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Periodic Paralysis Syndromes

  • Cynthia M. Johnson, MA
Publication Type:


Periodic Paralysis Syndromes

(Familial Periodic Paralysis; Hyperkalemic Periodic Paralysis; Hypokalemic Periodic Paralysis; Andersen-Tawil Syndrome; Paraneoplastic Periodic Paralysis)


Periodic paralyses (PP) are a rare group of disorders. With PP a person's muscle can briefly be very weak.

The most common types are:
  • Hypokalemic
  • Hyperkalemic
  • Thyrotoxic
  • Andersen-Tawil syndrome


Minerals like sodium and potassium are needed to make muscles work. With PP, the gateway for these minerals is disturbed. This causes problems with the muscles being able to work.

PP is caused by problems with genes. A parent can pass the gene to their baby.

Genetic Material.

Chromosome_DNAhttp://services.epnet.com/getimage.aspx?imageiid=72487248AU00031.jpgAU00031.jpgNULLjpgAU00031.jpgNULL\\hgfiler01a\intellect\images\AU00031.jpgNULL101NULL2008-11-074003307248_96851Copyright © Nucleus Medical Media, Inc.

Risk Factors

Things that may raise the risk of this problem are:

  • Having other people in the family who have PP
  • Thyroid problems


The main problems are briefly having arm or leg muscles lose their strength. Muscle strength returns to normal between attacks. The attacks may be triggered by things like working out or alcohol.

Other symptoms differ based on what type of PP a person has. They may also have:

  • Muscle pain or cramps
  • Muscle tingling
  • Weakness in the eyelids and face muscles
  • Abnormal heartbeats
  • Problems breathing or swallowing

Repeat attacks may lead to lasting muscle weakness later in life.

People with some types of PP are at risk for a problem known as malignant hyperthermia. It is a fast and harmful rise in body heat. It can happen when a person gets general anesthesia.


The doctor will ask about symptoms and health history. A physical exam will be done.

Tests that may be done are:

  • Blood tests to check:
    • Mineral levels
    • Thyroid hormone levels
    • For gene problems
  • Electrocardiogram (ECG, EKG) to check the electrical activity of the heart
  • Nerve conduction studies and an electromyography (EMG) to check the electrical activity of the muscles
  • A biopsy to test muscles
Electromyography (EMG).

Electromyogram EMGhttp://services.epnet.com/getimage.aspx?imageiid=68936893Electromyogram_EMG.jpgElectromyogram EMGNULLjpgElectromyogram EMGNULL\\hgfiler01a\intellect\images\Electromyogram_EMG.jpgNULL47NULL2008-01-294002266893_96851Copyright © Nucleus Medical Media, Inc.


There is no cure for PP. The goal of treatment is to prevent attacks and ease symptoms. Ways to do this are:

  • Lifestyle changes, such as dietary changes and limiting things that cause attacks
  • Medicines like acetazolamide to manage the type of PP that a person has


PP cannot be prevented.





  • Andersen-Tawil syndrome. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/andersen-tawil-syndrome.
  • Familial periodic paralyses. National Institute of Neurological Disorders and Stroke website. Available at: https://www.ninds.nih.gov/health-information/disorders/familial-periodic-paralyses.
  • Hyperkalemic periodic paralysis. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/hyperkalemic-periodic-paralysis.
  • Sansone, V.A. Episodic muscle disorders. Continuum (Minneap). 2019; 25(6): 1696-1711.


  • Rimas Lukas, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.