Migraine and related headaches are responsible for 20% of all clinic visits, and they are the leading cause for loss of man-hours at work. It’s no exaggeration to say that not only is migraine a problem for the sufferer – it’s a headache for employers as well!
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Do frequent episodes of migraine lead to structural brain damage[/caption]
A major concern for doctors and migraineurs alike is the burning question – do frequent attacks of headache lead to any lasting damage to the brain? Does a life-long battle with migraine leave scars in the brain? Do my headaches mean I am going crazy or demented?
I did my own search of the literature on this subject, and here’s what I found.
What is Migraine?
Migraine is a common neurologic disorder – migraneurs tend to have attacks of one – sided throbbing headaches along with other symptoms. There are several variants to this basic description.
About one – third of migraneurs found to have an additional symptom either prior to or during the attack, called an aura. These attacks are classified as Migraine with Aura. Other attacks are classified as Migraine without Aura.
Traditionally, migraine has been considered to be a benign disorder without long – term consequences for the brain. If a scan is done for a patient with migraine, it’s to exclude other causes for headache. Many times these imaging procedures reveal abnormalities of non – specific nature in the white matter, labelled as White Matter Abnormalities (WMAs); occasionally, revealing something called Infarct – Like Lesions (ILLs), which may be of concern for both doctor and patient.
Emerging data suggest that these silent lesions may be more frequent among migraneurs.
Recently a meta-analysis of all these studies was published in the journal called Neurology. A meta-analysis is sometimes very useful: the researchers sift through the available literature, eliminate those studies which don’t meet their criteria, sort them in terms of quality, reliability, and availability of relevant data, and then make an attempt to draw their own conclusions – taking cognizance of the fact that the studies may not have been done for exactly the same purpose.
Meta-analyses have limited utility, but are important nevertheless for us to look back and wonder.
The authors pooled data from 6 population – based and 13 clinic – based studies. These studies used MRI to characterize certain changes in the structures in the brains of patients who had migraine.
From this review, the authors concluded that migraine may be a risk factor for structural changes in the brain. In comparison to non – migraneurs, migraneurs have more WMAs and ILLs.
There was an association between WHITE MATTER ABNORMALITIES (WMA, see picture) and Migraine with Aura. This association was true for women, though, and not for men.
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White Matter Abnormalities are non – specific and may not signify any major brain damage[/caption]
There was no association between frequency of migraine attacks, or treatment of migraine – whether preventive or abortive (with Triptans).
The lesions increased in number as the condition became chronic (long-duration), but there was no association with cognitive decline, memory problems, or dementia.
Whether these lesions increase in number with increasing frequency of migraine attacks is not yet clear from the studies.
The clinical and functional significance of these lesions is uncertain.
The AAN and The American Headache Consortium do not recommend MRI for migraneurs who have a normal neurological examination. Only patients with an atypical headache, a recent change in headache pattern, other symptoms (such as a fit), or focal neurological symptoms or signs are recommended for MRI of the brain.
Patients with WMAs can be reassured; those with ILLs should be evaluated for stroke risk factors.
In the future, additional longitudinal studies with a broad range of disease frequency and severity are needed to fully understand:
- the association between migraine and structural brain changes in the MRI
- to clarify the association between attack frequency and disease duration
- the influence of the lesions on brain function and prognosis
- the role of drugs used for migraine – prophylaxis in preventing progression of lesions