Periodic paralysis is a group of diseases with a genetic basis that belong to the so-called channel diseases and affect the membrane-bound ion channels. The therapy consists mainly of dietary measures. The course of the disease is predominantly described as favorable.
What is periodic paralysis?
Periodic paralysis is characterized by recurring muscle paralysis. They are included in the group of diseases known as channel 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 transport of ions and are therefore crucial for muscle excitability. See electronicsencyclopedia for Slang Ego Disorder.
Periodic paralysis is a chronically progressive myopathy and develops over a long period of time. In addition to periodic hypokalemic paralysis, periodic hyperkalemic paralysis belongs to the group of periodic paralysis. 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 distinct from hyperkalemic paralysis.
Causes
Periodic paralysis has genetic origins. Periodic hypokalemic paralysis has a prevalence of one case per 100,000 population. The paralysis usually appears 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 affected women.
A gene defect in the gene CACNA1S on chromosome 1 was proven to be the cause of the disease. The gene product corresponds to a misconfigured subunit of the voltage-gated calcium channels in the tubular system of muscle cells. 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 retained. There is extracellular potassium deficiency. Due to the increased conductivity of sodium across the cell membranes, the membrane potential and thus muscle excitation is disrupted. The first symptoms appear before the age of 20 and initially appear at intervals of several months.
The frequency and severity of cases of paralysis increases continuously from the onset of the disease. The frequency only decreases again after middle age and usually fades away in the 50th year of life. Paralysis mainly occurs at night or in the morning hours. The seizures are often preceded by mental excitement, high-carbohydrate meals or physical exertion. Accompanying symptoms are a feeling of fullness, sweating, paresthesia 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 from several hours to several days. In the case of periodic hyperkalemic paralysis, too high a potassium level causes 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. Paralysis is usually preceded by high potassium intake or heavy physical exertion. Compared to hypokalemic paralysis, the attacks are shorter but more frequent. A strong feeling of thirst occurs concomitantly. In addition to the legs, the facial muscles are particularly affected.
Diagnosis & course of disease
In periodic hyperkalemic palsy, the electrocardiogram is abnormal and characterized by the tented T waves, widened QRS complex, flattened P wave, and prolongation of the PQ interval, as seen in hyperkalemia. The muscle 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, intrinsic muscle reflexes are weakened and muscle tones are reduced. In the EMG, the individual potentials are low or short. In addition, there is a clearing of the activity pattern. Serum potassium levels are usually less than 2 mmol/L. A reduction in serum creatinine is conceivable. The same applies to increases in sodium and lactic acid levels. In addition to a prolonged QT time, the electrocardiogram shows an ST segment 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 only rarely develops over time. There is no correlation between seizure frequency or severity and ultimate disease severity.
Complications
Periodic paralysis is always a complication that can even be fatal in very severe cases. In the long term, the development of an inability to walk is also possible. Paralysis suddenly occurs during the seizures, which can lead to complete temporary paraplegia. People who are at risk should therefore not travel alone.
A paralysis attack can result in complete inability to move. However, the severity of the paralysis and muscle weakness often varies between different seizures. In addition to harmless mild paralysis, which only appears as sensory disturbances (paresis), complete paralysis of all four limbs can also occur. This phenomenon is known as tetraplegia and is considered a special form of paraplegia.
During this severe paralysis, the affected person is completely dependent on outside help. Bladder and rectum can also be paralyzed. However, the respiratory muscles are usually not affected. In rare cases this also happens. This condition represents an extremely life-threatening complication. Life can only be saved with immediate ventilation.
In a few cases, dangerous cardiac arrhythmias also occur during the paralysis attack, which 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 to the point of being unable to walk.
When should you go to the doctor?
Disorders of the muscular system, loss of physical performance and sensory disturbances must be presented to a doctor. A doctor is needed if there are problems with locomotion, restrictions in movement options or rigidity of the muscles. The special feature of periodic paralysis are intermittent phases of freedom from symptoms. Although spontaneous healing occurs, a doctor is needed. Since paralysis will return after a period of time, it is advisable that the sufferer is adequately prepared for this situation.
Sweating, vegetative disorders and irregular heart rhythms must be examined and treated. Inner weakness or restlessness, sleep disorders and reduced well-being are signs of a health impairment. A doctor should be consulted so that a diagnosis can be made and a treatment plan drawn up. In the case of a feeling of fullness or discrepancies in the digestive tract, the person concerned needs medical care.
If the risk of accidents and injuries increases or if you can no longer cope with everyday demands without help, a doctor’s visit is advisable. In the case of psychological problems, a persistent experience of stress and anxiety, it is advisable to ask a doctor for support. In most cases, without medical treatment, there is an increase in symptoms and emotional stress. The increased feeling of thirst is characteristic of the disease.
Treatment & Therapy
In the case of hypokalemia, a seizure can be interrupted therapeutically with high doses of potassium chloride. The administration takes place orally and the ECG is checked continuously during the therapy. In the long term, the attacks of this form of periodic paralysis can be avoided by eating a low-carbohydrate, low-salt diet.
In addition to these dietary measures, avoiding heavy muscle loads can be effective in preventing seizures. In addition, acetazolamide is often given as medication to prevent seizures. Other medicinal procedures are also possible, such as the administration of triamterene or lithium. The treatment of the hyperkalemia 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 potassium-rich foods are recommended for seizure prophylaxis. A carbohydrate-rich diet and sufficient salt intake are also recommended for this form of periodic paralysis. The administration of acetazolamide and hydrochlorothiazide can be considered as prophylactic drugs.
Outlook & Forecast
Paralysis that occurs periodically can be of two different types. The first variant is described as intermittent hypokalemic paralysis. The second variant is periodic hyperkalemic paralysis. What both have in common is that the periodic symptoms of paralysis are closely linked to the level of potassium in the blood.
If there are deviations in the potassium level in these so-called “channel diseases”, paralysis occurs. However, these disappear again when the potassium level is raised or lowered. The paralysis affects the muscles. The process that triggers muscular activity depends on complex mechanisms. These have not yet been adequately researched. However, potassium plays a major role in these.
The extremities near the trunk are most commonly affected by periodic paralysis from potassium deficiencies or overdoses. It is treated with either potassium chloride or calcium gluconate. Periodic paralysis caused by hypokalemia can last for several days. Hyperkalemic paralysis, on the other hand, only lasts a few minutes. But they can also affect the facial and pharyngeal muscles. Periodic paralysis significantly reduces the quality of life of those affected.
If the potassium level is balanced, those affected have no discernible symptoms. However, after many years of the disease, many of the affected patients develop chronic progressive myopathy due to their periodic paralysis. The prognosis worsens as the muscle disease becomes chronic.
Prevention
Periodic paralysis cannot be prevented so far, since it is a genetic disease and not all the causal relationships of the disease have been clarified.
Aftercare
Some illnesses go away after therapy. Follow-up care is then aimed at preventing the symptoms from recurring. Periodic paralysis, on the other hand, is a genetic defect. This is not curable. Medical measures and aftercare extend throughout life.
Those affected can reduce their suffering through self-help measures if necessary. A change in diet and an adjustment of the home furnishings to specific needs resulting from the disease are suitable, for example. A doctor usually provides relevant information as part of the initial diagnosis.
The actual follow-up care for periodic paralysis is aimed at 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 also 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. This is because periodic paralysis leads to temporary helplessness and inability to move. Symptoms become more common as patients age. Aftercare can then often only be carried out by specialist therapeutic staff. Accommodation in an assisted living unit is usually unavoidable.
You can do that yourself
People with periodic paralysis have a genetic defect that, despite their best efforts, they cannot correct. Therefore, measures must be taken that must be applied lifelong. Medical care and regular check-ups are necessary to adequately check the health of the person concerned. The therapy developed with the doctor should be adhered to and followed so that no further irregularities occur.
If the patient has a potassium deficiency, the person concerned can also change their diet. Beetroot, lamb’s lettuce, 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 in periodic paralysis, the environment of the person affected should be adapted to the symptoms of the disease. The furniture in the apartment is optimized so that the patient does not suffer any injuries if the muscle problems occur. Since the symptoms of paralysis last for several hours or days, those affected and their families should be prepared and create a working schedule for taking immediate measures. In many cases, patients develop an increased awareness of the processes in their own body. You recognize warning signals in good time and can therefore take preventive action. Sharing information with other patients can also be helpful.
