Hyperkalemic periodic paralysis

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Muscular atrophy

Hyperkalemic periodic paralysis

Alternative Names:

Paramyotonia congenita; Periodic paralysis - hyperkalemic
Symptoms:

Weakness/paralysis
- Most commonly located in the shoulders and hips
- Arms and legs may also be involved
- Occurs intermittently
- May occur on awakening
- May be triggered by rest after exercise
- May be triggered by fasting
- May be triggered by cold exposure
- May be triggered by eating small amounts of potassium
- Usually lasts for less than 2 hours
Spontaneous recovery of normal strength between attacks
Normal alertness during attacks

Signs and tests:

text continues below

The health care provider may suspect hyperkalemic periodic paralysis based on other family members having the disorder, symptoms that come and go, normal or high results of a potassium test, and ruling out other disorders as the cause of intermittent weakness.

Between attacks, examination is normal. During an attack, the following may be observed:

Reflexes may be decreased or absent.
Weakness is flaccid (loose) rather than spastic (tight).
Weakness is greater in proximal muscle groups (near the body, such as shoulders and hips) than in distal groups (away from the body, such as arms and legs).

Attacks are not triggered by tests that reduce serum potassium (such as giving insulin and glucose) but may be triggered by giving potassium. Serum potassium is normal or high during attacks and may be normal or high between attacks.