Temporal lobe epilepsy

Temporal lobe epilepsy is a chronic neurological condition in which recurring, unprovoked seizures originate in the temporal lobe of the brain, making it the most common form of focal epilepsy diagnosed in adults. Seizures beginning in the mesial, or inner, portion of the temporal lobe, often in the hippocampus, tend to produce a rising sensation in the stomach, a sense of deja vu, and altered awareness, while seizures arising in the lateral, or outer, temporal lobe are more likely to cause auditory or visual disturbances. Known causes include hippocampal sclerosis, brain tumors, traumatic brain injury, malformed blood vessels, abnormal neuronal migration during brain development, infections such as encephalitis and meningitis, autoimmune limbic encephalitis, and inherited genetic disorders. Diagnosis relies on electroencephalography to record the brain's electrical activity together with magnetic resonance imaging to look for structural causes. Anticonvulsant medication is the first line of treatment, but a substantial share of patients do not achieve seizure control with drugs alone; surgical removal of the affected temporal lobe tissue and specialized ketogenic diets are established alternatives for medication-resistant cases. The condition falls under codes G40.1 and G40.2 of the ICD-10 classification, reflecting its localization to the temporal lobe.