According to the United States National Library of Medicine, headaches are one of the most common health complaints. An atypical migraine is a migraine that is not accompanied by typical migraine symptoms.
Migraine headaches are classified into two types, typical and atypical. Typical migraines begin with visual disturbances, called an aura. The headache that follows is severe and usually one-sided, and can be accompanied by nausea and vomiting. Sensitivity to light, sound and physical activity are common symptoms. Atypical migraines involve some but not all of the elements of typical migraines.
Atypical migraines can involve the whole head, instead of just one side. They may include brief but severe neurological symptoms, such as paralyzation of one side of the body. Atypical migraines sometimes present with typical migraine symptoms such as visual disturbances and nausea, but no headache.
The cause of atypical migraines is not known. Doctors speculate that migraines begin when blood vessels in the brain constrict or spasm, resulting in decreased blood flow to areas of the brain. Following the spasm, the blood vessels react by widening, culminating in an acute headache.
Atypical migraines can be treated on an episode-by-episode basis, with medications that lessen the severity and duration of the symptoms. They can also be treated with medications taken daily to prevent episodes.
Atypical migraines can be triggered by stress, specific foods, food additives such as MSG, smoking or alcohol.