Millions of people experience migraines, a type of headache that is often severe and can be disabling. In most cases, migraines occur without warning signs. However, some people who get migraines experience a variety of mostly visual sensations that come before and sometimes accompany the pain of a migraine attack, a condition called migraine with aura.
Most often, a migraine with aura is characterized by visual disturbances such as flashes of light, patterns or blind spots. However, a migraine with aura may also be accompanied by other sensations such as numbness or tingling in parts of the body and speech problems.
The migraine aura sufferer will first notice a black spot in the field of vision. This black spot is often surrounded by flashing lights or bright zig zag lines. The size of the black spot gradually enlarges over a period of minutes. The combination of loss of vision with flashing lights or zig zag lines is a typical and distinctive feature of migraine aura.
The aura is due to changes that take place in the cortex, the outer layer of the brain. A spreading depression of nerve cell activity is believed to account for the pattern of development of the typical aura. In the migraine aura, symptoms build up gradually and move slowly from one visual region or one part of the body to another.
Changes in body chemistry, certain foods, and dozens of environmental influences such as a change in weather, can trigger the attack. These internal or external events stimulate different nerves of the brain, and these nerves relay the stimuli to one or more nerve centers in the brain stem. From these brain stem centers, another set of nerve impulses are sent to the cortex of the brain, causing the aura.
The blacking out of vision is due to depressed nerve activity. The illuminated visual symptoms are due to the resulting zone of hyperactive nerve cells. A sudden shutting off of blood supply to certain areas of the brain cause a gradual loss of function.
While pain relievers may relieve migraine head pain, there’s no treatment for relieving the aura component of migraine with aura. Preventive medications and self care measures, including avoiding migraine triggers, may help prevent a migraine with aura.
Cannabis was a standard treatment for migraines from 1874 and 1942. It has been reported to help people through an attack by relieving the nausea and dulling the head pain as well as preventing the headache completely when used as soon as possible after the onset of pre migraine symptoms such as aura. A pharmaceutical company is currently conducting trials of a cannabis extract nasal spray for migraine.