Periodic paralysis is a rare groups of conditions. It causes occasional episodes of severe muscle weakness. The most common types of periodic paralysis are
hyperkalemic and Andersen-Tawil syndrome. Less common forms include paramyotonia congenita
von Eulenburg, thyrotoxic, distal renal
tubular acidosis, X-linked episodic muscle weakness syndrome, and
congenital myasthenic syndromes.
Periodic paralysis is a condition that is present from birth. Elements in the body are needed to make the muscles contract. With periodic paralysis, the gateway for these elements are disturbed and disrupt the ability to contract.
Familial periodic paralysis is inherited, but may occur without a known family history. With the inherited form of the disorder, only 1 affected parent is needed to transmit the gene to the baby. Rarely, the condition occurs as a result of a noninherited genetic defect.
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Factors that increase your chance of developing periodic paralysis include: Family history of periodic paralysisThyroid disorder—high thyroid hormone levels, particularly in Asian males
Episodes of severe weakness in the arms and legs are the main symptom. Typically, these episodes 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 musclesMuscle painIrregular heartbeats, especially with Andersen-Tawil syndromeDifficulty breathing or swallowing—requires emergency care
Although muscle strength returns to normal between attacks, repeated episodes of weakness may lead to chronic muscle weakness later in life.
Some features are specific to the type of periodic paralysis.
Hypokalemic (due to low potassium levels in the body):
Frequency of attacks varies from daily to yearlyAttacks usually last between 4-24 hours, but can last for several days
Hyperkalemic (due to high potassium levels in the body):
Attacks are usually shorter, more frequent, and less severe than the hypokalemic form; breathing and swallowing difficulties are rareBetween attacks, patients often experience muscle spasms or difficulty relaxing their muscles, a condition is known as myotonia Andersen-Tawil Attacks may last 1 hour to several days and weakness may persist after attacksAssociated with some abnormal facial features
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.
Because this primarily is an inherited condition, the most important part of diagnosis is obtaining a family history. You will be asked about your symptoms and your medical history. A physical exam will be done.
Your doctor may want to bring on an attack during an office visit. This should only be done under careful monitoring by an experienced neurologist. If an attack is triggered, several tests may be done, including: Blood testsThyroid testsElectrocardiogram
Your muscle tissue may need to be tested. This can be done with a
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Since there is no cure for periodic paralysis, lifelong treatment is usually required. Treatment focuses on preventing attacks and relieving symptoms.
Dietary changes can help influence the level of potassium in the body. Depending on your situation, you may be referred to a dietitian for help with meal planning.
You may also be advised to avoid strenuous exercise and drinking alcohol. They could make symptoms worse.
The type of medications prescribed depend on the type of periodic paralysis.
Medications for hypokalemic, hyperkalemic, and Andersen Tawil syndrome include:
Acetazolamide—may prevent an attack by reducing the flow of potassium from the bloodstream into the cells of the body.Diuretics (water pills)Drugs to control abnormal heart beats
Potassium may stop an attack; IV potassium may be prescribed for severe weaknessAvoiding certain commonly prescribed medications may help reduce the onset of attacks.If you have a thyroid condition, be sure to get treatment for it.
Thiazide diuretics, or water pills, may be prescribed to prevent an attack.Glucose
and insulin, or calcium carbonate may be prescribed to slow or stop an attack.
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.
Andersen-Tawill syndrome. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated August 3, 2012. Accessed May 11, 2016.
Finsterer J. Primary periodic paralyses.
Acta Neurol Scand. 2008 Mar;117(3):145-58.
Hyperkalemic periodic paralysis. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed. Updated April 30, 2013. Accessed May 11, 2016.
Jurkat-Ratt K, Lehmann-Horn F. Paroxysmal muscle weakness-the periodic paralyses.
J Neurol. 2006;253:1391-1398.
NINDS familial periodic paralyses information page.
National Institute of Neurological Disorders and Stroke website. Available at:
http://www.ninds.nih.gov/disorders/periodic_paralysis/periodic_paralysis.htm. Updated August 10, 2015. Accessed May 11, 2016.
Patient page: attacks of immobility caused by diet or exercise? The mystery of periodic paralyses.
Last reviewed June 2016 by Michael Woods, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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