If only the portion of the brain controlling movement of a limb is involved, that limb may tremble or jerk uncontrollably. If the affected brain area spreads, more of the body may begin to move erratically. If the brain section governing hearing or vision is involved, the person may experience auditory or visual hallucinations. Sometimes the emotional centers of the brain are the hardest hit during a seizure and a person starts to cry for no apparent reason, or becomes angry or afraid. These seizures are termed partial because only part of the brain is involved.
Many people mistake a person undergoing a partial seizure as drunk or mentally ill.
A complex partial seizure, for example, may cause the person to be dazed, unresponsive and clumsy, and to mumble, pick at clothing, or make chewing movements. Another type of generalized seizure called atonic causes abrupt loss of muscle tone, and the person falls to the ground. Sometimes people, particularly those with complex partial seizures, experience a distinctive warning sign before a seizure, called an aura. The aura is itself a form of partial seizure, but one in which the patient retains awareness. One man with epilepsy, an ardent racetrack gambler, always hears the roar of a crowd followed by the name of a favorite racehorse just before falling unconscious.