Diagnosing dementia

Alzheimer's Association diagnostic guidelines across the disease continuum
Essentials of a diagnostic workup
- clinical exam
- medical history
- assessment of multiple cognitive domains
- lab tests
- MRI and/or CT scan, in some cases
The original diagnostic criteria for the diagnosis of Alzheimer's disease were developed in 1984. The Alzheimer's Association and the National Institute on Aging (NIA) recently updated and added to those guidelines.
Role of advanced imaging and biomarkers
As disease-modifying therapies become available, initiating therapy early in the disease, before clinical signs emerge, will be critical, so research on new strategies for earlier diagnosis is among the most active areas in Alzheimer's science. Although there are no validated biomarkers for Alzheimer's disease, researchers are investigating genetic risk profiling, cerebrospinal fluid biomarkers, such as beta-amyloid and tau, and advanced brain imaging techniques that will allow clinicians to detect and monitor genetic, metabolic, vascular and cellular changes related to Alzheimer's disease.
Differential diagnosis
Alzheimer's disease accounts for up to 80 percent of all dementia cases. Diagnosis may be complicated by other forms of dementia that have symptoms and pathologies similar to Alzheimer's disease. Knowing the key features and pathology of each type of dementia can help in the accurate diagnosis of patients, so they will receive the treatment and support services appropriate for their condition and maintain the highest possible quality of life.
- The following table identifies some of the clinical differences between the major dementias
Clinical Differentiation of the Major Dementias
Disease First Symptom Mental Status Neuropsy-
chiatryNeurology Imaging AD Memory loss Episodic
memory lossInitially normal Entorhinal cortex and hippocampal atrophy FTD Apathy; poor judgment/
insight, speech/
language; hyperoralityFrontal/
executive, language;
spares drawingApathy, disinhibition, hyperorality, euphoria, depression May have vertical gaze palsy, axial rigidity, dystonia, alien hand, or MND Frontal, insular, and/or temporal atrophy; spares posterior parietal lobe DLB Visual hallucinations, REM sleep disorder,
delirium, Capgras' syndrome, parkinsonismDrawing and frontal/
executive;
spares memory; delirium proneVisual hallucinations, depression,
sleep disorder, delusionsParkinsonism Posterior parietal atrophy; hippocampi larger than in AD CJD Dementia,
mood, anxiety, movement disordersVariable,
frontal/
executive,
focal cortical, memoryDepression, anxiety Myoclonus, rigidity, parkinsonism Cortical ribboning and basal ganglia or thalamus hyperintensity on diffusion/
FLAIR MRIVascular Often but not always sudden; variable; apathy, falls, focal weakness Frontal/
executive, cognitive
slowing; can spare memoryApathy,
delusions,
anxietyUsually motor slowing, spasticity; can be normal Cortical and/or subcortical infarctions, confluent white matter disease Abbreviations: AD, Alzheimer's disease; CBD, cortical basal degeneration; CJD, Creutzfeldt-Jakob disease; DLB, dementia with Lewy bodies; FTD, frontotemporal dementia; MND, motor neuron disease; PSP, progressive supranuclear palsy
Reproduced with permission. Seeley WW, Miller BL. Alzheimer's disease and other dementias. In: Harrison's Neurology in Clinical Medicine. 3rd edition. ©The McGraw-Hill Companies, Inc.
Healthcare Professional Topic Sheets
Healthcare professional topic sheets are available for the following dementias and dementia-like conditions:
Disclosure of an Alzheimer's disease diagnosis
Almost 90 percent of Americans say if they were exhibiting confusion and memory loss, they would want to know if the cause of the symptoms was Alzheimer's disease. Disclosure and discussion of a diagnosis of Alzheimer's disease or other dementia is an ongoing process that should be addressed during multiple office visits. You can refer patients and their families to the Alzheimer's Association to learn about Alzheimer's disease, find a support group, get advice about caregiving or participate in a clinical trial.
Instructional videos
The following videos show the disclosure of an Alzheimer's disease diagnosis and a peer-to-peer discussion of important aspects of assessing cognition and disclosing an Alzheimer's disease diagnosis during a primary care visit. The videos, part of a three-part instructional series developed for primary care providers, use an actual primary care physician and patient with Alzheimer's disease.
Disclosing an Alzheimer's Diagnosis (approx. 11 min)
Peer-to-peer discussion of important aspects of assessing cognition and disclosing Alzheimer's disease during primary care visits (approx. 11 min.)
Videos produced by the American College of Physicians Foundation and the Alzheimer's Association.
References
1. Seeley WW, Miller BL. Alzheimer's disease and other dementias. In: Hauser SL, ed. Harrison's Neurology in Clinical Medicine. 3rd edition. New York: McGraw-Hill Medical; 2013.
2. Harvard School of Public Health, Alzheimer's Europe. Value of knowing - Research - Alzheimer Europe. Value of Knowing. Available at: . Accessed October 13, 2011.
For Your Patients
24/7 Helpline 800.272.3900 — We can help your patients and their caregivers with questions and local support resources.
You might also like



