Neurostimulation to treat migraine
Latest from American Headache Society Meeting in Boston
Today there were several papers on neurostimulation. Here’s my summary, hopefully, in a nutshell. The bottom line???….. it has enormous potential as a treatment for migraine, but the studies today were a bit disappointing in terms of their quality and conclusions can only be tentative.
Here’s more detail
What is neurostimulation?
A neurostimulator is a medical device that applies a weak electrical impulse over a nerve. The electircal impulse is created by a generator. The generator, which looks a bit like an oversized watch battery, sends the electrical impulse along a wire to the nerve - in the case of headache, this is the greater occipital nerve (which sits at the back of your head). A neurostimulator has to be implanted using a surgical procedure.
How does neurostimulation work?
It is now known that nerves at the back of the head have strong connections to nerves which send pain signals to your brain during a migraine attack. By stimulating the greater occipital nerve, your brain is tricked into thinking that the pain is no longer present, and pain relief occurs. This network of nerves is called the trigeminocervical complex.
What proof is there that neurostimulation can treat migraine?
There are now 4 studies of neurostimulation in chronic migraine, including a total of 94 people. The largest of these the ONSTIM study was presented today in Boston.
Overall, there are some very encouraging results, but many more questions remain unanswered.
Before today, 2 of the 4 studies had said that a significant reduction in migraine related disability was experienced by up to 50% of those stimulated. In the long term 80% of those stimulated had a 75% reduction in migraine related disability. At face value this is impressive, given that these patients were previously resistant to other treatments and would have had medication detox as well!
Today’s ONSTIM trial is a bit less impressive, but its methods were slightly more rigorous, with an attempt (not to good I must say) at blinding the researchers from whether the patient was stimulated or not. In ONSTIM, 39% of those treated with neurostimulation for chronic migraine reduced the amount of migraine by 50%. Those that did not receive stimulation had no benefit whatsoever.
Is neurostimulation to treat migraine safe?
Neurostimulation is safe, but there is a high chance that the wire connecting the generator to the end of the nerve may move (your neck is a very mobile structure). If you take an average acroos all the studies, 25/94 participants had their wires moved - that means more surgery to re-implant the wire. This is a significant inconvenience, and potential risk. Smaller devices e.g. the BION (TM) microstimulator device are about 30mm by 3mm in size. The BION (TM) contains its own generator and will a major advance if approved by regulatory authorities.
Can I recommend neurostimulation to treat migraine headaches?
At the present time, I would consider it for a very small select group of patients, but I have reservations about the risk of wire movement. To receive a neurostimulator you would ned to have tried all available lifestyle interventions, used prophylactic medication appropriately, and have kept medication to an absolute minimum. At that stage I would still go for occipital nerve injection first, and if that failed a neurostimulator could be attempted (but remember its cost - thousands of pounds/dollars).