TOS MRI Directors Blog

Good day, and welcome to the TOS Director’s Blog!

I received a question about TOS in pregnancy:

“Does pregnancy worsen the symptoms of TOS? I can only sleep on my sides and I wake up in pain daily!”

Many sources state that pregnancy is a predisposing cause for neurogenic TOS. Presumed etiologies (mechanisms) include the following:

 1. Increased body fat during pregnancy causes increased compression of the vital structures in the thoracic outlet.

2. Retained fluid during pregnancy causes increased compression of the vital structures in the thoracic outlet.

3. Overall increased body weight causes hyperlordosis of the lumbar spine (increased curvature of the lower spine), resulting in abnormal posture.

4. Increased breast size causes more weight to fall on the chest wall.

While these are all reasonable and plausible mechanisms, none are supported by any medical literature.

My search of the literature regarding TOS and pregnancy reveals only one significant paper: “Upper extremity deep venous thrombosis”, by Kommareddy, et al at Michigan State University (Reference: Semin Thromb Hemost. 2002 Feb;28(1):89-99). Upper extremity deep venous thrombosis (blood clot) may be caused by venous TOS. Venous TOS, although rare, may occur in overhead athletes or during pregnancy. It is well-known that pregnancy may cause hypercoagulability, meaning an increased tendency for the blood to clot. Since upper extremity blood clots are rare, doctors look for unusual underlying causes when such a clot occurs. If such a clot occurs in a pregnant woman, the pregnancy with its secondary hypercoagulability are usually assumed to be the cause. Thus, a connection exists between pregnancy and the venous form of TOS.

This does not explain your pain (I am assuming you have neurogenic TOS), since venous TOS, as discussed in the paper above, causes swelling and cyanosis (a dark purple/blue color of the affected arm).

In my opinion, the mechanisms stated above are all logical but unproven. In addition, there is nothing in these mechanisms that would allow a significant treatment beyond the usual treatments for TOS. I am sorry that you have to wake up each day with pain, but I hope you are being treated by a TOS specialist who is working with you to relieve or resolve the underlying causes. I do not believe there is any contraindication to physical therapy during pregnancy, although there may be some limitations. If you have been diagnosed with TOS, conservative management including physical therapy should always be the first step. Please ensure that if you are undergoing physical therapy, your therapist is familiar with the diagnosis and mechanisms of TOS, and is familiar with appropriate and specific treatment of TOS. An excellent and widely-renowned TOS physical therapist is Dr. Peter Edgelow (http://www.edgelow.com/).

Thank you for your question!

A Different Issue (related to venous TOS)

Another major league baseball pitcher has developed TOS. Jeremy Bonderman, the hard-throwing starting pitcher for the Detroit Tigers, developed venous TOS, may undergo surgery, and could miss the rest of this season.

http://www.sportingnews.com/blog/FantasySourceFastball/154876

First, I would like to wish the best for Mr. Bonderman. I am sure he has worked long and hard to reach the peak of his profession, and is obviously a very talented elite athlete. It must be hard for such an athlete to lose a large part of a season, to contemplate and undergo surgery, and to then have to spend a lot of time rehabilitating to get back to a sport and job he loves. Hopefully, all will turn out well for this young man.

Overhead athletes, such as baseball players (especially pitchers), tennis players, volleyball players, and swimmers are vulnerable to the development of TOS. Mr. Bonderman is not the only famous athlete to develop TOS. In my next blog, I will discuss some of the other famous athletes who developed this disease.

Thank you for reading. I look forward to seeing you again!