Introduction

Dementia is progressive deterioration in intellectual function and other cognitive skills, leading to a decline in the ability to perform activities of daily living. Diagnosis is by history and physical examination. Potentially reversible causes of cognitive impairment (eg, drugs, delirium, depression) should be excluded. Treatment is with general measures and usually a cholinesterase inhibitor, memantine, or both.

Geriatric Essentials

• Dementia is one of the most common causes of institutionalization, morbidity, and mortality among the elderly.
• Mild slowing of cognitive processes is normal with aging and, by itself, does not suggest dementia.
• Self-reported memory loss in elderly patients who function normally is often caused by aging or depression rather than by dementia.
• Dementia is typically preceded by a state of mild cognitive impairment, which may last for several years.
• In every patient, evaluation for dementia requires a thorough review of drugs, including OTC drugs.
• For most patients with mild to moderate dementia, being in a familiar, supportive environment and remaining active enable them to compensate and may slow the decline in function.
• Currently used drugs may modestly improve cognitive performance or temporarily delay cognitive and functional decline due to dementia.
• Treating depression, which is common among patients with dementia, may improve function and quality of life.
• Providing a source for ongoing education and support for caregivers (including, when possible, time away from the patient) can help protect caregivers' health and prevent mistreatment of the patient.
• As early in the disorder as possible, decisions about a surrogate to handle finances and a health care proxy should be made, and end-of-life preferences should be discussed and documented.

Dementia is characterized by cognitive decline and a normal sensorium (ie, delirium is absent). The prevalence of dementia doubles every 5 yr after age 60 until about age 90. Dementia affects only 1% of people aged 60 to 64 but 30 to 50% of those > 85. In the US, about 4 to 5 million people are affected. Dementia is the leading cause of institutionalization among the elderly; prevalence among elderly nursing home residents is estimated to be 60 to 80%.

Dementia differs from age-related memory loss, which is much milder, is not substantially progressive, and does not significantly impair function. In people with age-related memory loss, cognitive performance is essentially unimpaired, but they may require extra time and encouragement. They learn new information and recall previously learned information but do so less efficiently. Daily functioning remains unaffected. People with this condition are often more concerned about it than are family members; reassurance and coping strategies are helpful.

In mild cognitive impairment, memory or another aspect of cognition is impaired (not merely slowed) but not severely enough to interfere with daily functioning. Up to 50% of patients with mild cognitive impairment that affects memory develop dementia within 3 yr. Currently, there is no clear way to predict which patients will develop dementia.

Etiology

Causes (see Table 40-1) are difficult to differentiate because definitions and clinical criteria for diagnosis of many causes are imprecise; causes can be confirmed by postmortem pathologic examination, which is not usually done. Also, mixed dementias (eg, Alzheimer's disease plus vascular dementia) are common.

Alzheimer's disease is the most common type; it accounts for about 2/3 of cases of established dementia. Vascular dementia is probably the next most common type, and dementia with Lewy bodies may account for many cases.

Symptoms and Signs

The natural history varies depending on the cause of dementia. However, typically, intellectual and other cognitive functions decline inexorably over 2 to 10 yr. Although the decline occurs in a continuum, symptoms can be divided into mild (early), moderate, and severe (late). Personality and behavior changes may develop during any stage. Depression affects up to 40% of patients with dementia, usually when dementia is mild or moderate, and may cause vegetative symptoms (eg, withdrawal, anorexia, weight loss, insomnia). Depression can aggravate disability in dementia; distinguishing between cause and effect is often difficult.

Many people who develop dementia lose weight before other symptoms appear. Some experts hypothesize that weight loss may result from impairment of appetite or metabolic control centers in the brain.

Motor and other focal neurologic deficits occur at different stages, depending on the type of dementia; they occur early in vascular dementia and late in Alzheimer's disease. The incidence of seizures increases throughout the course of dementia. Psychosis (hallucinations, delusions, or paranoia) occurs in about 25% of patients with dementia.

Mild dementia: Short-term memory is impaired, as is language function, especially word finding. Aphasia (impaired ability to comprehend or use language), agnosia (impaired ability to identify objects despite intact sensory function), and apraxia (impaired ability to perform previously learned motor activities despite intact motor function) can develop. Executive function (eg, ability to plan, organize, and sequence) is impaired. Apathy is common. As a result, patients function less well. Patients may forget the name of a recent dinner guest or get lost on the way to the store. They may have progressive difficulty with formerly mastered complex activities (eg, driving) and moderately complex daily activities (instrumental activities of daily living; eg, handling finances, preparing meals, housekeeping). Patients are less likely to take the initiative. They have difficulty following directions.

Emotional lability is common. Patients may be irritable, hostile, and agitated.

Although mild dementia may not compromise sociability, family members may report that patients are not acting like themselves or are doing uncharacteristic things (eg, a miserly widower gives thousands of dollars to a questionable charity). Poor judgment is common.

Patients with mild dementia can usually compensate reasonably well and follow established routines at home. Difficulty often results from disruption of routine or a change in surroundings. For example, an elderly parent who visits a child's unfamiliar home may become disoriented or manifest behavioral symptoms and functional disability, which do not occur in more familiar surroundings.

Moderate dementia: The ability to perform simple daily activities (basic activities of daily living; eg, bathing, dressing, toileting) becomes impaired. Patients cannot learn new information.

Normal environmental and social cues for time and place do not register, increasing disorientation. Because patients cannot effectively use these cues, they may become lost even in familiar surroundings (eg, they cannot find their bedroom or bathroom). Patients remain ambulatory but are at increased risk of falls and accidents due to confusion and poor judgment.

Personality changes may progress. Patients may become irritable, anxious, self-centered, inflexible, or angry more easily, or they may become more passive, with a flat affect, depression, indecisiveness, lack of spontaneity, or general withdrawal from social situations.

Psychotic symptoms may occur. Significant paranoia (eg, specific, often persecutory delusions; generalized suspicion) occurs in about 25% of patients. The most common delusions are beliefs that people are stealing and that a spouse is unfaithful. One particularly poignant delusion results from loss of self-recognition in mirrors; some patients with this delusion worry that strangers have entered the home, but others enjoy the "visitor's" company. Patients often misidentify other people at this point (eg, thinking their husband is their father or their daughter is their wife).

Behavior disorders may develop. Wandering can be a significant problem, particularly if patients are trying to return to familiar surroundings that no longer exist. Patients may become physically aggressive or agitated or act in sexually inappropriate ways. Sleep patterns are often disorganized.

Severe: Eventually, patients cannot perform the most basic activities (eg, eating, walking) and become totally dependent on other people. Memory for recent and remote events is completely lost, and patients may be unable to recognize even close family members. The ability to walk is variably affected in different dementias but is usually lost in the late stages; patients may become unable to move even while in bed. Patients may become incontinent. Reflex motor function (eg, ability to swallow) is lost, putting patients at risk of dehydration, undernutrition, and aspiration (which increases risk of pneumonia). The combination of immobility and undernutrition increases risk of pressure ulcers. Eventually, patients become mute.

Total functional dependence usually requires that patients be placed in a nursing home or that similar support be implemented in the home. Conscientious nursing care may delay complications (eg, dehydration, undernutrition, aspiration, pressure ulcers). Because many patients cannot describe symptoms to a physician and because elderly patients often have no febrile or leukocytic response to infection, health care practitioners must rely on experience and acumen to detect infections whenever patients appear ill.

End-stage dementia results in coma and death, usually due to infection originating in the respiratory tract, skin, or urinary tract.

Diagnosis

For all elderly patients, mental status should be evaluated at each regular checkup and whenever a change in mental status is suspected. The Folstein Mini-Mental State Examination is most commonly used. The initial evaluation is based on interviews with the patient and the people who spend the most time with the patient. The patient's appearance should be observed because it may provide clues (eg, poor hygiene) that confirm poor judgment or difficulty with some daily activities. A complete physical examination is also done.

Diagnosis focuses first on determining whether dementia, another disorder with similar symptoms (eg, delirium, age-related memory loss, dementia of depression), or a combination is present. If dementia is diagnosed, the cause of the dementia is identified, and potentially reversible contributing factors are sought.

Recommendations about diagnosis of dementia are available from the American Academy of Neurology (AAN). According to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision (DSM-IV-TR), diagnosis requires impairment of memory and of at least one other area of cognition: language, ability to execute skilled motor activities, recognition of objects, or executive function. Often, many or all of these areas are impaired. Other diagnostic criteria include progressive worsening of memory and other cognitive functions, exclusion of delirium, and functional impairment due to cognitive decline. Slow onset of symptoms is typical, but in some rare forms of dementia, onset or progression can be rapid.

History: The history provides essential information about the presence and nature of impairments, time of onset, and pattern of progression. Whenever possible, family members should be interviewed about these factors and about symptoms suggesting dementia (see Table 40-2) because family members are usually more aware of them than are patients. Family members can refer to a checklist of the 10 warning signs of Alzheimer's available from the Alzheimer's Association.

Because symptoms of most dementias begin gradually, family members may notice symptoms only after the patient reaches a certain threshold (eg, can no longer perform some daily activity) or only after a specific event (eg, hospitalization, a move, a trip, loss of spouse) precipitates a more abrupt decline. Thus, family members may report gradual decline as acute and may need to be carefully questioned about the patient's level of functioning before cognitive decline became obvious. Patients with truly acute decline in cognition should be evaluated promptly for delirium because it is usually reversible if treated quickly (some forms of dementia are also reversible). These patients should also be evaluated for other potentially reversible or treatable disorders that can cause acute cognitive impairment (eg, infection, electrolyte abnormalities, renal or hepatic dysfunction, subdural hemorrhage, other focal brain disorders). Treatment of such disorders can improve overall function, mood, and behavior.

Mental status examination: Because dementia must be promptly distinguished from delirium, attention is assessed first. If a patient is overly distractible or otherwise unable to maintain attention, the diagnosis is likely to be delirium, although dementia also impairs attention, especially in later stages. Other features that suggest delirium rather than dementia (eg, abrupt onset, physical symptoms or signs suggesting an acute disorder, moment-to-moment variability, psychomotor changes) are determined by the history, physical examination, and tests for specific causes.

The ability to register information is evaluated by presenting the names of 3 objects to patients, who are asked to repeat the names immediately. If patients cannot do so, the problem is usually attention, not memory. If patients can register information, short-term memory is tested: After 5 min, patients are asked to recall the 3 names. Patients with dementia forget such simple information within 1 to 5 min. Asking patients to name objects within categories (eg, animals, articles of clothing, pieces of furniture) is another useful test. Patients with dementia struggle to name a few; those without dementia easily name many. The Functional Activities Questionnaire, available from the Alzheimer's Association, is used to evaluate whether cognitive impairment affects a patient's ability to perform instrumental and other complex activities of daily living.

Formal mental status examination is essential to diagnosis. Serial assessments can help determine whether cognition is declining; however, small changes detected by cognitive screening instruments are often meaningless unless the changes progress.

Evaluation for contributing factors: Drug history is recorded because use of drugs, including OTC drugs, may be the most common and most easily reversible factor contributing to cognitive impairment. Before dementia can be diagnosed, all psychoactive drugs should be eliminated if possible. The drugs most likely to affect cognition are sedative-hypnotics, antidepressants (especially tricyclic antidepressants), anticholinergic drugs, and opioids, but many other drugs can affect cognition. Repeating the mental status examination 6 wk after optimal modification of the drug regimen is a reasonable strategy. A history of alcohol use should also be obtained.

The physical examination should focus on identifying acute disorders and exacerbations of chronic disorders that may be contributing to cognitive decline. Neurologic examination may detect focal neurologic findings indicating cerebrovascular disease, extrapyramidal signs indicating parkinsonism, symptoms of other neurodegenerative disorders, or symptoms of neuropathies or myopathies suggesting a treatable systemic disorder that may impair cognition.

Dementia should be distinguished from cognitive changes due to depression (so-called dementia of depression), which resolves when depression is treated. If patients have dementia and depression, cognitive deficits persist after mood improves. Depressed elderly patients may experience cognitive decline, but unlike patients with dementia, they tend to exaggerate their memory loss and rarely forget important current events or personal matters. Decline is usually more gradual than that in dementia. Neurologic examination is normal except for signs of psychomotor slowing. When tested, patients with depression make little effort to respond, but those with dementia often try hard but respond incorrectly. Every elderly patient with a cognitive problem should be evaluated with a full mood assessment, including a symptom review (using the SIG E CAPS [Sleep, Interest, Guilt, Energy, Concentration, Appetite, Psychomotor, Suicide] evaluation) and a standardized instrument such as the Geriatric Depression Scale short form.

Other testing: Routine laboratory tests include thyroid functions and vitamin B₁₂ measurement. Routine use of CBC, renal function tests, liver function tests, and electrolyte and albumin measurement is controversial because yield is low. Other laboratory tests (eg, ABGs, serologic tests for syphilis, drug levels, examination of CSF for evidence of infection) should be done only in high-risk patients.

Routine use of brain imaging with noncontrast CT or MRI to look for a cause of dementia is usually recommended as part of the initial evaluation of dementia and after any sudden change in cognition or mental status. Imaging can identify potentially reversible structural abnormalities (eg, normal-pressure hydrocephalus, chronic subdural hematomas, brain tumors). However, these disorders are uncommon and can often be identified by their characteristic presentation. MRI can provide information that may help differentiate Alzheimer's disease from vascular dementia. Currently, the role of positive emission tomography (PET) and single-photon emission CT (SPECT) in the diagnosis of dementia is limited. These tests distinguish Alzheimer's disease from dementias affecting the frontal lobes and may help in the diagnosis of dementia with Lewy bodies.

Detailed neuropsychologic testing is not required routinely. Testing helps primarily in differentiating (1) between age-related memory loss, mild cognitive impairment, and dementia, particularly when cognition is only slightly impaired or when the patient or family members are very concerned and desire additional reassurance, and (2) between dementia and focal syndromes of cognitive impairment (eg, amnesia, aphasia, apraxia, visuospatial difficulties) when the distinction is not clinically evident. A thorough history, physical examination, and mental status examination can usually differentiate causes of dementia better than neuropsychologic testing.

Treatment

After confirming the diagnosis of dementia and after attempting to understand the patient's values and family dynamics, a physician should usually disclose the diagnosis to the patient. If the patient has difficulty understanding, the physician may talk with family members first. The course of the dementia and treatment options should be discussed, and the patient and family members should be given time to ask questions, as well as written materials about the dementia and a list of resources. The other members of the health care team (eg, nurses, social workers, psychologists) should be present during this discussion, if possible, to help answer questions. Disclosing the diagnosis early enables the patient to participate in treatment decisions and to prepare advance directives.

Recommendations about treatment of dementia are available from the AAN.

Correction of contributing factors: Treatment or elimination of all potentially reversible contributing factors may substantially improve daily functioning and quality of life and may delay severe disability and institutionalization. Patients with significant depressive symptoms should be treated, even if all criteria for major depression are not met. Treatment of depression improves attention, concentration, and energy levels and sometimes substantially reduces disability in patients with dementia. The drug of choice is usually an SSRI (eg, escitalopram, fluoxetine, paroxetine, sertraline), started at a low dose and increased into the therapeutic range as tolerated. After 6 to 12 wk of treatment, mental status examination and mood assessment should be repeated. Some physicians try methylphenidate (5 to 10 mg bid), especially if vegetative symptoms are present; a trial of only several days is necessary.

Environmental measures: The next step is to create an appropriate, safe, and supportive environment in which patients can function optimally.

Patients with mild to moderate dementia usually function best in familiar surroundings. A home safety evaluation and appropriate modifications to help patients function better should be considered for all patients who live at home. For example, signs can be posted to cue patients for orientation and safety, especially in the kitchen and bathroom. Guns and other dangerous items (eg, power tools) should be removed. Use of appliances should be monitored; confirmation that certain appliances are shut off after use may be necessary, unless the appliances have an automatic shut-off feature.

Homemaking services can help with instrumental activities of daily living; home health aide services can help with basic activities of daily living. Visiting nurses can supervise drug use. Patients may need to have meals prepared for them and be monitored to ensure that meals are eaten.

Patients with mild dementia may be able to continue to drive. However, in most states, a diagnosis of dementia must be reported to the Department of Motor Vehicles, which is likely to require a driving test. Patients and their family members should be advised that patients will at some point become unable to drive and that their ability to drive should be reevaluated periodically (eg, with cognitive tests and sometimes a driving test). Arrangements for alternative means of transportation should be planned.

If wandering is a problem, patients can be registered in the Safe Return program. Information is available from the Alzheimer's Association.

A supportive environment includes encouragement of and opportunities for physical and mental activity and social interaction. These activities may help slow cognitive, physical, social, affective, and functional decline.

Decisions about how to balance safety and independence must be individualized. Whether placement in a more supportive living situation is necessary is determined by many factors, including severity of the dementia, other clinical factors, values or preferences of the patient and family members, the patient's ability to care for self (eg, manage drugs, use the telephone, travel safely outside the home, avoid exploitation), the availability of family members or close neighbors to provide discreet assistance or surveillance, the feasibility of paid helpers, and financial resources. Such placement may be necessary even early in the course of dementia.

Nursing-home care: Nursing homes should be designed to reinforce orientation and to be cheerful; they should provide regular low-stress activities and minimal new stimulation. Such measures can help by giving patients a sense of some control and personal dignity.

Large calendars and clocks and a routine for daily activities help reinforce orientation; medical staff members can wear large name tags and repeatedly introduce themselves. Changes in surroundings, routines, or people should be explained to patients precisely and simply; nonessential procedures should be eliminated. Patients should be given time to adjust and become familiar with the changes. Telling patients about what is going to happen (eg, about a bath or feeding) may avert resistance or violent reactions. Frequent visits by staff members and familiar people encourage patients to remain social.

The room should be reasonably bright and contain sensory stimuli (eg, radio, television, night-light) to help patients remain oriented and focus their attention. Quiet, dark private rooms should be avoided.

Patients with dementia are susceptible to muscle disuse atrophy, which can be delayed by adequate physical exercise and nutrition. A regular, supervised exercise program (eg, 15 to 20 min/day of walking) is recommended. Exercise can reduce restlessness, improve balance, maintain cardiovascular tone, help improve sleep, and reduce frequency and severity of behavior disorders.

Mental activities, usually focused on the patient's interests before the onset of dementia (eg, current events, reading, art), should be encouraged. These activities should be enjoyable and provide some stimulation, but they should not involve too many choices or challenges nor be used as tests of mental function. Occupational therapy helps maintain fine motor control; music therapy provides nonverbal stimulation.

Special effort may be required to ensure continuing interaction, with the same people if possible (eg, with family members or friends when available, with people in support groups, or otherwise with adult day care or companion services workers). Group therapy (eg, reminiscence therapy, socialization activities) may help maintain conversational and interpersonal skills.

Behavior disorders are best treated with individualized behavioral interventions, rather than with drugs. However, frank psychotic symptoms (eg, paranoia, delusions, hallucinations) should be treated with antipsychotic drugs, started at a low dose. Patients must be carefully monitored for adverse effects.

Because dementia is a strong risk factor for other problems (eg, falls, urinary incontinence), prevention and treatment strategies for these problems should be implemented.

Drugs: Eliminating or limiting drugs with CNS activity often improves function. Sedating and anticholinergic drugs, which tend to worsen dementia, should be avoided.

The cholinesterase inhibitors donepezil, rivastigmine, and galantamine are somewhat effective in delaying the progression of Alzheimer's disease and dementia with Lewy bodies and may be useful in other forms of dementia. These drugs inhibit acetylcholinesterase, increasing the acetylcholine level in the brain. Memantine, an NMDA (N-methyl-D-aspartate) antagonist, may help defer progression of moderate to severe dementia and can be used with a cholinesterase inhibitor (see Table 40-3).

Caregiver support: Caregiver stress is common. It may result from worry about protecting the patient, from the effort of doing so much to care for the patient (causing frustration, exhaustion, anger, and resentment), or from both. Thus, health care practitioners must provide support for family members and caregivers of patients with dementia. Such support helps prevent mistreatment of patients. Educational materials about dementia in general and about the specific type (if known) can be very helpful but are no substitute for the specific advice, listening, and understanding of a health care practitioner.

Some family members and caregivers cope with the stress of care more easily than others. The health of those who care for patients with dementia should be monitored, especially for stress-related problems and exacerbation of chronic disorders. Family members and other caregivers should also be encouraged to obtain respite care and be referred to available support services (eg, Alzheimer's Association support groups, social workers, aging services).

End-of-life issues: Medical and financial planning is imperative before dementia becomes severe. Patients with mild dementia retain the capacity to make many of these decisions. They should appoint a surrogate to handle finances and a health care proxy. Patients should discuss health care preferences with the proxy and a cooperative primary physician, and decisions should be documented. When making these decisions, patients with dementia are vulnerable to coercion and undue influence, and physicians should assist in guarding against such manipulation.

As dementia worsens, highly aggressive interventions and hospital care provide less benefit and may not be worth their costs, discomforts, and risks. Palliative care should be routinely offered. Decisions about artificial feeding and treatment of acute disorders are best discussed before such a situation occurs and then discussed again when the situation arises. In severe dementia, maximizing comfort may be more appropriate than attempts to prolong life.

This topic was last updated February 2006.