Which type of dementia is characterized by amyloid deposition and neurofibrillary tangles?

Alzheimer's disease is specifically characterized by the presence of amyloid-beta plaques and neurofibrillary tangles composed of hyperphosphorylated tau protein. These pathological features are critical in the diagnosis of Alzheimer’s and are distinct from other types of dementia.

Amyloid plaques are formed when amyloid precursor protein (APP) is improperly processed, leading to the accumulation of amyloid-beta peptides in the extracellular space of the brain. Neurofibrillary tangles result from the destabilization and aggregation of tau, a protein associated with microtubule stabilization. The progressive accumulation of these plaques and tangles is strongly correlated with the cognitive decline seen in Alzheimer's disease.

In contrast, other forms of dementia—like vascular dementia, frontotemporal dementia, and diffuse Lewy body dementia—have different pathophysiological features and mechanisms of neurodegeneration. Vascular dementia is primarily caused by cerebrovascular disease, leading to blood flow reduction and resultant cognitive decline, while frontotemporal dementia is associated with degeneration of the frontal and temporal lobes and characterized by different proteinopathies such as tau or TDP-43. Diffuse Lewy body dementia involves the accumulation of alpha-synuclein protein, leading to Lewy bodies in the brain