Purpose of review: Mesial temporal lobe epilepsy is the most common indication for epilepsy surgery, yet little is known about its 'natural' history from initial onset. The review considers the available evidence and gaps in our current knowledge of the subject.
Recent findings: Although usually surgically treated in adulthood, the majority of people with refractory mesial temporal lobe epilepsy have their initial onset in childhood and adolescence. The course of the disorder is complex and may appear relatively benign at first with intractable seizures emerging only later. Early diagnosis of mesial temporal lobe epilepsy is made difficult due to the near absence of its MRI correlate, i.e. hippocampal atrophy, a lesion that seems to develop over time and is rarely present at initial onset. Early diagnosis is further complicated by the fact that there are likely many different entities that are localized to the temporal regions and are not clearly differentiated from each other initially.
Summary: Advances in understanding mesial temporal lobe epilepsy will require concerted efforts to characterize epilepsy with precision from onset and document its course over prolonged periods of time. Better recognition of specific subtypes currently lumped together as temporal lobe epilepsy is also needed.