Tag Archives: migraine

New evidence gives supporters of chiropractic a headache

The Conversation

Michael Vagg, Deakin University

A paper was published and much discussed online recently, which demonstrates all the problems that I – and other critics – have with the way research is done and interpreted in the world of chiropractic.

The study looked at the effect of chiropractic neck manipulation on people who have migraines.

On the face of it, the article concerned looks like a pretty fair and well conducted study. Despite the methodological difficulties of randomisation and blinding of participants with manual therapies, a genuine effort was made as part of the study design to allow for this.

The trial was a three-armed study comparing chiropractic spinal manipulation (CMST) with a sham manual therapy and a group who continued with their usual care.

Although the deliverers of the manual therapy would know what they were providing, a level of blinding to treatment allocation was possible. It was refreshing to see as well that they had checked to confirm that the blinding of subjects was maintained throughout the study. This is extremely important in assessing the validity of a study, and as the authors point out

The importance of our successful blinding is emphasized by the fact that all previous manual-therapy RCTs on headache lack placebo._

The outcome measures chosen were reasonably fair and representative of the group studied. The statistical analysis was conventional enough. They had performed power calculations using a reasonable comparator, which again increases confidence in the validity of the results and shows they were taking the methodology seriously.

The robustness of the methodology is likely the reason it was included in the European Journal of Neurology – a solid, second-tier journal with a credible reputation.

I would not quibble with the summary of their conclusion, published in the paper’s abstract, that said:

It is possible to conduct a manual-therapy RCT with concealed placebo. The effect of CSMT observed in our study is probably due to a placebo response.

This is the correct scientific interpretation of the data. If it was a drug trial, we would conclude there was no pharmacologically relevant effect within the parameters shown, and it would be considered a negative study.

How very different then is the analysis of the same study by chiropractors. The Chiropractors’ Association of Australia (CAA) mentioned it in their press release titled saying “chiropractors welcome latest evidence of headaches”. The relevant quote is:

A paper published in the European Journal of Neurology in September 2016 was the latest in a series of papers to confirm the effectiveness of chiropractic health care in treating people with migraines. The study of 104 people in Norway found that Migraine symptoms were substantially reduced as a result of chiropractic treatment.

Critical reporting of this study, such as found on the website of the American Council on Science and Health, throws up some interesting conversations and interpretations in the comments section.

While I don’t generally read online comment sections (apart from this column naturally) it’s worth making the effort in this particular case. The author of that piece has made the same basic epidemiological arguments as I have above, and come to the correct conclusion that it is a negative study.

One of the commenters accuses the author of deliberate bias and makes the following piquant observation:

To show how much spin this “article” has the title could have been: Have a Migraine? Skip the meds, sham and Gonstead CSMT both effective. more than medical care.

This commenter appears to be making the same error of interpretation as the CAA. The point of a three-armed study is to differentiate between the effect of any intervention in the study (due to placebo responses) and the improvement due to simply being observed in an artificial situation (known as the Hawthorne effect).

If a treatment is genuinely efficacious, one expects to see three divergent curves with: a minor improvement in the no-intervention group; a larger improvement in the sham intervention group; and a clearly larger improvement in the true intervention group.

A treatment which lacks effectiveness will produce results in which the two intervention groups are indistinguishable. That is exactly what this study returned. Observe the graphs for yourself.

The graphs that tell the story. European Journal of Neurology

Note carefully that the authors of the original study are careful to claim the only conclusion that can be drawn is that it is feasible to conduct a manual therapy study in a single-blinded fashion.

They made no claims about the efficacy of the intervention apart from the fact it was equivalent to sham, and in fact are explicit about the fact they believe the treatment effects were all placebo. Outright claiming the opposite is a new peak of disingenuousness for supporters of chiropractic.

Another characteristic of treatments which do not have efficacy is that the more rigorous the study, the more the claimed effect disappears into the statistical noise. To be definitive about a lack of efficacy, a much larger study would be needed.

The results above would not inspire me to spend a couple of million dollars on a study with 200 people in every arm. Results like this over the years have killed off hundreds of medications which were being developed by Big Pharma.

Academic chiropractors are in the invidious position of trying to establish that an ideologically-based treatment system has a scientific basis. They should be careful what they wish for when conducting rigorous studies, as they may find their fondest beliefs being dashed on the rocks of reality.

The ConversationMichael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Deakin University

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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Why different painkillers are only effective for certain types of pain

The Conversation

Maree Smith, The University of Queensland

Whether it’s your head, tooth or back, when you’re in pain, it’s hard to think about anything else. If it’s not too strong, some can ride it out. But in many cases, the pain just gets worse and won’t go away until you take something.

Medicines that kill pain are called analgesics and they vary in how they work. No single painkiller can relieve all types of pain. Those that work for mild pain usually have little effect on severe pain unless combined with a stronger painkiller.

If you want to effectively control your pain, you will need to match your medication to its type and severity.

https://charts.datawrapper.de/J2Llk/index.html

Nociceptive pain

Nociceptive pain is caused by damage to body tissue. If the pain is mild, such as a headache or a sprained ankle, commonly used over-the-counter painkillers are effective. These include tablets containing paracetamol (Panadol), aspirin, or non steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Nurofen).

Paracetamol helps to dampen pain signals to the brain. NSAIDs inhibit the activity of the enzymes that lead to pain, inflammation and fever being produced in the body.

If you want to control your pain, you will need to match your
medication to its type and severity. 
Author provided

Combination tablets, which have a small dose of codeine plus paracetamol, aspirin or ibuprofen, can be used to treat moderate pain. In Australia, you can buy these kinds of painkillers only in a pharmacy. Those sold over the counter have brand names such as Panadeine, Aspalgin and Nurofen Plus.

The government recently announced it will make any medication containing codeine available only with a prescription from mid-2016.

It is important to remember the maximum adult dosage for paracetamol is four grams (eight tablets) per day. Taking more than the recommended dose can cause damage to your liver.

Painkillers typically prescribed by a doctor to relieve acute to moderate pain are codeine together with paracetamol tablets (Panadeine Forte) and tramadol tablets, which are opioid pain killers.

The severe pain you experience following a broken bone or an operation usually needs strong painkillers that your doctor would prescribe. This may be morphine given as a tablet or by injection.

Morphine-like medicines relieve pain by interacting with specific proteins called opioid receptors, which are located in the brain, spinal cord and other parts of the body. These opioid receptors are the same ones the body’s own natural pain-killer molecules, called endorphins, use.

Neuropathic pain

Neuropathic pain is pain caused by damage to the nerves. Painkillers such as morphine, NSAIDs and paracetamol that are effective for the relief of nociceptive and inflammatory pain conditions are not effective for the relief of neuropathic pain.

This is because the underlying mechanisms that cause neuropathic pain following nerve injury are different from those that induce nociceptive and acute inflammatory pain.

Medications originally developed to treat depression and epilepsy are recommended as first-line treatments for the relief of neuropathic pain.

Antidepressants alleviate neuropathic pain by boosting the body’s own pain-fighting pathways. This includes boosting signalling in the brain which inhibits pain-signalling at the level of the spinal cord. The detailed mechanisms by which anti-epileptic drugs alleviate neuropathic pain are diverse but the net effect is to dampen pain signals.

Migraine pain

Paracetemol is an effective painkiller for mild pain.
Pete/Flickr, CC BY

Migraine is a particularly debilitating type of pain. It is often accompanied by nausea, vomiting and sensitivity to light and sound. It can last for a few hours or several days.

Migraine affects about 12% of Australians. Some experience auras such as flashing lights or changes in smell perception, which can serve as early warning signs the migraine is coming.

If painkillers such as paracetamol, aspirin, ibuprofen or ergotamine (made specifically to relieve migraine by narrowing blood vessels in the brain) are taken at the onset of the aura, the migraine can often be stopped or its severity reduced. For those suffering a severe migraine attack, prescription medications known as triptans can be effective treatments by reversing the brain blood vessel dilation.

Chronic inflammatory pain

Chronic pain affects up to one in five adults. One of the most common is pain from osteoarthritis, the most common type of arthritis.

Osteoarthritis pain is a chronic inflammatory pain caused by arthritic joint disease, typically in the knee or hip. As the joint cartilage and underlying bone break down, the joint becomes inflamed and this triggers the pain. The first-line painkiller for osteoarthritis pain is paracetamol.

For people with more severe pain, NSAIDs such as naproxen may be more effective. But chronic use of these is associated with an increased risk of side effects, especially bleeding and ulceration of the stomach lining. Less commonly, morphine or strong morphine-like analgesics are prescribed.

Cancer pain

Most cancer pain is caused by the tumour pressing on bones, nerves or other organs in your body. Pain can also be caused by the cancer treatment such as chemotherapy or radiotherapy. Oral morphine-like analgesics taken regularly, often in combination with paracetamol, are prescribed for moderate to severe chronic cancer pain.

Although drowsiness usually occurs at the start of treatment or after a dosage increase, this typically reduces after a couple of weeks. Anti-nausea and laxative agents are given at the beginning of treatment to minimise the side effects of nausea, vomiting and constipation. Nausea usually lasts no more than two to three weeks.

However, as constipation persists, it is very important that laxative use is maintained. For cancer pain involving nerve impingement, your doctor will add a prescription painkiller for neuropathic pain.


This article is part of a series focusing on Pain. Read other articles in the series here.

The ConversationMaree Smith, Executive Director, Centre for Integrated Preclinical Drug Development and Professor of Pharmacy, The University of Queensland

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.
 

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Health Check: what causes headaches?

The Conversation

Michael Vagg, Barwon Health

We all get headaches from time to time. In fact, nearly every second person in the world had a headache at least once in the past year. But these can feel very different, depending on which of the nearly 200 types of headache you have.

More than half (52%) of people will have a tension-type headache at some point in their life, around 18% will get a migraine, and 4% will suffer from chronic daily headaches. These are the most common headache-related diagnoses. Although there are some variations globally, the figures seem remarkably consistent across populations.

Secondary headaches can be initiated by triggering factors such as medication overuse, medication side effects, neck pain, sinus disease or dental problems. These account for small percentages individually compared to the primary headaches, but may be more treatable if the predisposing problem can be sorted out.

Tension-type headache

Tension-type headaches (TTH) feel like a dull or heavy, non-pulsating band of pain, usually on both sides of the head. The name comes from an erroneous belief that overly tight muscles are the main reason for the headache.

TTH usually occurs in episodes, with each lasting from several hours up to a few days at a time. There is not usually much associated nausea, light sensitivity or sound sensitivity.

Chronic TTH is a less common form and is diagnosed when you have experienced at least 180 days with a headache per year. It is generally not aggravated by routine physical activity; it’s just there all the time.

Genetic tendencies explain some of the risk for developing TTH, with your own risk increased threefold if you have an immediate family member with the condition.

Infrequent episodic TTH does not appear to be strongly associated with psychological stress, despite this common belief. Chronic TTH has a stronger association with higher psychological distress, but it is unclear whether this is a cause or effect of having long-term disabling headaches.

Strangely for such a common and problematic condition, there is still little agreement about exactly how the pain is produced in TTH.

The most attractive hypothesis to me is that it represents a “virtual” pain whereby multiple low-grade inputs (likely including inputs that are “almost-painful”, or below the threshold for conscious pain) add up to produce sensitisation of the trigeminal nerve nuclei (the nerve shown in orange below).

stihii/Shutterstock

This turmoil registers as pain referred to the distribution of the head, usually the forehead, temple and back of the head locations. Examination of these areas doesn’t show any abnormalities because in TTH, there is no one driving mechanism of the headache.

Treatment remains almost trivially simple, despite years of research. It’s almost true to say that the proverbial “cup of tea, a Bex and a good lie down” sums it up. Aspirin, paracetamol or ibuprofen plus rest and possibly some cold packs seem to be the most reliable treatment. There is conflicting or negative evidence for almost every other, fancier therapy.

Migraine

Migraine alone is the sixth most disabling condition globally.

Migraines are usually one-sided, associated with nausea and light sensitivity (photophobia) and may also be preceded by idiosyncratic sensory experiences called an “aura”. Aura phenomena can include moods or emotions, such as deja vu, visual symptoms (flashing lights or jagged lines are common) or problems with speech.

Migraine is a clinical diagnosis; there is no objective test that can verify it with our current technology. But compared to the frustration of researching and treating tension-type headaches, migraine has been steadily giving up its secrets over the past decade.

Migraine physiology is extremely complex. The headaches seem to arise because of dysfunctional regulation of the tone of some of the blood vessels inside the skull.

Migraine sufferers – Migraineurs – may have genetic vulnerability to migraines because of overly responsive calcium channels in their nerve membranes or other mutations which result in them having overactive signalling pathways in the brain.

Environmental or internal triggers can provoke these nerves to over-react, resulting in the activation of a reflex pathway. This dysregulation of normal structures causes the headache, nausea, photophobia and phonophobia (sound sensitivity) typical of an attack.

Migraines are often associated with light sensitivity. Rishi Bandopadhay/Flickr, CC BY-NC

The period of headache in a migraine attack corresponds with a rise in the blood levels in the head of a peptide called calcitonin gene-related peptide (CGRP). CGRP is one of the most common pain-inducing signal molecules in the body. When the CGRP falls, the headache goes away. Where the extra CGRP comes from is not clear but it probably is released from the overactive networks of cells in the brainstem.

The most effective group of drugs for migraine are the triptans. So effective and specific are these drugs that the diagnosis of migraine needs to be reconsidered if they don’t abort the headache attacks most of the time.

Triptans work by activating certain subtypes of serotonin receptors in the brain. Taking a triptan early in a migraine attack seems to directly lower the CGRP release and oppose its effects on blood vessels thereby stopping the attack. Triptans are not however useful to prevent frequent attacks of migraine.

Migraine prophylaxis is achieved by several drugs of different classes, with radically differing mechanisms of action. Some are anticonvulsants, which clearly work by suppressing the nerve overactivity typical of migraineurs. Others, such as the beta-blockers (propranolol) and calcium-channel blockers (verapamil) target the nerve endings on the blood vessels. Others which are known to be effective, such as botulinum toxin (Botox) and amitriptyline (Endep) work by means which are yet to be fully understood.

Severe migraineurs suffer years of disability and as a public service I would like to suggest that if you know someone who has severe migraines (you almost certainly do) please read this excellent list of what not to say to them when trying to be sympathetic or helpful.

Chronic daily headache

Imagine that you never had a day without headache. You can remember vaguely the time when you didn’t feel that pounding in the temples, squeezing in the back of the head or piercing pain above the eyes but it seems like another life. Such is the lot of sufferers of chronic daily headache (CDH).

Some headaches begin as as frequent but clearly episodic tension-type headache, or migraine, but then “transform” into what seems to be basically a continuous headache for at least some part of every day.

There are a number of rare headache types which may cause chronic daily headache and diagnosis of the these can lead to specific treatments which work well. This is the role of a neurologist or pain specialist with a special interest in headache.

If you have more than just the occasional headache, it pays to get a proper diagnosis. Jared Earle/Flickr, CC BY-NC-ND

Possibly the most common reason why tension-type headache or migraine can transform is medication overuse, especially short-acting opioids such as codeine. The best solution to this problem is to avoid long-term regular use of codeine for headaches, though the evidence would suggest we may never achieve this goal except by making codeine prescription-only.

Frequent use of triptans is also believed to sensitise the trigeminovascular networks in the brainstem, thereby lowering the bar for triggering of migraine attacks. If the threshold for an attack becomes too low, they may never quite switch off, and one attack will run into the next one.

If you have more than just the occasional headache, it pays to get a proper diagnosis, as the reasons for your headache can be many and varied. Some have specific treatments for them, and others such as TTH seem quite difficult to find a specific treatment for. There are new classes of drug treatment under development, for migraine in particular, so it looks hopeful that future generations may not have to labour under the burden of poorly treated headaches.

The ConversationMichael Vagg, Clinical Senior Lecturer at Deakin University School of Medicine & Pain Specialist, Barwon Health

This article was originally published on The Conversation. (Reblogged by permission). Read the original article.

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