Jan 23 2009

Some Follow Up On Migraines

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Yesterday I wrote about a new Cochrane review of acupuncture and migraines. The most significant result of the review was that published studies show no difference between “real” acupuncture and “sham” acupuncture. This is the part of trials that can be blinded – well, single-blinded at least (the subject does not know which is real vs sham, but the acupuncturist does). This blinded data is negative, indicating that it does not matter where you stick the needles, which is a strong indication that the underlying philosophy of acupuncture is false. Further, now that acupuncture studies are being done with placebo acupuncture – opaque sheaths and dull needles that do not penetrate the skin, allowing for double-blind studies – these are also coming out negative.

Therefore, I think it is reasonable to conclude from the literature that it does not matter where you stick acupuncture needles, or even if you stick them. Therefore, any observed benefit must be either: 1) an artifact of the study design (i.e. placebo effects); or 2) a result of other things that are happening in association with the acupuncture treatment.

Several points were raised in the comments I want to address in some detail. Further, there are many questions about migraines, and since migraines make up a significant portion of my clinical practice I can clear up some of the confusion as well.

Migraines

First some background on migraines.   Migraines are a specific kind of primary headache, meaning that the headache is the disorder and is not secondary to an underlying problem, like a brain tumor. Migraine are variable in their presentation, and so are defined as having some of a list of symptoms. These include unilateral (one-sided), throbbing, can be triggered by various things, and associated with nausea, vomiting, and sensitivity to light, sound, and strong odors. Migraines can also occur with an aura, which is a neurological symptom occuring before or during the headache, most commonly visual changes like dark spots (scotoma) or flashing lights (visual fortifications).

Although there is no objective laboratory diagnostic test for migraines – the standard headache workup will be negative – the diagnosis can be reliably made in many cases based upon a very typical clinical presentation. Of course, the edges are blurry, and some patients overlap with tension or other types of headache. Despite the lack of an objective test, there are documented physiological changes that occur during migraines. There is a vasocontrictive phase which is associated with  a wave of decreased electrical activity (called spreading depression) across the cortex. This is followed by a vasodilation phase. It was originally thought that these vascular changes were what caused the migraine, but now it seems as if this is just one consequence of the deeper physiological mechanisms of migraine.

The current synthesis is that a migraine is an attack, not unlike a seizure, in the trigeminovascular reflex which is mediated in the brainstem. The trigeminal nucleus, which mediates sensation to the face and part of the scalp, becomes hypersensitive, causing a cascade of effects. There is still much we do not understand about migraine physiology, but I am just giving a superficial overview of what we do know.

One more interesting bit – there is a genetic condition known as familial hemiplegic migraine which results in frequent severe migraines associated with stroke-like neurological deficits. The mutation is in a gene for a calcium channel, which is evidence that calcium regulation may play a role in migraine in some patients.

Another aspect of migraine that is important to understand is that it is probably not one discrete entity but a collection of physiological entities that all lead to a final common pathway of trigeminovascular activation. Therefore, different patients with migraine may have significant physiological differences in terms of their triggers and which treatments they are likely to respond to.

The good news is that migraines are very treatable. There are a number of strategies which have to be individualized to the patient. The first consideration is migraine frequency. If a patient is having one migraine every 3-4 months than preventive treatments are not likely to be worth it. You can focus on acute treatments (called abortive therapy, because they are aimed at aborting the migraine in progress).  If, however, someone is having 3-5 migraines per week then abortive therapy has to be minimized and the focus should be on preventive therapy.

Prevention takes several forms. The first preventive therapy to try is always removal of triggers, because they are the safest, easiest, and most effective. The most common trigger is caffeine – which can trigger a migraine when used, or when one is withdrawing from the caffeine. Caffeine withdrawal can cause headaches in non-migraineurs as well, but that is distinct from a caffeine-withdrawal triggered migraine. Either way – remove caffeine, wait a couple of months, and then reassess migraine frequency. Other triggers include bright light, strong odors, lack of sleep (very important and often overlooked) and various kinds of foods.  Therefore step one is removal of triggers and lifestyle changes.

If these measures are not sufficient and headaches remain frequent, then there are a number of supplements and medications that can be effective. Vitamin B2, magnesium, and Coenzyme Q10 have all been shown to be effective for migraine prophylaxis. These can be used as initial prophylaxis for milder cases, in patients who want to avoid medications, or as adjuctive therapy with a prescription medication. The medications that have shown to be effective include verapamil, some antidepressants like amitryptyline, and anti-seizure medications like topiramate.

Although controversial for a while, recent large controlled trials support the use of botulinum injections (Botox) for migraine prevention.  There are several possible mechanisms for this, including the obvious muscle relaxation. But also, the botulinum is known to be taken up by the nerve endings and is transported to the cell body. Therefore it may act in the trigeminal nucleus to inhibit activity and increase the threshold for a migraine attack.

At this point the only way to know which treatment will be most effective for which patient is trial and error. I do anticipate the day, however, when a genetic profile might greatly enhance our ability to predict response.

Abortive therapy involves adequate hydration, treating nausea if present, and treating the migraine attack itself (not just the pain). The two components of the attack that are targetted are inflammation (usually with NSAIDS or aspirin-like drugs), and changes in serotonin. Triptans (like sumatriptan, brand-name Imitrex) target serotonin receptors. For some patients rest is often a critical component as well.

Acupuncture for migraine

You will notice I did not add acupuncture to the list, for the reasons I stated above. The research clearly indicates, in my opinion, that there is no mechanism and no added value to acupuncture needles – whatever you do with them. In response to my post yesterday, Sonic wrote:

Dr. N- I understand what you are saying about the unblinded and sham acupunture. But-

http://www.cochrane.org/reviews/en/ab001218.html
“In the four trials in which acupuncture was compared to a proven prophylactic drug treatment, patients receiving acupuncture tended to report more improvement and fewer side effects.”

If that statement is true, then the ‘rituals’ of acupunture work better than the ‘proven prophylactic drug treatment.’
So wouldn’t it be wise to do what works? That is the actual question, right? If a ritual is a better pain reliever than a chemical- why not use the ritual? (I’ll bet there is less liver damage from the ritual…)

The “liver damage” comment refers to one drug, valproic acid, that can cause liver toxicity. This is an older drug and, although it is one of only two drugs actually FDA approved for migraine prevention, it is rarely used for this reason.  I personally never use it. There are many newer drugs with no organ toxicity to use.

Sonic’s assumption is that, of the two possibilities for a recorded effect that I mentioned above, artifact vs non-specific effects, it is the non-specific effects that are important. I disagree with this. Although we cannot say for sure, the fact that the difference between acupuncture and no acupuncture is unblinded opens the door wide for artifacts. Typically, the people doing these studies are acupuncture proponents. We know from reviews of the literature that if proponents fund studies (let alone actually carry them out) they are much more likely to be favorable. It is probable that subjects who would volunteer for such a study are also open to acupuncture, and may have strong beliefs in it. Therefore most of the people involved in these studies want them to work, and therefore I put very little faith in any unblinded results.

Only tight protocols are of any value in such situations, and the tight protocols are negative. The simplest explanation for that is that acupuncture does not work.

Second – the degree to which the effect is real but due to non-specific effects also does not justify using acupuncture. These non-specific effects include relaxation, palpation of the muscles prior to needle insertion, positive therapeutic attention, expectation, conditioning, and the temporary effect of introducing a novel component into therapy (all proven to have a measurable effect). It is unscientific to conclude that a specific intervention (acupuncture in this case) works because of non-specific effects.

In my reviews of these studies the control group getting standard medical treatment is inadequate as a control. Typically they give a single drug, often underdosed or for too short a period, and not comprehensive migraine treatment as I outlined above. This leaves the door wide open for non-medical interventions that are known to work and which can ride along with the acupuncture to give the appearance of an effect.

What this means is that we should eliminate acupuncture entirely from the equation. Any benefit from the ritual of acupuncture can be derived by using the non-specific elements stripped away from the pseudoscience of acupuncture itself. This already is done – with massage, relaxation therapy, biofeedback, stress reduction, or just plain exercise – all of which improve migraines.

Conclusion

This brings me back to the original reason for my post yesterday – it is highly deceptive to conclude from this recent review that “acupuncture works.” That is a lie, or a gross misinterpration of the science. Rather, we can conclude from these reviews the exact oppostive – that acupuncture does not work. We need to finally set aside the needles (which, btw, have their own complications) and all the pseudoscientific claims that come with them. They are a distraction, they are insidious in that they instill unscientific and bizarre beliefs in the public that will cause mischief downstream, and they are a scientific dead-end.

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