No matter what specialization, general practitioners, geriatricians, or neurologists, doctors are increasingly seeing more dementia patients. Estimates vary, but experts report more than 7 million people ages 65 or older had dementia in 2020. If current demographic and health trends continue, more than 9 million Americans could have dementia by 2030 and nearly 12 million by 2040.
According to ICD-10 (International Classification of Diseases), dementia is present when the following criteria are present:
Cognitive deficits relevant to everyday life
Lasting for more than six months
Unclouded consciousness (no sedatives, drug or alcohol influence)
Senses are unimpaired to the extent that is usual for the person (i.e., the person is wearing the hearing aid and glasses during the test if needed).
Dementia can be diagnosed clinically (medical history, neurological exam, and cognitive testing).
Examples of cognitive, functional, and behavioral tests include:
Ascertain Dementia 8 (AD8)
Functional Activities Questionnaire (FAQ)
Mini-Mental State Exam (MMSE)
Montreal Cognitive Assessment (MoCA)
Neuropsychiatric Inventory Questionnaire (NPI-Q)
But what about biomarkers, PET brain scans, MRIs, and spinal taps? Are they not helpful? The experts are not at one with this question.
Some argue that the diagnosis of Alzheimer's disease can be made solely based on the biomarkers like β-Amyloid, Tau, etc. Alzheimer's is, therefore, present as soon as the biomarkers are detected - the symptoms, as mentioned in the ICD-10 criteria, do not matter.
According to these experts, Alzheimer's is already present, although there are hardly any symptoms.
A second group of experts argues that a disease cannot only be diagnosed and treated solely based on biomarkers when nobody exactly knows when it will break out and to what extent. This group relies on the research that showed that dementia symptoms vary considerably among people with the same underlying level of pathology. Although two people may have the same amount of dementia-related brain damage, one may experience debilitating effects while the other demonstrates only a few symptoms.