A temporal aura is a distinct experience that serves as a warning or signal of an impending seizure, though it is the first part of the seizure itself. These events are characterized by unusual sensory, emotional, or cognitive changes. The aura is classified as a Focal Aware Seizure (FAS), meaning the abnormal electrical activity is localized to a specific brain region. During this event, the person remains conscious and aware. Auras are often brief, lasting from a few seconds up to a couple of minutes, providing a unique window into the localized brain disturbance before a potential progression to a larger seizure.
The Neurological Basis of Temporal Auras
Temporal auras originate in the temporal lobes of the brain, a region situated beneath the temples that plays a large role in processing emotions, memory, and sensory input. The abnormal electrical activity that causes the aura is a localized burst of energy within this specific lobe. Because the temporal lobe is involved in complex functions like short-term memory and processing emotional responses, a seizure starting here produces symptoms that are highly subjective and often psychological in nature.
The term “aura” is now understood to be an outdated name for a Focal Aware Seizure, which localizes the seizure activity to a small area of the temporal lobe. If this localized electrical disturbance spreads, the seizure may progress to a Focal Impaired Awareness Seizure, where consciousness is lost or altered, or even a generalized tonic-clonic seizure.
The medial temporal lobe, which includes structures like the hippocampus and amygdala, is the most common site for these seizures to begin. The hippocampus is responsible for memory formation, and the amygdala processes emotions, explaining why temporal auras frequently involve memory disturbances and strong feelings. Damage or scarring in the hippocampus, known as hippocampal sclerosis, is a frequent underlying cause of temporal lobe epilepsy, which presents with these types of auras.
Specific Sensory and Emotional Manifestations
Temporal auras are characterized by a variety of distinct symptoms that reflect the functions of the affected brain regions. One of the most common manifestations is an experiential phenomenon that involves a distortion of memory or reality. This includes déjà vu, a sudden, intense feeling that a current situation has been experienced before, or the less common jamais vu, an unsettling sensation that a familiar situation or person is completely new or unknown.
Emotional disturbances are also a prominent feature, often manifesting as a sudden, unprovoked feeling of intense fear, panic, or anxiety. While less frequent, auras can also cause feelings of sudden, intense joy or pleasure. These powerful, inappropriate emotions arise because the seizure activity is directly stimulating the amygdala, the brain’s center for emotional processing.
Sensory hallucinations related to smell and taste are highly specific to temporal lobe involvement. The person may experience phantosmia, which is perceiving an odor that does not exist, often described as an unpleasant, burnt, or metallic smell. Similarly, gustatory hallucinations involve tasting something that is not present, sometimes described as a bitter or acidic taste.
A common autonomic symptom is the “epigastric rising sensation,” a strange, churning, or rising feeling that originates in the stomach or abdomen and travels upward toward the chest or throat. This visceral sensation is often accompanied by nausea, a racing heart, or flushing of the skin. These physical changes occur because the temporal lobe also has connections to the autonomic nervous system, which controls involuntary body functions.
Diagnosis and Medical Evaluation
Experiencing a temporal aura warrants a full medical investigation by a healthcare professional, typically a neurologist, to determine the underlying cause and the risk of future seizures. The diagnostic process begins with a detailed clinical history, where a precise description of the aura’s symptoms, duration, and sequence of events is important. The clinical presentation of the aura provides significant clues about the seizure’s origin within the temporal lobe.
A key diagnostic tool is the Electroencephalogram (EEG), which uses electrodes placed on the scalp to record the electrical activity of the brain. While a standard EEG may not always capture the abnormal activity between seizures, it can reveal characteristic patterns, such as sharp waves or spikes, that are consistent with epilepsy. A sleep-deprived EEG or video-EEG monitoring may be used to increase the likelihood of recording the abnormal brain activity.
Neuroimaging is also a necessary component of the evaluation, with Magnetic Resonance Imaging (MRI) being the preferred method. A high-resolution MRI scan provides detailed images of the brain structure and can identify potential structural causes, such as tumors, vascular malformations, or the distinctive scarring of hippocampal sclerosis. Imaging is crucial for ruling out any treatable structural lesion that could be triggering the seizures.
If a diagnosis of temporal lobe epilepsy is confirmed, treatment generally involves anti-epileptic medications (AEMs) tailored to control the focal seizures. The goal of medication is to stop the abnormal electrical discharges from occurring or spreading. For individuals whose seizures do not respond to medication, specialized centers may consider advanced options, including further testing like PET scans or surgical evaluation.