🩸 Diagnosis
Dementia diagnosis is being revolutionized by blood-based biomarkers that can detect disease decades before symptoms appear. The era of diagnosing Alzheimer's only at autopsy is ending.
The Blood Test Revolutionstrong evidence
p-tau217 can detect Alzheimer's pathology with 89-91% accuracy, predict symptom onset 3-4 years in advance, and show signal up to 25 years before diagnosis. A fully automated platform (Lumipulse) has been validated for both primary and secondary care…
Brain Imagingstrong evidence
Structural MRI shows atrophy patterns specific to each dementia type (hippocampal loss in AD, frontal in FTD). Amyloid PET (florbetapir, florbetaben) visualizes plaque burden. Tau PET (flortaucipir) tracks Braak staging in vivo. FDG-PET shows metabol…
Cognitive Testing
MMSE (Mini-Mental State Exam): widely used, 30 points, but has ceiling/floor effects. MoCA (Montreal Cognitive Assessment): better sensitivity for mild cognitive impairment. CDR (Clinical Dementia Rating): standard outcome in clinical trials. Neurops…
Alpha-Synuclein Testingmoderate evidence
Seed amplification assays (SAA) for alpha-synuclein can now identify Lewy body pathology in living patients — 87% accuracy in CSF, 85% in skin biopsy. This is a breakthrough for Lewy body dementia diagnosis, which historically required autopsy confir…
Digital & AI Biomarkersmoderate evidence
Speech/language analysis can detect subtle word-finding changes years before diagnosis. Gait sensors identify motor changes (rest/activity is the most studied digital biomarker at 39% of studies). Retinal imaging: the Eye-AD deep learning framework a…
Synaptic Density (SV2A PET)moderate evidence
SV2A PET using [11C]UCB-J measures synaptic vesicle protein 2A — a direct marker of synapse density. Synaptic loss is the BEST correlate of cognitive decline (better than amyloid or tau). Shows widespread reductions in hippocampus, frontal, temporal,…