How rare is temporal lobe epilepsy onset in age 20?

Temporal lobe epilepsy usually begins around age 10 or 20, but it can start at any age. It is rare (10 cases per 100,000 is one figure I have seen), but it does happen. If you have symptoms (sudden sense of fear or anxiety, anger, sadness, joy), or have had a seizure with fever, or an injury to the brain, see your doctor or a neurologist for a proper evaluation.

Although relatively uncommon in general population, it is a common epilepsy variant. Typically it does present in one's 20's, and the combination of aura, alteration of awareness, automatisms, and post-event amnesia is the usual sequence. Often it is difficult for the patient to recognize these spells as they are focal and complex, with amnesia clouding recognition.