Headache: Vascular or Neurological?

The results of a recent study on high blood pressure meds and headache raises the question if headaches are vascular or neurological.

The study authors did a meta-analysis, which is a review of previously published research. In the 94 studies of four different kids of blood pressure meds that they reviewed, patients taking the drugs reported a third fewer headaches than those who took placebos. Study authors concluded that high blood pressure probably causes headache; that is, headaches are vascular in origin.

Donald Penzien, the director of the head pain center at the University of Mississippi in Jackson, disagrees. While blood pressure meds are used as headache preventives, he says that specialists are pretty sure that headaches are not caused by high blood pressure, but originate in the brain and may cause vascular changes temporarily.

Meds for lowering blood pressure are prescribed even to migraine patients with normal blood pressure and still seem to work. Indicating that the meds work because the characteristics that affect blood pressure also affect the brain. Penzien believes that the participants in the 94 original studies may have had undiagnosed migraine, which is why the blood pressure meds reduced their headaches.

Most evidence points to migraine and tension type headache as phenomena of the brain. An ACHE article by Stephen Silberstein provides a clear explanation of why headaches were originally thought to be vascular and why they are now considered neurological. Here’s an excerpt:

“Until recently, medical researchers believed that tension-type headache was caused by contraction of muscles of the head and neck, and that migraine headache resulted from the expansion (or dilation) of blood vessels in the brain and scalp. The migraine aura was thought to be due to a constriction of the blood vessels, which preceded the dilation and which reduced blood supply to the eyes and brain. These theories made sense to both physicians and patients, since they accounted for the tenderness and the throbbing experienced with these forms of headache, as well as the visual disturbances of aura. However, the vascular (involving blood vessels) theory could not explain many of the other symptoms of migraine, including the mood changes before and after the attack, and the nausea and vomiting that occur during the attack.

“The use of new noninvasive technology, such as MRI, PET and CT scans, along with the great advances in understanding the brain’s biochemistry, have taught us much more about the causes of head pain. As we now know, vascular changes may be an important factor in a headache attack, but they are not the whole story nor the root cause. A reduction in brain activity, rather than blood supply, seems to be linked to the migraine aura. Similarly, there is little evidence that muscle contraction causes tension-type headache. Some researchers think that several stages in the complex pain-producing process are similar for these two distinct headache disorders.”