Definition
| Causes
| Risk Factors
| Symptoms
| Diagnosis
| Treatment
| Prevention
Definition
Periodic paralysis is a rare condition that is usually inherited. It causes occasional episodes of severe muscle weakness. The two most common types of periodic paralysis are
hypokalemic
and
hyperkalemic.
Risk Factors
Factors that increase your chance of developing periodic paralysis include:
- Family history of periodic paralysis
- Thyroid disorder (particularly in Asian males)
Symptoms
Although muscle strength returns to normal between attacks, repeated bouts of weakness may lead to chronic muscle weakness later in life. The person remains alert and aware during attacks. There is no accompanying loss of sensation.
Episodic bouts of severe weakness in the arms and legs are the most prominent symptom. Typically, these bouts occur during sleep, early morning, or after strenuous activity. Cold, stress, and alcohol may also produce attacks. Other, less common, symptoms may include:
- Weakness in the eyelids and face muscles
- Muscle pain
-
Irregular heartbeats (
arrhythmias
)
- Difficulty breathing or swallowing—This requires emergency care.
Some features are specific to the type of periodic paralysis.
-
Hypokalemic:
- Potassium levels
are low during attacks
- Frequency of attacks varies from daily to yearly
- Attacks usually last between 4-24 hours, but can last for several days
- Attacks usually begin in adolescence, but they can occur before age 10
-
Hyperkalemic:
- Potassium levels are high or normal during attacks
- Attacks are usually shorter (lasting one to two hours), more frequent , and less severe than the hypokalemic form; breathing and swallowing difficulties are extremely rare
- Between attacks, patients often experience muscle spasms or difficulty relaxing their muscles. This condition is known as myotonia
- Attacks usually begin in early childhood
Persons with some types of periodic paralysis are at risk for a condition known as malignant hyperthermia. This can occur during the use of
general anesthesia
. Anyone with a family history of periodic paralysis needs to notify the anesthesiologist of this history prior to any surgery.
Treatment
Since there is no cure for periodic paralysis, lifelong treatment is usually required. Treatment focuses on preventing attacks and relieving symptoms.
Lifestyle Changes
There are a few behaviors you can adopt to reduce the frequency and severity of attacks:
-
Hypokalemic:
-
Hyperkalemic:
Medications
-
Both hypokalemic and hyperkalemic:
- Acetazolamide
(Diamox) may prevent an attack by reducing the flow of potassium from the bloodstream into the cells of the body.
-
Hypokalemic:
- Potassium (pill or liquid form) may stop an attack; intravenous potassium may be prescribed for severe weakness.
- Avoiding certain commonly prescribed medications may help reduce the onset of attacks.
- If you have a thyroid condition, be sure to get treatment for it.
-
Hyperkalemic:
- Thiazide diuretics, or water pills, may be prescribed to prevent an attack.
- Glucose, glucose and insulin, or calcium carbonate may be prescribed to slow or stop an attack.
Prevention
Familial periodic paralysis cannot be prevented. Because it can be inherited, genetic counseling may be advised for couples at risk of passing on the disorder.
For the hypokalemic type, attacks may be reduced by:
- Avoiding corticosteroids and glucose infusions
- Following a diet low in carbohydrates and sodium and rich in potassium
For the hyperkalemic type, attacks may be reduced by:
- Avoiding high potassium foods, fasting, and drugs known to increase potassium levels
- Engaging in regular, mild exercise