Delirium history and symptoms

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sara Zand, M.D.[2] Pratik Bahekar, MBBS [3]; Vishal Khurana, M.B.B.S., M.D. [4]

Delirium causes impairment in functions, sleep-wake cycle and also has a behavioral component. Common symptoms associated with delirium include altered level of consciousness, inattention, disorientation, hallucination, delusions, agitation, inappropriate speech, sleep–wake disturbances, Symptom fluctuation, emotional disturbance. Subclinical delirium or prodromal delirium may precede by 1 to 3 days prior to an overt delirium, which presents as restlessness, anxiety, irritability, distractibility, sleep disturbance with less severe cognitive impairment in comparison to delirium.

Common symptoms associated with delirium include:

• Altered level of consciousness
• Inattention
• Disorientation
• Hallucination, delusions
• Agitation
• Inappropriate speech
• Sleep–wake disturbances (daytime sleepiness, nighttime agitation, disturbances in sleep continuity, complete reversal of the night-day sleep–wake cycle, and fragmentation of the circadian sleep-wake pattern)
• Symptom fluctuation
• Emotional disturbance (anxiety, fear, depression, irritability, anger, euphoria, apathy, affective lability, rapid and unpredictable shifts from one emotional state to another

• Subclinical delirium or prodromal delirium may precede by 1 to 3 days prior to an overt delirium, which presents as restlessness, anxiety, irritability, distractibility, sleep disturbance with less severe cognitive impairment in comparison to delirium. ^[1]
• Seizures may occur in delirium, particularly among patients with alcohol or withdrawal, cocaine intoxication, head trauma, hypoglycemia, strokes, or extensive burns.^[2]

• Simple cognitive testing such as Mini-mental Scale examination should be administered in all elderly patients admitted to hospital. However these test can not differentiate delirium from other cognitive disorders.^[3]
• Serial measurement maybe helpful to detect new-onset delirium.
• History from relatives is often useful to determine the onset, progress, and duration of delirium. Patients with confusional states may not provide an accurate history.
• A detailed history must include the following:

1. History of prescribed and non‑prescribed medicines
2. History of alcohol and other recreational drugs
3. History of activities of daily living such as payment of bills
4. Onset, progression and duration of confusion
5. Previous history of acute or chronic confusion
6. Social circumstances and support
7. Any other co-morbid illness such as epilepsy
8. Symptoms suggestive of underlying cause (infection)
9. Motor or sensory deficits
10. Aids used ( hearing aid, glasses)

• Delirium may occur in very many grades of severity, all symptoms may occur with varying degrees of intensity. ^[4]
• A mild disability to focus attention may result in only a disability in solving the most complex problems.
• However, as delirium becomes more severe, it disrupts other mental functions, and maybe so severe that it borders on unconsciousness or a vegetative state.
• In the latter state, a person may be awake and immediately aware and responsive to many stimuli, and capable of coordinated movements, but unable to perform any meaningful mental processing task at all.

• The delirium-sufferer loses the capacity for clear and [[coherent] thought.^[5]
• This may be apparent in disorganized or incoherent speech, the inability to concentrate (focus attention), or in a lack of any goal-directed thinking.
• Disorientation (another symptom of confusion, and usually a more severe one) is described as the loss of awareness of the surroundings, environment, and context in which the person exists.
• Disorientation may occur in time (not knowing what time of day, day of the week, month, season or year it is), place (not knowing where one is) or [[person] (not knowing who one is).
• Cognitive function may be impaired enough to make medical criteria for delirium, even if orientation is preserved.
• A patient who is fully aware of where they are and who they are, but cannot think because they cannot concentrate, maybe medically delirious.
• The state of delirium most familiar to the average person is that which occurs from extremes in pain, lack of sleep, or emotional shock.
• Because most high-level mental skills are required for problem-solving, including the ability to focus attention, this ability also suffers in delirium.
• However, this is a secondary phenomenon, since problem-solving involves many sub-skills and basic mental abilities, any of which may be impaired in a delirious patient.

• Impairments of cognition may include a temporary reduction in the ability to form short-term or long-term memory.
• Difficult short-term memory tasks inability to repeat a phone number may be continuously disrupted during a delirium, but easier short-term memory tasks like repeating single words, or remembering simple questions long enough to give an answer, may not be impaired.
• Reduction in the formation of new long-term memory (which by definition survive the withdrawal of attention), is common in delirium because the initial formation of (new) long-term memories generally requires an even higher degree of attention, than do short-term memory tasks.
• Since older memories are retained without the need of concentration, previously formed long-term memories ( those formed before the period of delirium) are usually preserved in all but the most severe cases of delirium (and when destroyed, are destroyed by the underlying brain pathology, not the delirious state per se).

• Hallucinations (perceived sensory experience with the lack of an external source) or distortions of reality may occur in delirium.
• Commonly these are visual distortions, and can take the form of masses of small crawling creatures (particularly common in delirium tremens, caused by severe alcohol withdrawal) or distortions in size or intensity of the surrounding environment.
• Strange beliefs may also be held during a delirious state, but these are not considered fixed delusions in the clinical sense as they are considered too short-lived (they are temporary delusions).
• In some cases patients may be left with false or delusional memories after delirium, basing their memories on the confused thinking or sensory distortion which occurred during the episode of delirium.
• Other instances would be the inability to distinguish reality from dreams.
• Abnormalities of affect may include many distortions to perceived or communicated emotional states.
• Emotional states may also fluctuate, so that a delirious person may rapidly change between, for example, terror, sadness, and jocularity.

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