Temporal lobe epilepsy

In the field of neurology, temporal lobe epilepsy is an enduring brain disorder that causes unprovoked seizures from the temporal lobe. Temporal lobe epilepsy is the most common type of focal onset epilepsy among adults. Seizure symptoms and behavior distinguish seizures arising from the medial temporal lobe from seizures arising from the lateral (neocortical) temporal lobe. Memory and psychiatric comorbidities may occur. Diagnosis relies on electroencephalographic (EEG) and neuroimaging studies. Anticonvulsant medications, epilepsy surgery and dietary treatments may improve seizure control. Under the International League Against Epilepsy (ILAE) 2017 classification of the epilepsies, focal onset epilepsy occurs from seizures arising from a biological neural network within a single cerebral hemisphere. Temporal lobe epilepsy occurs from seizures arising within the temporal lobe. Temporal lobe epilepsy is the most common focal onset epilepsy, and 80% of temporal lobe epilepsy is mesial (medial) temporal lobe epilepsy, temporal lobe epilepsy arising from the inner (medial) part of the temporal lobe that may involve the hippocampus, parahippocampal gyrus or amygdala. The less common lateral temporal lobe or neocortical temporal lobe seizures arise from the outer (lateral) temporal lobe. The ILAE 2017 classification distinguishes focal aware from focal impaired seizures. A focal aware temporal lobe seizure occurs if a person remains aware of what occurs during the entire seizure; awareness may be retained even if impaired responsiveness occurs during the seizure. A focal impaired awareness temporal lobe seizure occurs if a person becomes unaware during any part of the seizure. During a temporal lobe seizure, a person may experience a seizure aura; an aura is an autonomic, cognitive, emotional or sensory experience that commonly occurs during the beginning part of a seizure. The common mesial temporal lobe seizure auras include a rising epigastric feeling, abdominal discomfort, taste (gustatory), smell (olfactory), tingling (somatosensory), fear, déjà vu, jamais vu, flushing, or rapid heart rate (tachycardia).