Blood vessels, stroke and migraine

Stroke is slightly more common in migraine sufferers. There are two main types of stroke: hemorrhagic, which results from a burst blood vessel in the brain and ischemic, which is due to a blood clot closing off blood supply to a part of the brain. Closure of a blood vessel by a clot can be due to a blood clotting disorder, cholesterol plaque, or dissection of a blood vessel. Dissection is a lengthwise tear in the blood vessel wall.

A study just published by Italian researchers in JAMA Neurology included 2,485 patients aged 18 to 45 years with first-ever acute ischemic stroke. Of these patients 334 or 13% had a dissection and 2151 or 87% had a stroke not caused by dissection. Migraine was more common in the dissection group 31% vs 24% in non-dissection group. These differences are relatively small, but the importance of the study is that it should make doctors consider the possibility of a dissection when a patient with migraines develops a different type of headache or has a new onset of neck pain. If a dissection is suspected, a CT angiogram or an MRA should be done. Luckily, many dissections do not cause strokes and heal on their own. However, we do recommend blood-thinning medications (anticoagulants) for several months after the dissection even in the absence of a stroke.

My previous post described a scientific review on this topic, that showed a two-fold increase in the risk of dissection in migraine sufferers. Another practical aspect of these studies, which is mentioned in that previous post, is that if you suffer from migraines, avoid neck manipulation by chiropractors. If you do see a chiropractor, ask them not to do high velocity manipulations (sudden jerky movements), as I did when I visited a chiropractor.