Question
QUESTION: I am a 34 year old female experiencing numbness in one or both hands every morning upon waking for the past three years.  No doctor can tell me what this could be.  Any ideas?  Tested neg for carpal tunnel, had bloodwork and xrays too.  I wonder if it's serious?  Doesn't matter what position I sleep in either.  Usually I sleep on my left side, but it happens on my back and stomach too.  I was in a car accident where I was side swiped on the right side of the car, but I didn't have any known injuries.  I don't know what this could be from.
ANSWER: Dear Nancy,

I would like to get a bit more information from you.

Have you had an MRI of the neck?  If so what results?
What kind of testing did you have for carpal tunnel?  Nerve conduction velocity?
How long ago was the car accident in relationship to your ongoing symptoms?

From the symptoms you have described it sounds as though this is a centralized problem due to the fact that the numbness and tingling is bilateral...it leads me to think of the structure of the spine in relation to the nerve roots that supply sensation to the hands, or possibly the spinal cord in the neck.  

There is a condition called a syrinx which is like a cyst in the spinal cord which produces the types of symptoms you are describing.  It is not common, but a possibility. This would only be found with an MRI...x-rays will not see it, and blood work would be negative as well.  

Let me know about the above questions so I can consider this further.

Respectfully,
Dr. J. Shawn Leatherman
www.suncoasthealthcare.net



---------- FOLLOW-UP ----------

QUESTION: The accident was about three months prior to the numbness.  I do recall the first time it happened...I awoke in the middle of my night sleeping on my stomach on both hands.  I was also taking a mail order diet pill to lose a few extra pounds and I blamed that and stopped taking it right away.  I have not had a MRI, but I keep thinking I should.  The carpal tunnel test involved some electric shocking device that was very uncomfortable that made me jerk my fingers. The doctor said maybe a little weakness in my pinkies, but nothing major.  It seems I am in deep sleep when this happens, so I can never keep track of what fingers, what hand, what position.  Sometimes when I cross my legs my feet fall asleep, but I think that is normal?  I am otherwise healthy as far as I know, never get sick, eat healthy, don't smoke, fair bit of exercise.  I do have lower back pain, but it is only after sitting or standing too long.  Thank you for helping me.  

Answer
Okay Nancy, thanks for the follow-up information. It is possible that the collision could be responsible for the onset of the problem, even though side swipe types of crashes are the least likely to result in injury, and it seems as though you did not receive any active treatment or diagnosis after the collision.

So what does this leave us with, some more ambiguity!  you see there are multiple cause of numbness and tingling into the hands.  Arterial compromise, nerve compression or irritation, anatomical structures that have not been found, medications, Vitamin B12 deficiency, or toxicity issues.  But the main common cause for you seems to be your sleeping positions which would tend to rule out metabolic cause such as toxicity or deficiency.  

This leave me with the thought of a mechanical problem in the neck which is exacerbated by sleeping positions.  You had mentioned sleeping on your stomach, which is actually the worst sleeping position you could have...it places large amounts of stress and strain on the neck.  The best sleeping position would be flat on your back with your head resting on an orthopedic cervical pillow that is designed to support the neck curve and reduce strain.

It is possible that you may have a problem with the thoracic outlet. What is the thoracic outlet?  It is an anatomical location where the neck and chest meet on each side of the body where the nerves and blood supply to the arms are located.  

The nerves and blood vessels that go into the arm and hand start at the side of the neck. Nerves come out of the spine through small openings along the side of each vertebra. These openings are called neural foramina. They travel between muscles in the neck called the scalene muscles and over the top of the rib cage. The thoracic outlet is this opening between the scalenus muscles and the rib cage. The nerves and blood vessels then go under the collarbone (also known as the clavicle), through the armpit (the axilla), and down the arm to the hand.

The main cause of TOS is that the nerves and blood vessels going to the arm and hand get squeezed near the thoracic outlet. This can occur for many reasons.

Pressure on nerves and vessels can happen in people who have fractured their clavicle. It can also happen in people who have an extra first rib or an alteration in the transverse process of the 7th cervical vertebra in which it has developed larger than normal, although this doesn't always result in TOS.

Extra muscle or scar tissues in the scalene muscles can put pressure on the nerves and arteries.  Heavy lifting and carrying can bulk up the scalenus muscles to the point where the nerve and arteries get squeezed, or forward head posture in relation to the chest can place then at tension.

It is important to note that the scalenes are often injured in car crashes and have residual scar tissue: Traumatic accelerations or movement from a crash can cause problems that lead to TOS due to the shoulder harness of the seat belt straining or tearing the muscles. As they heal, scar tissue can build up, putting pressure on the nerves and blood vessels at the thoracic outlet.

Neck and arm positions used at work and home may contribute to TOS. People who have to hold their neck and shoulders in awkward alignment sometimes develop TOS symptoms. TOS symptoms are also reported by people who have to hold their arms up or out for long periods of time.

People with TOS often slouch their shoulders, giving them a "drooped" appearance. The poor body alignment of slouching can compress or irritate the nerves and arteries near the thoracic outlet. Being overweight can cause problems with posture, and women who have very large breasts may also have increased pressure and abnormal posture. For some reason, TOS affects three times as many women as men.  This is a possible diagnosis for your condition...although TOS often produces pain as well.

This diagnosis is often hard to document and has become controversial due to the lack of imaging findings and the fact that nerve conduction velocities may be normal, but that does not mean it does not occur.  Often chiropractic adjustments of the first rib, or spine at the base of the neck will reduce or eliminate these symptoms.  Stretching of the affected scalene muscle must also be incorporated for increased function and proper motion to reduce continued problems.  you may want to get a chiropractic examination due to the fact that we are usually the only doctors who treat this.

Now, having said all that, I must still consider the fact that you could have the syrinx formation that I had mentioned previously, and remember that the only way to diagnose this is with the MRI of the neck. I wish I could give you a more definitive answer.

Respectfully,
Dr. J. Shawn Leatherman
www.suncoasthealthcare.net