Chapter 14: Late Life & Neurocognitive Disorders

Defining Neurocognitive Disorders (NCDs)

• Definition under DSM-V: Neurocognitive disorders (NCDs) are categorized as disorders where the core, primary diagnostic features are cognitive in nature.

• Distinction from Other Disorders: While cognitive deficits may appear as symptoms in various other psychological or medical conditions, in NCDs, the impairment to cognition is the central and defining feature required for diagnosis.

• Target Population: Elderly individuals represent the demographic most vulnerable to the development and progression of NCDs.

Misconceptions and Realities of Aging

• Common Myths: There is a prevalent societal perception that older adults are characterized by being slow, confused, and easily agitated. Many believe that aging inevitably leads to becoming unhappy, dissatisfied, having significant difficulty coping with problems, and focusing entirely on declining health.

• The Reality of Late Life: Research and data indicate that the majority of elderly people do not experience severe cognitive dysfunction. Many of these common negative perceptions are false.

• Emotional Regulation: Contrary to stereotypes, older adults are often more skilled than younger individuals at conveying and regulating their emotions.

• Social Selectivity Theory: This concept posits that as individuals age, their priorities shift. Rather than focusing on forming new social relationships, older adults prioritize cultivating and appreciating meaningful existing relationships, particularly those with family and close friends.

Challenges and Vulnerabilities in Late Life

• Physical and Psychological Strain: The elderly may experience the highest frequency of problems compared to any other age group, encompassing both physical and psychological domains.

• Primary Stressors:

  • Physical decline and physical disabilities.

  • Sensory deficits (e.g., vision and hearing loss).

  • Neurological deficits.

  • Loss of loved ones and social support networks.

  • The cumulative impact of a lifetime of negative experiences.

  • Societal stigmas directed toward their age group.

  • A decline in both the overall quality and the depth of sleep patterns.

• Specific Health and Medication Complications:

  • Chronic health problems in the elderly tend to worsen over time rather than diminish.

  • Risks associated with the interactions between multiple medications (polypharmacy).

  • A mismatch in drug design, as many psychoactive drugs are originally formulated and tested for younger populations.

DSM-V Criteria for Major Neurocognitive Disorders

• Significant Cognitive Decline: Evidence of significant cognitive decline from a previous level of performance in one or more cognitive domains (such as attention, executive function, learning, memory, language, perceptual-motor, or social cognition).

• Evidence Requirements:

  1. Concerns expressed by the patient, a clinician, or a close associate regarding the decline.

  2. Substantial neurocognitive impairment, preferably documented by standardized neuropsychological testing or an equivalent clinical assessment.

• Impact on Functioning: The cognitive deficits must interfere with independence in everyday activities (e.g., requiring assistance with complex instrumental activities of daily living like paying bills or managing medications).

• Exclusionary Criteria: The deficits do not occur exclusively in the context of delirium and are not better explained by another psychological disorder (e.g., major depressive disorder or schizophrenia).

Overview of Dementia

• Core Feature: Dementia is defined as a deterioration or decline in cognitive abilities that leads to an impaired state of daily functioning.

• Prevalence Statistics:

  • Approximately $0.4\%$ of the worldwide population is affected by dementia.

  • Prevalence increases significantly with advanced age.

  • Aged $60$ to $69$: $1-2\%$

  • Aged $85$ and older: $20\%$

• Clinical Course: The progression can be progressive (getting worse), static (unchanging), or remitting (improving), depending entirely on the underlying cause of the cognitive decline.

• Four Primary Types of Dementia:

  1. Alzheimer's disease.

  2. Frontotemporal Dementia.

  3. Vascular Dementia.

  4. Dementia with Lewy Bodies.

• General Symptoms:

  • Difficulty remembering things (memory impairment).

  • Confusion regarding time, place, or identity.

  • Impaired judgment and decision-making.

  • Lack of impulse control.

  • Disturbances in emotion and affect (e.g., irritability or apathy).

  • Language disturbances (aphasia).

Alzheimer’s Disease (AD)

• Pathology: AD involves a progressive and irreversible deterioration of brain tissue, manifesting in both cognitive and behavioral symptoms.

• Mortality: It is currently the $7^{\text{th}}$ leading cause of death for men and women aged $65$ and older.

• Clinical Presentation: Patients experience a gradual decline in language skills, visual-spatial abilities, and memory.

• Biological Markers:

  • Beta-amyloid Plaques: Marked increase in protein clusters between neurons.

  • Neurofibrillary Tangles: Intracellular tangles consisting primarily of tau protein.

  • Structural Changes: Significant neuronal death and a visible reduction in cortical tissue.

• Brain Activity: Positron Emission Tomography (PET) scans reveal reduced brain activity in AD patients, indicated by blue and black areas on the scan, compared to the higher activity levels in a normal brain.

• Risk Factors:

  • Advanced age.

  • Genetics, specifically the presence of the Apolipoprotein E-$4$ (APOE-$4$) gene.

  • Smoking.

  • Mood disorders, such as depression.

  • Low social support.

• Protective Factors (Lowering Risk): Regular physical exercise, higher levels of education, and greater levels of cognitive engagement.

Frontotemporal Dementia (FTD)

• Brain Regions Affected: Characterized by neuronal death in the frontal and temporal regions, specifically the anterior temporal and prefrontal cortices.

• Onset and Progression: Onset typically occurs in the mid-$50$s, and the disease progresses rapidly.

• Key Distinction from AD: Unlike Alzheimer’s disease, memory is not usually severely impaired during the initial stages.

• Diagnostic Criteria ($3$ or more of the following):

  1. Loss of empathy.

  2. Impaired executive function (planning and organizational skills).

  3. Loss of the ability to inhibit behavior.

  4. Compulsive, ritualistic, or perseverative behavior.

  5. Hyperorality (the tendency to put nonfood objects into the mouth).

  6. Apathy.

Vascular Dementia

• Cause: This form is diagnosed only when vascular disease or injury (such as a stroke) results in dementia symptoms.

• Mechanism: It most commonly follows a series of strokes that lead to brain infarction or the development of white matter lesions.

• Risk Factors: These are identical to cardiovascular disease risks, including smoking, high cholesterol, and high blood pressure.

• Co-occurrence: Vascular dementia can co-occur with Alzheimer’s disease.

Management and Treatment of Dementia

• Current Limitations: There is currently no cure for any type of dementia. While certain drugs can protect against some effects of decline, their efficacy is limited and they cannot restore memory to previous levels.

• Research Focus: Because amyloid plaques and tangles can accumulate for years before symptoms appear, research is shifting away from treating existing damage toward general prevention and studying people with mild cognitive impairment or early biological markers for AD.

• Pharmacological Interventions:

  • Cholinesterase Inhibitors: These drugs interfere with the breakdown of acetylcholine. Examples include donepezil (Aricept) and rivastigmine (Exelon). These are often poorly tolerated due to side effects like nausea.

  • Glutamate Regulators: Memantine (Namenda) affects glutamate receptors involved in memory processes.

  • Symptom Management: Antidepressants or antipsychotics may be used to treat psychological symptoms such as depression, apathy, or agitation. Note that there are currently no medications specifically for FTD symptoms.

• Psychological and Lifestyle Treatments:

  • Supportive Psychotherapy: For patients and families to provide information, allow for the expression of feelings, and encourage realistic attitudes toward challenges.

  • Exercise: Shows benefits in improving cognitive function in diagnosed AD patients.

  • Cognitive Aids: External memory aids such as lists and labels.

  • Engagement: Participating in pleasant activities to decrease comorbid depression.

Delirium

• Definition: A state of acute mental confusion characterized by rapid onset and fluctuation.

• DSM-V Criteria:

  • Disturbances in attention and awareness.

  • Change in cognition (orientation, language, memory, etc.) not accounted for by dementia.

  • Rapid onset (hours or days) with symptoms that fluctuate throughout the day.

  • Evidence that symptoms are caused by a medical condition, substance, or toxin.

• Clinical Presentation:

  • Extreme trouble focusing attention and fragmented thinking.

  • Disturbances of the sleep/wake cycle.

  • Frequent transitions between being lucid/coherent and being disoriented (a key differentiator from Alzheimer's).

  • Visual hallucinations (frequent but not always present), delusions, and mood swings.

• Etiology (Causes): Drug intoxication/withdrawal, metabolic and nutritional imbalances, infections, fevers, neurological disorders (head trauma, seizures), and stress from major injury.

• Prognosis and Treatment:

  • Mortality: If untreated, the mortality rate is high; $1/3$ of people die within a year.

  • Recovery: Complete recovery is possible if the underlying medical cause is treated promptly.

  • Medication: Atypical antipsychotics are used for confusion and hallucinations.

  • Prevention: Addressing risk factors like dehydration, sleep deprivation, and proper medication use.