Surgical treatment of occipital epilepsy: Basic and clinical approach

A kainic acid microinjection into unilateral occipital cortex induced an experimental model of occipital lobe epilepsy in cats and rats. Elicited focal seizures in the occipital cortex promptly propagated to the bilateral cortices and also to the subcortical structures. Behavioral and EEG observations were well correlated to the human occipital lobe epilepsy. Metabolic study using 14C-deoxyglucose autoradiography in rats demonstrated a rapid propagation of the hypermetabolic area in the parietal, frontal, temporal and contralateral occipital cortices and also to the thalamus, basal ganglia, MRF and lateral geniculate body. The result shows that not only Meyer’s loop but also subcortical fasciculus between occipital lobe and other lobules may have an important role in the mechanism of seizure evolution and propagation of the occipital lobe epilepsy.