Rotation Prep


Published July 10, 2019

Dementia

Dementia is a progressive neurodegenerative disorder that results in difficulties in memory, language, and behavior that impact and impair function. There are several types of dementia and underlying pathological processes.

The risk for dementia increases with age, affecting nearly 40% of individuals older than 80 years. Common causes of dementia include Alzheimer disease (50%), vascular dementia (25%), and Lewy-body-related dementia (15%). Often Alzheimer dementia exists together with vascular or Lewy body dementia, also referred to as “mixed dementia.”

Guiding Questions

  • What are the best screening tools for dementia?

  • What features distinguish Alzheimer from other forms of dementia?

  • What are the available treatments for dementia, and how effective are they?

Screening

When screening for dementia, it is important to evaluate for reversible causes of memory disorders (e.g., medication side effects, infections, and hypothyroidism).

The Mini-Cog test is a useful initial screening tool for dementia. It involves the tasks of drawing a clock and three-word recall. Abnormal results of the Mini-Cog require further evaluation.

As part of the work up for dementia, the American Academy of Neurology (AAN) recommends screening for depression, vitamin B12 deficiency, and hypothyroidism. 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 is not required for the diagnosis.

A summary of other assessment tools for diagnosis of dementia can be found in this review.

Treatment

Treatment for dementia consists of nonpharmacologic and pharmacologic interventions:

  • Nonpharmacologic interventions include:

    • optimizing overall health

    • establishing routines

    • maximizing social stimuli

  • Pharmacologic interventions include:

    • minimizing existing medications that can worsen cognition

    • cholinesterase inhibitors and memantine 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 of starting treatment and loses effectiveness within 6–12 months.

A summary of the AAN guidelines on the detection, diagnosis, and management of dementia can be found here.

Advanced Dementia

As dementia progresses, advanced dementia is marked by profound memory deficits (e.g., inability to recognize family members), minimal verbal abilities, inability to ambulate independently, inability to perform activities of daily living, and incontinence. The Functional Assessment Stage Tool (FAST) can be used to measure the severity of disease.

Once a patient develops advanced dementia, advance care planning becomes crucial. 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 of ≤6 months) once they reach stage 7c on the FAST scale.

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

  • Eating problems

    • Patients develop oral and pharyngeal dysphagia, increasing the risk of aspiration and progressing eventually to refusal to eat.

    • Use of a feeding tubes is not recommended because no evidence indicates that it prolongs longevity. Further, feeding tubes increase risk of pressure ulcers and 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

    • Infections of all kinds are common, but inappropriate use of antibiotics is also quite common.

    • When a patient is hospitalized for possible infection, make sure that treatment is within 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.

 Minimal Criteria for Initiating Antibiotics in Patients with Advanced Dementia

Suspected UTISuspected Pneumonia
A. No indwelling Foley catheter
Acute dysuria alone
OR
Temperature >100°F or 2°F >baseline or rigors AND ≥1 of the following:
  1. New or worse frequency

  2. Urgency

  3. Costovertebral tenderness

  4. Gross hematuria

  5. Suprapubic pain

  6. Mental status change* 

B. Indwelling Foley catheter
≥1 of the following:
  1. Temperature >100°F or >2°F >baseline

  2. Rigors

  3. Mental status change*

A. Temperature <102°F
New productive cough AND ≥1 of the
following:
  1. Pulse >100 beats/minute

  2. Respiratory rate >25 breaths/minute 

  3. Rigors

  4. Mental status change* 

B. Temperature >102°F
≥1 of the following:
  1. Respiratory rate >25 breaths/minute

  2. New productive cough 

C. Afebrile with COPD
New/increased cough with purulent
sputum
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