Central pontine myelinolysis
Classification according to ICD-10 | |
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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:
- very low-salt diet with high drinking quantities (in case of malnutrition or anorexia )
- Side effects of medication ( diuretics , carbamazepine, and other substances taken alongside or with diuretics)
- Hormonal disorders ( SIADH = syndrome of inadequately increased ADH secretion = Schwartz-Bartter syndrome, especially paraneoplastic in tumor diseases , central salt loss syndrome )
- "Water poisoning" in the case of drowning accidents or incorrect infusion therapy
- alcoholism
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
- Medical history survey
- Neurological exam to check for symptoms
- Evoked potentials - especially the AEP
- CSF puncture to rule out inflammation
- Magnetic resonance imaging (changes often only after a few weeks!)
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):
- Physiotherapy for paralysis
- Ventilation for respiratory paralysis
- Tracheotomy for severe swallowing disorders
- Prevention of complications of being confined to bed ( thrombosis , pneumonia , decubitus )
- Speech therapy for dysarthria and dysphagia
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
- RJ Martin: Central pontine and extrapontine myelinolysis: the osmotic demyelination syndromes. In: Journal of Neurology, Neurosurgery, and Psychiatry . Volume 75 Suppl 3, September 2004, pp. III22-III28, ISSN 0022-3050 . doi : 10.1136 / jnnp.2004.045906 . PMID 15316041 . PMC 1765665 (free full text). (Review).
- R. Laureno, BI Karp: Myelinolysis after correction of hyponatremia. In: Annals of internal medicine . Volume 126, Number 1, January 1997, pp. 57-62, ISSN 0003-4819 . PMID 8992924 . (Review).
- CP Harris, JJ Townsend, JR Baringer: Symptomatic hyponatraemia: can myelinolysis be prevented by treatment? In: Journal of Neurology, Neurosurgery, and Psychiatry . Volume 56, Number 6, June 1993, pp. 626-632, ISSN 0022-3050 . PMID 8509775 . PMC 489611 (free full text). (Review).
Individual evidence
- ↑ 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.