Delirium and Dementia

Delirium

Definition

State of mental confusion; global mental dysfunction with prominent alteration, often fluctuating, of alertness or attention.

Common features: disorientation, fluctuating level of consciousness, inability to maintain attention, agitation. May progress for hours or days. Often worse at night. Usually reversible.
Variable features: drowsiness, restlessness, incoherence, irritability, emotional lability, perceptual misinterpretations (illusions), hallucinations.

Etiology

Primary Neurologic Disorders

Head injury, stroke, raised intracranial pressure, epilepsy, CNS infection.

Delirium tremens: follows alcohol withdrawal (24 to 48 hours); tremor, hallucinations, autonomic hyperactivity; potentially fatal.

Systemic Illness

Delirium present in 10–20% of patients in hospital.

Systemic infection, dehydration (especially in older patients).

Cardiovascular, endocrine, toxic-metabolic derangement.

Medications: atropine, barbiturates, benzodiazepines (chlordiazepoxide, diazepam, flurazepam), cimetidine, clonidine, cocaine, digitalis, dopamine agonists (pergolide, pramipexole, ropinirole), haloperidol and other neuroleptics, lithium, mephenytoin, meprobamate, opioids, phencyclidine hydrochloride (PCP), phenytoin, prednisone, propranolol, tricyclic antidepressants.

Evaluation