1st February 2024

Background

Epidemiology

• Unlike Alzheimer’s dementia, this is higher in males.
• It is a disease of middle-aged and older people.
• It constitutes 10% of dementias.

Pathophysiology

Lewy Body dementia is a broad term that includes two subtypes:

1. Dementia with Lewy bodies- the individual develops fluctuating cognition-related problems that affect the way they think and behave. They would also experience changes in their visual perception, resulting in visual hallucinations. These symptoms occur first or together with movement and mobility problems.
2. Parkinson’s disease dementia- In this type of dementia, Parkinsonian symptoms are seen earlier than cognitive difficulties. The cognitive difficulties may be seen many years later in general.

In both these types of dementia, the common factor is the presence of Lewy bodies. The site of location of the Lewy bodies determines these two subtypes. They are small round neuronal inclusions comprised of altered neurofilament proteins (Tau proteins and tangles). 

In dementia with Lewy Body, the Lewy bodies are mainly concentrated in the cerebral cortex. In Parkinson’s disease, it is more in the substantia nigra, whilst in Parkinson’s disease dementia; the Lewy bodies are seen in both the cerebral cortex and substantia nigra.

Risk factors

• No specific risk factors. It is generally multifactorial.