The international classification of headache disorders lists many different types of migraines – migraine with aura, hemiplegic, retinal, chronic, and others. Chronic migraine is present if a person has a headache on 15 or more days each month. If the headache is present on fewer than 15 days, the condition is called episodic migraine.
The division into chronic and episodic migraine is not based on any scientific evidence. Research by Dr. Richard Lipton and his colleagues showed that patients often cycle from chronic into episodic migraines and back. This happens even without any treatment.
They concluded: “Our data suggest that the use of a 15 headache day/month threshold to distinguish episodic and chronic migraine does not capture the burden of illness nor reflect the treatment needs of patients.”
One damaging aspect of having a category of chronic migraine as it applies to clinical practice is the fact that Botox is approved only for chronic migraines. I know from 25 years of experience injecting Botox that it works very well for some patients who have as few as four migraines a month. Unfortunately, insurance companies do not pay for Botox unless you have chronic migraine. This deprives many patients of this very effective and safe treatment.
The second very costly effect is on the research of new preventive drugs. The FDA requires a separate set of studies for chronic and episodic migraines. These additional trials of the four approved injectable CGRP monoclonal antibodies added many millions of dollars to the development costs. The trials showed good relief for both episodic and chronic migraine sufferers.
Hopefully, the next, fourth classification of headache disorders will eliminate the category of chronic migraines.
