This is the "main" forum that contains new introductions and other topics. A place to talk about your experiences, thoughts and advice.

Moderator: gloria

By admin
What is rare? and how many people have Primary Orthostatic Tremor?

Is OT present at a rate of 1 per 100,000 people for a total of 70,000 people throughout the world,
or 1 in a million for a total of 7,000 people worldwide?

Question - What is a Rare Disorder?

The definition changes depending upon where you live.

USA - A Rare disease is defined in the USA as fewer than 200,000 Americans at any given time. (approximately the population of Boise, Idaho or Richmond, Virginia)
Calculated for the current population of the US (324 million) a rare disease would effect roughly 617 people per million


EU - A Rare disease is defined in the European Union (EU) as fewer than 245,000 people (approximately the population of Nantes, France or Wolverhampton, UK) at any given time. Or, defined as rare when it affects less than 1 in 2000 citizens.
Calculated for the current population (508 million) a rare disease would effect 393 people per million


The population in the world today exceeds 7 billion. Where does OT fit into this picture?

Orphanet** is a consortium of approximately 40 countries, coordinated by the French INSERM team. Among the many tasks of this group are to gather information on research. And in the document - Orphanet Report Series - Diseases listed by decreasing prevalence or number of published cases they determined the prevalence of 2000 rare diseases. Included in the document is a very reasonable statement and something that we should keep in mind when considering any statistics.
The exact prevalence rate of each rare disease is difficult to assess from the available data sources...Therefore, these estimates are an indication of the assumed prevalence but may not be accurate.
There a 2 parts to the Orphanet report. The first list contains diseases that are more prevalent and therefore Orphanet was able to estimate how many people are effected by the disease per 100,000. This group which we will call Group 1, is a list includes 600 of the more "common" rare diseases. The least common disease in this list is a rare tumor that effects 25 people per 100,000. This would be equal to 81,000 people in the USA. But OT is not in Group 1 because it is less prevalent and as a result less data is available.

The second part of the Orphanet report, Group 2 contains rare diseases with less prevalence and too little data to estimate how many people as a percentage of the population. This second list is where Primary Orthostatic Tremor falls. They have determined that from the beginning of the 20th century until now, there have been 391 published cases of Primary Orthostatic Tremor, worldwide. This number, 390, doesn't tell us how many people have OT but it does give us some clues as to where it falls amongst other rare diseases. A Mayo Clinic retrospective research study published in 2016 included all 184 OT patients from 1976-2013. As a result this may change the number used by Orphanet in the future. As reported in US News, Mayo Clinic locations see roughly 500,000 people each year. Many of these may be repeat patients, but even so, 500,000 people each year compared to 184 people with OT over a 37 year span does lead us to an idea of the rarity of OT.

The lowest ratio of people in the Group 1 that has adequate information and are therefore more prevalent, is 25 people per 100,000. Since OT is in the Group 2 we might conclude that OT is then below the ratio of 25 people per 100,000. Within Group 2 which includes OT, it ranks relatively high. Of the approximate 1130 diseases in this group, OT is 32nd, based upon the number of individuals included in published research papers.

OT is in the group of ultra-rare diseases with a prevalence of less than 25 per 100,000 ... but how much less?

To make this a little more approachable, we will consider the population of the USA and how many people may have OT. The least prevalent disease in the Group 1 would have roughly 81,000 people in the USA. But OT is in Group 2 with less prevalence and roughly 1/3 the way down this list. This might indicate no more than 53,000 people in the US may have OT. And that number is likely to be very far off. This group is not using the same methods of the more prevalent diseases in group 1 so it may be 53,000 or 4,000 people, or less. And considering that most specialists have only known 1-6 patients with OT over a career, the "guess-estimate" of people with OT continues to drop. To put the rarity of OT into perspective, it is estimated that in the USA there are 7 million people with Essential Tremor, and 0.5 - 1 million people with Parkinson's Disease.

  • USA population 324 million:
    Essential Tremor - 7 million (USA) - SOURCE
    Parkinson's Disease - 1 Million (USA) - SOURCE

    Orthostatic Tremor - is it less than 53,000 worldwide (not just the US) or possibly as low as 7,000 people ... 1 in a million?

    note: 1 in a million would only be 324 people in the US. My guess is this number does fall short, and the ratio is larger simply based on the 1,200 people that have registered on this website. Even though they are not all from the US, and clearly only a small portion of people have registered. It is easy to remember the phrase 1 in a million, but it's more likely that it is somewhere between 2-20 people per million. That's a wide range but it is only a guess.

What about the number of people that are misdiagnosed or undiagnosed?

As with many rare diseases, mis-diagnosis or no diagnosis is a problem. Primary Orthostatic Tremor is not unique with this challenge. Accurate diagnosis would in theory lift all of the numbers of people with rare diseases within the Orphanet report.

I know that it's disappointing to have read this far without an absolute number, but hopefully we have a better understanding of how rare Orthostatic Tremor is.

Lack of data leads to plenty of guessing, and this article has it's share. Do you have any thoughts about the prevalence of OT? please click reply and share your ideas


Many thanks to Orphanet* and Inserm for the very helpful report on rare disease prevalence.

**Orphanet is led by a consortium of 35 countries (and 5 contact points) , coordinated by the French INSERM team. National teams are responsible for the collection of information on expert centres, medical laboratories, ongoing research and patient organisations in their country and translation in their language if funding available.
By MikeS
What a fantastic piece of information .My only comment is that the odds of getting OT is about the same as winning the lottery ! Oh well hey ho what would I do with a $100,000,000 Teddy bear legs are ok :lol:
By gloria
Hi! Mike:
It is so great to have you back posting again with your incredible uplifting humor by using the example of the science of lottery or Vegas which is right up there with the best guesses!!!!!!!!! I personally have felt thru the years the biggest problem hindering our " prevalence" is how we were treated in our history of existence , for example mis-diagnosis or no diagnosis has been a HUGH problem for OT..therefore the available data sources do not even come close to the number of real cases of OT. Would love to hear the continuing input from our OT friends and how they feel about our present station with OT ?????? Gloria
By Dwight Kraai
Dear All Members:
Congratulations to Gloria whose web site just signed up its 1000th. member.
We may not know how many people have Orthostatic Tremor but we do know there are 1000 we can communicate with.
What a wonderful addition Gloria and her web site have made to our lives.

Dwight Kraai
By ginny12
I have OT diagnosed in April, 2006. I had been having mild symptoms for several years which were becoming worse. My internist referred me to a neurologist who had been an associate director of the movement disorder clinic at Harvard and after a couple of tests, he immediately diagnosed it as OT. I have been subscribed various meds which have helped some but now the OT has progressed to fairly severe making it very difficult to function.

When I originally posted my first post, I stated the neurologist who diagnosed my OT was formerly an associate director of the movement disorder clinic at Harvard but it was actually at Yale. As asked by Gloria, I live in a tiny town in south GA about 20 miles north of the FL line. My doctors including my neurologist are in a town 15 miles from my home. It is considered a small town. In March, my symptoms had worsened and the doctor increased my meds (gabapentin & clonazepam) considerably. At first, I thought it was helping but now I can hardly stand for a minute before sitting and get so exhausted. I have AFib and a pacemaker but just went to my cardiologist who said everything was O.K. I have my annual physical soon so if something else is going on, I should find out then.
Last edited by ginny12 on Wed May 20, 2015 9:10 pm, edited 1 time in total.
By gloria
It was good your internist directed you to the Harvard Movement Disorder Clinic for a proper diagnosis. Unfortunately OT has a history of being GREATLY misdiagnosed or not finding a diagnosis. We are pleased to have you as a new registered member of our great OT COMMUNITY FORUM where  you will find a group of friends who really UNDERSTAND what it is like to live with OT!!!  Hope you will continue to participate on the Forum, posting your experiences and questions.  Reporting what our lives are like with OT helps the medical community  to have a better understanding of our symptoms .....Your registering as part of the OT Community helps our numbers grow so we will  become a greater interest for research.

I see you forgot to leave your location in your  PROFILE when your registered so please for reasons “why and how to” just click on the following : ... f=16&t=313  

I'm looking forward to reading your posts on the Forum, Your OT Partner, Gloria, New Jersey, USA
By jitterbug2
How many people with OT have never been on an aeroplane? My experiences with flying have led me to consider compression / decompression as a causal factor.
Vertigo? Is that a factor? On reading the comments on ophthalmic conditions I wonder how these are all related.
I have noticed as my condition deteriorates that entering / working in darkened spaces (woodlands for example) my balance is affected.
Any comments or further observations will be appreciated.
By gloria
Jitterbug: The statistics that you are asking for are hard to come by and we are all searching for cause. Your observation of darkened spaces definitely affects our OT balance. Thanks to everyone posting their OT experiences helps to add pieces to the OT puzzle. Gloria
By jitterbug2
Thanks, Gloria,
I am always impressed by your constant, careful attention to "the flock."
My observation is based on the reaction I get after flights. Since retiring I have not done much air travel but have noticed exaggerated symptoms of unsteadiness, dizziness and affected gait along with a long recovery period in each case.
This got me to consider differential air pressure as a causal factor. Maybe air travel is one of the triggers that set off the neuro sensors?
I sympathise with all the others who feel embarrassed about using wheelchairs where some are perfectly able to walk. How about medication? Does it help to pop a couple extra Gabapentin?
I am hoping to make the trip to Baylor in March 2016 but do not want to arrive there as quivering jelly too tired to contribute to the proceedings.
Appreciate everyone's input.
By Nin
I too get more shaky with air travel, but it starts on the way to the airport and continues for about a day after. I think for me it has to do with nerves. Will I make it to the plane on time? Will the plane be delayed? And the excitement of going to a new place with a different daily routine. AND the crush of people on the plane. Wish I could travel first class but that's never my choice as I'd rather spend the extra $ on other things. Probably an extra anti-anxiety pill would help, but then I'm afraid I wouldn't be as sharp and would miss something important. I do much better traveling by car. :)
By Peachy
This is Peachy from Mississippi. Is there anyone else in Mississippi that has OT? Would like to know where you live. The last couple of weeks has been rough on me.Blessings to all of you who deal with this.
By gloria
Hi Peachy:
I understand how you feel that you would like to meet other people with OT we all do and it is very helpful to us. However, when you registered you forgot to leave your location in your PROFILE and although you are giving this information in this posting it will only show with this post and not be on the membership list which would show with your name whenever you post again. For example: On the right side of this post is my name and location automatically shows whenever I post because I gave my location when I registered in my PROFILE. We are a rare disorder and it is important to give the geographic picture of where we are located. This helps with the formation of support groups, connecting with others living within a reasonsonable distance and for researchers planning research. Your general location is all that is needed and it is not recommended to post specific addresses. For other reasons "why and how" to leave your location just click on the following: ... ?f=16&=313 Hope this helps,Gloria
By margie1627
I'm wondering about the name Primary Orthostatic Tremor POT. Has anyone tried medicinal marijuana?
Is POT telling us something? :?: :?:
By Tigermoth
I meant to ask my Uk doc, tickled by the idea of having a legal prescription. But I forgot... surely that's the wrong way round!
Hohoho... sorry bad joke.

Pot, surely bound to help with spasticity and relieve aching etc. If the mood change stuff agrees with you. Lethargy last thing I need in my life.
By Leigh
Hello, I'm new to all this. I was diagnosed about 2 months ago with Orthostatic hypotension and then all of of a sudden my legs would start shaking and my hands, so my primary Dr sent me to a neurologist and he ordered a MRI on my brain which was normal. He then diagnosed me with OT. I have never heard of this before. It's very frustrating!! I take topimax and it makes me nauseous and very lethargic. Is there a cure. I feel so lost right now.
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