Update on Interventional Therapies For Migraine
Just back from the 6th world congress of the World Institute of Pain meeting in Miami. I was excited to attend a symposium dedicated to interventional approaches to headache, including migraine. The speakers were anesthesiologists who specialize in interventional therapies.
They began the session by appropriately commenting that there's not a lot of controlled research studies testing the benefits of most interventional therapies in migraine sufferers. Therefore, they were generally recommending those techniques they had found most helpful in their own patients and only considered these treatments when patients had failed to respond to more conventional migraine therapies. The symposium focused on nerve blocks and nerve stimulation, with recommendations given for procedures involving the occipital nerves, sphenopalatine ganglion, and possibly the trigeminal nerve. These procedures involve the injection of a small amount of an anesthetic (or novocaine-like medication) or the application of electrical nerve stimulation to nerve areas believed to interrupt the migraine pain pathway.
The occipital nerve leaves from the base of your skull and travels over the top of your head toward the eye. Doctors can inject an anesthetic under the skin at the back of the head where these nerves exit the neck. This is a fairly straight forward office procedure that many doctors can perform. Pilot data on occipital nerve stimulation were presented last year in the journal Cephalalgia. In this study of patients with chronic migraine, headache frequency decreased by 39 percent when adjustable stimulation was used.
The sphenopalatine ganglion is a large collection of nerves that sits at the back of the nose. This nerve group is often blocked by soaking cotton swabs (like Q-tips) in an anesthetic and then carefully inserting them into the nose so the anesthetic can be absorbed through the back of the nose. The nerve may also be stimulated by temporarily placing stimulator wires behind the upper jaw. A small study published in the journal Headache in 2009 found migraine improvement for about half of those getting sphenopalatine ganglion stimulation. The use of these procedures was reviewed last year in the journal Progress in Neurological Surgery.
The trigeminal nerve and ganglion make up the main relay station for pain messages from the head and face. This structure is buried deeper in the skull and is more challenging for the doctor to get to. Because of this, procedures involving the trigeminal nerve or ganglion are more likely to have unwanted complications and are generally only performed by specialists with a lot of expertise in these procedures.
Who will likely benefit from blocks or nerve stimulation?
In general, the studies evaluating the benefits from these procedures have been small and often no comparison treatment has been tested at the same time. This makes it hard to know for certain how beneficial the treatment might be. Most of these treatments have been used in people with very frequent or chronic migraine that have failed to respond to a wide range of more conventional therapies. Overall, these procedures might be expected to result in modest reduction in migraine frequency, which might be very helpful to those with frequent and disabling attacks.
Can you tell when a migraine attack is coming?