Published April 8, 2020
In 2015, about 47 million people were living with dementia, and this number is expected to triple by 2050. The risk for dementia increases with age, affecting nearly 40% of people older than 80 years. Dementia is a progressive neurodegenerative disorder that results in difficulties in at least two of the cognitive domains (memory, executive function, language, and behavior) that influence and potentially impair function.
Brain imaging can show differences among patients with normal cognition, mild cognitive impairment, and Alzheimer disease as illustrated in this figure:
The arrows depict the hippocampal formations and the progressive atrophy characterizing the progression from normal cognition (Panel A) to mild cognitive impairment (Panel B) to Alzheimer's disease (Panel C).
(Source: Mild Cognitive Impairment. N Engl J Med 2011.)
In this section, we will review:
Types of Dementia
Screening for Dementia
Management of Dementia
There are several types of dementia and underlying pathological processes.
Alzheimer disease is the most common cause of dementia, accounting for 50% of cases. Common features of Alzheimer disease include the inability to remember new information, mood changes, and difficulty with multitasking. Neuropsychiatric symptoms are common from disease onset, while motor abnormalities typically occur later in the disease course. Alzheimer dementia often coexists with vascular or Lewy-body dementia, a condition known as “mixed dementia.”
Vascular dementia is the second-most common cause of dementia, accounting for about 25% of cases. It is characterized by disabling cognitive decline caused by cerebrovascular disease or impaired cerebral blood flow.
Lewy-body–related disease, occurring in 15% of patients with dementia, is characterized by fluctuating cognition and visual hallucinations with features of parkinsonism. The condition is similar to Parkinson disease with dementia, although in Lewy-body–related dementia, motor symptoms develop more than a year before cognitive and psychiatric symptoms.
Frontotemporal dementia is characterized by atrophy of the frontotemporal lobes and is another type of dementia to consider in patients with changes in personality and behavior.
Other causes of dementia include normal-pressure hydrocephalus, liver disease, HIV-related cognitive impairment, multiple sclerosis, and Huntington disease.
Given the insidious onset of symptoms, dementia can be difficult to diagnose. No recommendations for widespread screening for dementia currently exist. Screening should be initiated in response to a patient’s complaints about cognition, missed appointments, confusion over medications, increasing frequency of medical visits, or concerns from family and caregivers.
Screening for dementia should first focus on evaluation for reversible causes of memory disorders. As part of the workup for dementia, the American Academy of Neurology (AAN) recommends screening for depression, vitamin B12 deficiency, hypothyroidism, and medication side effects. Screening for syphilis is not recommended unless the patient has known risk factors. Structural neuroimaging with noncontrast CT or MRI should also be considered, but such testing is not required for diagnosis.
Several screening tools are available to help diagnose dementia. The Mini-Mental State Examination had been the gold standard, but trademark restrictions now limit its use. The Montreal Cognitive Assessment (MoCA) includes a measure of executive function, but it also has been recently trademarked.
The Mini-Cog involves a clock-drawing task and three-word recall. Inability to recall more than one word or recall of just two words with an abnormal clock drawing, suggests cognitive impairment, which requires further evaluation.
A summary of other assessment tools for diagnosis of dementia can be found in this review. A summary of the AAN’s guidelines on the detection, diagnosis, and management of dementia can be found here.
Management of dementia is complex and involves a multidisciplinary team to individualize care to the patient and his or her caregivers — and to account for changes as the disease progresses. Several issues are important to consider:
Motor vehicle crashes can have devastating effects on older adults.
Driving cessation is associated with negative outcomes.
Medical conditions can impair driving.
A number of algorithms are available to help with driving assessment, including the plan for Older Driver Safety from the American Geriatric Society.
Understand sources of income as well expenses.
Consider planning for financial aspects of long-term care.
Treatment: Dementia care can involve nonpharmacologic and pharmacologic interventions.
Optimize overall health.
Establish daily and other temporal routines for the patient.
Maximize social stimuli, including music therapy.
Consider palliative-care consultation to help with symptom management in advanced disease.
Minimize use of existing medications that can worsen cognition.
Acetylcholinesterase inhibitors (donepezil, galantamine, and rivastigmine) and memantine (an N-methyl-D-aspartate [NMDA]–receptor antagonist) may be used for mild-to-moderate dementia but are not recommended for mild cognitive impairment or advanced dementia. These therapies rarely improve cognition but merely slow the rate of cognitive decline. Response to therapy usually occurs within 3 months after starting treatment, and effectiveness diminishes within 6 to 12 months.
Pain levels are difficult to assess in patients with dementia. Validated tools, such as the Pain Assessment in Advanced Dementia (PAINAD) tool, are useful to assess for pain.
Initiate pain management with nonopioids and topical agents.
If starting systemic analgesics, start at a lower dose and titrate slowly.
Advanced dementia is marked by profound memory deficits (e.g., inability to recognize family members), minimal verbal abilities, inability to walk independently, inability to perform activities of daily living, and incontinence. The Functional Assessment Staging Tool (FAST) can be used to measure the severity of disease (see table).
(Source: Advanced Dementia. N Engl J Med 2015.)
Once a patient develops advanced dementia, advance care planning becomes crucial. It is important to inform patients and their families about the trajectory of disease. For some patients, hospice care may be a consideration. Estimating expected survival is challenging, but a patient usually becomes eligible for Medicare hospice benefits (life expectancy ≤6 months) upon reaching stage 7c on the FAST scale.
The following table highlights key steps to decision-making in patients withadvanced dementia.
(Source: Advanced Dementia. N Engl J Med 2015.)
The main complications and causes of death in advanced dementia are as follows:
Patients develop oral and pharyngeal dysphagia, increasing the risk of aspiration and progressing eventually to refusal to eat.
Use of a feeding tube is not recommended because no evidence indicates that it prolongs longevity. Further, feeding tubes increase risk for pressure ulcers. Pain and the use of physical or chemical restraints to prevent self-removal of tubes is associated with physical and psychological risks, all of which can lead to unnecessary hospitalizations for tube-related problems.
Hand-feeding is encouraged for patient comfort.
Infections are common in patients with advanced dementia, and inappropriate use of antibiotics occurs often.
When a patient is hospitalized for possible infection, ensure that treatment is consistent with the patient’s preferences.
Diagnosing infections can be challenging because of the patient’s inability to communicate symptoms. The following table describes minimal criteria for starting antibiotics in patients with advanced dementia.
|Suspected UTI||Suspected Pneumonia|
|A. No indwelling Foley catheter|
Acute dysuria alone
Temperature >100°F or 2°F >baseline or rigors AND ≥1 of the following:
≥1 of the following:
|A. Temperature <102°F|
New productive cough AND ≥1 of the
≥1 of the following:
New/increased cough with purulent