Subacute sclerosing leukoencephalitis: causes, symptoms, diagnosis, treatment

The subacute sclerosing leukoencephalitis group includes peculiar forms of chronic and subacute encephalitis with a progressive severe course (encephalitis with Dawson inclusions, subacute sclerosing leukoencephalitis of Van Bogart, nodular panencephalitis of Pette-Dering). Since the differences in their clinical picture and morphology are relative and insignificant, they are now interpreted as one disease, most often called "subacute sclerosing panencephalitis". This group of diseases also includes Schlierder's periaxial encephalitis (diffuse peri-axial sclerosis), which has some fairly clearly outlined clinical and pathomorphological features.

[1], [2], [3], [4], [5], [6], [7]

The causes of subacute sclerosing leukoencephalitis

In the etiology of subacute sclerosing encephalitis, a major role is played by a persistent viral infection, apparently, measles, enterovirus, tick-borne encephalitis virus. In patients with subacute sclerosing panencephalitis, very high titres of measles are found in the blood and CSF (not noted even in patients with acute measles infection).

The pathogenesis of the disease is played by the role of autoimmune mechanisms, as well as the acquired or congenital defect of the immune system.

Pathomorphology

Microscopically, there is a pronounced diffuse demyelination and gliosis of the white matter of the cerebral hemispheres. In some cases, identify a lot of glial nodules. In other cases, there are oxyphilic inclusions in the nuclei of neurons of the cortex, subcortex, and brainstem on the background of their dystrophic changes. Axial cylinders first remain relatively intact, then die. Mark moderate perivascular infiltration with lymphoid and plasma cells. For Schuleder's leucoencephalitis, glia proliferation with lesions of sclerosis is characteristic.

Symptoms of subacute sclerosing leukoencephalitis

The disease affects mainly children and adolescents aged 2 to 15 years, but sometimes the disease occurs and in adulthood. The onset of the disease is subacute. Symptoms appear that are regarded as neurasthenic: distraction, irritability, fatigue, tearfulness. Then there are signs of personality changes, deviations in behavior. Patients become indifferent, lose the sense of distance, friendship, duty, the correctness of relationships, discipline. Primitive drives begin to dominate: greed, selfishness, cruelty. At the same time, disorders of higher cerebral functions appear (agraphy, aphasia, alexia, apraxia), spatial orientation, and disorders of the body scheme. 2-3 months after the onset of the disease, neurological status reveals hyperkinesia in the form of myoclonias, torsion spasm, hemiballism. At the same time there are convulsive epileptic seizures, small epileptic, persistent partial seizures like Kozhevnikovskaya epilepsy. In the future, as the disease progresses, hyperkinesis weakens, but Parkinsonism and dystonic disturbances begin to increase until decerebral rigidity. Extrapyramidal disorders are usually combined with pronounced vegetative disorders: facial smoothness, drooling, hyperhidrosis, vasomotor lability, tachycardia, tachypnea. Often there are involuntary laughter and crying, sudden screams ("gull cry"). A common symptom is static and locomotor ataxia of frontal origin (the patient does not keep the body in a vertical position).

In the late stage of the disease mono-, hemi-and tetraparesis of a spastic character occur, superimposed on extrapyramidal and frontal-cerebellar motor disorders. Sensory and motor aphasia, auditory and visual agnosia are revealed. Progression of cachexia.

Current and forecast

In the course of subacute sclerosing encephalitis, 3 stages are distinguished.

• In the first stage, the main symptoms are personality changes, behavioral disorders, increasing defects in higher brain functions, various hyperkinesis, convulsive and non-convulsive seizures.
• In the second stage, extrapyramidal disorders of tone and autonomic central regulation disorder increase.
• Stage III is characterized by cachexia and complete decortication.

The course of sclerosing encephalitis is steadily progressing and always ends lethal. Duration of the disease is usually from 6 months to 2-3 years. There are forms that occur chronically with periodic remissions. Death occurs in a state of complete immobility, cachexia, marasmus, most often in epileptic status or due to pneumonia.

[8], [9], [10], [11], [12],

Diagnosis of subacute sclerosing leukoencephalitis

There are some difficulties in the early stage, when often wrongly diagnosed neurasthenia, hysteria, schizophrenia. In the future, differential diagnosis is carried out with a brain tumor. In diagnosis, one should rely on the diffuse (and not single-point) lesions, the lack of intracranial hypertension, the displacement of the median brain structures in Echo, MRI, and the pathognomonic picture of EEG results. The diagnosis is confirmed by the results of molecular genetic, immunological studies and neuroimaging methods.

Symptoms of Schilder's leucoencephalitis have some peculiarities: the pyramidal symptoms dominating over extrapyramidal are more pronounced, and more often epileptic seizures are noted. In the initial stages of the prevalence of mental disorders. It is possible that the flow is in the form of a pseudo-tumorous form with signs of an increase in single-focal hemispheric symptoms accompanied by intracranial hypertension. Characteristic is the damage to the cranial nerves, especially the II and VIII pairs. Possible amblyopia up to amavroz. On the fundus there is an atrophy of the discs of the optic nerves. In some cases, amaurosis retains pupillary responses to light, which is due to the central character (due to the defeat of the occipital lobe) amaurosis.

In the cerebrospinal fluid there is a moderate pleocytosis, an increase in the protein content and y-globulin. The colloid Lange reaction gives a paralytic curve in subacute sclerosing encephalitis, inflammatory and mixed - with Schilder's leukoencephalitis. Pathological changes in the Lange reaction and hypergammaglobulinorahia are early signs of leuko- and panencephalitis. With EEG, periodic stereotyped regular bilaterally synchronous high-amplitude discharges of electrical activity (Rademecker complexes) are recorded. With Echo, conducted in cases with a pseudotumorous course of leukoencephalitis, displacement of the median structures is not detected. The most informative is axial CT.

[13], [14], [15]