybridization in situ or PTsR.

Treatment of a subacute sclerosing panencephalitis:

Use of glucocorticoids belongs to pathogenetic methods of therapy, however this treatment ineffectively is quite frequent. For stopping of spasms use barbiturates (phenobarbital, benzonal, a hexamidine) in combination with carbamazepine (Finlepsinum, Tegretolum) or valproic acid derivatives (Depakinum, Convulexum) in age doses. Apply Mydocalmum, Baclofenum (lioresal) to decrease in a muscle tone. Appoint vasodilating drugs (Cavintonum, сермион), nootropil, group B vitamins, in some cases anabolic hormones (nerobolil, retabolil), fortifying means.

There are data that inosine пранобекс (100 mg/kg/days inside) sometimes allows to prolong life and to improve a state, but they are contradictory.