Unifying concept for Alzheimer's disease, vascular dementia and normal pressure hydrocephalus - a hypothesis

Area of Science:

• Neurology
• Neuroscience
• Geriatrics

Background:

• Alzheimer's disease (AD), vascular dementia (VD), and normal pressure hydrocephalus (NPH) are common dementias in the elderly.
• These conditions often present with overlapping clinical and imaging features, complicating diagnosis.
• Current understanding often treats these pathologies separately, despite potential interconnections.

Purpose of the Study:

• To propose a unifying concept for the pathophysiology of AD, VD, and NPH.
• To explain the overlapping clinical and neuroimaging features observed in these dementia types.
• To explore potential therapeutic implications arising from a unified understanding.

Main Methods:

• Review and synthesis of existing research on cerebrospinal fluid (CSF) dynamics.
• Analysis of proposed links between CSF dynamics, amyloid deposition, and hypoperfusion.
• Hypothesizing a unified model integrating AD, VD, and NPH pathogenesis.

Main Results:

• Altered CSF dynamics may contribute to hydrocephalic changes and impaired amyloid clearance, linking NPH and AD pathology.
• Defective amyloid clearance can lead to amyloid angiopathy, perpetuating hypoperfusion and linking AD and VD.
• Hypoperfusion impacts CSF dynamics and amyloid clearance, further interconnecting AD, VD, and NPH.

Conclusions:

• A unifying concept suggests that altered CSF dynamics and hypoperfusion are interlinked in the pathogenesis of AD, VD, and NPH.
• This interconnectedness may explain the observed overlapping features of these dementia types.
• Identifying patients with a potential AD-NPH syndrome could benefit from CSF drainage procedures.