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...