Delirium With Catatonic Features: A New Subtype?

Delirium has been recognized and described since antiquity. It is a brain disturbance manifested by a syndrome of diverse neuropsychiatric symptoms. Various terms have been used for delirium, such as acute brain disorder, metabolic encephalopathy, organic brain syndrome, and ICU psychosis. The DSM-IV model views delirium as an acute reversible neuropsychiatric syndrome caused by general medical conditions and/or exogenous substances.1 DSM-IV criteria for delirium require a disturbance of consciousness or attention and a change in cognition that develops acutely and tends to fluctuate in severity. Lipowski2 characterized delirium as a disorder of attention, wakefulness, cognition, and motor behavior.