What type of headache do you have?
The answer should be simple. The diagnostic criteria set out for each disorder are clear and distinct, however there are many sufferers who’s symptoms blur the boundary between headache types, and will shift from one definition to another as the headache progresses, and they just don’t fit the arbitrary boundaries that have been set by the International Classification of Headache Disorders.
What does this mean for the treatment of these people, and what does it mean for the medical approach to headaches?
In National Headache Awareness week 2018 I was fortunate enough to attend a talk given by Dr Michael Eller on ‘Migraine management and treatment options’. He began the talk with a little of the history of headache management through time and went on to talk about how migraines are classified – in other words how you can tell it’s a migraine compared to other forms of headache. I was a little shocked, but overwhelmingly in agreement with Dr Eller’s comment that the classification system is ‘a little bit silly really’.
Anyone who has been to see more than 2 or 3 doctors for their condition will know exactly why a leading specialist in Melbourne would make such a comment. You will rarely end up with the same diagnosis from the same doctors, and despite the attestation of experts that ‘an accurate diagnosis is essential to good care’ the facts remain that this diagnosis is difficult to obtain.
The classification system is based on the differences in how each headache type looks, but many experts over the years have argued there are more similarities between headache types than there are differences, and that instead of ‘headaches being separated diagnostically by subtle clinical nuances of dubious reliability’ we should view headaches as slightly different manifestations of the same underlying process (Cady et al 2002).
So what does a migraine look like? Some people would say if they have aura then it’s a migraine, but aura only occurs in 20% of cases. Others would say if they feel nausea or the headache throbs then its migraine, but as we will see sometimes that’s not the case.
We have the following definitions according to the International Classification of Headache Disorders (ICHD) 3:
A.At least 5 attacks fulfilling criteria B-D
B.Headache attacks lasting 4-72 hours (untreated or unsuccessfully treated)
C.Headache has at least two of the following four characteristics
3.Moderate or severe pain intensity
4.Aggravation by or causing avoidance of routine physical activity (e.g. walking or climbing stairs)
D.During the headache at least one of the following:
1.Nausea and/or vomiting
2.Photophobia and phonophobia
E.Not better accounted for by another ICHD-3 diagnosis
So to satisfy the criteria for a migraine we could have moderate pain on one side of the head with nausea. Easy right?
So let’s compare to a frequent tension-type headache (TTH):
- At least 10 episodes of headache occurring on 1-14 days/month on average for >3 months (≥12 and <180 days/year) and fulfilling criteria B-D
- Lasting from 30 minutes to 7 days
- At least two of the following four characteristics:
- bilateral location
- pressing or tightening (non-pulsating) quality
- mild or moderate intensity
- not aggravated by routine physical activity such as walking or climbing stairs
- Both of the following:
- no nausea or vomiting
- no more than one of photophobia or phonophobia
- Not better accounted for by another ICHD-3 diagnosis1.
A patient reporting moderate throbbing/pulsing pain on one side of the head with sensitivity to light, but no nausea or sensitivity to sound will not meet the criteria for migraine. Those having a unilateral and pulsing headache will not meet the criteria for tension-type headache either. So what do they have? That depends on the doctor you see. Is it important to know? Probably not.
What about a client with bilateral headache of moderate intensity and no nausea or sensitivity to light and sound? That’s a TTH according to the rules. If we add nausea then it’s a migraine – simple. Unless it’s occurring more than 15 days per month. Chronic TTH can have nausea as part of the diagnosis – so which do you have?
‘it doesn’t matter what you call it, it’s the frequency of headache that’s often going to guide the treatment’.
When your treatment involves stopping the train from leaving the platform at the first station (i.e. decreasing brainstem sensitivity – Melbourne Headache Centre) then it really doesn’t make a huge difference which train you are referring to. We can potentially deal with all of them.