Confusion characterized by prominent disorders of attention and perception, which interfere with the speed, clarity, and coherence of thinking, the formation of memories, and the capacity for performance of self-directed and commanded activities.¹

Three major clinical syndromes can be recognized.

One is an acute confusional state in which there is manifest reduction in alertness and psychomotor activity.

A second syndrome, alluded to above as a special form of confusion, agitated delirium, is marked by overactivity, sleeplessness, tremulousness, and prominence of vivid hallucinations, sometimes with excessive sympathetic activity.

These two disorders tend to develop acutely, to have multiple possible causes and, except for a few cerebral diseases, to remit within a relatively short period of time of days to weeks, leaving the patient without residual damage.

The third syndrome is one in which a confusional state occurs in persons with an underlying chronic cerebral disease, particularly a dementia.

Note on Psychotic Confusion

From the neurologic perspective, the generic term psychosis applies to states of confusion in which elements of hallucinations, delusions, and disordered thinking comprise the prominent features. An important point to be made here is that psychoses typically leave the sensorium relatively unclouded and allow for normal attentions and high-level performance of many mental tasks.