Paroxysmal myoplegia is a neuromuscular disease characterized by a sudden increase in pain localized in skeletal muscle. The disease is very serious, causes immobility.
What is the reason for its appearance? Are there any prerequisites? What symptoms can be considered alarming? How is the diagnosis carried out, treatment carried out? These and many other questions should now be answered.
A bit of history
The pathology under consideration was first described in 1874. After 6 years, a detailed description of this disease appeared. I.V. Shakhnovich and K. Westphal determined the hereditary nature of the pathology. By the way, at that time the disease was named in their honor. In the 19th century, myoplegia was called Westphal-Shahnovich’s disease.
As time went on, research continued. In 1956, J. Gamstorp studied the hyperkalemic form of the disease (it will be discussed in more detail below). This was medical progress. Of course, the disease was given the name "Hamstorp’s disease."
Just 5 years later, scientists Poskanzer and Kerr made a discovery - they revealed a third form of the disease. This is a normokalemic form, extremely rare. Medicine knows so few cases that treatment tactics remain undeveloped to date. It was only possible to prove that "Diacarb" (carbonic anhydrase inhibitor) can help cope with an attack.
Also, specialists managed to find out that myoplegia in some cases is secondary, symptomatic. It can occur as a consequence of such pathologies:
- Tumors of the adrenal gland.
- Pyelonephritis.
- Thyrotoxicosis.
- Adrenal insufficiency.
- Gastrointestinal diseases accompanied by vomiting and diarrhea.
- Hyperaldosteronism.
- Malabsorption syndrome.
It is also proven that paralysis can begin to appear in people who have previously suffered from barium poisoning, as well as in those who have abused laxatives and diuretic drugs.
Pathogenesis
To date, the mechanism of development of paroxysmal myoplegia is still the subject of study by physiologists, biochemists and physicians around the world.
It was previously assumed that this pathology occurs due to increased excretion of aldosterone. The version seemed plausible, since antagonist therapy gave a positive result. However, it was later proved that all shifts in the concentration of this hormone are secondary.
There are assumptions regarding a genetically determined violation of the permeability of the membranes of cell membranes and myofibrils in striated muscle tissue. Allegedly for this reason, water and sodium ions accumulate in vacuoles, and neuromuscular transmission is blocked due to a change in balance.
If the reason lies in this, then the pathology can be considered similar to Thomsen's myotonia. So far, the assumptions regarding the dysfunction of the channels of cell membranes are the most logical and scientifically sound.
Hypokalemic myoplegia
A little attention should be paid to the classification. Hypokalemic paroxysmal myoplegia is the most common form of the disease. This is an autosomal dominantly inherited disease characterized by incomplete gene penetrance.
The risk group includes people aged 10 to 18 years. Pathology is much less common in people over 30, and more often in men than in women.
Neither objective nor subjective signs of hypokalemic paroxysmal myoplegia are determined. But the following factors can provoke an attack:
- Binge eating.
- Alcohol abuse.
- Physical overstrain.
- Eating large amounts of salt or carbohydrates.
In women, seizures often occur on the first day of menstruation. Or 1-2 days before its start.
Attack
Paroxysm of hypokalemic type can be felt in the morning or at night. Awakening, a person realizes that he is paralyzed. Neck, limbs, muscles - everything is constrained. If the case is severe, then paralysis can affect even the facial or respiratory muscles.
Of the other manifestations, the following symptoms are noted:
- Sharp muscle hypotension.
- Loss of tendon reflexes.
- Hyperemia of the face.
- Tachycardia.
- Rapid breathing.
- Polydipsia.
It is important to note that the attack is also accompanied by disorders of the cardiovascular system. ECG readings change, systolic murmurs appear. But consciousness remains.
The attack can last from one hour to 1-2 days. But such cases are rare. More often it takes 2-4 hours. In the end, there is a slow increase in muscle strength, which begins with the distal extremities.
You can quickly restore lost functions if the patient contributes to this with his active movements.
How common are seizures? In severe cases, they occur daily. This provokes the appearance of chronic muscle weakness. This phenomenon often leads to malnutrition.
Hyperkalemic myoplegia
This form is found at times less than the above. Paroxysmal myoplegia of this type is characterized by autosomal dominant inheritance (high penetrance). Interestingly, in some cases, this pathology did not occur in families for four generations.
The disease with equal frequency affects both male and female persons. But this paroxysmal myoplegia in children occurs most often, it practically does not affect adults. At risk are babies under the age of 10 years.
It provokes an attack of hunger or rest after prolonged physical activity. First there are paresthesias in the facial region, then they arise in the limbs. Weakness extends to the distal legs and arms, and then to other muscle groups. In parallel, tendon areflexia and hypotension occur. Symptoms are as follows:
- Increased heart rate.
- An agonizing thirst.
- Arterial hypertension.
- Profuse sweat.
- Vegetative disorders.
As a rule, such an attack does not last more than two hours. The timely provision of assistance is very important, since due to what happened a person can be completely immobilized (this is called plegia).
Normokalemic myoplegia
This is an extremely rare pathology. The number of cases described in the literature can be counted on the fingers. Paroxysmal myoplegia of this type has a hereditary autosomal dominant character.
It is characterized by severe symptoms. The disease can manifest itself as moderate weakness, so complete paralysis affecting the facial muscles. Hypertrophy is possible, accompanied by the formation of an athletic-looking physique. There is paroxysmal myoplegia in children, occurs during the first 10 years of life.
It is provoked, as a rule, by intense physical activity or hypothermia. It can also occur due to too long sleep. It manifests itself as a slow increase in weakness. These feelings pass even more slowly.
This form of the disease is also distinguished by its duration. The attack can pass either in 1-2 days, or in several weeks.
Diagnostics
She does not present any particular difficulties. Diagnosis of paroxysmal myoplegia does not even require specific measures. The disease manifests itself in a typical course of seizures and the absence of neurological disorders during periods of "lull". Plus, there is always a family history.
However, there are sometimes difficulties in establishing a diagnosis. They occur with the initial appearance of paroxysm, the abortive nature of the attacks, or in the sporadic case.
The diagnosis is verified by a geneticist. Consultation with an endocrinologist and a neurologist is also required.
Periodically, you need to donate blood for biochemical analysis. In the periods between attacks, deviations are not detected, but with paroxysms, a reduced level of serum potassium is observed - up to 2 mEq / l and even lower. Also, a decrease in the amount of phosphorus, an increase in sugar is recorded.
But this is with the hyperkalemic form of paroxysmal myoplegia (code according to ICD-10 - E87.5). In the case of hypokalemia, a lowered sugar level and an increased potassium content are recorded.
Sometimes electromyography is performed. It in any form allows you to identify the lack of bioelectric activity.
It is also possible to administer a solution of potassium chloride to a person. If paroxysm begins to develop after 20-40 minutes, then the patient has a hyperkalemic form of the disease. Of course, the solution is administered for diagnostic purposes.
With frequent seizures, a muscle biopsy can be performed. It often helps to identify the vacuolar form of pathology.
Why do we need diagnostic measures for paroxysmal myoplegia, the symptoms of which already indicate its presence? In order to differentiate the disease from hysteria, myopathy, Conn's disease, Landry's paralysis, as well as from spinal circulatory disorders.
Therapy of hypokalemic disease
We should talk about the treatment of paroxysmal myoplegia. Therapy is carried out differentially, a lot depends on the form of the disease.
If, for example, the ailment has a hypokalemic form, then the attack is eliminated by taking a 10 percent solution of potassium chloride. You need to use it every hour. Injections of a solution of magnesium and potassium asparaginate are recommended.
When a person’s bouts do not bother, he needs to take the spironolactone diuretic. But with great care. In women, it can cause hirsutism, the menstrual cycle is often disturbed. Men often suffer from gynecomastia and impotence. Therefore, "Acetazolamide" becomes an alternative. Many experts consider Triamteren as effective.
Diet
It is imperative to adhere to proper nutrition. If a hypokalemic type of paroxysmal myoplegia is diagnosed, the amount of carbohydrate and salt consumed should be reduced. It is better to refuse the latter.
It is also necessary to enrich the diet with products that contain a sufficient amount of potassium. The "champions" in the content of this element include:
- Potatoes.
- Sun-dried tomatoes.
- Beans
- Dried apricots.
- Prunes
- Avocado.
- Salmon.
- Spinach.
- Pumpkin.
- Oranges.
The potassium content in tea, soy, cocoa, wheat bran, nuts, seeds, wild garlic and garlic greens, leafy vegetables, bananas, mushrooms and fermented milk products is still high.
Lifestyle
Since we are talking about the symptoms and treatment of hypoxemia-type paroxysmal myoplegia, you need to pay attention to this topic.
In addition to diet, it is important to follow a certain lifestyle. It is necessary to exclude heavy physical exertion and any overvoltage. But a long stay at rest is also contraindicated. It is important to make a compromise. You can make periodic trips to the pool or evening walks in the fresh air in your regime.
It is also important to avoid overheating and hypothermia. The temperature should be comfortable.
Therapy of hyperkalemic disease
The attacks of this disease subside after the injection of a 40% glucose solution with insulin or calcium chloride (10%).
Sometimes a good result is noted after inhalation of "Salbutamol". It is believed that this method not only relieves seizures, but also prevents them.
During remission periods, the patient should take "Acetazolamide" or "Hydrochlorothiazide".
Diet
With hyperkalemic paroxysmal myoplegia, the causes and symptoms of which were listed earlier, it is necessary to limit the use of all foods enriched in potassium. Enrichment of the diet with carbohydrates and salt is strongly recommended. In general, the provisions are completely opposite to the diet shown for hypokalemic disease.
Under no circumstances should starvation begin to occur, since it is precisely this that provokes seizures. That is why it is important to switch to fractional nutrition, at least once every few hours. You can’t overeat, you just need to maintain a full state.
Forecast
It cannot be denied that the disease in question affects the quality of life and causes problems to the patient. But in general, the forecast is favorable. Cases of death at the time of seizures are extremely rare. In addition, observing therapeutic recommendations and leading the right lifestyle, you can quickly stop them.
And, of course, the treatment of symptomatic periodic paralysis is important. It implies the healing of the underlying pathology, as well as the restoration of electrolyte balance.