Alzheimer's Disease 12 Nov, 2021 Read Time: 3 mins

Implications of an early diagnosis of Alzheimer’s disease

Early diagnosis of Alzheimer’s disease provides patients and their families with the opportunity to implement changes in lifestyle, participate in clinical treatment studies, and take current and future treatments that might alter the course of the disease. Who should undergo the complex investigations to confirm the diagnosis? and What needs to be considered by healthcare professionals, patients, and their families before ordering diagnostic tests? were topics at a satellite symposium at EAN 2021.

The diagnostic process

Early diagnosis can lead to interventions that might alter the course of the disease

Patients given an early diagnosis of Alzheimer’s disease (AD) have the opportunity to seek appropriate support and information and to benefit from changes in lifestyle and appropriate therapies that may improve symptoms.1

The diagnostic process is complex, however, explained Professor Alessandro Padovani, University of Brescia, Italy, and includes:

The diagnostic process includes cognitive tests, lumbar puncture, and brain imaging

  • Cognitive tests to demonstrate cognitive impairment
  • Lumbar puncture to test for the presence of amyloid-beta (Aβ) and tau in the cerebrospinal fluid
  • Positron emission tomography (PET)—amyloid PET to reveal Aβ deposits in the brain and fluorodeoxyglucose (FDG) PET to reveal areas of reduced brain metabolism
  • Magnetic resonance imaging to evaluate brain atrophy2

New blood tests to measure plasma Aβ42 and Aβ40,3 p-tau1814 and p-tau217,5 are expected to contribute to the diagnostic process in the future.

 

Who should undergo the diagnostic process?

Diagnostic tests should be restricted to people with specific AD phenotypes who also have positive biomarkers

Both Aβ and tau pathology may be seen in people without cognitive impairment who will not develop clinical AD in their lifetime. People with Aβ and tau pathology who have no cognitive impairment should therefore be considered as only at-risk of progression to AD.6

As a result, the International Working Group has proposed that an AD diagnostic process should be restricted to people with specific AD phenotypes who have positive biomarkers, said Professor Padovani.6

 

Issues to consider before carrying out diagnostic tests

Making an early diagnosis of AD has important implications for patients and their families that need to be discussed before carrying out the diagnostic tests, said Professor Giovanni Frisoni, Geneva, Switzerland. Ensure that the patient and their family understand:

An early diagnosis of Alzheimer’s disease has implications for patients and their families

  1. What mild cognitive impairment and AD are before ordering investigations
  2. The diagnostic process and the investigations involved
  3. What will be disclosed about the results and to whom (only disclose to the family if the patient consents)
  4. Where to access support, resources, and research options
  5. The implications of an AD diagnosis, including safety issues such as driving
  6. That a patient’s ability to enjoy life does not change after a diagnosis
  7. They are free to ask any questions

 

This satellite symposium was organised and funded by Biogen.

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Our correspondent’s highlights from the symposium are meant as a fair representation of the scientific content presented. The views and opinions expressed on this page do not necessarily reflect those of Lundbeck.

References

  1. Alzheimer’s Disease International. Importance of early diagnosis. Available at: https://www.alzint.org/about/symptoms-of-dementia/importance-of-early-diagnosis/ Accessed 26 June 2021.
  2. Jack CR, et al. NIA-AA Research Framework: Toward a biological definition of Alzheimer's disease. Alzheimers Dement 2018;7:257–62.
  3. Palmqvist S, et al. Performance of fully automated plasma assays as screening tests for Alzheimer disease–related β-Amyloid status. J Alzheimers Dis 2018;62:1857–63.
  4. Karikari TK, et al. Blood phosphorylated tau 181 as a biomarker for Alzheimer's disease: a diagnostic performance and prediction modelling study using data from four prospective cohorts. Lancet Neurol 2020;19:422–33.
  5. Mattsson-Carlgren N, et al. Longitudinal plasma p-tau217 is increased in early stages of Alzheimer’s disease. Brain 2020;143:3234–41.
  6. Dubois B, et al. Clinical diagnosis of Alzheimer's disease: recommendations of the International Working Group. Lancet Neurol 2021;20:484–96.