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Migraine

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 Understand and Prevent Migrain

 

People who suffer from intermittent attacks of migraine know the symptoms all too well, the inconvenience of unexpected attacks, the frustration of “cures” that have not worked, and the expense of lost work and healthcare.

Understanding migraine – the different types, the symptoms, and the possible causes -gives you the knowledge to deal more effectively with your condition.


Migraine is a condition that can affect anyone at any time. Some people are more likely to experience migraine attacks than others but, if the right mix of conditions come together, almost anyone can experience a migraine. It is a condition that affects not just you and your quality of life but your family and friends and colleagues as well. How often have you had to miss a family party, not been able to make an important meeting, had to go to bed early or lost the first three days of your holiday just because of your migraine? By its very nature, migraine is unpredictable. We all like to feel in control of our lives but migraine can strike at any time and often at the most inopportune time. The more you, as an individual, understand about your migraine and how it affects you, the greater chance you have of being able to control your migraine. Or at least feel in control of it some of the time if not all of the time.

 

(45) Migraine

Migraines Caused By Bipolar and Depression Disorders

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ALL ABOUT MIGRAINE

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Research and the future

 You need to understand what scientific research is about before you can understand how to interpret the results that make the headlines. You need to be sure that the information presented is not just spin before you can decide that a treatment or intervention is worth the risk and does actually offer any benefit. I hope that what follows answers some of your questions as to what research is all about and what the future might offer the headache sufferer.

The internet has ensured that a vast amount of information is readily accessible. However, you need to be sure that the quality of that information is high and relevant to you. The best place to start is usually the UK-based headache charity websites. They will often have links to other reputable and well-researched websites. Try to stick to UK-based sites, as some drugs and interventions mentioned on sites in other countries may well not be available in the UK.

RESEARCH: THE WHYS AND WHEREFORES

Why is research important?

There would be no new drugs without research. Research is crucial to our understanding of how the brain works – without that knowledge, scientists and clinicians would not be able to suggest ways of tackling medical conditions and altering or modifying the progress of disease.

Without research we would not have brain scanners, we would not have triptans and we would not know the best and safest ways of repairing holes in the heart or removing brain tumours.

Why is research relevant in migraine?

Research is relevant because without asking questions we cannot understand what is happening, and without knowing what is happening we cannot find ways of changing or modifying it.

In the context of migraine, if scientists had not found out about 5-HT receptors and what they do, we would not have had triptans.

As more is understood about 5-HT receptors, better triptans or other drugs can be developed that work more effectively.

What is ‘anecdotal’ evidence, and why do we have to prove that something works when people I know tell me it works?

When choosing a holiday or a place to stay, listening to someone else’s experience can be helpful in deciding whether you want to go to a particular place or stay in the same hotel. The downside is that if, when you get there, the weather is bad or the hotel is run by different people, your experience might not be as good – so you would never go there again.

A few days, weeks or months later, someone else goes there and has a great time – do you go back or not?

That is decision-making based on ‘anecdotal’ evidence. If you reflect on the example above and transfer that sort of decision-making across to medicine, the issues raised and challenges faced become potentially quite difficult and in some instances even life-threatening.

Any decision you make needs to be sound, safe and cause no harm, hence the need for research and, above all, good research.

What is good research?

Good research is about making sure you ask the right question, in the right way, and set about answering that question using all the right resources, in the right way.

In the context of migraine and triptans you need to evaluate a series of features and factors.

To name just a few:

• Is this drug safe?

– in everyone?

– in the young?

– in the elderly?

– in those who are pregnant?

• Does the drug work?

• Is there a right dose or an optimal dose?

– does the maximum dose cause too many side effects?

– does the dose vary in different age groups?

• Is the patient headache-free?

– in one hour?

– in two hours?

– in four hours?

• Is the headache only eased?

Any piece of research must be able to answer all of these questions and many, many more.

How should good trials be constructed?

Agood trial needs a clear starting point, which means asking a clear and precise question or series of questions.

In the context of preventative drugs or interventions:

• Will X reduce the total number of headache days?

• Will X reduce the total number of headache days by more than 50%?

• Will X make the headache easier to treat with current acute treatment?

• Does X cause side effects?

• What are those side effects?

• Are those side effects sufficient to cause the patient to stop taking the drug?

• Does X perform better than a placebo?

• Does X perform better than the drug the patient was using before?

• Does X perform better than the ‘gold standard’ or most commonly used drug for, in this case, migraine prevention?

The patients recruited to the study must have the correct diagnosis; in this case the standard is migraine as defined by the International

Headache Society

There must be enough people recruited to the study to ensure that any statistical analysis will have value. There should at the very least be a placebo or ‘dummy’ group, and, if feasible, a comparison with a drug already used to treat the condition. No one, that is to say neither the people who are co-ordinating the study and reviewing the patients in the study nor those involved or participating in the study, should know if they are taking active drug or placebo (this is called ‘double blind’). If there is a placebo group, it is always interesting to swap this group over to the active drug and assess their response, and vice versa (referred to as ‘cross over’).

There has to be a baseline period to collect and collate information, in the form of diary cards, to better understand the group being studied. Patients in the trial must stop all other drugs that may have been used, usually for a minimum of four weeks.

There needs to be a minimum number of headache days and a maximum number of headache days recorded within this baseline period, so that patients meet clear recruitment criteria.

Once the trial drug is started, there must be a clear method of increasing the dose, over fixed time intervals, to monitor how effective it is and any side effects (adverse events). There is often a balance between effectiveness and side effects. There must also be a clear way of recording side effects, and identifying at what dose these develop.

The study drug has to be taken long enough to ensure that the full effect of treatment (e.g. maximal reduction in headache days) is recognised and seen, and a follow-up to assess how long the benefit is felt (e.g. for three months? six months?) or sustained.

How is a decision made, based on trial information?

This is never easy but initially it is important that enough patients were recruited to give value to the study: 300 are better than 30.

The statistics are examined to see whether they reach ‘significance’ and that should be highlighted in the conclusions or even the initial abstract of the report. It will often say that the ‘difference was statistically significant’ and quote a ‘probability’ (p) value – the result of the statistical calculation made.

There may be times when the study did not go on long enough and so the results did not reach statistical significance, or the study recruited enough patients to reach statistical significance in one area but not in another.

It is often difficult to tease out the detail from an article or scientific paper but the bottom line in acute drug treatment for migraine is:

• Is the patient headache-free at 2 hours?

• Is there a sustained pain-free response?

• Does ‘rescue’ medication have to be taken?

• Are the side effects less than with a placebo?

And, for preventative drugs:

• Is there a reduction in the total number of headache days?

• Is there a greater than 50% reduction in headache days?

• How long did the drug have to be taken for an effect to be seen?

• At what dose did the drug need to be taken for maximum benefit to be achieved?

• Are the side effects less than with a placebo?

As is often the case, there is a trade-off between effectiveness and side effects. Decision-making is never easy, and rarely straightforward.

There is no drug out there that will fix all of your headaches all of the time. Hopefully, as more is known and understood about headache symptoms, newer drugs will be developed that work well.

How can I become involved in research?

There are always trials going on somewhere, and the best source of information is probably the headache charities.

Alternatively, many of the specialist headache centres around the UK will be involved in research of some sort, although not always drug-based research. Some research uses special types of brain scan to understand more about what happens in the brain; other trials are about understanding more about what effect migraine and other headaches have on your life – impact studies. Other types of research are looking at interventions such as acupuncture or osteopathy to see if they help headache patients.

How are patients selected for trials?

Patients tend to be selected on the basis of their headache diagnosis in the first instance, then on their age and whether they are interested in being involved. You need to be aware that you may not be given any active drug or intervention but will be given the dummy or placebo drug or intervention instead.

There are always strict inclusion and exclusion criteria that depend on the question being asked. If the trial is for acute treatments, you have to be prepared to use only the trial drug for a series of attacks; often patients are selected only if they have never treated their

migraine with anything other than simple painkillers; it just depends. If the trial is for a preventative drug, there are other inclusion and exclusion criteria that apply. For example, the number of headache days each week or month, how many different preventative drugs you have tried in the past and at what doses you tried them, whether you took them for long enough.

How do I know that a new drug is safe to take?

This is always difficult to answer, as newspaper headlines sometimes attest. Drugs will have gone through significant assessment and evaluation before they are given to humans, but all animal and computer models are just that – a model. There is no way to predict exactly what effect a drug will have on the human body until it is administered for the first time.

If you want to become involved in a drug trial, you will be given a lot of information to read, absorb and understand. It is your responsibility to make sure that you clearly do understand and ask all and any questions that need an answer before you are ready to sign the consent form.

In many ways there is no way of knowing a drug is safe until it has been used for many years. Drugs that have been used for decades have been found to be associated with previously unrecognised risks.

Sometimes it is about weighing up the balance of potential and theoretical risk against the benefit you get.

If I agree to be involved in a trial and I feel that I am getting worse, can I opt out?

You can opt out at any time. When you do so you will be asked a series of questions so that the researchers doing the trial can understand why: this helps them assess all potential problems associated with the drug or intervention they are investigating.

 

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 What to expect: BOTOX® treatment for chronic migraines

FDA Approves Botox to Treat Chronic Migraines

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Botulinum Toxin and Headache: Does it help?

Botox is one of those areas where everyone knows someone who feels that it helped them. The evidence, however, is not quite so positive, which is always disappointing, especially with such positive anecdotal experiences.

What is Botox?

Botox is a brand name for botulinum toxin A. Botulinum toxin is a neurotoxin, and is produced by a particular bug (bacterium) called Clostridium botulinum, which can cause botulism. Botulism is a condition of paralysis that affects both sides of the body and was thought, in the early 19th century, to be caused by eating spoiled sausage. The Latin for ‘black sausage’ is botulus, hence botulism.

The toxin was first used to treat spasm in muscles, hence the popularity now with people wanting Botox injections for their facial wrinkles. It is also used to treat muscle problems in a wide range of conditions, including muscle spasm in people who have had a stroke and, more recently, for patients with headache

Is there any evidence that Botox can help tension-type headache?

Half of the studies did so far have looked at Botox and tensiontype headaches. Of the good-quality studies there was no evidence to support the use of Botox in treating tension-type headache. Of the middleranking, not quite so good, studies two said it helped and two said it didn’t. It was only the poorest quality studies that found it could help.

Is there any evidence that Botox can help migraine?

As with tension-type headache, one has to reflect on the quality of the studies and again it was only the poorest studies (three) that suggested it could help with migraine symptoms. The better studies gave conflicting reports, one saying it helped and the other saying it did not.

What constitutes a good Botox study?

As I have indicated in the first section of this chapter, there must be enough patients in both the active and the placebo groups. It is crucial that the patients taking part have the correct diagnosis, be it tension-type headache or migraine. Many of the studies on Botox were small, and may well have been too small to show a significant difference between the active and the placebo groups.

With Botox there must be consistency of the injection site among individuals and among study groups. There must also be standardization of the dose of Botox, and different doses need to be used to see which dose, if any, is effective.

Is Botox safe?

Although Botox is a toxin, it is generally accepted that it is safe at low doses. In the studies that looked at the use of Botox, side effects were reported more commonly in the treatment groups than in the placebo groups.

The sorts of side effects reported included:

• Facial weakness

• Difficulty swallowing

• Disturbed/unusual local sensation

• Pain at the injection site

• Muscle cramps

• Flu-like symptoms

• Feeling of weakness of neck muscles

• Transient, short-lived weakness of the eyelids or neck, or both

• Transient pain in the neck or jaw joint

What about the future and Botox?

There is no doubt that, before a final decision is reached about Botox, we need good studies that look at the different headache types, including migraine, tension-type headache and medication overuse headache, as well as cluster headache.

There must be studies that look at the dose needed to produce benefit and at exactly where those doses should be injected. There also needs to be adequate recording and documentation of side effects in both the treatment and the placebo groups.

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 Migraines are quite common among people with bipolar disorder

Migraine and Bipolar Disorders

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INJECTION OF THE GREATER OCCIPITAL NERVE

 Nerve ‘blocks’ have been used to relieve the pain in a variety of situations and medical conditions, including the following:

 

  • Pain control during surgery, avoiding the need for a general Anaesthetic
  • Pain control for patients with fractured bones
  • Neuralgia resulting from local injury or trauma to the nerve
  • Nerve pain caused by cancer

 

What is a nerve block?

Anerve block is a way of altering or modifying the response of a nerve so that pain cannot be felt or experienced. It can be done in a variety of ways, including the injection of a local anaesthetic, usually between the site of injury or damage and the spinal cord, thereby altering the pain response.

Another method uses a high radiofrequency signal that causes the nerve to become hot, resulting in damage to the nerve and thus in a permanent break of communication between the nerve, the spinal cord and therefore the brain. Traditionally this was done by heating the nerve to 80ºC for 60 to 90 seconds, resulting in the destruction of the nerve. Currently a ‘pulsed’ method is used with a more gentle process, gradually heating the nerve to 42ºC for 10 to 15 minutes, which means that the nerve is not destroyed but the pain response is altered.

In some patients – usually only those with life-threatening or terminal conditions – the nerve might be destroyed by injecting it with a solution designed to kill it.

What is used when doing a nerve block?

Different specialists and different centres use different drugs and drug combinations. Generally, a local anaesthetic is used and this can be combined with a steroid. Studies looking at occipital nerve block have considered both local anaesthetics alone and local anaesthetic combined with steroid.

What can be done to make the nerve block as effective as possible?

Generally speaking, the right balance of local anaesthetic and steroid must be used and has to be injected in the right area to produce the desired nerve block.

Are nerve blocks safe?

In the right hands, yes, they are but remember that no procedure or intervention is totally without risk. There is always the chance that the nerve is missed and no benefit achieved. There is a chance that an infection may develop at the injection site but if appropriate sterile techniques are used this should not occur. If the needle is slightly out of position then other nerves may be affected, but this effect will wear off. If too much drug is used, the effect may be prolonged – often not a bad thing.

What is a greater occipital nerve block?

The greater occipital nerve is shown in Figure 16.1. The nerve is located by the clinician who is doing the block, using specific markers on the scalp, and the area is palpated (felt) to find where there is maximal tenderness – basically where it hurts the most. The skin is cleaned, the needle is inserted and a mix of steroid and local anaesthetic is injected over an area designed to produce an adequate block.

What is the evidence that greater occipital nerve block is effective for headache symptoms?

The evidence, as always, is mixed. Some studies show that it can help some headaches but others are less conclusive. There is no doubt that nerve blocks are very helpful in the management of neuralgia, but the current evidence base is by no means conclusive in relation to headache.

There must be a range of good-quality double-blind placebocontrolled trials looking carefully at the response to occipital nerve blocks in patients with each of the different types of headaches, including migraine, tension-type headache and medication overuse headache as well as cluster headache.

WHAT ABOUT ‘HOLES IN THE HEART’? PFO AND MIGRAINE

Of all the things to hit the headlines recently ‘hole in the heart’ – patent foramen ovale (PFO) – has, in many ways, been the most exciting but also the most controversial. There is no doubt that there is an association between a PFO and migraine. There is also no doubt that closing a large PFO to try to prevent stroke may be appropriate, but the big question is: are the potential risks of surgery worth it in the context of migraine? At the time of writing, the evidence does not support PFO closure, despite the high level of interest and enthusiasm generated by anecdotal evidence.

What actually is a patent foramen ovale?

Aforamen ovale is the opening between the two upper chambers of the heart – the atria (singular = atrium) – that allows the blood to circulate oxygen safely and effectively in the fetus (baby) during pregnancy. After the baby is born the foramen ovale closes in 75–85% of cases. If it remains open, it is called ‘patent’, hence the term patent foramen ovale, or PFO.

The atria normally allow blood to pass from the venous circulation to the ventricles. On the right side this means blood passes from the body to the right ventricle and from there to the lungs, collecting oxygen along the way before passing back to the left atrium, to the left ventricle and from there back to the body.

What conditions might be associated with a PFO?

APFO has been recognised coincidentally at post-mortem in up to 30% of individuals. Most people with a PFO have no symptoms related to its presence. As patients with specific medical conditions are looked at more closely, the picture seems to change a little, but this is an association; deciding on cause and effect is something else again.

 

  • Stroke: In people who have had a stroke under the age of 50 years, between 40 and 60% had a PFO; the larger the PFO the more likely they were to have had a stroke.
  • Divers: As many as 60% of divers who have had recurrent bouts of decompression sickness (‘the bends’) have been found to have a PFO.
  • Migraine: Studies so far have found that 22–57% (higher than the ‘control’ population) of patients with migraine with aura have a PFO, and 14–21% (similar to the ‘control’ population) of those with migraine without aura have a PFO.

 

How can a PFO be diagnosed?

There are a variety of techniques used to diagnose a PFO, including:

 

  • Transthoracic echocardiography (TTE, through the chest)
  • Transoesophageal echocardiography (TEE, through the oesophagus, the tube from the back of your throat to your stomach)
  • Transcranial Doppler (TCD) imaging (through the base of the skull) An echocardiogram is a way of looking at how the heart is pumping.

 

It uses ultrasound waves to produce a visual display of the heart on a monitor.

A contrast transthoracic echocardiogram was used to screen patients for the MIST (Migraine Intervention with STARFlex Technology) study.

The MIST study was the first to have a placebo, or sham, part to the study. Patients selected for the study had migraine with aura and had failed to respond to two previous preventative drugs. Patients in the placebo group were taken to the catheter lab, anaesthetised and had an incision made so they had no way of knowing whether they had had a device fitted. This was done because it was recognised that the highest quality study was needed to answer the questions relating to PFOs and migraine, and whether PFOs should be closed if found in migraine sufferers.

How can a PFO be closed?

PFOs are closed using any of a variety of devices; the one used in the MIST trial was called STARFlex. This can best be described as a double-layered umbrella that, when opened, can sit either side of the hole and cover it up, hence it is ‘closed’.

How does the implant get to where the PFO is in the heart?

Atube (catheter) is inserted into the femoral vein (a vein in the leg) and moved through the venous system to the heart. This is done in a sterile operating theatre under the guidance of echocardiography, which allows the surgeon to see exactly where the catheter is and to make sure it is put into the right place.

The safety of this sort of procedure depends in large part on the skill of the surgeon. No procedure is without risk but complications on the whole are fortunately rare; they include:

 

  • Short-lived heart arrhythmias (irregular heart beats)
  • Damage to the vein, or bleeding at the site where the catheter is inserted
  • Damage to the heart muscle
  • Reaction to medication used during the procedure

 

In the MIST study the complications in the active group included:

 

  • Cardiac tamponade (pressure on the heart from fluid collecting in the sac around it)
  • Pericardial effusion (fluid collecting in the sac that surrounds the heart)
  • Retroperitoneal bleed (bleeding within the abdomen)
  • Atrial fibrillation (an irregular heart beat)
  • Chest pain

 

And in the placebo, or sham, group:

 

  • Bleeding at the incision site (where the catheter is inserted)
  • Anaemia
  • Nose bleed
  • Brainstem stroke

 

Will closing a PFO really cure migraine?

The answer to your question is that closing the PFO will not completely ‘cure’ your migraine. It may reduce the number of headache days you have but so will a variety of other drugs or interventions. Closing a PFO is not without risk and needs to be considered

very carefully. The MIST study showed that there was a 37% reduction in the number of headaches in the intervention group compared with 17% in the placebo group. This suggests that closing the PFO on the basis of the current evidence is no better than current preventative options

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