Catatonia is a state of stupor or unresponsiveness in a person who is otherwise awake. Catatonia can occur in association with a psychiatric disorder, like schizophrenia, or in association with a medical condition such as encephalitis. In some patients, catatonia may be present without a known cause. Catatonia is usually episodic, meaning that episodes of catatonia come and go. Symptoms that accompany catatonia can include rigidity, staring, withdrawal, immobility, posturing, and grimacing. Since a person with catatonia cannot give an accurate medical history, it is important in making a diagnosis to determine the specific symptoms from others who have observed the catatonic state. Some causes of catatonic behavior, like nonconvulsive status epilepticus or neuroleptic malignant syndrome, are medical emergencies.