What is Alzheimer’s Disease?
Alzheimer’s is the most common form of dementia, a general term for memory loss and other intellectual abilities serious enough to interfere with daily life. Alzheimer’s disease accounts for over 50% of all dementia cases. Other dementia types include vascular dementia, dementia with Lewy bodies, and frontotemporal dementia. Mixed dementia, such as Alzheimer’s with vascular dementia, is also a common subtype.
The most common early symptom of Alzheimer’s is memory impairment, mainly with difficulty remembering newly learned information. Early symptoms of possible Alzheimer’s is often referred to as Mild Cognitive Impairment, or MCI. MCI is an intermediate stage condition between normal cognitive functioning and Alzheimer’s disease or other types of dementia:
Some (but not all) people diagnosed with MCI later decline into Alzheimer’s. Current research puts the probability of a person with MCI converting to Alzheimer’s at around 10% to 15% per year. Amnestic MCI, a subtype characterized by subtle but noticeable memory loss, is the most common type of MCI that can lead to Alzheimer’s.
Since MCI is a transitional stage condition that may (or may not) continue on to Alzheimer’s or another form of dementia, there isn’t one simple test that can be used to diagnose MCI. However, one of the best methods to detect a change in cognitive functioning is through routine, annual health screenings.
Concerned family and friends can use the Alzheimer’s-Dementia Symptom Checklist.
Also, there are several paper-based cognitive screening tests available, along with newer computer-based (or tablet) cognitive testing tools as well. In 2011, Medicare launched a preventive health initiative known as the Annual Wellness Visit (AWV), which is meant as a health screening visit. The AWV includes detection of cognitive impairment as a screening service.
Looking into the future, there are some interesting experimental imaging tests, blood tests and spinal fluid tests that could be helpful in diagnosing MCI and predicting the chances of converting to Alzheimer’s. However, the National Institute on Aging recommends against biomarker testing for MCI and Alzheimer’s in general practice offices (primary care) until several important reliability issues have been resolved.