Being muscular has to be good for everything right? Sometimes there are side effects to muscular hypertrophy when it has to do with the nerves and arteries that come from your neck and provide sensation and blood flow to your arm.
Most times when people present to the office complaining of tingling in their fingers, a doctor can detect the cause by taking an excellent history and performing a complete and directed physical exam. Tingling in the fingers, which has a medical word called paresthesias, are usually caused by a nerve compression. Compressions can occur at different areas starting from the neck where nerves branch off the spinal cord. The nerves then travel down the neck, into the chest region, into the arm, forearm, and hand ending at the tips of the fingers.
One reason for tingling in the fingers starts at the neck where you can develop a disc herniation or a pinched nerve as the nerve travels through the exiting tunnel or foramen.
Another area of compression is at the elbow which is called cubital tunnel syndrome which can give tingling into your small and ring finger because the ulnar nerve is affected. Carpal tunnel is the most common compressive syndrome at the wrist which affects the median nerve supplying your middle finger index finger and thumb.
A condition which is not seen or diagnosed frequently that causes tingling into the fingers is called Thoracic outlet syndrome (TOS). This can occur when the nerves or blood vessels that come from the neck down into the chest region and axilla become compressed by large muscles, the first rib or an extra cervical rib.
If this happens to the nerve, then its function becomes compromised. This can take the form of pain in the arm, numbness, tingling, or weakness. When this occurs to the artery, these same symptoms develop, but also due to the tourniquet-like effect, the skin can change color and become pale.
There is a special test to diagnose Thoracic outlet syndrome on physical exam called the Adson test. This is performed by feeling the radial pulse of the patient with their arm at their side. The arm is then abducted and externally rotated. A severe case of thoracic outlet syndrome will cause the pulse to disappear. This occurs because of compression in the neck region as described above. If the pulse is still present the examiner can rotate the neck away from the arm and sometimes this will obliterate the radial pulse vibrations. Another way to diagnose this is to perform an MR arteriogram with the arm at the side and then abducted. The MRA can show constriction of the artery.
The treatment for Thoracic Outlet is always Physical Therapy first to try to open the outlet and decrease the constriction on the nerve or artery. There is a surgical treatment if this fails but it is extremely rare to resort to this option. Surgery focuses on either release of the scalene muscles or resection of the first rib.