A perceptual disturbance experienced before the onset of some migraine headaches and seizures. Scientists believe that auras are caused by disruptions in the neurotransmitters, the chemicals that carry signals from one nerve cell to another.
The symptoms of an aura vary considerably from person to person. Most commonly, they take the form of visual disturbances, such as various shapes, bright spots, zig-zag lines, flashes of light, a vibrating visual field, or even temporary vision loss. According to the Mayo Clinic, the best-known visual aura is called a fortification spectrum, which begins as a pinpoint of light or bright geometric line or shape and may expand into a sickle or C-shaped object with zig-zag lines.
A sensory aura, which may or may not occur in conjunction with a visual aura, may take the form of tingling, a “pins and needles” sensation in an arm or leg, or a feeling of numbness that can travel up the arm to one side of the face or tongue. Sometimes the face or limbs may become numb on one side of the body. An aura may also cause temporary difficulties with language or speech. People may also smell odors that aren’t there. If you experience symptoms of an aura, especially if you don’t know their source, contact your doctor immediately.