DELIRIUM, from deliro, to rave or talk idly. When the ideas excited in the mind do not correspond to the external objects, but are produced by the change induced on the common sensory, the patient is said to be delirious. The Greeks call it paraphrenesis. In the English there is no word for it, except light-headedness be admitted.
The paraphrenesis, or delirium, differs from a madness, in not being perpetual, which happens in deliriums without a fever.—The proximate cause of a delirium is an affection of the brain; but the remote causes may be an irritation, sometimes a very slight one, of any part of the nervous system. See (the Index subjoined to) MEDICINE.