The author of this current article1 reviews both the previously published literature and case studies regarding the types and circumstances of posttraumatic migraine.
Trauma has been found to cause migraine since it alters brain structure and functioning. Yet, more evidence is necessary to formulate a solid idea of the relationship.
In some cases trauma may be the sole precipitating factor. Usually, a migraine attack occurs immediately following trauma. These instances can be marked by blindness, confusion, and impaired consciousness. Some studies have shown a familial pattern with migraine. Patients with mild head injury (MHI) seem to be at a higher risk of developing migraine symptoms if other family members also have a history of migraine.
The author suggests that migraine is an "inborn biochemical dysfunction" that may be triggered by a traumatic event. This is a bit of an overstatement, as there is no definitive proof of such "inborn dysfunction" in the literature.
It is more likely that migraine is simply part of a continuum of headache that is experienced by patients exposed to head or neck trauma. That is, migraine may not be any different than tension headache, but simply worse. This idea has been written about extensively by other authors, including Teasell and McCain.2 Solomon suggests a similar relationship between trauma and headache:
"Headache is one of the most common symptoms of the posttraumatic syndrome, and sometimes the headaches are characteristic of migraine or are migraine-like. Bouts of migraine usually occur upon a background of chronic daily or almost daily tension-type headaches."
He then goes on to summarize the entire phenomenon of mild head injury:
"The posttraumatic syndrome is manifested by somatic (especially neurological), psychological, and cognitive symptoms. Of the somatic symptoms, headache and dizziness are the most common. The headache has qualities of tension-type headache or migraine or both. Dizziness may range from lightheadedness to vertigo. Less common symptoms are photophobia, phonophobia, tinnitus, and easy fatigability."