20th July 2023

Lewy body Dementia (LBD)

LBD is a progressive form of dementia caused by the neurodegeneration of the central nervous system manifesting as changes in cognition, motor function, sleep, behaviour and autonomic systems. It is caused by abnormal clumps of Lewy bodies (protein in neurons) being deposited through the brain. This causes neuronal dysfunction, leading to a dopamine dysfunction and a loss of acetylcholine producing neurons.

LBD manifests as motor dysfunction, and autonomic dysfunction, and patients often report visual hallucinations (usually animals and people, often children) and vivid dreams. Patients are often aware that their hallucinations are not real. Autonomic dysfunction typically manifests as postural hypotension. Psychiatric symptoms appear as altered behaviour, depression, apathy, attention deficits, and executive and visuospatial dysfunction.

For diagnosis, cognitive impairment should appear within one year of parkinsonism features. However, a definitive diagnosis is only possible by autopsy. It usually takes years to diagnose, and is commonly misdiagnosed as there is a lot of overlap with other conditions such as Parkinson’s disease and Alzheimers.

Cholinesterase inhibitors such as donepezil and rivastigmine are used to try and help with cognition and function. Melatonin is used for sleep to try to restore the day/night cycle.