Minnesota Twins starting pitcher David Festa avoided a worst-case scenario last week, as reported by the Minnesota Star Tribune, when he received a Botox injection to relieve compression placed on the nerves in his neck causing thoracic outlet syndrome.
Thoracic outlet syndrome is a complex condition that comes in multiple varieties. All four share a common theme: something that runs from the neck to the hand is getting pinched. With the neurologic variation, it’s the nerves of the brachial plexus; with the arterial, it’s the main artery; veinous, the main vein; and complex, some combination of the above. Festa, by all accounts, is dealing with only the neurologic variation, and the Twins are calling it “very, very mild.”
Botox injections—so named for the botulinum toxin that serves as the medication’s active ingredient—is a flaccid paralytic agent, meaning the injection causes the musculature it is injected into to not only relax, but also be unable to contract. The brachial plexus—a conduit of nerves that eventually branches out into the major nerves of the arm—leaves the neck and passes through a group of muscles called the scalenes and underneath the pectoralis minor of the shoulder, a small muscle located underneath the pectoralis major or “pecs.”
The scalenes and pectoralis minor often bulk up with repeated throwing, which can lead to compression of the brachial plexus; this is one of the reasons why thoracic outlet syndrome is more common in high-level pitchers compared to the general public. Flaccid paralysis of these muscles induced by a Botox injection should, theoretically, reduce the compression on the nerves and allow for Festa to resume baseball activities with time; a recent systematic review reported that roughly 50% of individuals with neurogenic thoracic outlet syndrome experienced reduced symptoms following a Botox injection. (Botox injections eventually wear off, so Festa’s muscles aren’t permanently paralyzed; this is also why people have to continually get Botox injections to relieve their forehead from wrinkles.)
In rare cases, individuals grow an extra bone in their neck that is similar to a rib. The rib may also compress the brachial plexus; the scalenes may or may not attach to the rib. In such cases, the rib is surgically removed and the scalenes are “released,” or have their attachment cut. Whether or not Festa has an extra rib is unknown, but statistically speaking, it’s unlikely.
Thoracic outlet syndrome has traditionally been known as a “diagnosis of exclusion,” meaning all other potential explanations for one’s symptoms are ruled out before one is given the label of thoracic outlet syndrome. As such, it often takes a long time for one to be treated correctly, increasing the likelihood of failed treatments and/or permanent nerve damage.
Luckily, Festa’s condition was diagnosed relatively quickly, and as such, it did not progress to the point where surgery was immediately on the table. If the injections and corresponding physical therapy prove effective, it’s not unreasonable to expect a normal offseason for Festa. The Twins appear to have dodged a bullet here.