Migraine aura are fully reversible attacks involving disruption of vision, sensation, balance, strength, cognition, language, or other central nervous system functions. Like a migraine attack, they usually affect one side of the visual field, face, or body, and develop gradually before being followed by a moderate to severe headache. Visual auras are the most common type of migraine aura and may be experienced as bright zigzag lines, flashing lights, difficulty focusing, and blind spots. While it’s most common for the aura to occur in the hour preceding the pain of a migraine attack, the aura can be experienced by itself.
Other types of aura
The visual disturbances described above are the most common aura symptoms, and other subtypes are more rare. However, these types can be very distressing to experience because the symptoms appear quite serious (such as hemiplegic migraine, which can feel like a stroke). It is important to recognise these subtypes so that people can differentiate migraine symptoms from other diseases.
One form of migraine aura arises from the base of the brain (the brainstem). Brainstem aura typically occurs alongside other aura symptoms (e.g., flashing lights, blind spots, difficulty focusing), and can cause difficulty talking, ’spinning’ dizziness (vertigo), ringing sound in the ears (tinnitus) or other hearing issues, double vision, and decreased consciousness. These aura symptoms can be experienced in isolation, or in the hour preceding the pain of a migraine attack.
Hemiplegic migraine is characterised by temporary weakness on one side of the body. Symptoms can range from weakness with numbness and tingling through to temporary paralysis in the arm and leg on one side of the body. Unlike a stroke, the symptoms of a hemiplegic migraine come on gradually and fully resolve once the migraine attack subsides. In comparison, the symptoms of a stroke come on instantaneously and people are often left with permanent weakness. As with other aura symptoms, those of hemiplegic migraine usually occur in the hour preceding head pain, although they can occur in isolation. Hemiplegic migraine can be passed down genetically, referred to as Familial Hemiplegic Migraine, or the condition can happen without any family history – referred to as Sporadic Hemiplegic Migraine.
Migraine with retinal aura causes fully reversible visual disturbances in one eye, such as shimmering or flickering of vision, blind spots, or blindness. Symptoms last anywhere from 5 minutes to one hour and are usually accompanied or followed by a head pain. In migraine with retinal aura, the visual symptoms typically only occur in one eye. This is different to the more common type of visual aura that is experienced by many people with migraine. In the more common type, if you cover one eye, the visual change (e.g., black spot) will still be present when looking through the eye that remains open.
Migraine – a common and distressing disorder – a detailed introduction and overview of migraine
New Treatment Updates – CGRPs and their PBS application/approval status
A Richer View of Aura – why it happens and the biological processes involved (Nature Research, October 2020)