Partial seizure: A seizure that affects only one part of the brain. Symptoms depend on which part is affected. One part of the body, or multiple body parts confined to one side of the body, may start to twitch uncontrollably. Partial seizures may involve head turning, eye movements, lip smacking, mouth movements, drooling, rhythmic muscle contractions in a part of the body, apparently purposeful movements, abnormal numbness, tingling, and a crawling sensation over the skin. Partial seizures can also include sensory disturbances, such as smelling or hearing things that are not there, or having a sudden flood of emotions. Although the patient may feel confused, consciousness is not lost. Also known as a focal seizure or a local seizure.