My doctor wants to use Botox to inject my neck muscles and see if this will help take away the pain and numbness in my arm. Will it leave my arm puffed up afterwards? I know movie stars get Botox injections to make their lips fatter.
BOTOX stands for Botulinum toxin, which is a protein produced by a bacteria. It is used for various cosmetic and medical procedures because it is a powerful neurotoxin. In other words, it can paralyze a nerve. When the physician suspects arm pain and numbness are symptoms from thoracic outlet syndrome (TOS), Botox can be used on the scalene (neck) muscles as a test to see if that's part of the problem.
The main cause of TOS is that the nerves and blood vessels going to the arm and hand get squeezed near the thoracic outlet. The thoracic outlet is this opening between the scalene (neck) 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.
Extra muscle or scar tissues in the scalene muscles can put extra 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. Muscle blocks can also be done to prevent muscles (like the scalenes) from contracting fully. The injection weakens the scalene muscle enough that it can no longer pull the first rib up against the nerves and blood vessels passing through the thoracic outlet. Such a test helps identify overused muscles that might be a problem.
Botox used for cosmetic purposes doesn't make the lips look fuller (you are probably thinking of silicone injections for that). Botox is used more often to temporarily paralyze the muscles of the face to hide lines formed from raising the eyebrows or smiling.
When used to aid in the diagnosis of thoracic outlet syndrome by weakening scalene muscles, you should not experience any intentional swelling or fullness from the injection. Although small, there is always the risk of infection, swelling, or other unintended side effects from any invasive medical procedure.