What is Normokalemic Periodic Paralysis?

Hello All,

What is Normokalemic Periodic Paralysis?  

Before writing about Normokalemic Periodic Paralysis, I believe it best to review Periodic Paralysis in general. I have written several articles previously about the different forms of Periodic Paralysis namely Hypokalemic Periodic Paralysis, Hyperkalemic Periodic Paralysis and Andersen-Tawil Syndrome.

What is Periodic Paralysis?

One of the neurologists who diagnosed me recently said, “Periodic Paralysis is a disease unlike any other. It is not a neuromuscular, mitochondrial or autoimmune disease nor is it a muscle myopathy. It is in a category all its own and needs to be treated in non-conventional ways.” He further stated, “Doctors need to keep an open mind and think ‘outside of the box’ when it comes to diagnosing and treating Periodic Paralysis.”

The following is an overview of the condition gleaned from years of research and my own experience.

Periodic Paralysis (PP) is an extremely rare, difficult to diagnose, hereditary, mineral metabolic disorder characterized by episodes of muscular weakness or paralysis, a total lack of muscle tone without the loss of sensation while remaining conscious. It is passed from either the mother or the father to any of the children, male or female. It is an ion channelopathy, a condition involving dysfunction of an ion channel for potassium, sodium, chloride or calcium. Ion channels regulate ions as they flow in and out of the cells.

There are several known types:

Hypokalemic Periodic Paralysis (Hypo PP): Paralysis results from potassium moving from the blood into muscle cells in an abnormal way. It is associated with low levels of potassium (hypokalemia) during paralytic episodes.

Hyperkalemic Periodic Paralysis (Hyper PP): Paralysis results from problems with the way the body controls sodium and potassium levels in cells. It is associated with high levels of potassium (hyperkalemia) during paralytic episodes.

Normokalemic Periodic Paralysis (Normo PP): Paralysis results from the movement or shifting of potassium within ranges, which are normal (normokalemia).

Andersen-Tawil Syndrome (ATS): Paralysis results when the channel does not open properly; potassium cannot leave the cell. This disrupts the flow of potassium ions in skeletal and cardiac muscle. During paralytic episodes, ATS can be associated with low potassium, high potassium or shifts in the normal (normokalemia) ranges of potassium.

Normokalemic Periodic Paralysis

The commonly accepted range for normal potassium in human beings is 3.5 to 5.0 mEq/l (milliequivalents per liter), but these numbers may vary somewhat among labs. Our bodies work to naturally maintain a fine balance, which is within that normal range. Ninety-eight percent of potassium in the body is located within the cells and the other two percent of potassium is outside of the cells in the blood. Blood testing in a lab is used to measure the potassium in the body. There are also a few different types of potassium readers available for purchase and use in the home.

For individuals with Periodic Paralysis, the “normal” ranges of potassium may vary significantly from person to person. Results from a survey revealed some feel well and are at their best at about 5.0 while others may do best at 3.8 or 4.3. The potassium for these individuals shifts in several ways depending on the type of PP causing many symptoms as discussed previously. It may shift higher or lower. These shifts may be very slight yet cause paralysis as well as other serious symptoms including but not limited to heart, breathing and blood pressure issues. The shifting may also happen very quickly and be undetectable. This shifting is then within the “normal” ranges of potassium, thus the name “Normokalemic” Periodic Paralysis, although some research indicates it is not necessarily a distinct or different form of Periodic Paralysis, but rather Hyperkalemic Periodic Paralysis. However, it appears that 58% of those with all forms of PP actually have episodes of potassium shifting within normal ranges according to a recent survey of individuals diagnosed genetically and clinically.

Because most of the emphasis, literature and studies written about Periodic Paralysis are about Hypokalemic Periodic Paralysis (low potassium) and Hyperkalemic Periodic Paralysis (high potassium), the majority of medical professionals do not understand or recognize Normokalemic Periodic Paralysis or the knowledge that the potassium does not have to shift outside of normal ranges or that it may shift too quickly to be detected to create the paralysis or other symptoms which may be serious or life-threatening. It may also shift high or low and return to normal ranges before an individual can be tested in a lab or be seen in the ER.

This makes it difficult when an individual is seeking a diagnosis. Neurologists suspect neurological issues and prescribe very harmful medications, which may cause new symptoms or physical therapy, which can be painful and cause episodes of paralysis. Unfortunately, this may then lead to misdiagnoses of pseudo-seizures, conversion disorder, malingering, attention seeking, and/or hypochondria. More inappropriate and harmful medications and treatments are prescribed to treat these issues. The mis-labels follow the patient from doctor to doctor and the individual is never taken seriously.

These same issues are rampant in an ER situation. Potassium in normal ranges, with paralysis and other issues and uninformed medical professionals, can add up to all of the above and the administration of IVs filled with sodium or glucose with a psychotropic drug to treat pseudo seizures. This can lead to more serious symptoms, permanent damage and even death for an individual with Periodic Paralysis.

Another problem resulting from potassium shifting within normal ranges for someone who has a diagnosis of Periodic Paralysis, especially Hypokalemic Periodic Paralysis (low potassium), is the issues of automatically taking a dose of potassium when symptoms begin or being given an IV with potassium in the ER when the potassium never left normal range. This may then cause a shift into high potassium levels and create new or worse symptoms.

For those who have symptoms and paralysis while potassium levels remain within normal ranges, the best way to know how to treat it is to take note of the symptoms and record them. If one is able to record the levels of potassium at home, keeping a running tally when symptoms begin will eventually show either a trend toward high or low potassium or a shifting both ways as is common in ATS. Depending on whether one gets better or worse when taking potassium, may also be a clue of either high or low potassium. Discovering and avoiding the triggers that set it off is recommended.

When in paralysis and accompanying symptoms, there may be actually nothing that can be done except for time to pass and things to return to normal, because the potassium is already in normal range. Remaining calm is also recommended in order to avoid stress which can cause more shifting of potassium. If at previous times, taking potassium helped, then it may be recommended. If the potassium made it worse, it might be wise to avoid it.

An ambulance does not need to be called nor does someone need to be rushed to the ER, doctor or hospital every time they become weak or paralyzed due to potassium shifting. Most individuals will be fine in a few hours. However, if one is having serious difficulty with breathing, heart, choking or swallowing, then an ambulance may be necessary. Otherwise, the only important reason for going to the ER, if a person does not have a diagnosis, is to get the attacks documented, a "paper trail" is often needed. Proof of the episodes must be established.

From Wikipedia:

“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.”

For more information on when to call for emergency care can be found at:

http://livingwithperiodicparalysis.blogspot.com/2013/12/when-to-call-for-ambulance-december-3.html

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

http://www.nlm.nih.gov/medlineplus/ency/article/003484.htm

http://www.ncbi.nlm.nih.gov/pubmed/22926674

http://omim.org/entry/170600

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

www.bami.us/Diet/Hyperkalemia.html

October 1, 2014

I would like to add another important source to this article:

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

Added July 25, 2015

"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


Until later…‎