Acute Delirium Syndrome

• The symptoms of delirium syndrome include illusions, lethargy, and changes of consciousness.
• Stroke, dementia, and brain tumor may cause illusions and auditory hallucination, which can be worsen by some medicines and metabolic conditions.
• Causes for acute delirium include abnormal liver and kidney functions, electrolyte imbalance, elevated blood sugar, lack of vitamin Bs, nutritional imbalance, inflammatory disorders, infectious disorders, brain tumor, and drug-drug interaction.
• Many senior patients or in-patients, particularly during their stay at ICU (intensive care unit), had acute delirium; they quite often mentioned that they had heard or seen their late family members, which frightened their caregivers.

Take patients with ischemic stroke for example, if the stroke location falls on visual cortex, they quite often have visual illusion. The images look so vivid that patients do not realize they are not real. Thus, others may think the patients see ghosts or encounter evil spirits.

Dementia and Illusion

The early symptoms of dementia, such as Alzheimer’s disease, usually include deteriorated memories and forgetfulness. Patients may develop illusion in mid and late stages. In addition, dementia with Lewy bodies and frontotemporal lobe degeneration may cause illusion as well.

More than 20% of patients with dementia with Lewy bodies developed illusion in early and mid stage. Patients usually see some complex images of people, events and objects. Illusion is an important symptom for diagnosing dementia with Lewy bodies, which can facilitate the differential diagnosis from Alzheimer’s disease, with 83% of accuracy.

Parkinson’s Disease and Illusion

Half of the patients with Parkinson’s disease develop illusion; they might see illusions such as people and animals, just like patients with dementia with Lewy bodies. However, patients with Parkinson’s disease often develop illusion alongside with motor symptoms and their illusion often occur before the decline of their cognition. On the contrary, patients with dementia with Lewy bodies develop illusion early in the disease course after the cognitive decline.

Neurologists may arrange brain CT and brain MRI for evaluation about the cause of illusion and auditory hallucination.