A seizure aura is a subjective sensation that serves as an internal warning sign, marking the beginning of a seizure event. For many individuals, this distinct feeling occurs immediately before a more noticeable seizure begins. It is a brief neurological event that can last from a few seconds up to a minute or two, and it is considered the first stage of the seizure process. Recognizing this initial sign is important because it can give a person a moment to seek safety before the seizure progresses.
What Exactly is a Seizure Aura?
An aura is classified as a focal aware seizure, meaning it involves abnormal electrical activity starting in one specific area of the brain. During this type of seizure, the person remains fully conscious and aware of their surroundings, even while experiencing the unusual sensation. This event is called an aura only when it precedes a larger seizure, but it can also occur in isolation, not progressing further.
The specific feeling of an aura is determined by the region of the brain where the electrical disturbance originates. For example, activity beginning in the occipital lobe, which processes vision, will result in a visual aura. Similarly, a disturbance in the temporal lobe may cause changes in smell, taste, or emotional state. Since the onset location is usually consistent for each person, the aura symptoms are typically individualized and predictable.
The Spectrum of Sensory and Emotional Feelings
Auras can manifest as strange sensory experiences, often involving distortions of the five senses. A visual aura, arising from the occipital lobe, might involve seeing flashing or flickering lights, colored spots, wavy lines, or temporary blind spots. These visual phenomena are usually simple hallucinations.
Disturbances in the temporal lobe can produce phantom smells (olfactory auras) or tastes (gustatory auras). These smells are frequently unpleasant, sometimes described as burnt rubber or a foul odor. The tastes can be metallic, sour, or bitter. An auditory aura may cause a person to hear buzzing, ringing, or drumming sounds that are not actually present in the environment.
Emotional and cognitive shifts are common, particularly with activity in the temporal and frontal lobes. A person may be overcome by a sudden, intense feeling of fear, anxiety, or panic without any apparent cause. Other cognitive experiences include déjà vu, an overwhelming sense that the current moment has been experienced before, or the opposite, jamais vu, where a familiar setting suddenly feels completely foreign.
Physical and Autonomic Warning Signals
Beyond sensory and emotional changes, auras can also involve distinct physical and autonomic symptoms. A common physical signal is a strange sensation in the stomach, often described as an unpleasant churning, emptiness, or a rising feeling in the abdomen that moves up toward the chest or throat. This gastrointestinal disturbance is linked to seizure activity in the mesial temporal lobe.
Autonomic signals can include sudden changes in circulation, such as heart palpitations, a racing heart rate, or abrupt flushing and sweating. Some people feel localized tingling or numbness, known as paresthesias, starting in a hand or foot, which indicates the seizure began in the somatosensory cortex. Dizziness, lightheadedness, or a spinning sensation may also occur.
Because these signals precede a potential loss of awareness or motor control, recognizing them allows for immediate safety measures. If an aura begins, the person should quickly move away from any hazards, such as sharp objects or machinery, and sit or lie down in a safe space. If possible, alerting someone nearby to the impending seizure can ensure help is available if the event progresses.