Dementia

Dementia is a progressive decline in cognition, affecting two or more of the cognitive domains (memory, executive function, language, and behavior) that result in impaired function. In 2021, about 6.2 million people aged 65 and older were living with Alzheimer dementia in the U.S. This population is projected to reach 13.5 million by 2060. The prevalence of Alzheimer dementia increases with age; currently, adults aged 85 and older account for about 36% of patients with Alzheimer dementia.

Mild cognitive impairment (MCI) represents an intermediate state of cognitive function between the changes seen in aging and those fulfilling the criteria for dementia. MCI is characterized by impairment in both memory and other cognitive domains (e.g., executive function, visual-spatial, expressive language) but does not impair normal function. Longitudinal studies suggest that individuals with MCI are at increased risk for the development of dementia.

Imaging demonstrates changes in specific areas of brain, such as the hippocampus in 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 review:

• Types of Dementia

• Diagnosis of Dementia

• Management of Dementia

• Advanced Dementia

Types 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 other types of dementia, including vascular or Lewy-body disease, 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, impaired cerebral blood flow, or both.

Lewy-body-related disease, occurring in 15% of patients with dementia, is characterized by fluctuating cognition and visual hallucinations with features of parkinsonism. Initial symptoms are behavioral and cognitive with delayed onset of motor symptoms, whereas motor features predominate early in Parkinson's dementia.

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 such as impulsivity, reduced inhibition, apathy, and decline in personal hygiene.

Other causes of dementia include Parkinson dementia, normal-pressure hydrocephalus, liver disease, HIV-related cognitive impairment, multiple sclerosis, and Huntington disease.

Diagnosis of Dementia

Given the insidious onset of symptoms, dementia can be difficult to diagnose. No recommendations for widespread screening for dementia currently exist. Evaluation 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.

Evaluation for dementia should first focus on 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 is recommended by the AAN but is not required for diagnosis.

Several 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 cognitive domains of visuospatial/executive, naming, memory, attention, language, abstraction, delayed recall, and orientation (to time and place), but it also has been recently trademarked. Despite these limitations, an objective assessment is still necessary.

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

Management of dementia is complex and involves a multidisciplinary team to individualize care for the patient and his or her caregivers — and to account for changes as the disease progresses. Several issues are important to consider:

• Driving

  • 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.

• Finances

  • Understand sources of income as well expenses.

  • Consider planning for financial aspects of long-term care.

• Social support and caregiving needs

Treatment

Dementia care can involve nonpharmacologic and pharmacologic interventions.

• Nonpharmacologic interventions include the following:

  • Optimize overall health, with a focus on cognitive and physical exercise and mitigating risk factors.

  • 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.

• Pharmacologic interventions include the following:

  • 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 do not improve cognition or change the trajectory of the disease but rather 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.

  • Aducanumab is the first potentially disease modifying drug approved by the FDA for early-stage Alzheimer disease, although the fast-track conditional approval is controversial. Aducanumab is a monthly IV monoclonal antibody infusion that reduces amyloid beta plaque, which is implicated in the pathogenesis of Alzheimer disease. The clinical benefits are currently uncertain.

  • Brexpiprazole is an atypical antipsychotic that was approved by the FDA for use in the treatment of agitation in patients with Alzheimer dementia.

Pain Management

• 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

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 of urine and stool.

The Functional Assessment Staging Tool (FAST) can be used to measure the severity of disease as described in the following table:

(Source: Advanced Dementia. N Engl J Med 2015.)

Advanced Care Planning

Once a patient develops advanced dementia, advance care planning becomes crucial 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 with advanced dementia.

(Source: Advanced Dementia. N Engl J Med 2015.)

Complications of Advanced Dementia

The main complications and causes of death in advanced dementia are as follows:

Challenges with feeding

• 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 or provides a cure for aspiration. 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 while the patient is awake and alert and practicing appropriate aspiration precautions is encouraged for patient comfort.

Infections

• Infections are common, especially urinary tract infections and pneumonia, 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.