Early Alzheimer's Disease: Recognition and Assessment.
Guideline Overview No. 19
Dementia is a syndrome in which progressive deterioration in intellectual abilities is so severe that it interferes with the person's usual social and occupational functioning. An estimated 5 to 10 percent of the U.S. adult population ages 65 and older is affected by a dementing disorder, and the incidence doubles every 5 years among people in this age group.
Alzheimer's disease is the most common form of dementia in the United States. It and related dementias affect at least 2 million, and possibly as many as 4 million, U.S. residents. Despite its prevalence, dementia often goes unrecognized or is misdiagnosed in its early stages. Many health care professionals, as well as patients and family members, mistakenly view the early symptoms of dementia as inevitable consequences of aging.
Some disorders that result in dementia are "reversible or potentially reversible," which means that they can be treated effectively to restore normal or nearly normal intellectual function. Among the most frequent reversible causes of dementia are depression, alcohol abuse, and drug toxicity. In elderly persons, drug use—particularly drug interactions caused by "polypharmacy" (simultaneous use of multiple drugs)—is a common cause of cognitive decline. Depression also is an underdiagnosed condition in this population.
The majority of dementias, including Alzheimer's disease, are considered nonreversible. Even for these conditions, correct diagnosis of the problem in its early stages can be beneficial. Correct recognition can prevent costly and inappropriate treatment resulting from misdiagnosis, and give patients and families time to prepare for the challenging financial, legal, and medical decisions that may lie ahead. In addition, many of the nonreversible dementias such as Alzheimer's disease include symptoms that can be treated effectively (for example, incontinence, wandering, depression).
According to the National Institute on Aging, an estimated $90 billion is spent annually for Alzheimer's disease alone, and the noneconomic toll is incalculable. Although State and local governments and the Federal Government bear some of the economic burden, largely through Medicare and Medicaid, a substantial proportion is borne by families that provide unpaid care. Changes caused by dementia may advance relentlessly over many years, creating not only deep emotional and psychological distress but practical problems related to caregiving that can overwhelm affected families.
Addressing the Problem
In 1992, the Agency for Health Care Policy and Research, a Federal Government agency within the Public Health Service, convened a panel of private-sector experts to develop a clinical practice guideline on screening for Alzheimer's disease and related dementias. This topic was selected because:
- Dementia in the adult population is a serious and growing medical, social, and economic problem.
- Alzheimer's disease and related dementias exact a massive toll in health care costs, disability, and lost productivity of both patients and family caregivers.
- Early symptoms of dementia are commonly overlooked, mistakenly attributed to normal aging, or misdiagnosed.
- Failure to diagnose early-stage dementia can result in needless and possibly harmful treatment.
After extensive literature searches and meta-analyses, the panel decided to focus on early detection of dementia in persons exhibiting certain characteristics or triggers that signal the need for further assessment, rather than recommend general screening of segments of the population, such as those over a certain age. The panel made this decision after concluding that:
- No evidence exists to support recommending some of the most frequently used screening tests over others.
- None of the tests has a high sensitivity for early or mild dementia.
- No evidence supports the efficacy of a general screen for Alzheimer's disease or related dementias, given the lack of unequivocally effective treatment and the difficulty of recognizing early dementia.
The panel subsequently limited its scope specifically to the subject of recognition and initial assessment and therefore did not address differential diagnosis, management, or treatment issues after diagnosis.
The panel's principal objective was to increase the likelihood of early recognition and assessment of a potential dementing illness so that (1) concern can be eliminated if it is not warranted; (2) treatable conditions can be identified and addressed appropriately; and (3) nonreversible conditions can be diagnosed early enough to permit the patient and family to plan for contingencies such as long-term care.
Specifically, the panel's goals were to:
- Improve the detection of Alzheimer's disease and related dementias in their early stages in persons exhibiting certain signs and behaviors.
- Educate health professionals, patients, and their families about symptoms that suggest the need for an initial assessment for a dementing disorder.
- Identify areas for further research on early recognition of dementia.
The panel's major findings include:
- Certain triggers should prompt a clinician to undertake an initial assessment for dementia rather than attribute apparent signs of decline to aging.
- An initial clinical assessment should combine information from a focused history and physical examination, an evaluation of mental and functional status, and reliable informant reports. It also should include assessment for delirium and depression.
- An assessment instrument known as the Functional Activities Questionnaire is a particularly useful informant-based measure in the initial assessment for functional impairment.
- Among effective mental status tests, the Mini-Mental State Examination, the Blessed Information-Memory-Concentration Test, the Blessed Orientation-Memory-Concentration Test, and the Short Test of Mental Status are largely equivalent in discriminative ability for early-stage dementia.
- Clinicians should assess and consider factors such as sensory impairment and physical disability in selection of mental and functional status tests, and other confounding factors such as age, educational level, and cultural influences in interpretation of test results.
In asymptomatic persons who have possible risk factors (e.g., family history and Down syndrome for Alzheimer's disease), the clinician's judgment and knowledge of the patient's current condition, history, and social situation (living arrangements, support services, isolation) should guide the decision to initiate an assessment for dementia.
Initiating an Assessment
For a diagnosis of dementia, current criteria in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), require evidence of decline from previous levels of functioning and impairment in multiple cognitive domains, not solely memory. Because evidence of decline in previous abilities is critical in establishing dementia, a personal knowledge of the patient is invaluable to the clinician in assessing symptoms and interpreting results of an initial assessment for dementia.
A focused history is critical in the assessment for dementia. It is particularly important to establish the symptoms' mode of onset (abrupt versus gradual); progression (stepwise versus continuous decline; worsening versus fluctuating versus improving), and duration.
A focused physical examination, including a brief neurological evaluation, is an essential component of the initial assessment. Special attention should be placed on assessing for those conditions that cause delirium, since delirium represents a medical emergency. During the focused physical examination, health care providers should be alert to signs of abuse and neglect of patients by caregivers and report suspected abuse to the proper authorities.
Informant reports (information obtained from family members or caregivers) can supplement information from patients who have experienced memory loss and may lack insight into the severity of their decline. Health care providers, however, should consider the possibility of questionable motives of informant reports, which may exaggerate, minimize, or deny symptoms.
Brief mental status tests can be used but they are not diagnostic. They are used to (1) develop a multidimensional clinical picture; (2) provide a baseline for monitoring the course of cognitive impairment over time; (3) reassess mental status in persons who have treatable delirium or depression on initial evaluation; and (4) document multiple cognitive impairments as required for a diagnosis of dementia.
Assessing for Depression
Depression can be difficult to distinguish from dementia, and it can coexist with dementia. Changes in memory, attention, and the ability to make and carry out plans suggest depression, the most common psychiatric illness in older persons. Marked visuospatial or language impairment suggests a dementing process. The clinical interview is the mainstay for evaluating and diagnosing depression in older adults. Two self-report instruments with established reliability and validity are the Geriatric Depression Scale (GDS) and the Center for Epidemiological Studies Depression Scale (CES-D).
Three results are possible from the combination of findings from assessments of mental and functional status: (1) normal, (2) abnormal, and (3) mixed.
When results of both mental and functional status tests are normal and there are no other clinical concerns, reassurance and suggested reassessment in 6 to 12 months are appropriate. If concerns persist, referral for a second opinion or further clinical evaluation should be considered.
When both mental and functional status tests yield findings of abnormality, further clinical evaluation should be conducted. However, a laboratory test should not be used as a screening procedure or part of an initial assessment. Laboratory tests should be conducted only after (1) it has been confirmed that the patient has impairment in multiple domains that is not lifelong and represents a decline from previous levels of functioning; (2) delirium and depression have been excluded; (3) confounding factors such as educational level have been considered; and (4) medical conditions have been be ruled out.
Mixed results—abnormal findings on the mental status test with no abnormalities in functional assessment or vice versa—call for further evaluation. For example:
- Patients who have abnormal results on only the mental status test require more complete testing. Results that indicate possible neuropsychiatric or systemic neurological problems call for referral to an appropriate specialist.
- Patients who have declining function but normal mental status test results require either (1) further neurological evaluation for systemic neurological diseases or (2) psychiatric or psychological evaluation if evidence suggests depression or other emotional problems.
The Role of Neuropsychological Testing
Neuropsychological tests can examine performance across different domains of cognition. This broad battery of tests can help in identifying dementia among persons with high premorbid intellectual functioning, discriminating patients with a dementing illness from those with focal cerebral disease, and differentiating among certain causes of dementia.
The Importance of Followup
Followup, with assessment of declining mental function, may be the most useful diagnostic procedure for differentiating Alzheimer's disease from normal aging. For this reason, the mental status test should be repeated over a period of 6 to 12 months. In cases of referral, it is important to make sure that test results and medical records follow the patient from the specialist back to the referring clinician.
Key Points About Alzheimer's Disease
For Health Care Providers
- Although changes in memory or cognition may accompany normal aging, significant impairment and disability are not a part of normal aging.
- It is important for clinicians, as well as patients and family members, to recognize symptoms that should trigger an initial assessment for dementia.
- Some causes of dementia can be treated effectively to eliminate or greatly improve cognitive performance.
- Among older persons, depression and interactions from multiple medications are two common and highly treatable causes of dementia symptoms.
- An initial assessment for dementia can (1) lead to effective treatment of causes; (2) prevent unnecessary and possibly harmful treatment resulting from misdiagnosis; and (3) avoid the trauma of a diagnosis of dementia or Alzheimer's disease where it does not exist.
- The prolonged course of deterioration found in many dementias takes a major emotional, psychiatric, and physical toll among family members and caregivers.
- Learn more about symptoms that may indicate early-stage dementia and how to conduct an initial assessment. Read Recognition and Initial Assessment of Alzheimer's Disease and Related Dementias, Clinical Practice Guideline No. 19, and use its companion Quick Reference Guide for Clinicians. Give the Consumer Version to patients, family members, and other caregivers.
- Dementia is different from normal aging. Only certain tests can show that difference. Symptoms that suggest Alzheimer's disease or a related dementia should be brought to the attention of the family's health care provider as soon as possible.
- Some memory and other problems can improve or disappear with appropriate treatment.
- Although there is not yet a clearly effective treatment for Alzheimer's disease, resources are available to help patients and families cope with this condition and prepare for the future.
- Order the consumer booklet, Early Alzheimer's Disease: Patient and Family Guide from the U.S. Government's Agency for Health Care Policy and Research. It provides information about the early stages of Alzheimer's disease and similar illnesses. It also includes a list of resources where readers can find out more about the medical, financial, and social support services that are available in their communities.
- The Agency for Health Care Policy and Research also has a Clinical Practice Guideline and a Quick Reference Guide for health care providers about early identification of Alzheimer's disease and other forms of dementia.
Symptoms That Might Indicate Dementia
Does the person have increased difficulty with any of the activities listed below? Positive findings in any of these areas generally indicate the need for further assessment for the presence of dementia.
- Learning and retaining new information. For example: is more repetitive; has more trouble remembering recent conversations, events, appointments; more frequently misplaces objects.
- Handling complex tasks. For example: has more trouble following a complex train of thought, performing tasks that require many steps such as balancing a checkbook or cooking a meal.
- Reasoning ability. For example: is unable to respond with a reasonable plan to problems at work or home, such as knowing what to do if the bathroom flooded; shows uncharacteristic disregard for rules of social conduct.
- Spatial ability and orientation. For example: has trouble driving, organizing objects around the house, finding his or her way around familiar places.
- Language. For example: has increasing difficulty with finding the words to express what he or she wants to say and with following conversations.
- Behavior. For example: appears more passive and less responsive; is more irritable than usual; is more suspicious than usual; misinterprets visual or auditory stimuli. In addition to failure to arrive at the right time for appointments; the clinician can look for difficulty discussing current events in an area on interest and changes in behavior and dress. It might also be helpful to follow up on areas of concern by asking the patient or family members relevant questions.
The Agency for Health Care Policy and Research convened an 18-member private-sector, interdisciplinary panel composed of psychologists, psychiatrists, neurologists, an internist, geriatricians, nurses, a social worker, and consumer representatives. The panel conducted extensive literature searches to identify empirical studies of assessment of mental status instruments for differentiating persons with and without dementia and instruments used in the assessment of persons with Alzheimer's disease. It conducted additional literature searches related to assessment of functional impairment and risk factors for dementia and conducted meta-analyses. The panel also held a public hearing to give interested organizations, individuals, and agencies an opportunity to present oral or written testimony for the panel's consideration.
The results of the literature reviews and meta-analyses were used to develop a draft guideline. Copies were distributed for two peer review cycles. Reviewers were selected to represent a broad range of disciplines and clinical practice areas. A total of 109 reviewers submitted comments, which were collated and reviewed by the panel co-chairs and used to develop the final guideline.
Additional guideline information will be available later this year (Winter 1996) in several forms:
- Clinical Practice Guideline, intended for the health care provider, contains a discussion of the issues and the panel's findings and recommendations, with supporting evidence and references. It also includes a series of tables and a flow chart summarizing the panel's recommended approach to early recognition and initial assessment of suspected dementia.
- Quick Reference Guide for Clinicians, also intended for health care providers, is a brief summary of and companion piece to the Clinical Practice Guideline. It provides highlights of initial assessment and interpretation of findings and presents the tables and flow chart.
- Consumer Version, published in English and Spanish, is a brochure for patients, their families, and the general public that describes the problem, outlines procedures for identifying dementia in its early stages, and provides resource information for those who must deal with a diagnosis of probable Alzheimer's disease or a related dementia.
To obtain further information on the availability of the Quick Reference Guide or Consumer Version, call the AHCPR Publications Clearinghouse at (800) 358-9295.
Single and bulk copies of the Clinical Practice Guideline, Recognition and Initial Assessment of Alzheimer's Disease and Related Dementias, may be purchased, when available, from the U.S. Government Printing Office by calling (202) 512-1800.
The Clinical Practice Guideline, Quick Reference Guide, and Consumer Version will also be available on the Internet through the AHCPR Home Page. You can access the guideline products by using a Web browser, specifying the URL http://www.guideline.gov/ and clicking on Clinical Practice Guidelines Online.
AHCPR, a part of the U.S. Public Health Service, is the lead agency charged with supporting research designed to improve the quality of health care, reduce its costs, and broaden access to essential services.