Clouding of Consciousness - Delirium

Some think that the term clouding of consciousness should be dropped in favor of the term delirium on the basis that it merely refers to the pathophysiological abnormality responsible for delirium. Delirium is commonly emphasized to have an acute onset, an acute duration, and a fluctuating course between hyperactive, hypoactive, and normality over a 24 hour period as a way to clinically distinguish it from other disorders. However, so-called delirium can also have a subacute onset, have a subacute duration, have a chronic duration that can continue indefinitely if the underlying etiology is not reversed, be purely hypoactive, or be purely hyperactive. The stereotyped image of delirium as an agitated psychotic state misrepresents most patients who have a hypoactive presentation with no psychotic symptoms. Such patients are quiet, passive and withdrawn and their inattention, forgetfulness and misunderstanding may pass unremarked by the nurse or disregarded by the doctor. There is a tendency to “psychologize” this hypoactive presentation as being caused from stress and to mislabel the patient as having depression. So-called subsyndromal delirium, which is basically clouding of consciousness without the other essential criteria of delirium, is not recognized as a type of delirium. Rather, it is put under the miscellaneous category of "cognitive disorder not otherwise specified" in the DSM-IV-TR. It is less severe than a delirium being somewhere on a continuum from normality to delirium. Delirium of this type is understudied and neglected either because delirium is "expected" to happen during severe illness or because medical resources are preferentially dedicated to managing the more immediate "life-threatening" problems. Some doctors think that it is not clinically relevant to focus on delirium being acute and that it should be seen as a "unitary" syndrome of variable duration and severity ranging from mild to very severe. Still others think that the term clouding of consciousness should be reserved for the least disturbed level of consciousness, that is less severe than a delirium, characterized by mild levels of confusion and disorientation.