Occipital lobe epilepsy surgery: treating seizures in the posterior cortex.

Occipital lobe epilepsy (OLE) is an uncommon type of extratemporal epilepsy constituting roughly 2-13% of symptomatic partial epilepsies and epilepsy surgery cases. Over two-thirds of patients with OLE present with two characteristics: (1) ictal semiology compatible with an occipital seizure focus (e.g., ictal blindness, visual perceptual disturbance, eye blinking, nystagmus), and (2) lateralizing features referable to the posterior cortex (e.g., visual field defects, contralateral head deviation). The remaining one-third of patients present with ≥ 2 seizure types, indicative of spread to other lobes. A common representation of this cortical spread is the altered mental status and generalized tonic-clonic activity seen in patient with OLE. While the key clinical symptoms include visual hallucinations, it may be difficult to elicit on history, especially from children, and are not always present.