The diagnosis of Migraine

There is no simple blood or urine test to diagnose migraine and neither are there any characteristic or easily measured changes in the brain or other parts of the body. So diagnosis has to rely very much on the doctor’s assessment of the person’s medical history and symptoms. Unfortunately, this is often time-consuming and can be affected by communication problems within a busy general practice.

This issue was recently addressed by the Migraine Action Association. They sent out a questionnaire to new members and to GPs who were members of the Migraine in Primary Care Advisors group. Of particular relevance were questions that asked patients how GPs could best help them, and vice versa, set out below.

Given adequate time and exchange of information, migraine, tension and cluster headache can be separated from each other in most people, though there are some people who either do not quite fit into the readily recognised categories, or who have mixed symptoms.

Keeping a detailed diary of headaches and other symptoms over two or three months can be an especially valuable aid to diagnosis for people in this group.

During the consultation, the doctor will establish:

• the age at which the headaches started
• whether they are acute, chronic or something in between
• how often they occur and how long they last
• what time they start
• how they start, for example whether there are premonitory signs or visual disturbances such as blind spots and zigzag lines in the field of vision.
• the site (one-sided or two-sided) and radiation pattern of the pain
• the pain quality (i.e. round the eye, deep within the brain, on the scalp, throbbing, constant, or stabbing) and
• any associated symptoms such as nausea or sickness, diarrhoea, other abdominal pains, light, smell and/or sound sensitivity, confusion or dizziness

The doctor will also seek information about factors that you think may trigger the attacks and anything that provides some relief. More general questions will explore your overall health, lifestyle, emotional status, and medical history, and whether there is any hint of a family history of headache.

Armed with this information, a diagnosis of migraine with or without aura can usually be made. In a few people, such as those with progressively worsening headache or clinical signs of underlying disease, hospital examination will be necessary. This may include brain scans (X-rays, Computerised Tomography or Magnetic Resonance Imaging), assessment of the health of the arteries feeding the brain and, rarely, measurement of brain-wave patterns (electroencephalography).

To help determine the best treatment, your doctor may ask you to complete a short questionnaire to help assess the extent of any disability caused by your headaches.

The World Health Organisation defines disability as: ‘...any restriction or lack (resulting from an impairment) of ability to perform an activity in a manner or within the range considered normal for a human being’

In the last decade, measuring the level of disability caused by migraine has been found to be a good way to assess treatment needs. The concept emerged because one-third of patients feel moderately or severely disabled by their attacks, and three-quarters have to lie down during an attack. In Europe, 50 per cent of patients say that migraine affects work performance, education, family and social interactions. However, until recently there was no consistent method for measuring disability in migraine.

This problem was addressed by Drs Lipton and Stewart in the USA, who developed the Migraine Disability Assessment questionnaire (MIDAS). This measures disability by first assessing the headache grade. This is done by completing a simple questionnaire. To determine the headache grade and degree of disability, the number of days recorded for questions 1-5 only are added up and the score is read off – the answers to questions A and B are not included.

The method was subsequently validated by 49 physicians in 14 countries, of whom 89 per cent felt it was straightforward to complete. The use of this assessment helps the doctor determine the most appropriate medication for each individual case.