The National Institute On Aging has recently provided new guidelines and criteria to diagnose Alzheimer's disease (AD), which will make it possible to intervene earlier and more effectively delay its progression. Since the last revision of the guidelines in 1984, there has been great progress in understanding AD disease mechanisms, risk factors, biomarkers and treatments. The new guidelines incorporate the new knowledge and emphasize that earlier detection will lead to more effective treatment.
The new guidelines emphasize that AD can be diagnosed before dementia develops, during an earlier stage of decline called mild cognitive impairment (MCI). In typical AD patients, the MCI stage begins 7 to 22 years before dementia develops, and can be difficult to distinguish from memory and cognitive declines due to normal aging. However, brief but accurate tests are now available for primary care physicians and these tests can distinguish MCI from normal aging. Once MCI has been detected, the guidelines indicate how to diagnose whether it is due to AD or a related disorder (ADRD).
The new guidelines also clarify that mild cognitive impairment (MCI) and dementia are not diagnoses, but rather, levels of severity for classifying a decline in cognitive function. Such declines may be due to many different causes, including depression, Parkinson's and Lewy body disease, multiple sclerosis, stroke, heart disease, diabetes, hypertension, kidney, lung, liver and thyroid diseases, sleep apnea, head injury, chronic pain, chronic fatigue syndrome, hormonal and vitamin deficiencies, medications, etc.
While controversy exists about treatment efficacy, recent, carefully analyzed studies have found that certain combinations of Alzheimer's drugs (Namenda plus a cholinesterase inhibitor such as Aricept, Razadyne or Exelon), can delay progression at all clinical stages of AD by as much as 60%. Such a delay would substantially improve quality of life, lower healthcare costs, and significantly relieve caregiver burden. Unfortunately, many AD patients receive only a cholinesterase inhibitor, which is much less beneficial and has led to an overly negative perception of AD treatment efficacy.
An educational effort to raise public awareness and physician expertise could deliver tremendous potential benefits with regards to early, effective treatment of MCI due to ADRD. The main educational points are:
1.) Early detection of AD in the MCI stage can lead to more effective treatment than late detection of AD in the dementia stage.
2.) Because symptoms of early stage AD are similar to the signs of normal aging, early detection of AD requires a vigilant approach to monitoring cognition in primary care settings. This is especially true for patients aged 50 and older aswhen risk for developing MCI due to AD or a related disorder substantially increases.
3.) Combined therapy including Namenda plus a cholinesterase inhibitor is the most effective approach to delaying Alzheimer's progression and can yield meaningful benefits in many patients.
4.) The tests that have been used in the past, such as the Mini-Mental State Exam and the Clock Drawing Test, are not sensitive for detecting MCI. Other pragmatic tools are available that can quickly and accurately detect MCI in clinical practice.
5.) Identifying and managing risk factors for AD and related disorders are associated with up to a 50% reduction in the risk for developing MCI.
6.) Detection of AD in the MCI stage will help identify research subjects who can participate in clinical trials and make it possible to develop even better treatments.