Even after extensive testing, your doctor many not be able to diagnose with 100 percent certainty what conditions or diseases are contributing to your memory loss. Diagnoses are often listed as “tentative,” “possible” or “probable.”
One reason for this is that many health problems can contribute to memory loss – a recent study found that multiple conditions underlie most cases of memory loss. Another reason is that there is considerable overlap in symptoms and test results among diseases. For example, symptoms of vascular dementia are similar to those of Alzheimer’s disease.
Diagnoses of underlying diseases are usually based on criteria developed by groups of experts. Here are a few examples:
- In North America, the criteria most often used to diagnose Alzheimer’s are those in the American Psychiatric Association’s Diagnostic and Statistical Manual or those developed by the National Institute of Neurologic, Communicative Disorders and Stroke–AD and Related Disorders Association (NINCDS-ADRDA) Work Group. A group of researchers proposed a new set of criteria in 2007.
- One set of criteria used to diagnose vascular dementia (also called multi-infarct dementia) is the modified Hachinski score. You can read about this set of criteria in Table 7 of “Early Diagnosis of Dementia” from the American Academy of Physicians.
- Also in Table 7 are some criteria for diagnosing Dementia with Lewy bodies. These criteria have recently been updated.
- New diagnostic criteria for frontotemporal dementia were proposed in 2007.
Many of these criteria undergo periodic re-evaluation and updates with advances in sciences or changes in expert consensus.
While most medical experts say it’s possible to make an accurate diagnosis after a person dies and an autopsy is conducted, this may be difficult in some cases. In its "Practice Parameter: Diagnosis of Dementia", the American Academy of Neurology notes that although there are strong associations between clinical symptoms and the pathologies found at autopsy, they don’t always match. “There are many patients with atypical or nonspecific clinical presentations,” the document says. The Nun Study has documented cases where nuns showed no sign of memory loss, but their autopsies showed large numbers of Alzheimer’s plaques and tangles. Similarly, another study showed that the brains of people with no memory loss sometimes meet criteria for a diagnosis of Alzheimer’s at autopsy.
Learn More:
Alzheimer’s or Lewy Body Dementia (Part 2 of 3)
Lewy Body Dementia: The Importance of the Right Diagnosis
Dreaming About A Cure, Talking About Care: Part 1 of 4 - Is Alzheimer's Really A Disease?
Dreaming About A Cure, Talking About Care: Part 2 of 4 - More Care, Less "Cure"?
Dreaming About A Cure, Talking About Care: Part 3 of 4 - The Fantasy of "Cure"
Dreaming About A Cure, Talking About Care: Part 4 of 4 - New Ideas for Care and Cure
Cerebral Amyloid Angiopathy and Alzheimer's Disease: Dad's Double Burden
Cerebral Amyloid Angiopathy and Alzheimer's Disease: Evil Twins?
Beta Amyloid in Alzheimer's and CAA: Dr. Jekyll or Mr. Hyde?
National Institute on Aging 2007 Progress Report on Alzheimer’s Disease
Alzheimer’s Association Information on Steps to Diagnosis
Brief overview of diagnostic procedures from the Alzheimer’s Association
U.S. National Institute of Neurological Disorders and Stroke Discussion of Symptoms of Vascular, or Multi-Infarct Dementia
University of California, San Francisco Information about Diagnosing Frontotemporal Dementia
Medline Plus list of symptoms of Dementia with Lewy bodies
Los Angeles Times article on uncertainties about Alzheimer’s [free registration required]
