Middle myelinolysis of the bridge was previously associated with alcohol abuse, but it is now known that this disease most often results from … too intense medical interventions. The problem is serious because the changes in the central nervous system that occur in its course are irreversible. So what are the exact causes of middle bridge myelinolysis and what are the symptoms of this condition?
Contents:
- Middle myelinolysis of the bridge - causes
- Middle myelinolysis of the bridge - symptoms
- Middle myelinolysis of the bridge - diagnosis
- Middle bridge myelinolysis - treatment
- Middle bridge myelinolysis - prevention
- Middle bridge myelinolysis - prognosis
Central pontine myelinolysis (CPM) is a demyelinating neurological syndrome belonging to the group of alcoholic encephalopathy. .
Middle myelinolysis of the bridge is a unit that has been mentioned in the medical world for a relatively short time - its first description by Adams, Victor and Mancall dates back to 1959.
This document describes four autopsy cases of this unit - at that time, middle bridge myelinolysis was associated with alcoholism and severe malnutrition.
It was only after some time that it turned out that the main cause of middle bridge myelinolysis was a completely different problem - too quick correction of the decreased sodium level in the patients' organisms.
Middle myelinolysis of the bridge - causes
Middle bridge myelinolysis is one of the syndromes of osmotic demyelination. The essence of the problem is the rapid changes in the osmolality of the extracellular fluid.
Typically, the individual develops primarily in those who have suffered from hyponatremia, i.e. low blood sodium levels for a long time.
In such a situation, the organism tries to adapt to the changes that have occurred - in order to balance the osmolality between the interior of various cells and the surrounding environment, intracellularly the concentration of osmotically active substances, such as e.g. inositol or glutamine.
The body is capable offunction in this way for some time, but it is not ready for rapid changes in conditions prevailing in it for a long time.
Attempts to compensate the patient's sodium deficiency in the body too quickly may be the direct cause of myelinolysis of the middle pons.
In this case, the extracellular environment (more precisely, the fluid surrounding the cells) becomes hypertonic - this results in the movement of water from the cells into the extracellular environment. Ultimately, this leads to demyelination of the nerve fibers.
This process may appear in various regions of the brain, but typically it is most intense within the pons.
Why the problem appears in this particular location, it has not really been possible to determine this - it is suspected that the relatively poor vascularization of this part of the brain may be responsible for it.
The main cause of medial myelinolysis is therefore hyponatremia, or more precisely, it corrects too quickly in patients. Among the conditions that contribute to a low sodium concentration in the blood and thus increase the risk of this disease, the following can be mentioned:
- malnutrition (which may be promoted by severe eating disorders, e.g. in the form of anorexia)
- severe burns
- serious liver disease with impaired liver function (e.g. cirrhosis)
- AIDS
- regular peritoneal dialysis
- hypokalemia (low blood potassium)
Middle myelinolysis of the bridge - symptoms
In fact, the symptoms of middle bridge myelinolysis are quite uncharacteristic - they may concern both motor and cognitive functions, and they are ailments that generally indicate damage to structures belonging to the central nervous system. More specifically, patients with central myelinolysis of the bridge may have:
- muscle weakness or even complete paralysis (tetraplegia is quite common in the course of the disease)
- weakening or abolition of tendon reflexes
- disorders of the muscles supplying the eyeballs
- dyzartria
- dysphagia
- disturbance of consciousness
- imbalance
- involuntary movements (primarily in the form of tremors)
Middle myelinolysis of the bridge - diagnosis
Due to the fact that the symptoms of middle myelinolysis - as mentioned above - are non-specific, the diagnosis of this disease may be difficult.
The most important thing in diagnostics here is to link to emergenciesthe occurrence of various neurological deficits in patients with the commencement of correction of their sodium deficits in the blood.
It is possible to detect certain deviations in various studies, incl. in the examination of the cerebrospinal fluid (which may be an increased concentration of total protein and myelin basic protein) or in magnetic resonance, however, it should be emphasized that some of these abnormalities appear relatively late (for example, changes in head imaging become clearly noticeable after only about two weeks after the onset of the disease).
Before making a diagnosis of middle bridge myelinolysis, always exclude other possible causes of the patient's symptoms - in the differential diagnosis of the disease one should first of all take into account:
- stroke
- multiple sclerosis
- tumors of the central nervous system
- encephalitis
Middle bridge myelinolysis - treatment
The changes that will occur in the course of middle bridge myelinolysis are unfortunately irreversible - they cannot be undone with the use of any pharmaceuticals. Therefore, patients are treated primarily with such interactions that are to prevent the occurrence of complications of the disease, which may be:
- aspiration pneumonia
- deep vein thrombosis
- muscle atrophy and contracture
- bedsores
- urinary tract infections
The above-mentioned problems arise, among others, from from malnutrition and reduced mobility of patients, therefore, in patients with middle bridge myelinolysis, appropriate nutritional treatment and regular rehabilitation are necessary.
Middle bridge myelinolysis - prevention
Due to the fact that the changes occurring in the course of middle bridge myelinolysis simply cannot be undone, the most important are attempts to prevent its occurrence.
Correct - that is, rationally and slowly - correcting blood sodium deficits in patients with hyponatraemia plays a fundamental role in this case.
Usually, it is suggested that the administration of sodium chloride solutions to the patient should lead to an increase in the concentration of this substance by a maximum of 0.5 mmol / l / h, while daily changes in blood sodium concentration should not exceed 10 mmol / l.
Middle bridge myelinolysis - prognosis
It is simply impossible to clearly define the prognosis of a patient with middle bridge myelinolysis in the world, because the course of the disease can be very different.
In the past - Due to the fact that the problem was stated essentiallyonly in post-mortem examinations - it was believed that the disease always resulted in death, but it is now known that this is definitely not always the case.
Most patients who develop mid-bridge myelinolysis survive - an estimated 1/3 of them experience relief from symptoms, 1/3 have some symptoms but are able to function independently, and the remaining 1 / 3 unfortunately comes to a significant disability.
About the authorBow. Tomasz NęckiA graduate of medicine at the Medical University of Poznań. An admirer of the Polish sea (most willingly strolling along its shores with headphones in his ears), cats and books. In working with patients, he focuses on always listening to them and spending as much time as they need.Read more from this author