What're the symptoms of delirium?
The symptoms of delirium come on quickly, in hours or days, in contrast to those of dementia, which develop much more slowly. Delirium symptoms typically fluctuate through the day, with periods of relative calm and lucidity alternating with periods of florid delirium. The hallmark of delirium is a fluctuating level of consciousness.
A delirious person may have a clouding of awareness and consciousness. This impairment of consciousness typically fluctates, so the person may be aroused and alert for short periods of time before again relapsing into a clouded state. Fluctation may follow a pattern of diurnal variation, where consciousness levels change as the day progresses. Typically, a delirious person may be more consciousness impaired in the evening and at night.
Confusion may occur in delirium, where the sufferer loses the capacity for clear and coherent thought. It may be apparent in disorganised or incoherent speech, the inability to concentrate or a lack of goal directed thinking. Disorientation describes 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 week, month, season or year it is), place (not know where you are) or person (not knowing who are).
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 delusions in the clinical sense as they are considered too short lived. Interestingly, in some cases sufferers may be left with false or delusional memories after delirium, basing their memories on the confused thinking or sensory distortion which occurred. Abnormalities of affect include any distortions to perceived or communicated emotional states. Emotional states may also fluctate, so a person may rapidly change between, for example, terror, sadness and jocularity.
Memory deficits, especially where recent events are concerned (e.g., the reason for hospitalization or for care being given by nursing staff), are also prominent in patients with delirium. Patients may report not being bathed or bedding not being changed when, in fact, these events occurred earlier in the day. Disorientation to date, place, and situation is common. However, the latter can go unrecognized if patients are not directly asked for the information.
Patients with delirium may become agitated as a result of the disorientation and confusion they are experiencing. For example, a patient who is disoriented may think he or she is at home instead of in a hospital, and nursing staff may be mistaken for intruders in the home. Consequently, this patient may not comply with bed or activity restrictions and may try to climb over the bedrails to get out of bed. Likewise, intravenous (IV) and oxygen tubing may not be recognized as such, and the patient may remove them.
Sleep disturbances are common in patients with delirium. They may periodically fall asleep during the day and then be awake for several hours during the night. This pattern, combined with confusion, disorientation, and decreased nighttime environmental cues, can create an especially hazardous situation in patients who are at risk for falling and pulling out an IV, Foley catheter, or nasogastric tubing.
Several neurologic signs and symptoms may be present in delirium regardless of cause. They include unsteady gait; tremor; asterixis; myoclonus, paratonia (e.g., gegenhalten) of the limbs and especially of the neck; difficulty reading and writing; and visuoconstruction problems, such as copying designs and finding words.