People who experience migraines during middle age are more than twice as likely to be diagnosed with Parkinson’s disease later in their life than those without headaches, according to a new study

Migraines: The Link Between Migraines and Parkinson’s 

What the earlier research stated: Past studies have linked migraine with movement disorders like Parkinson’s and restless legs syndrome, in part based on shared features such as dysfunction in the brain’s responses to the neurotransmitter dopamine, Scher, and her colleagues note in the journal Neurology.

But those studies were limited to groups with specific disorders, so she and her team wanted to look at a broader population sample over time to see if the migraine was linked to later Parkinson’s.

The latest study: The researchers used data from an existing study started by the Icelandic Heart Association in 1967, which included people born between 1907 and 1935.

The men and women were randomly selected to be part of the study group to answer questions about headache symptoms at an average age of 51. If they reported at least one headache per month, they were asked follow-up questions to categorize the type of headaches based on migraine symptoms like nausea, pain on one side of the head, sensitivity to light, numbness, visual disturbance before or during a headache/

Non-migraine headaches include none, or at most one, of those symptoms. Someone who has a migraine might experience nausea, one-sided pain or sensitivity to light. Ocular Migraines are accompanied by flashing or shimmering lights, zigzagging lines, or stars. Some people describe psychedelic images. It may also cause blind spots in your field of vision. include visual disturbance or numbness in addition to any of the other symptoms, according to Healthline.

Of the 5,620 people included in the study, almost 4,000 had no headaches, 1,028 reported non-migraine headaches, 430 had ocular migraines and 238 had migraines.

Typically, Scher said, about a third of migraine sufferers have ocular migraines

In an interview at around age 77, participants answered questions about movement disorder symptoms like hand tremor, weak voice, stiff gait, arm rigidity, slowed arm movement or smaller handwriting.

Almost nine percent of the group reported four or more movement disorder symptoms.

All movement symptoms were more common for people who reported an ocular migraine earlier in life, especially hand tremor and arm rigidity.

Most symptoms were also more common for people without ocular migraines, but the connection was stronger for those with ocular migraines, according to study results.

Only 1.2 percent of the group as a whole reported being diagnosed with Parkinson’s disease. Those who reported ocular migraines were two and a half times more likely to be diagnosed with Parkinson’s than those with no headaches.

While Parkinson’s disease was strongly related to certain types of headaches, restless leg syndrome was more common for people with all types of headaches. The same connection has been found before, Scher said.

“You wonder because it’s a population-based study and done some time ago, whether some of those labeled as a migraine without aura did have aura,” said Dr. Peter J. Goadsby, a headache diagnosis, and treatment specialist at the University of California, San Francisco, who was not part of the new study.

He has almost never encountered a patient with headaches and Parkinson’s disease, but it is interesting to consider headaches earlier in life and Parkinsonism later, he told Reuters Health by phone.

People with migraines with aura tend to be at increased risk of stroke, and some types of Parkinsonism are also related to stroke or stroke risk, but based on these results, stroke doesn’t explain the connection, Scher said.

“We don’t think it’s the medications they’re taking either,” she said.

It could be that people with migraines and Parkinson’s may share a genetic trait that explains the connection, or it may be that those with migraines tend to have experienced more head injuries, which may then increase Parkinson’s risk, she said.

“This is all speculation,” Scher said. “It could be more than one thing and they could work together – genes and environment.”

It would be too speculative to suggest people with headaches could do to reduce their risk of Parkinson’s disease later in life, she said.

Although the study does not have immediate clinical applications, it may have implications for developing new therapies to treat migraines, Goadsby said.

“I’m really hopeful that this will someday lead to better understanding of what a migraine is,” Scher said.

Source: Reuters