Central pontine myelinolysis

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Centralpontine myelinolysis.JPG
Classification according to ICD-10
G37.2 Central pontine myelinolysis
ICD-10 online (WHO version 2019)

The central pontine myelinolysis ( ZPM ) ( Lat. Pons , bridge, pontine bridge on; Greek. Μῦελόν, spinal cord , Mark, λύσις, lysis, dissolution) is a neurological disorder in which there damage to the sheath of nerve fibers, particularly in Pons (brain stem) is coming. It is caused by the rapid correction of a pathologically reduced sodium level ( hyponatremia ) in the organism.

Extrapontine myelinolysis is a variant of ZPM . This leads to demyelination in the cerebellum , basal ganglia , internal capsula , bars and in the vicinity of the ventricles . Both forms are summarized as osmotic demyelinating disease or osmotic demyelinating syndrome , they can also occur simultaneously.

causes

Central pontine myelinolysis is triggered , among other things, by the rapid compensation of hyponatremia . The limit is a serum sodium of less than 126 mmol / l. The risk increases with prolonged hyponatremia.

Causes of hyponatremia are:

mechanism

The idea is based on the concept of osmosis (diffusion on semipermeable membranes). The water follows the electrolytes .

When sodium is lost from the blood, the sodium level slowly decreases in all other compartments of the body. This is usually well tolerated with a slow sinking. If the hyponatremia is diagnosed and compensated parenterally by infusion , depending on the speed at which the sodium level rises, water is shifted from the tissue into the blood, since sodium cannot diffuse into the other compartments (especially the cells) as quickly. The dehydration (drainage) of the brain leads to the destruction of the myelin sheaths by an unknown mechanism . The process is known as osmotic demyelination .

Symptoms and course

About half a week after the hyponatremia has been compensated for, the disease begins with impaired consciousness up to coma , increasing paralysis of all extremities ( tetraparesis ) and disorders of the brain stem function (eye movement disorders, facial paralysis, swallowing disorders, respiratory paralysis). The severity of the individual symptoms can range from slight fatigue and unsteady gait to a coma with complete paralysis and failure of the respiratory function.

The majority of patients largely recover. The improvement begins two weeks after the onset of the disease at the earliest; rehabilitation for severely affected patients often lasts over a year. A fatal outcome is possible, the cause of death is usually the complications of the problems to be treated in intensive care (e.g. pneumonia).

Diagnosis

Central pontine myelinolysis, MRT image of the brain axially in FLAIR weighting; the light ring in the middle of the picture is pathological
Autopsy case of a ZPM with loss of myelinated fibers (left half) in the brain stem (histology, myelin sheath staining)

treatment

A specific treatment after a rapid rise in serum sodium is not known, either in the days before the onset of the disease or afterwards.

Therefore, it is necessary to treat the signs of the disease (symptomatic therapy):

prevention

It is crucial to only slowly equalize the sodium level after hyponatremia has been determined. In the scientific literature, recommendations between 6 and 10 mmol / l per day are given. This requires laboratory checks two to four times a day. The sole use of isotonic infusion solutions does not provide adequate protection against CPM; the decisive factor is the rate of sodium increase.

literature

Individual evidence

  1. Burger Lichtenstein: Etiology is neglected. In: Deutsches Ärzteblatt. Volume 117, Issue 3, January 17, 2020, p. 41 f. - to the article by Johann Lamback and others: Central pontine myelinolysers and osmotic demyelination syndromes . In: Deutsches Ärzteblatt. Volume 116, Issue 35-36, 2019, pp. 600-606.