Temporal lobe epilepsy Genetics of temporal lobe epilepsy

Our traditional understanding is that TLE is an acquired condition, but only now are we beginning to understand the extent of genetic involvement I n the second half of the 19th century, John Hughlings Jackson proposed the concept of partial epilepsy, including ‘‘uncinate seizures’’, based on clinico-pathological observations from patients with structural lesions and further sup-ported by pioneering brain surgery.1 2 With the discovery of EEG in the early 20th century, the concepts of temporal lobe epilepsy (TLE) were further eluci-dated. Gibbs et al3 described widespread slow activity during ‘‘psychomotor attacks’’; they proposed a diffuse under-lying cerebral disturbance, which was not in line with Jackson’s observations. Jasper and Kershman4 then described focal temporal sharp waves in patients they diagnosed with ‘‘temporal lobe seizures’’. By the middle of the 20th century, the term TLE was widely utilised and much of the subsequent understanding of this disorder was based on pre-surgical studies of intract-able cases. Traditionally, TLE has been considered to be an acquired disorder secondary to lesions such as hippo-campal sclerosis, tumours, trauma, vascular malformations, and neuronal migration disorders.5 Falconer et al, however, studied the aetiology of TLE in 110 refractory cases and demonstrated 95 % of cases had underlying cerebral pathology, but also astutely stated, ‘‘these lesions, however may develop on a soil already predis-posed to convulsions’’.6 In the past 20 years, what is becoming more evident is this evolving key role of genetics in TLE