Serena J. Scott, MD and Barry D. Weiss, MD, College of Medicine, University of Arizona
TIPS FOR THE EARLY DIAGNOSIS OF DEMENTIA
Dementia, a progressive deterioration in cognitive function, occurs more frequently with increasing age. Approximately 1% of people in their 60s have dementia, and the prevalence doubles every 5 years to nearly 40% of people in their 90s. Dementia currently affects 47 million people worldwide, with 9.9 million new cases each year. This number is projected to be 75 million in 2030 and nearly triple to 132 million by 2050. In the US alone, approximately 5.5 million people are currently living with Alzheimer's, which accounts for only 60-80% of all dementia cases. Dementia is a major cause of disability and dependency in older adults, and can have profound impact on patients, caregivers and families. Therefore, any provider treating older adults should be alert to this common and serious problem.
It is important to remember that although age is the greatest risk factor, dementia is not a normal part of aging. Other risk factors for dementia include family history, apolipoprotein E4 genotype, cardiovascular comorbidities, chronic anticholinergic use, and lower educational level. Unfortunately, clinicians often do not recognize symptoms of dementia and, therefore, patients do not undergo an appropriate evaluation. Early signs are often overlooked, as the onset can be gradual. Research shows that providers identify dementia in fewer than 50% of patients who have the condition. Even at the point of nursing home placement, up to 33% of patients with dementia have not been previously diagnosed.
To make a formal diagnosis of dementia, a clinician must determine the existence of memory impairment, and, in addition, detect the presence of significant cognitive dysfunction in any one of the following areas: aphasia (language problems including naming of objects or difficulty with word finding); apraxia (inability to perform a previously routine and well-rehearsed task, such as cooking or brushing teeth); agnosia (inability to recognize previously familiar items and people); and/or a decrease in executive function (ability to form and carry out a plan). Consciousness is not affected. Many of these signs can be elicited by obtaining a thorough history from family members or caregivers, as patients themselves often have poor insight into, or will downplay, their symptoms.
While there is insufficient evidence to recommend routine screening for dementia in older adults, patients who present with even mild symptoms should undergo an evaluation of cognitive function. A variety of tests have been recommended for this purpose, and many are listed in Table 1. The Mini-Mental State exam is perhaps the most well-known, but many other screening tools exist. Often subtle clues can be discerned from just observing the hygiene and dress of the patient, or evaluating their organizational skills. Simple factual questions can often detect problems with memory, such as asking about medication schedules or important dates. Keep in mind that dementia and depression may present similarly in the older adult; it is therefore recommended to screen for depression as part of the assessment for dementia.
Table 1. Tests to Detect the Cognitive Impairment of Dementia*
|Cognitive Test||Time Required||Sensitivity||Specificity|
|Mini-Mental State Exam||7-10 minutes||81%||89%|
|Clock Drawing||1-3 minutes||83%||84%|
|Addenbrooke's Cognitive Examination-Revised (ACE-R)||15-20 minutes||92%||89%|
|Mini-Cog test||2-4 minutes||91%||86%|
|*see reference number 2 (Arevalo et al.)|
The Cost Of Missing The Diagnosis Of Dementia
Reversible Causes Go Undetected. Occasional patients, about 1 in 70, will have a reversible cause of dementia that can be detected with a straightforward diagnostic workup (Table 2). If dementia in these patients is not detected in its early stages, irreparable neurological impairment can occur. Patients may unnecessarily suffer further cognitive decline, loss of social interactions, or undergo nursing home placement.
Table 2. Tests to Exclude Reversible Causes of Dementia
Tests to consider based on clinical suspicion or risk factors
*Also recommended by the American Academy of Neurology
Safety. People with undiagnosed dementia who continue to drive automobiles present a danger to themselves and others. Firearms present another potential safety problem. Even more commonly, mismanagement of medications can lead to injury. An early diagnosis of dementia can allow institution of appropriately-timed safety interventions and avoidance of injury.
Family Stress. The acceptance of abnormal behaviors related to dementia varies widely among cultures. All caregivers/families of patients with dementia, however, ultimately face issues related to a decline in social functioning. If dementia goes unrecognized, psychosocial or behavior-modifying therapy that might help will not be provided, nor will addressing end-of-life issues prior to a serious decline in function otherwise help clarify the wishes, goals and values of the patient.
Delaying Drug Treatment. Although current drug treatments for dementia only delay progression and do not reverse disease, they can sometimes prolong the time a patient spends at home prior to institutionalized care. Failure to diagnose dementia in its early stages, however, deprives patients of any such benefit.
Why Is Dementia Under-Diagnosed?
While moderate or severe dementia may be obvious to clinicians, subtle symptoms can be easily missed - even ones that markedly increase the chance that a person has dementia (Table 3). Alzheimer's dementia can be particularly difficult to detect early, as everyday social interaction can be preserved. Eliciting any of the symptoms in Table 3 should prompt a dementia evaluation with the tests noted in Tables 1 and 2.
Table 3. Early Symptoms in the Diagnosis of Dementia
Common Dementia Syndromes * **
Dementia with Lewy bodies
* Mixed dementias involve more than one type
Check it Out!
To help ensure cultural competency throughout many practice environments, the Folstein Mini-Mental Status is now available in over fifty languages
References and Resources
- Alzheimer's Disease International. Early symptoms of dementia.
- Arevalo-Rodriguez I, et al. Mini-Mental State Examination for the detection of Alzheimer's disease and other dementias in people with mild cognitive impairment. Cochrane Database Syst Rev. 2015;(3):CD010783.
- Boise L, Neal MB, Kaye J. Dementia assessment in primary care: Results from a study in three managed care systems. J Gerontol A Biol Sci Med Sci. 2004; 59(6):M621-6.
- Brayne C, Fox C, Boustani M. Dementia screening in primary care: Is it time? JAMA. 2007; 298(20):2409-2411.
- Fage BA, et al. Mini-Cog for the diagnosis of Alzheimer's disease dementia and dementias within a community setting. Cochrane Database Syst Rev. 2015; (2):CD010860.
- Holsinger T, Deveau J, Boustani M, Williams JW Jr. Does this patient have dementia? JAMA. 2007; 297(21):2391-2404.
- Simmons BB, Hartmann B, Deioseph D. Evaluation of suspected dementia. Am Fam Physician. 2011; 84(8):895-902.
- Tsoi KK, Chan JY, Hirai HW, Wong SY, Kwok TC. Cognitive tests to detect dementia: a systematic review and meta-analysis. JAMA Intern Med. 2015; 175(9):1450-8.