Periodic Paralyses Information Page
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What is Periodic Paralyses?
Is there any treatment?
What is the prognosis?
What is Periodic Paralyses?
The periodic paralyses are inherited disorders of voluntary muscle, characterized by intermittent attacks of weakness, during which affected muscles become slack, weak, and unable to contract. Between attacks, however, the affected muscles usually work normally. The two most common types of periodic paralyses are hypokalemic (caused by mutations in the calcium channel gene on chromosome 1) and hyperkalemic (caused by mutations in the sodium channel on chromosome 17). Hypokalemic periodic paralysis, which is often referred to as familial, is characterized by a fall in potassium levels in the blood. Hypokalemic attacks are usually triggered by exercising too strenuously, eating too A lot of carbohydrates, or taking drugs such as insulin. Attacks of hypokalemic periodic paralysis begin in adolescence and may last for a few hours or persist for several days. Some patients may develop a fixed muscle weakness later in life. Hyperkalemic attacks, which are frequent and brief (lasting 1 to 2 hours), are usually triggered by strenuous exercise, stress, ingestion of certain foods, and administration of potassium. Individuals with hyperkalemic periodic paralysis may display a rise in potassium levels in the blood during attacks. Some attacks may be accompanied by myotonia (the inability to immediately relax a contracted muscle). Hyperkalemic attacks often begin at an early age (infancy to early childhood). Heart arrhythmias may also develop during these attacks in some families.
Is there any treatment?
Treatment of the periodic paralyses focuses on preventing further attacks and relieving acute symptoms. Medications such as acetazolamide and dichlorophenamide may be beneficial in preventing attacks from occurring or in decreasing the frequency of the attacks. Some attacks are often so brief that treatment is unnecessary. Potassium may be given during attacks of hypokalemic periodic paralysis in an effort to stop the attack.
What is the prognosis?
The prognosis for the periodic paralyses varies. Chronic attacks may result in progressive weakness that may persist between attacks. Some cases respond well to treatment, which may prevent, and in some instances reverse, progressive muscle weakness.
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