Clock hand and inner workings

Diagnostic Workup

Adding biomarker evidence to your existing algorithm may help increase diagnostic confidence in Alzheimer’s disease1-6

The neuropathology of AD is defined by the presence of both amyloid plaques and neurofibrillary tangles.4,5

Major advances in AD research have included the development of biomarker tools initially with CSF, followed by PET tracers and more recently in blood, that can detect key pathologies, including amyloid and tau.1-6

BIOMARKER PET SCANS

Used to determine presence or absence of abnormal amyloid plaque and aggregated tau NFTs. Approved biomarker PET scans are available for use at your discretion.

BLOOD TESTS

Collected via blood sample to determine amyloid beta protein levels.

CSF TESTS

Used to determine amyloid beta and tau* protein levels .

Other routine diagnostic tools used in the assessment of patients include:1,7

  • Routine labs (such as CBC, metabolic panel, LFTs, TSH, vitamin B12, folate)
  • Structural imaging (CT scan, MRI)
  • Neuropsychological assessment
  • FDG-PET scan

Biomarker evidence of AD pathology has been shown to increase clinician confidence in diagnosing AD6,8

In a study using amyloid PET scans in patients with cognitive impairment of unknown etiology or suspected AD, diagnostic confidence was tested pre- and post-PET scan8

  • Diagnostic uncertainty was reduced to 16% after use of amyloid PET scan (vs 72% prior to amyloid PET)

CBC=complete blood count; CSF=cerebrospinal fluid; CT=computed tomography; FDG-PET=fluorodeoxyglucose-positron emission tomography; LFT=liver function test; MMSE=Mini Mental State Exam; MRI=magnetic resonance imaging; NFT=neurofibrillary tangle; PET=positron emission tomography; TSH=thyroid-stimulating hormone.

*Total tau and phosphorylated tau.1-6

References:

  1. Hort J, O'Brien JT, Gainotti G, et al. EFNS guidelines for the diagnosis and management of Alzheimer's disease. Eur J Neurol. 2010;17(10):1236-1248.
  2. Grundman M, Pontecorvo MJ, Salloway SP, et al. Potential impact of amyloid imaging on diagnosis and intended management in patients with progressive cognitive decline. Alzheimer Dis Assoc Disord. 2013;27(1):4-15.
  3. Counts SE, Ikonomovic MD, Mercado N, et al. Biomarkers for the early detection and progression of Alzheimer’s disease. Neurotherapeutics. 2017;14(1):35-53.
  4. McDade E, Bednar M, Brashear HR, et al. The pathway to secondary prevention of Alzheimer's disease. Alzheimers Dement (N Y). 2020;6(1):1-9.
  5. Aisen PS, Cummings J, Jack CR, et al. On the path to 2025: understanding the Alzheimer's disease continuum. Alzheimers Res Ther. 2017;9(1):1-10. https://alzres.biomedcentral.com/track/pdf/10.1186/s13195-017-0283-5.pdf . Accessed August 13, 2021.
  6. McKhann GM, Knopman DS, Chertkow H, et al. The diagnosis of dementia due to Alzheimer's disease: recommendations from the national institute on aging-Alzheimer's association workgroups on diagnostic guidelines for Alzheimer's disease. Alzheimers Dement. 2011;7(3):263-269.
  7. Albert MS, DeKosky ST, Dickson D, et al. The diagnosis of mild cognitive impairment due to Alzheimer's disease: recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease. Alzheimers Dement. 2011;7(3):270-279.
  8. Rabinovici GD, Gatsonis C, Apgar C, et al. Association of amyloid positron emission tomography with subsequent change in clinical management among Medicare beneficiaries with mild cognitive impairment or dementia. JAMA. 2019;321(13):1286-1294.