Hyperkalemic periodic paralysis

Also known as: adynamia episodica hereditaria, familial hyperkalemic periodic paralysis, Gamstorp disease, Gamstorp episodic adynamy, hyperKPP, hyperPP, primary hyperkalemic periodic paralysis


Genetics Home Reference

Hyperkalemic periodic paralysis is a condition that causes episodes of extreme muscle weakness or paralysis, usually beginning in infancy or early childhood. Most often, these episodes involve a temporary inability to move muscles in the arms and legs. Episodes tend to increase in frequency until mid-adulthood, after which they occur less frequently. Factors that can trigger attacks include rest after exercise, potassium-rich foods such as bananas and potatoes, stress, fatigue, alcohol, pregnancy, exposure to cold temperatures, certain medications, and periods without food (fasting). Muscle strength usually returns to normal between attacks, although many affected people continue to experience mild stiffness (myotonia), particularly in muscles of the face and hands.

Most people with hyperkalemic periodic paralysis have increased levels of potassium in their blood (hyperkalemia) during attacks. Hyperkalemia results when the weak or paralyzed muscles release potassium ions into the bloodstream. In other cases, attacks are associated with normal blood potassium levels (normokalemia). Ingesting potassium can trigger attacks in affected individuals, even if blood potassium levels do not go up.

Go To Source: Genetics Home Reference


Hyperkalemic periodic paralysis (HyperPP) is a muscle disorder characterized by episodic attacks of muscle weakness associated with an increase in serum potassium concentration.

Go To Source: Orphanet


Medical Term Other Names Description
Periodic paralysis Episodic paralysis Episodes of muscle weakness.
Myotonia Delayed relaxation of muscle fibers after contraction An involuntary and painless delay in the relaxation of skeletal muscle following contraction or electrical stimulation.
Metatarsus adductus Metatarsus adductovarsus, Metatarsus varus, Forefoot varus, Intoe [more] The metatarsals are deviated medially (tibially), that is, the bones in the front half of the foot bend or turn in toward the body.
Muscle weakness Muscular weakness Reduced strength of muscles.
Alcoholism An addictive behavior defined as drinking excessive amounts of alcohol over a long period of time, having difficulty reducing the amount of alcohol consumed, strongly desiring alcohol and experiencing withdrawal symoptoms when not drinking alcohol.
Pregnancy exposure Exposure during pregnancy Exposure of pregnant women to toxins from any source, such as environmental toxins or chemicals, that may potentially cause problems such as miscarriage, preterm delivery, low birth weight, and, in some cases, developmental delays in infants.
Fatigue Tired, Tiredness A subjective feeling of tiredness characterized by a lack of energy and motivation.
Paralysis Inability to move Paralysis of voluntary muscles means loss of contraction due to interruption of one or more motor pathways from the brain to the muscle fibers. Although the word paralysis is often used interchangeably to mean either complete or partial loss of muscle strength, it is preferable to use paralysis or plegia for complete or severe loss of muscle strength, and paresis for partial or slight loss. Motor paralysis results from deficits of the upper motor neurons (corticospinal, corticobulbar, or subcorticospinal). Motor paralysis is often accompanied by an impairment in the facility of movement.
Hyperkalemia Elevated serum potassium levels An abnormally increased potassium concentration in the blood.

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