Grey matter heterotopia Case 1Case 2Case 3 Extensive periventricular grey matter heterotopia in a patient with epilepsy. 30-year-old patient with epilepsy had nodular grey matter heterotopic in the left frontal lobe. 16-year-old patient with a life long history of temporal seizures (deja vu and vacant episodes with secondary generalisation). MRI showed nodular grey matter heterotopia in the right temporal lobe. The right cerebral hemisphere and skull was smaller on the right.