This book describes Hypokalemic Periodic Paralysis, Diagnosis and Treatment and Related Diseases
Periodic paralysis is featured by occasional episodes of flaccid muscle weakness happening at irregular intervals. The most frequent is hypokalemic periodic paralysis.
Hypokalemic periodic paralysis (hypoPP) is a medical disorder that produces occasional episodes of muscle weakness and an occasional lower than normal level of blood potassium.
HypoPP is one of a group of genetic disorders that involves hyperkalemic periodic paralysis and thyrotoxic periodic paralysis.
HypoPP is the most frequent type of periodic paralysis.
It involves males more often.
Hypokalemic periodic paralysis (hypoPP or hypoKPP) is a rare disorder in which a person has episodes of painless muscle weakness and often paralysis
There are 2 types of hypoPP:
Paralytic: This type is most frequent.
In the paralytic type, intermittent, temporary episodes of muscle weakness or paralysis are involved.
Myopathy: This type is featured by permanent muscle weakness, fatigue, and pain.
More than 74 percent of older people with hypoPP have myopathy.
One of the first symptoms of myopathy is weakness or paralysis of the legs, induced by exercise.
HypoPP is congenital (happen at birth).
In most cases, it is inherited (passed down through families) as an autosomal dominant disorder.
Only one parent needs to pass the gene linked to this disorder on to their child in order for the child to be involved.
In some patients, the disorder may be the result of a genetic disorder that is not inherited.
Dissimilar to other types of periodic paralysis, people with hypoPP have normal thyroid function.
There is a very low blood level of potassium in these people during episodes of weakness.
This happens from potassium moving from the blood into muscle cells in an abnormal way.
HypoPP attacks are caused by not having sufficient potassium in the body.
As potassium ions dissolve in the body, they take up a positive electric charge.
This charge allows them to conduct electricity and transmit signals throughout the body.
Potassium ions do many tasks in the body, such as transmitting nerve impulses.
One on the most important actions of potassium is to help the muscles contract.
The muscles act by alternating between contracting and relaxing.
This is what moves all the muscles in the body.
People who have hypoPP have mutations in their genes that alter the way these protein channels function.
As a result, they do not have enough of the potassium required for their muscles to contract.
This is what induces the muscle weakness and paralysis.
While the episodic precipitants differ for each person, episodes of paralysis are often caused by:
Sugary or starchy foods
Salty foods
Going too long between meals
Eating a very large meal
Sleep
High levels of physical exertion
Temperature extremes
Strong emotion
Certain medications, such as anesthesia
Attacks normally start in the teen years, but they can occur before age 10.
During attacks the person stays alert.
The weakness or paralysis:
Most often happens at the shoulders and hips
May also involve the arms, legs, muscles of the eyes, and muscles that assist with breathing and swallowing
Happens off and on
Most often happens on awakening or after sleep or rest
Is rare during exercise, but may be triggered by resting after exercise
May be activated by high-carbohydrate, high-salt meals, stress, pregnancy, heavy exercise, and cold
Treatment comprises diet changes and avoiding things that trigger the attacks
Most cases are not life