Periodic paralysis

The periodic paralysis is a group of diseases with a genetic basis, which is one of the so-called channel diseases and affects the membrane-based ion channels. The therapy consists mainly of dietary measures. The course of the disease is mainly given as favorable.

What is Periodic Paralysis?

Periodic paralyses are characterized by recurring muscle paralysis. They fall into the group of so-called canal diseases and are associated with deviations in blood potassium levels. The disease group affects the ion channels as protein complexes in the cell membrane of the muscles. Ion channels are responsible for the passage of ions and are therefore decisive for muscle excitability.

Periodic paralysis are chronically progressive myopathies and develop over a long period of time. In addition to periodic hypokalemic paralysis, periodic hyperkalemic paralysis belongs to the group of periodic paralyses. Both diseases have a genetic basis.

The canal diseases also include paramyotonia congenita, congenital myotonia and Andersen syndrome, which are associated with similar symptoms and show progressive muscle weakness as a common symptom. Periodic hypokalemic paralysis is clinically and genetically different from hyperkalemic paralysis.

causes

Periodic paralysis is genetic. Periodic hypokalemic paralysis shows a prevalence of one case per 100,000 inhabitants. The paralysis usually shows up in adolescence or childhood and is subject to an autosomal dominant inheritance. This form of periodic paralysis mainly affects men, who usually show a more severe course than the few women affected.

A gene defect in the CACNA1S gene on chromosome 1 has been shown to cause the disease. The gene product corresponds to a misconfigured subunit of the voltage-dependent calcium channels in the tubular system of muscle cells. The hyperkalemic paralysis first manifests itself around the age of ten and is also subject to an autosomal dominant inheritance. In this subgroup of periodic paralysis, there is a genetic defect in the SCN4a gene on chromosome 17. The affected gene codes for the sodium channels.

Symptoms, ailments & signs

In hypokalemic paralysis, water and sodium are stored. There is a potassium deficiency extracellularly. Due to the increased conductivity of the sodium across the cell membrane, the membrane potential and thus the muscle excitation is disturbed. The first symptoms appear before the age of 20 and appear at intervals of several months.

The frequency and severity of cases of paralysis increases continuously from the onset of the disease. Only after mid-life does the frequency decrease again and usually ends in the 50th year of life. Paralysis occurs mainly at night or in the morning hours. The seizures are often preceded by emotional excitement, meals rich in carbohydrates, or physical exertion. Accompanying symptoms are, in addition to a feeling of fullness, sweats, paresthesias or feelings of weakness.

The respiratory muscles are usually not involved. If it is also affected, cardiac arrhythmias also occur. The symptoms of paralysis last for several hours to several days. In periodic hyperkalemic paralysis, too high a potassium level leads to a shift in the membrane electrolytes on the muscle cells. Potassium flows out of the muscle cells and sodium flows in.

The membrane potential is disturbed by increased depolarization. The reduced excitability of the muscles causes symptoms of paralysis. The paralysis is usually preceded by a high intake of potassium or heavy physical exertion. Compared to hypokalemic paralysis, the seizures are shorter but more frequent. A strong feeling of thirst occurs accompanying. In addition to the legs, it is primarily the facial muscles that are affected.

Diagnosis & course of disease

In periodic hyperkalaemic paralysis, the electrocardiogram is conspicuous and is characterized by the tent-like T-waves, widened QRS complex, a flattened P-wave and a lengthening of the PQ time, as occurs in hyperkalaemia. The muscular reflexes are extinguished in this paralysis. The electromyogram shows reduced potentials and decreased amplitudes. There is increased serum potassium in the blood.

In hypokalemic paralysis, the muscle reflexes are weakened and the muscle tone reduced. In the EMG, the individual potentials are low or short. In addition, there is a clearing of the activity pattern. The serum potassium values ​​are usually below 2 mmol / l. A decrease in serum creatinine is conceivable. The same goes for an increase in sodium and lactic acid levels. The electrocardiogram shows a prolonged QT time, an ST stick depression and U-waves.

Muscle biopsy can show central and glycogen-filled vacuoles in the fibers in this type of periodic paralysis. The prognosis for both cases is considered favorable. Inability to walk is rarely developed over time. There is no correlation between the frequency or severity of the seizures and the ultimate disease severity.

Complications

Periodic paralysis always represents complications, which in very severe cases can even be fatal. In the long term, it is also possible that the patient may become unable to walk. During the seizures, paralysis suddenly occurs, which can lead to complete temporary paraplegia, so people at risk should not be alone.

Because paralysis can result in complete inability to move. However, the severity of the paralysis and muscle weakness is often different for different seizures. In addition to harmless weak paralysis, which only appear as sensory disturbances (paresis), it can also lead to complete paralysis of all four limbs. This phenomenon is known as tetraplegia and is a special form of paraplegia.

During this severe paralysis, the affected person is completely dependent on outside help. The bladder and rectum can also be paralyzed. As a rule, however, the respiratory muscles are not affected. In rare cases this also happens. This condition is an extremely life-threatening complication. Only with immediate ventilation can life be saved.

In a few cases, dangerous cardiac arrhythmias also occur during the paralysis attack that require immediate medical attention. Various therapeutic measures and adherence to a certain diet should help to reduce the number of seizures in order to prevent long-term damage to the muscles of the extremities, including the inability to walk.

When should you go to the doctor?

Disorders of the muscular system, loss of physical performance and sensitivity disorders must be presented to a doctor. A doctor is required if there are problems with locomotion, restrictions in movement options or a stiffening of the muscles. The peculiarity of periodic paralysis are intermittent phases of freedom from symptoms. Although spontaneous healing occurs, a doctor is needed. Since the paralysis will return after a certain period of time, it is advisable that the person concerned is adequately prepared for this situation.

Sweats, vegetative disorders and irregularities in the heart rhythm must be examined and treated. An inner weakness or restlessness, sleep disorders and a decreased well-being are signs of a health impairment. A doctor should be seen so that a diagnosis can be made and a treatment plan drawn up. In the event of a feeling of fullness or discrepancies in the digestive tract, the affected person needs medical care.

If the risk of accidents and injuries increases or if the daily demands can no longer be mastered without help, a visit to a doctor is advisable. If you have mental health problems, persistent stress or anxiety, it is advisable to ask a doctor for support. In most cases, without medical treatment, there is an increase in symptoms and emotional distress. The increased feeling of thirst is characteristic of the disease.

Therapy & Treatment

In hypocalimaic paralysis, an attack can be interrupted therapeutically with high doses of potassium chloride. It is administered orally and the ECG is continuously checked during therapy. In the long run, the attacks of this form of periodic paralysis can be avoided by eating low-carbohydrate and low-salt diet.

In addition to these dietary measures, avoiding heavy muscle loads can be useful in preventing seizures. Acetazolamide is also often given as a drug to prevent seizures. Other drug methods are also possible, such as the administration of triamterene or lithium. The therapy of the hyperkalimean form consists mainly of an intravenous infusion of calcium gluconate, glucose or insulin during an attack.

These methods reduce the existing hyperkalemia. Dietary measures such as avoiding foods rich in potassium are recommended for seizure prophylaxis. A high-carbohydrate diet and adequate salt intake are also recommended for this form of periodic paralysis. The administration of acetazolamide and hydrochlorothiazide can be used as prophylactic medication.

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Outlook & forecast

Periodic paralysis can be of two different types. The first variant is described as intermittent hypokalemic paralysis. The second variant is periodic hyperkalemic paralysis. Both have in common that the periodically occurring symptoms of paralysis are closely related to the potassium level in the blood.

If there are deviations in the potassium level in these so-called "canal diseases", paralysis occurs. However, these disappear again when the potassium level is raised or lowered. The paralysis affects the muscles. The process that triggers the muscular activity depends on complex mechanisms. These have not yet been explored sufficiently. However, potassium plays an important role in these.

The extremities near the trunk are most frequently affected by periodic paralysis due to potassium deficiencies or overdoses. Treatment is either with potassium chloride or calcium gluconate.The periodic paralysis caused by hypokalemia can last for several days. The hyperkalemic paralysis, however, lasts only a few minutes. But they can also affect the facial and throat muscles. The periodic paralysis significantly reduces the quality of life of those affected.

When the potassium level is balanced, those affected have no noticeable symptoms. However, after many years of the disease, many of the affected patients develop chronically progressive myopathy due to their periodic paralysis. With the chronification of the muscle disease, the prognosis worsens.

prevention

Periodic paralysis cannot be prevented so far, as it is a genetic disease and not all causal connections have been clarified.

Aftercare

Some illnesses subside after therapy. Follow-up care then aims to prevent the symptoms from recurring. In contrast, periodic paralysis is a genetic defect. This is not curable. Medical measures or aftercare extend over the entire life.

Those affected can reduce their suffering by taking self-help measures. For example, a change in diet and adaptation of the home furnishings to specific needs resulting from the illness are suitable. A doctor usually provides relevant information as part of the initial diagnosis.

The actual aftercare for periodic paralysis aims to provide everyday support and long-term treatment. Doctor and patient agree on an individual rhythm for presentations. In addition to a detailed discussion about the current state of health, a physical examination takes place. Some doctors also use an electromyogram for control purposes. Follow-up care consists of drug treatment.

In particular, the social environment should be included. Because the periodic paralysis leads to a temporary helplessness and inability to move. Symptoms become more common as patients get older. Follow-up care can often only be carried out by specialist therapeutic staff. Accommodation in an assisted living unit is usually inevitable.

You can do that yourself

People with periodic paralysis have a genetic defect that despite their best efforts, they cannot fix. Therefore, measures must be taken that must be applied for life. Medical care and regular check-ups are necessary to adequately check the health of the person concerned. The therapy worked out with the doctor should be adhered to and followed so that no further irregularities occur.

If the patient has a potassium deficiency, the person affected can also change their diet. Beetroot, lamb's lettuce, Swiss chard, kohlrabi or artichokes are foods that are rich in potassium. Meals should be prepared with fresh and untreated vegetables so that as many vitamins and nutrients as possible can get into the organism.

In order to minimize the general risk of accidents caused by periodic paralysis, the person's surroundings should be adapted to the symptoms of the disease. The home furnishings must be optimized so that the patient does not suffer any injuries if the muscle complaints occur. Since the symptoms of paralysis last for several hours or days, those affected and relatives should be prepared and create a functioning schedule for taking immediate measures. In many cases, patients develop an increased awareness of what is going on in their own body. You recognize warning signals in good time and can therefore act preventively. An exchange with other sick people can also be helpful.