From the Guidelines
Dementia is an umbrella term for over 100 different neurodegenerative conditions, with the most common types being Alzheimer disease, vascular dementia, Lewy body dementia, frontotemporal dementia, and mixed dementia. The various forms of dementia can be broken down into:
- Alzheimer disease, which is the most prevalent type
- Vascular dementia, resulting from reduced blood flow to the brain
- Lewy body dementia, characterized by abnormal protein deposits in nerve cells
- Frontotemporal dementia, affecting personality, behavior, and language due to damage in the brain's frontal and temporal lobes
- Mixed dementia, involving multiple types occurring simultaneously, most commonly Alzheimer's with vascular dementia [ 1 ]. Other less common forms of dementia include:
- Parkinson's disease dementia
- Huntington's disease
- Korsakoff disease
- Creutzfeldt-Jakob disease, a rare and rapidly progressing form caused by abnormal proteins called prions. It is essential to note that these conditions share memory and cognitive impairment symptoms but differ in progression, additional symptoms, and underlying brain changes, making accurate diagnosis crucial for appropriate treatment and management [ 1 ].
From the Research
Forms of Dementia
- The most common forms of late-onset dementia are: + Alzheimer's disease + Dementia with Lewy bodies + Vascular dementia + Frontotemporal dementia 2, 3
- These forms of dementia are characterized by the aggregation of misfolded proteins and cerebrovascular disease, with mixed neuropathologies frequently detected in the brains of older people with dementia 2
- Alzheimer disease is the leading cause and prototypical form of dementia, presenting insidiously and causing progressive cognitive impairment with increasing severity over a period of years 3
- Vascular dementia is the second most common form of dementia and often co-occurs with other progressive cognitive disorders 3
- Lewy body dementias encompass Parkinson disease dementia and dementia with Lewy bodies, which have similar features and are differentiated primarily by the order of motor and cognitive symptom onset 3, 4, 5
- Frontotemporal dementias occur earlier than other forms of dementia, progress rapidly, and often have a genetic component 3
- Dementia with Lewy bodies is characterized by the accumulation of aggregated α-synuclein protein in Lewy bodies, similar to Parkinson's disease and Parkinson's disease dementia, and is often accompanied by aggregation of amyloid-beta and tau, the pathological hallmarks of Alzheimer's disease 4, 5
Diagnosis and Biomarkers
- Neuroimaging with amyloid positron emission tomography (PET) scanning and newly found PET tracers are effective in diagnosing Alzheimer's and amnesiac mental cognitive impairment 6
- Vast improvements in neuroimaging techniques have led to newly discovered biomarkers and diagnostics, with neuroimaging with amyloid PET scanning surpassing what had been considered the dominant method of neuroimaging and MRI 6
- Continued research and studies must be conducted to improve current findings and streamline methods to further subcategorise neurodegenerative disorders and diagnosis 6
- Imaging modalities can improve diagnostic accuracy and improve management of dementia with Lewy bodies, which can provide a diagnostic challenge due to the frequent overlap of clinical signs with other neurodegenerative conditions 5