Migraine is a heterogeneous, polygenic disorder with a spectrum of different symptoms that can manifest among patients. In addition, a single patient can experience variable expressions or different clinical features. This is extremely important, both clinically and from the perspective of patient education. Patients can learn to recognize and differentiate between headaches (eg, fully disabling migraine vs lower-grade migraine), and they can understand that a lower-grade migraine, if allowed to progress, can smolder into a fully disabling migraine in the presence of enough trigger factors or lack of adequate treatment. As such, trigger avoidance and prompt abortive treatment are critical. Among clinicians, awareness of these differing manifestations plays a role in deciding whether to recommend preventative treatment. A patient reporting 5 migraines per month might just have 5 days of headache, or they may be actually be experiencing headache every day and only 5 of them are events that become fully disabling migraines.

Turning to PPTH, there are some fascinating similarities to note. Many experts suspect that most people have the genetics for either migraine or tension-type headache. If 2 individuals are subjected to similar head trauma, the one with tension-type headache genetics may develop a mild to moderate headache that lasts for days to weeks and then resolves spontaneously. The other individual, with a genetic predisposition to migraine, will likely develop a more severe, pounding headache with migrainous features that tends to be longer in duration. For reasons that are not fully understood, some of these headaches will persist indefinitely. Even after months or years, headaches in these patients can continue to escalate in severity and often require more aggressive therapy.

Interestingly, those with no history of migraine who develop migraine-like headaches subsequent to a traumatic head injury will often endorse a family history of migraine, suggesting that genetic predisposition plays a role in the long-term effects of head trauma. In addition to a genetic predisposition, the nature and intensity of the trauma can also certainly influence the subsequent development of symptoms. The injury itself may alter the wiring of the brain in such a way that, along with episodic flares of migraine, the patients experience cognitive dysfunction, vertigo, and other symptoms that affect their daily function indefinitely.

A practical takeaway from this overlap is that, when treating patients who experience head trauma, if the focus of treatment is on the balance, visual, and cognitive issues, there is a tendency at times to overlook the treatment of the headache component. Addressing the patient’s headache symptoms is critically important, as migraine-specific medications not only treat the patient’s pain but can also address the entire PPTH symptomatic complex. Some patients will undergo months and years of concussion rehabilitation and treatment with nonspecific pain medications, but they can experience a more robust improvement in cognition, vertigo, and other symptoms when treated with migraine-specific medications.