Introduction
Periodic paralysis is a group of diseases characterized by recurrent, self-limiting episodes of skeletal muscle flaccid paralysis. According to the change of blood potassium at the time of onset, it can be divided into three types: hypokalemia type, hyperkalemia type and normal blood potassium type. Periodic hypokalemia(hypokalemic periodic paralysis) is characterized by flaccid paralysis of skeletal muscle and a decrease in serum potassium at the onset. The disease is autosomal dominant, with incomplete penetrance, and scattered cases. The disease gene is located in the long arm region of chromosome 1 (Iq3.1-3.2).
the reason
(1) Causes of the disease
In Europe and the United States, most of them are autosomal dominant, while in China, sporadic cases are more common. Satisfaction, alcoholism, cold, strenuous exercise, excessive mental stress, injection of glucose and insulin, use of adrenal cortex hormones can induce the disease. The cause is not yet clear and is currently thought to be related to fluctuations in potassium concentration inside and outside the cell.
(two) pathogenesis
Since the amount of potassium excretion did not increase before the onset, it is speculated that the decrease in serum potassium during the attack may be caused by the shift of blood potassium to muscle cells. Electrophysiological studies have confirmed that the sarcolemma is hyperpolarized when the extracellular potassium concentration decreases. Muscles have reduced stimuli to the nerves and may cause muscle paralysis. Pathological findings showed that muscle biopsy during the episode revealed that sarcoplasmic vacuoles were formed, and vacuoles contained glycogen, suggesting that the disease may be caused by defects in carbohydrate metabolism in muscle fibers. When muscle function is restored, vacuoles disappear. Generally, the muscle biopsy of the onset of the disease should show normal. When the lesion becomes irreversible, it is permanent myopathy (PM), so patients with PM can see degeneration changes such as vacuoles even during interictal muscle biopsy.
symptom
The disease is reported to have a first incidence of 7 to 21 years in 88% of cases. Beijing Children's Hospital has seen that the incidence of a child is 4 years old, which is consistent with foreign reports. Boys are more common. There were no symptoms in the intermittent episodes and no muscle atrophy. Intermittent periods can vary from a few days to several years. The time of paralysis is uncertain, and it is more common when you wake up and rest. Overeating carbohydrates, fear, mental stress, trauma, infection and menstruation are all predisposing factors. Local flaccid paralysis can sometimes be induced by immersion of cold water in the limbs. The limb can be gradually relieved after being immersed in warm water.
There are often prodromal symptoms before the attack, such as muscle stiffness, fatigue, abnormal limbs, drowsiness, headache, etc., or excitement, nervousness, anxiety, polydipsia and other symptoms one day before the attack. Larger children are more predictive of the onset and severity. Paralysis often begins with the proximal muscles of the extremities. A particularly common first symptom is weakness in both lower extremities and distal to the extremities. The range of paralysis varies from a group of muscle groups to the whole body. The lighter is only weak and can walk; in addition to the facial muscles, the eye muscles, the muscles associated with pronunciation and speech, the diaphragm, the sphincter, the skeletal muscles of the whole body can be affected. The degree of paralysis can be complete or incomplete. If the range of paralysis is widespread, it can sometimes cause respiratory problems, heart enlargement or heart failure. During the episode, the sputum reflexes disappeared or disappeared, feeling normal, and there was no change in consciousness and consciousness. The duration of each episode is as short as 1 to 3 hours, and sometimes 6 to 24 hours. Individual cases can last up to 1 week.
In 1891, Oppenheim first reported that permanent myopathy can occur in patients with periodic paralysis. Can be seen in children, adolescents and adults. Beijing Children's Hospital has been diagnosed in 1 case, the clinical manifestations of chronic progressive proximal muscle weakness and muscle atrophy, especially the band muscle, quadriceps weakness, shoulder muscles and neck muscles are relatively light. The disease is mostly neglected, and the severe person can affect the distal muscles of the limbs, and even lose muscle function, and can only be in a wheelchair or bedridden. It is reported that permanent myopathy has nothing to do with the frequency and severity of paralysis; but it is closely related to age. The older the age, the higher the incidence and the more severe the symptoms, thus supporting the disease to damage the muscle tissue. the opinion of.
The disease can be recurrent, and severe cases often die from heart failure or respiratory disorders. Generally speaking, there is a tendency for seizures to decrease after middle age.
diagnosis
Diagnose based on:
1. History provides epileptic skeletal muscle flaccid paralysis without sensory disturbance.
2. The serum level of serum in the laboratory examination is less than 3.5mmol/L.
3. The therapeutic response to potassium salt is effective.
4. Exclude other diseases to rule out secondary hypokalemia caused by other diseases.
Identification
For the first author, it should be differentiated from acute polyradiculitis, polymyositis, and secondary hypokalemia caused by other causes.
The disease is distinguished from the Guillain-Barre syndrome. The latter is more common in the onset of lower limbs and affects both upper limbs and symmetrical flaccid paralysis. When the progressive aggravation is 5-7 days, the disease peaks. May be associated with sensory impairment, cerebrospinal fluid has protein cell separation phenomenon. Electromyography showed neurogenic damage.
complication
It can cause respiratory disorders, heart enlargement or heart failure, and permanent myopathy can occur.
treatment
Western medicine treatment
Nasal feeding or oral administrationPotassium chloride0.1 to 0.2 g/kg, if necessary, can be taken once more after 15 to 30 minutes. If the patient has severe arrhythmia or respiratory muscle paralysis, the potassium-containing 40mmol/L solution should be slowly instilled under the ECG monitoring. According to reportsAcetazolamideIt has the effect of controlling seizures and improving muscle strength, while using a low-carbohydrate diet to limit sodium intake.
prevention
1. Avoid incentives to avoid seizures such as cold, excessive exercise, etc.
2. Taking potassium chloride every night before taking a bath to prevent seizures.
Prognosis
Being able to pay attention to avoid seizures and effective preventive measures can reduce and alleviate seizures, and the prognosis is good.
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