Epilepsy and Migraine: A Common Ground?
Epilepsy and Migraine: A Common Ground?
Migraine and epilepsy have several things in common: they often co-occur and share similar symptoms, each is generally undertreated, one is often misdiagnosed as the other,1 and various medications are effective in treating both disorders.2 Recent research may help elucidate the relationship between the two and shed light on more appropriate diagnosis and treatment options.
“Patients with migraine are more likely to have epilepsy, and patients with epilepsy are more likely to experience migraine,” Pavel Klein, MD, director of the Mid-Atlantic Epilepsy and Sleep Center, told Neurology Advisor. In fact, people with seizure disorders are twice as likely to experience migraines which can often lead to misdiagnosis.3
There are commonalities between the two disorders “in clinical symptomatology, particularly with regard to visual and other sensory disturbances, pain, and alterations of consciousness.”3 For instance, if a patient has a migraine that causes focal neurological symptoms — numbness in the arm or face, for example — it can appear to be a seizure. It is also known that stress can trigger seizures, and in a less common scenario, “in someone with very severe migraine, it is possible that the stress of the pain could trigger a seizure,” Klein explained.
The potential reasons for the close relationship between the two disorders are just as varied. “There could be common substrates that cause both headaches and seizures,” said Klein. For example, a condition called benign epilepsy of childhood is commonly associated with migraine and is often misdiagnosed as such,3 while another possibility is that migraine could lead to mild forms of brain damage that increase the risk of epilepsy. Studies have found that MRI of some patients with migraine show small areas of abnormal lesions or scarring.4,5 Researchers are not yet sure of the cause, but it is possible that the scarring is a result of a stroke that is otherwise asymptomatic, and the “scarring leads to reorganization of the local network that could lead to seizures,” said Klein.
What Role Do Genetics Play?
Research published in Epilepsia in 2013 was the first to investigate the role of genetics in the co-occurrence of migraine and epilepsy.5 After testing 730 participants with epilepsy, researchers divided them into two non-overlapping groups — one with migraine with aura and one with migraine without aura — and interviewed participants about their family history of seizure disorders. The results showed that a history of migraine with aura was “significantly increased in enrolled participants with two or more additional affected first-degree relatives,” supporting the researchers' hypothesis of a shared genetic susceptibility to migraine and epilepsy.
“The hope of scientists, caregivers, and families with epilepsy is that genetics will offer a novel and wider understanding of the causes and the pathophysiology of epilepsy,” study co-author Melodie R. Winawer, MD, MS, an associate professor of neurology at Columbia University, told Neurology Advisor.
Approximately two thirds of epilepsy cases have no known cause, and genetic factors may play a critical role in that subset of cases. A ground-breaking aspect of these findings is in regards to reconceptualizing disease boundaries.
“A disorder does not stand alone but can be seen as part of a network of intersecting disorders — in fact, there have been intersecting bidirectional relationships identified for epilepsy, migraine, anxiety, depression, suicidality, and psychosis,” she said. “As we start to understand that some of these disorders are occurring in a network or a cluster rather than standing by themselves, I think it is going to completely transform treatment strategies” and potentially affect preventive efforts.
Ultimately, the knowledge of a shared pathophysiology could lead to the development of new treatment options, as well as recognition of accompanying disorders beyond seizures that can severely impact a patient's quality of life.
After all, failing to treat co-occuring disorders is a disservice to patients, said Winawer. Treatment of any condition — including migraine and epilepsy — should consider potential comorbidities that could worsen or improve depending on the chosen treatment. “We really need to understand epilepsy in its context,” said Winawer. “There is a huge move in the last few years to do that and I think this work is part of that larger question.”
- Davies PTG, Panayiotopoulos CP. Migraine triggered seizures and epilepsy triggered headache and migraine attacks: a need for re-assessment. Journal of Headache Pain. 2011; 12(3): 287–288.
- Nye BL, Thadani VM. Migraine and Epilepsy: Review of the Literature. Headache: The Journal of Head & Face Pain. 2015; 55(3):359-80.
- Epilepsy Foundation. Seizures and Headaches: They Don't Have to Go Together. Retrieved on 9/28/15 from http://www.epilepsy.com/article/2014/3/seizures-and-headaches-they-dont-have-go-together
- Scher AI, Gudmundsson LS, Sigurdsson S, et al. Migraine headache in middle age and late-life brain infarcts. JAMA. 2009; 301(24):2563-70.
- Kruit MC, van Buchem MA, Hofman PA, et al. Migraine as a Risk for Subclinical Brain Lesions. JAMA. 2004; 291(4):427-34.
- Winawer MR, Connors R, EPGP Investigators. Evidence for a shared genetic susceptibility to migraine and epilepsy. Epilepsia. 2013; 54(2):288-95.