When a person with temporal lobe epilepsy is having an epileptic seizure, part of the brain' s temporal lobe produces abnormal electrical impulses, which can often, but not always, be detected through a test called an electroencephalogram (EEG)
Ttherefore, although a positive EEG reading -- that is, evidence of abnormal electrical impulses -- during an apparent seizure is a reasonably reliable indicator of temporal lobe epilepsy,
a negative reading does not mean that temporal lobe epilepsy can be ruled out