Andersen-Tawil Syndrome (ATS): A Simple Overview and Why Diagnosis Takes So Long

 

Andersen-Tawil Syndrome (ATS):
A Simple Overview and Why Diagnosis Takes So Long

By Susan Q. Knittle-Hunter,
Founder – Periodic Paralysis Network, Inc.

Andersen-Tawil Syndrome (ATS) is a rare genetic condition (mineral metabolic disorder) within the family of Periodic Paralysis disorders. It is most commonly associated with mutations in the KCNJ2 gene and is considered a type of ion channel disorder, or channelopathy.

ATS is often described as having three main features, though not everyone experiences all of them:

• Episodes of muscle weakness or paralysis
  These episodes may come and go, vary in severity, and may be triggered by rest after activity, stress, illness, or dietary changes.
• Heart rhythm abnormalities (arrhythmias)
  Individuals may experience irregular heartbeats, palpitations, or changes on an ECG, sometimes without obvious symptoms.
• Distinct physical traits (in some individuals)
  These may include subtle differences such as curved fingers, a small jaw, low-set ears, or shorter stature. Many individuals, however, have few or none of these traits.

One of the most important things to understand about Andersen-Tawil Syndrome is that it does not look the same in everyone. Even within the same family, symptoms can vary widely.

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⏳ Why Does It Take So Long to Diagnose ATS?

For many individuals, diagnosis can take years—or even decades. This is not uncommon, and there are several well-recognized reasons for this delay.

1. Not all symptoms appear together

Many people do not present with the “classic triad.” Some may only have muscle symptoms, while others may only have cardiac involvement.

2. Symptoms overlap with other conditions

Muscle weakness may be attributed to other forms of periodic paralysis or neurological conditions, while heart symptoms may be treated separately by cardiology.

3. Laboratory results are often inconclusive

Potassium levels may appear normal, and routine testing does not always reveal the underlying issue.

4. Limited awareness among physicians

Because ATS is rare, many healthcare providers have little or no experience with it, and some rely on outdated information.

5. Genetic testing is not always definitive or accessible

While ATS is commonly linked to KCNJ2, not all individuals test positive, and access to testing may be limited.

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🌱 A Perspective from the Community

Within the Periodic Paralysis community, many individuals have shared similar journeys—years of searching for answers, being misdiagnosed, or being told that symptoms did not fit a known pattern.

ATS does not always follow textbook descriptions. That does not make the condition any less real—it simply means that understanding it requires looking beyond rigid definitions and listening carefully to patient experience over time.

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📚 References (For Medical Review)

• GeneReviews – Andersen-Tawil Syndrome
• National Institutes of Health – Genetic and Rare Diseases Information Center (GARD)
• Tristani-Firouzi M, et al. Clinical and genetic aspects of Andersen-Tawil syndrome (Heart Rhythm, Neurology)
• Plaster NM, et al. KCNJ2 mutations and ATS characterization (Cell, foundational study)

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📄 Doctor-Friendly Reference Summary (Handout Style)

Andersen-Tawil Syndrome (ATS) – Key Clinical Points

• Rare genetic channelopathy, often associated with KCNJ2 mutations
• Variable presentation; may include:
• Episodic muscle weakness/paralysis
• Ventricular arrhythmias or ECG abnormalities
• Dysmorphic or skeletal features (not always present)

Diagnostic Challenges:

• Incomplete or absent triad
• Normal potassium levels during episodes
• Overlap with other neuromuscular and cardiac conditions
• Variable genetic confirmation

Clinical Consideration:

ATS should be considered in patients presenting with unexplained episodic weakness combined with cardiac irregularities, even in the absence of classic physical features.

Primary References:

• GeneReviews: Andersen-Tawil Syndrome
• NIH/GARD Rare Disease Database
• Peer-reviewed literature in Neurology and Heart Rhythm

**This article has been enriched by the utilization of tools developed by Open AI 

Periodic Paralysis: Overview of the Varying Forms

 Periodic Paralysis: Overview of the Varying Forms

 

Periodic Paralysis (PP) is a fascinating yet challenging condition that intersects the worlds of genetics, metabolism, and everyday wellness. Classified as a mineral metabolic disorder, it falls under the broader umbrella of ion channelopathies—a group of conditions where ion channels in muscle cells function improperly. These channels are crucial for muscle contractions and relaxation, and their malfunction leads to episodes of muscle weakness or paralysis that can vary widely in duration and intensity. For those drawn to managing their health through natural means, PP presents a unique set of challenges and opportunities. By understanding the triggers, which can range from dietary factors to stress and temperature changes, individuals can explore lifestyle adjustments aimed at maintaining balance and reducing the frequency of episodes. This natural management approach emphasizes diet, stress management, and environmental modifications tailored to one's unique symptoms and triggers.

Hyperkalemic Periodic Paralysis (HyperKPP) is a rare genetic disorder characterized as both a mineral metabolic disorder and an ion channelopathy. This condition is primarily due to mutations in the SCN4A gene, which encodes for the alpha subunit of the skeletal muscle voltage-gated sodium channel Na_v1.4. These mutations lead to dysfunction in the sodium channels, resulting in an abnormal influx of sodium ions into muscle cells. This dysfunction disrupts the normal flow of ions, which is essential for muscle contraction and relaxation, leading to episodes of muscle weakness or, in severe cases, temporary paralysis.

HyperKPP is notable for the episodes being triggered by elevated potassium levels in the blood, hence the name "Hyperkalemic." Unlike some other forms of periodic paralysis, where symptoms might be ameliorated by changes in diet or potassium intake, HyperKPP management focuses on avoiding triggers that can cause potassium levels to rise. These triggers include fasting, rest after exercise, cold exposure, and certain foods high in potassium.

For individuals looking to manage HyperKPP naturally, here are a few strategies that may be beneficial, grounded in a general understanding of similar conditions:

1.    Dietary Management: While avoiding high potassium foods might seem intuitive for managing Hyperkalemic Periodic Paralysis, it's essential to consult with a healthcare provider to balance your diet correctly. In some cases, excessively low potassium levels can also trigger symptoms. A balanced intake of nutrients is critical..

2.    Avoiding Cold and Stress: Exposure to cold can trigger episodes, so staying warm is advisable. Stress management techniques such as meditation, yoga, or deep breathing exercises may also help prevent episodes triggered by stress.

3.    Regular Eating Schedule: Fasting or skipping meals can lead to episodes, so maintaining a regular eating schedule and avoiding large carbohydrate-rich meals that can affect potassium levels might be beneficial.

4.    Hydration: Adequate hydration is essential, especially before, during, and after exercise, to help maintain electrolyte balance and prevent episodes.

While these strategies can offer some relief and help manage symptoms, it's crucial for individuals with HyperKPP or any health condition to work closely with healthcare professionals who absolutely understand Periodic Paralysis for diagnosis, treatment, and management tailored to their specific needs and medical history. Due to the genetic nature of HyperKPP, genetic counseling might also be recommended for affected individuals and their families to understand the condition better and discuss the risks for future generations.

 

Hypokalemic Periodic Paralysis (HypoKPP) is also a genetic disorder, recognized as both a mineral metabolic disorder and an ion channelopathy, similar in nature to Hyperkalemic Periodic Paralysis but with distinct triggers and management strategies. It is primarily characterized by episodes of muscle weakness or paralysis that occur due to low levels of potassium in the blood (hypokalemia). These episodes can range from mild weakness to complete paralysis, affecting the ability to move parts of, or, the entire body.

The condition is usually caused by mutations in genes responsible for ion channels in muscle cells, particularly those that govern the flow of potassium and sodium ions. These mutations disrupt the normal balance of ion flow, leading to sudden and temporary paralysis or muscle weakness. The most commonly implicated genes are CACNA1S and SCN4A, which encode for the calcium and sodium channels, respectively.

For individuals seeking natural management strategies for HypoKPP, focusing on lifestyle and dietary adjustments can be beneficial:

1.    Dietary Adjustments: Since episodes are triggered by low potassium levels, individuals with HypoKPP may find it helpful to include potassium-rich foods in their diet to prevent episodes. However, potassium levels should be carefully balanced, as too high potassium levels could also lead to complications.

2.    Avoid Triggers: Certain factors such as stress, fasting, carbohydrate-rich meals, and rest after strenuous activities have been known to trigger episodes. Identifying and avoiding personal triggers is crucial.

3.    Staying Warm: For some individuals, cold temperatures can trigger episodes of weakness. Keeping warm, especially during colder months, may help reduce the frequency of episodes.

4.    Stress Management: Techniques such as yoga, meditation, and deep breathing exercises may be helpful in managing stress, which can be a trigger for some individuals.

5.    Regular Eating Schedule: Maintaining a regular schedule for meals can help avoid fluctuations in potassium levels that could trigger an episode. Small, frequent meals may be more beneficial than large meals.

6.    Hydration: Adequate hydration is important, especially around exercise, to help maintain electrolyte balance.

Working closely with healthcare professionals should work closely with healthcare professionals who absolutely understand Periodic Paralysis is important for individuals with HypoKPP to receive a proper diagnosis, understand their condition, and manage their symptoms effectively. A tailored approach that considers the individual's specific triggers, lifestyle, and medical history is essential for effective management. Genetic counseling may also be beneficial for affected individuals and their families to discuss the inheritance patterns, risks to future generations, and any concerns regarding family planning.

 

Normokalemic Periodic Paralysis (NormoKPP) is a variant of periodic paralysis that shares characteristics with both hyperkalemic and hypokalemic forms but uniquely occurs without significant changes in blood potassium levels during episodes. It is a genetic disorder and falls under the category of ion channelopathies, where ion channels in muscle cells function improperly, leading to episodes of muscle weakness or paralysis while blood potassium levels remain within the normal range. The exact genetic causes of NormoKPP can vary and may involve mutations in ion channel genes, but for many cases, the specific genetic alteration remains unidentified.

For managing NormoKPP naturally, individuals may focus on lifestyle modifications to reduce the frequency and severity of paralysis episodes. Here are some strategies that may be beneficial, drawing from general principles applicable to periodic paralysis management:

1.    Identify and Avoid Triggers: As with other forms of periodic paralysis, certain triggers can precipitate episodes of muscle weakness. These may include sudden rest after exercise, stress, drastic changes in diet, or even shifts in temperature. Recognizing and avoiding personal triggers is crucial.

2.    Balanced Diet: Even though NormoKPP episodes aren't directly triggered by fluctuations in potassium levels, maintaining a balanced diet can contribute to overall health and potentially reduce episode severity. A nutritionist can provide guidance on a diet that supports muscular health without adversely affecting potassium levels.

3.    Stress Management: Since stress can be a trigger for NormoKPP episodes, practices such as yoga, meditation, or any relaxing activities can be beneficial in managing stress levels.

4.    Maintain Warmth: For some individuals, cold can trigger episodes of muscle weakness. Keeping warm, especially in colder environments, may help prevent episodes.

5.    Stay Hydrated: Proper hydration is essential, particularly before, during, and after exercise, to maintain electrolyte balance and support overall health.

Collaborating with healthcare professionals who absolutely understand Periodic Paralysis for a tailored management plan is vital for individuals with NormoKPP. Since the condition and its triggers can vary significantly among individuals, a personalized approach based on the patient's unique experiences, triggers, and symptoms is essential for effective management. Genetic counseling may also offer valuable insights for affected individuals and their families about the condition's inheritance patterns and implications for future generations.

 

Andersen-Tawil Syndrome (ATS) is a unique and rare genetic condition that serves as a prime example of an ion channelopathy, a disorder resulting from the dysfunction of ion channels within the body. Specifically, ATS affects potassium ion channels, leading to a triad of distinctive features: episodes of muscle weakness or paralysis, significant cardiac arrhythmias, and distinctive facial and skeletal anomalies.

ATS is caused by mutations in the KCNJ2 gene (Type 1 ATS), which is responsible for around 60% of cases, or, less frequently, by mutations in the KCNJ5 gene or unidentified mutations (Type 2 ATS), accounting for the remaining 40% of cases. The KCNJ2 gene plays a crucial role in regulating the flow of potassium ions into muscle cells, vital for the electrical stability and proper function of muscle and cardiac cells. Mutations in this gene disrupt this flow, leading to the characteristic symptoms of ATS.

For individuals with Andersen-Tawil Syndrome aiming to manage their condition through natural means, a comprehensive, symptom-oriented approach focusing on lifestyle adjustments can be beneficial:

1.    Environmental Awareness and Adaptation: Given the role of physical activity and rest in triggering episodes of muscle weakness, individuals may need to find a personal balance that allows physical engagement without overexertion. Similarly, avoiding extreme temperatures or sudden temperature changes can help manage episodes.

2.    Dietary Considerations: ATS is directly linked to fluctuating potassium levels as in other forms of periodic paralysis, so maintaining a balanced diet and adequate hydration is essential for overall well-being and might help mitigate some symptoms of the condition.

3.    Stress Management: Implementing stress reduction techniques, such as meditation, breathing exercises, or yoga, can help manage the stress that might exacerbate the symptoms of ATS, especially considering the cardiac aspects of the syndrome.

4.    Community and Support: Connecting with others living with ATS, through support groups or online forums, can provide valuable insights and emotional support. While direct interactions with specific associations were not explored, generalized advice highlights the importance of community in managing chronic conditions.

Individuals living with Andersen-Tawil Syndrome should work closely with healthcare professionals who absolutely understand Periodic Paralysis to tailor a management plan specific to their symptoms and lifestyle. This collaborative approach ensures that management strategies, whether natural or medical, are safely and effectively integrated into their care regimen, taking into account the unique presentation of ATS in each individual.

Given the rarity of ATS and the complexity of its manifestations, a personalized and informed approach to managing the condition is essential. Understanding one's own body, recognizing triggers, and making adjustments based on personal experience with the syndrome can significantly contribute to improving quality of life and managing symptoms effectively.

 

Paramyotonia Congenita (PMC) is a rare genetic disorder categorized under ion channelopathies, highlighting a dysfunction in the ion channels of muscle cells. This condition is characterized by muscle stiffness (myotonia) that worsens with continued activity and exposure to cold temperatures. Unlike other forms of periodic paralysis, the unique aspect of PMC is that the symptoms of muscle stiffness increase with exercise and do not subside immediately with rest, often exacerbating in colder environments.

Management of Paramyotonia Congenita naturally focuses on lifestyle adjustments to mitigate and prevent the exacerbation of symptoms:

1.    Avoidance of Cold: Individuals with PMC should take measures to avoid cold temperatures, as exposure can significantly worsen symptoms. This may involve dressing warmly in colder weather and avoiding situations where prolonged exposure to cold is expected.

2.    Regulated Exercise: While exercise can provoke muscle stiffness in PMC, regular, moderate activity may be beneficial. It is crucial to find a balance that allows for physical conditioning without triggering severe symptoms. Warming up before exercise and gradually cooling down can help manage exercise-induced stiffness.

3.    Stress Management: As with many conditions, stress can exacerbate symptoms of PMC. Techniques such as meditation, yoga, or any relaxation practices that reduce stress can be beneficial in managing the condition.

4.    Diet and Hydration: While PMC is not directly influenced by potassium levels as in hyperkalemic or hypokalemic periodic paralysis, maintaining a healthy diet and staying well-hydrated is essential for overall health and can help manage symptoms.

5.    Warm-Up Strategies: Before engaging in physical activity, especially in cooler environments, warming up the muscles through gentle exercise or using heat packs can reduce the risk of severe myotonia.

It's important for individuals with Paramyotonia Congenita to collaborate closely with healthcare professionals who absolutely understand Periodic Paralysis to tailor a management plan that suits their specific needs and lifestyle. Given the genetic nature of PMC, discussing the condition with a genetic counselor may provide valuable insights into the inheritance patterns and implications for family planning.

Due to the condition's rarity and the specific challenges it presents, personal experiences and triggers may vary widely. A personalized approach, focusing on understanding one's own body and symptoms, is key to effectively managing PMC and maintaining a high quality of life.

*Thyrotoxic Periodic Paralysis (TPP) is a condition that features muscle weakness episodes in those with an overactive thyroid, typically presenting with low blood potassium levels. It is recognized as a channelopathy, due to its association with mutations in ion channels, but is not a form of Periodic Paralysis. Managing TPP focuses on treating low potassium carefully to prevent rebound hyperkalemia and addressing the underlying hyperthyroidism. Lifestyle adjustments to avoid known triggers until the hyperthyroidism is under control can prevent further attacks.

Conclusion: The forms of Periodic Paralysis, including Hypokalemic, Hyperkalemic and Normokalemic Periodic Paralysis, Paramyotonia Congenita, Andersen-Tawil Syndrome and Thyrotoxic Periodic Paralysis, represent a group of rare medical disorders called mineral metabolic disorders characterized by episodes of muscle weakness. Each form has unique triggers and management strategies, but all stem from mutations affecting ion channels, categorizing them as channelopathies. For those seeking natural management methods, understanding the triggers, maintaining a balanced diet and using stress management can be beneficial. Recognizing and addressing the underlying causes and symptoms holistically can significantly improve quality of life for individuals with these conditions.


*** This article was written, and the image was created, with the assistance of Artificial Intelligence through ChatGPT-4 ***

"The image represents the concept of Periodic Paralysis. It depicts a figure in a state of rest or partial immobilization, surrounded by symbolic elements that represent both the periodicity and the paralysis aspect of the condition. This includes elements of a clock to symbolize the periodic nature, and chains or weights to represent the paralysis. The background was designed to evoke a sense of medical understanding, including faint depictions of nerve cells and muscle fibers to indicate the physiological basis of the condition. It was designed to convey the complexity and impact of the condition through a blend of symbolic elements."

Normokalemic Periodic Paralysis Update

Hello All,

I have put together a list of articles, etc proving the existence of Normokalemic Periodic Paralysis....This may be used if you have doubting doctors...

You can make copies of the articles and put them in your medical file and other medical records to share with your doctors....

There is a form of Normokalemic PP...found by Dr Lehman-Horn...a real genetic mutation...CACNAIC.

It also happens in Andersen-Tawil Syndrome, Hypokalemic Periodic Paralysis and Hyperkalemic Periodic Paralysis.

Newest studies indicate that potassium does not have to shift at all to create the symptoms/paralysis.

The information is below:

Normokalemic Periodic Paralysis

Blog Article:

http://livingwithperiodicparalysis.blogspot.com/2014/02/what-is-normokalemic-periodic-paralysis.html

Articles:

Normal Potassium levels with PP:

Interesting information about Normokalemic Periodic Paralysis from the MDA in England.....Very very important to read and pass along to the doctors who are questioning those whose potassium remains in normal levels while having PP symptoms and paralysis......

”Normokalaemic periodic paralysis: In these attacks the blood potassium remains normal

In fact, it has recently been discovered that it is not the change in the blood potassium level that is the primary problem in periodic paralysis. The primary problem in all of these conditions is that the normal pores which exist in the walls of the muscle cells don’t work properly. It does seem that changes in blood potassium levels can further hinder the function of these pores and that is why changes in blood potassium can be relevant. However, other factors separate from blood potassium can also worsen the function of the pores, so a change in blood potassium is not essential." http://www.musculardystrophyuk.org/app/uploads/2015/02/periodic-paralyses.pdf

Link for PP Labs: Normokalemic Periodic Paralysis

While researching something else today, I came across this and thought I should share it. Perhaps it can answer some of your questions about lab results and how they relate to our different forms of PP..

Hypokalemic Periodic Paralysis:

"Serum potassium level decreases during attacks but not necessarily below normal." "Creatine phosphokinase (CPK) level rises during attacks."

Hyperkalemic Periodic Paralysis:

"Serum potassium level may increase to as high as 5-6 mEq/L. Sometimes, it may be at the upper limit of normal, and it seldom reaches cardiotoxic levels. Serum sodium level may fall as potassium level rises."

http://emedicine.medscape.com/article/1171678-workup

https://rarediseases.info.nih.gov/gard/4009/normokalemic-periodic-paralysis/resources/1

http://www.ncbi.nlm.nih.gov/pubmed/1438924

http://omim.org/entry/170600

“Also of note is that potassium levels do not have to range outside of normal limits to cause serious, even life-threatening paralysis. These diseases are not the same as having a very low level of potassium (hypokalemia) or high potassium (hyperkalemia) and must not be treated as such. The total body store of potassium is usually normal; it is just in the wrong place.”

https://en.wikipedia.org/wiki/Periodic_paralysis

Andersen-Tawil Syndrome:

Paralysis/symptoms while potassium is in normal ranges:

”Attack frequency, duration and severity are variable between and within affected individuals and may not correlate with ictal serum K levels, which may be reduced, normal or elevated.”

http://brain.oxfordjournals.org/content/129/1/8

Genetic mutation for Normokalemic Periodic Paralysis:

New information has been published to relate mutations on the CACNAIC gene, also known as Cav1.1, is the first calcium channel related to Normokalemic Periodic Paralysis.

According to Lehman-Horn F. et al, “This study shows for the first time that functional characterization of omega pore currents is possible using a cultured cell line expressing mutant Ca(v)1.1 channels. Likewise, it is the first calcium channel mutation for complicated normokalaemic periodic paralysis.”

http://www.ncbi.nlm.nih.gov/pubmed/24240197/

Added July 19, 2016:

This is about normal EMG's and info from article about Electrodiagnostic Evaluation of Myopathies with comment that, "EDS studies may be normal in selected muscle diseases"... in which the author includes endocrine myopathies. Important to note that MDA refers to PP as 'endocrine metabolic myopathy' in their  2011 Quest Magazine.

Electrodiagnostic Evaluation of Myopathies Sabrina Paganoni, MD, PhDa, *, Anthony Amato, MDb

"EDX studies may be normal in selected muscle diseases (certain endocrine, metabolic, congenital, and mitochondrial myopathies). Thus, in the appropriate clinical context, normal EDX studies do not necessarily rule out the presence of a myopathy. EDX studies are most useful to diagnose a myopathy when further data are needed to exclude alternative diagnoses, confirm the presence of a muscle disease, and narrow down the differential. "

http://www.myositis.org/storage/documents/General_Research/diagnosis_of_myopathies.pdf


Added 10/09/2016:"
In Today's Mailbox: 1963 Normokalemic Periodic Paralysis and NOT part of the nervous system?? Here is one to share with the unbelieving doctors....
http://jamanetwork.com/journals/jamaneurology/article-abstract/564501


Added 1/22/2017:
INTERESTING and VALUABLE info to use when told, "Can't be PP because potassium is normal. Or ECG normal. Or PP not life-threatening. (From Maureen...thanks!)


THE FOLLOWING STATEMENTS ABOUT POTASSIUM LEVELS DURING EPISODES AND THAT POTASSIUM DEPLETION MAY NOT BE FUNDAMENTAL DISORDER (cause) AND ECG's BEING NORMAL DURING ATTACKS AND THAT PP CAN CAUSE DEATH ARE FROM THE FOLLOWING ARTICLE THAT INCLUDED REVIEW and SUMMARY OF DATA OF 400 CASES of PP and A STUDY of 33 individuals during episodes that occurred naturally and 4-6 individuals who had episodes induced...


" It seems probable, therefore, that periodic paralysis as described in the literature is produced by more than one mechanism or that the serum potassium depletion is not the fundamental disorder." Talbot 1941


"we observed no striking hypopotassemia during attacks in the patients whom we studied in detail."


"Occasional instances of paralysis without depression of serum potassium levels have been reported" (7).


"DURING episodes of mild and severe paralysis we have obtained repeated serum samples which have been analyzed for sodium, potassium, and magnesium, as well as a number of other substances. All of these values have been consistently normal."


"We have observed no values below 3.5 meq./L except in association with the glucose-insulin infusions."


"Electrocardiograms taken during the attacks showed no change from the control tracings."


"Again, the paralysis may be so extreme in some cases as to cause death". (13, 14).



https://www.jci.org/articl…/view/102465/version/1/pdf/render


Downloaded from
http://www.jci.org
https://doi.org/10.1172/ JCI102465


EXCERPTS FROM:
STUDIES IN DISORDERS OF MUSCLE. VII. CLINICAL MANIFESTATIONS AND INHERITANCE OF A TYPE OF PERIODIC PARALYSIS WITHOUT HYPOPOTASSEMIA 1 By FRANK H. TYLER, F. E. STEPHENS, F. D. GUNN, AND G. T. PERKOFF (From the Laboratory for the Study of Hereditary and Metabolic Disorders, the Departments of Medicine and Pathology, and the Division of Biology, University of Utah, Salt Lake City, Utah) (Submitted for publication December 13, 1950; accepted, March 12, 1951)


In 1941 Talbot(6) summarized the data concerning more than 400 cases of periodic paralysis. The disorder has been usually referred to as familial or family periodic paralysis. It seems best to us as it did to Talbot to call the disease periodic paralysis, specifying the hereditary nature of the disorder when it is genetically determined, and referring to the other cases as sporadic, associated with thyrotoxicosis or in other ways specifying the mechanism involved where it is known.


Talbot concluded that the syndrome probably represented a clinical entity due to a single metabolic dysfunction. In our study of a kindred in which 33 individuals with clinically typical periodic paralysis were known to have occurred, we observed no striking hypopotassemia during attacks in the patients whom we studied in detail. This led us to undertake a critical review of the data dealing with this disorder in the literature. A poor correlation between the onset and the severity of the attacks and the magnitude of the depression of serum potassium values has been noted and commented upon by several authors, including Talbot (6). Occasional instances of paralysis without depression of serum potassium levels have been reported (7).


Furthermore, the levels of serum potassium found during attacks in patients with periodic paralysis usually have not been as low as those observed in patients who do not carry this genetic trait but who have hypotassemic paralysis resulting from better understood metabolic abnormalities (3, 6, 8, 9). A corollary observation is the apparent lack of specificity of potassium in relieving or preventing the paralysis in certain patients with periodic paralysis in contrast to its excellent effect in the other metabolic hypokaliemias (1, 6, 10, 11). It seems probable, therefore, that periodic paralysis as described in the literature is produced by more than one mechanism or that the serum potassium depletion is not the fundamental disorder.


MORE excerpted from this article:
"Talbot concluded that the syndrome probably represented a clinical entity due to a single metabolic dysfunction...It was also postulated that the defect is related to the central nervous system, to the permeability of muscle cells, to hepatic or muscular glycogenesis or to a chronic deficit of potassium in the muscle." (10, 28)



https://www.jci.org/articl…/view/102465/version/1/pdf/render





Until later...