Cerebral implant

A cerebral implant is when somebody sticks something in your noggin. Generally its an electronic device of some sort, the purpose of which may vary. Sometimes its may be used for something benign such as monitoring a patient's brain wave patterns. In most cases however, its usually equipped with some sort of explosive device. At the discretion of some merciless bastard, a mild headache can turn into a five-alarm KABLOOEY! In other cases, cerebral implants may be used as a form of behavior modification.