Periodic paralyses are a group of inherited neurological disorders caused
by mutations in genes that regulate sodium and calcium channels in nerve cells. They are
characterized by episodes in which the affected muscles become slack, weak, and unable to
contract. Between attacks, the affected muscles usually work as normal.
The two most common types of periodic paralysis are:
Hypokalemic periodic paralysis is characterized by a fall in potassium
levels in the blood. In individuals with this mutation attacks often begin in adolescence
and are triggered by strenuous exercise or high carbohydrate meals. Weakness may be mild
and limited to certain muscle groups, or more severe and affect the arms and legs. Attacks
may last for a few hours or persist for several days. Some patients may develop chronic
muscle weakness later in life.
Hyperkalemic periodic paralysis is characterized by a rise in potassium
levels in the blood. Attacks often begin in infancy or early childhood and are
precipitated by rest after exercise or by fasting. Attacks are usually shorter, more
frequent, and less severe than the hypokalemic form. Muscle spasms are common.
Treatment for Periodic Paralysis
Treatment of the periodic paralyses focuses on preventing further attacks
and relieving acute symptoms. Avoiding carbohydrate-rich meals and strenuous exercise, and
taking acetazolamide daily may prevent hypokalemic attacks. Attacks can be managed by
drinking a potassium chloride oral solution. Eating carbohydrate-rich, low-potassium
foods, and avoiding strenuous exercise and fasting, can help prevent hyperkalemic attacks