In approximately 10% of people who suffer from migraines, the actual migraine attack begins with neurological disturbances. The period during which these disturbances can be observed is called the aura. The origin of the word "aura" is attributed to Pilops, a teacher of Galen. Pilops observed the typical spreading phenomenon of migraines. The neurological disturbances began in the hand or foot and gradually spread upwards to the head. As an explanation for this spreading, Pilops hypothesized that cold vapors from the extremities gradually spread upwards through the body to the brain. These rising, air-laden vapors were thought to move in the veins. Accordingly, he called the processes during the neurological symptoms of migraine attacks "air-laden vapor": The word "aura" is the Greek word for vapor. Modern concepts regarding the origin of migraines assume that during an attack, the function of the cerebral cortex is temporarily disrupted, and these disturbances spread over time. It is therefore understandable that symptoms can occur precisely within the functions of the cerebral cortex with all its integrative capabilities.
Migraine aura can affect all neurological and psychological functions of the central nervous system. A characteristic feature of migraine aura is that the symptoms occur episodically in attacks, gradually increasing over a specific timeframe and then subsiding again. Simple, structural changes include, for example, bright sparks, flashes of light, geometric figures such as zigzag lines, circles, sawtooth-like patterns, and other imaginable or unimaginable visual phenomena. These visual impressions can occur singly in the visual field, or they can move across the field in multitudes, almost like flocks of birds. The impressions can be pleasant, interesting to the affected person, and even observed with delighted emotion due to their beauty. On the other hand, they can also be experienced as painful due to their great intensity and, for example, in the case of blindness, be associated with great anxiety and fear. The impressions can be perceived incidentally, as if the glasses were slightly dirty with streaks and a veil on the lenses. Others experience these impressions as if looking through heated air and seeing a corresponding streaky image. Still others perceive their visual impressions like a reflection of the surroundings on a wind-rippled water surface – blurred and restless.