Changes in the Elderly

Normal Changes in the Elderly

Normal changes in the elderly should not impair daily functioning, such as self-care, everyday activities, managing finances, and medication management.

Neurocognitive changes

Anatomic and physiologic changes:

• ↓ Brain volume:
  • Greatest in the frontal and temporal lobes
  • White matter affected more than gray matter
• ↓ Cerebral blood flow
• ↓ Levels of neurotransmitters

Effects:

• Intelligence: 
  • Decline in reaction time and psychomotor skills
  • Decline in ability to process new information quickly (fluid intelligence)
• Memory:
  • Decline in declarative memory, which includes:
    • Semantic memory (language, meaning of words)
    • Episodic memory (memory of past events)
  • Nondeclarative memory (learned skills) does not decline with aging.
  • Decline in recall ability
• Attention and concentration: 
  • Decline in multitasking abilities
  • ↓ Concentration
• Language: decline in verbal fluency and naming objects (expressive aphasia)
• Decline in visuospatial abilities
• Decline in executive functioning (ability to plan, solve problems)

Sensory function

Anatomic and physiologic changes:

• Eyes:
  • Periorbital tissue atrophy
  • ↑ Flaccidity of the eyelids
  • ↓ Lacrimal gland function
  • Conjunctival atrophy
  • Corneal deposits
  • ↓ Lens elasticity
  • ↓ Ciliary muscle strength
• Ears:
  • Thinning of the external auditory canal walls
  • Cerumen is drier.
  • Loss of hair cells in the organ of Corti

Effects:

• Visual acuity
• Presbyopia (↓ ability to focus on nearby objects)
• Presbycusis (↓ in high-frequency hearing acuity)
• Trouble with speech discrimination and sound localization
• ↓ Olfaction Olfaction The sense of smell, or olfaction, begins in a small area on the roof of the nasal cavity, which is covered in specialized mucosa. From there, the olfactory nerve transmits the sensory perception of smell via the olfactory pathway. This pathway is composed of the olfactory cells and bulb, the tractus and striae olfactoriae, and the primary olfactory cortex and amygdala. Olfaction → loss of taste (cause is not entirely clear)

Sleep patterns

• ↓ REM and slow-wave sleep Sleep Sleep is a reversible phase of diminished responsiveness, motor activity, and metabolism. This process is a complex and dynamic phenomenon, occurring in 4-5 cycles a night, and generally divided into non-rapid eye movement (NREM) sleep and REM sleep stages. Physiology of Sleep
• ↑ Sleep onset latency
• ↑ Early awakenings
• ↑ Frequency of nighttime awakenings

Organ system changes

• Cardiovascular function:
  • Mild ↓ in heart rate and ↓ response to exertion/stressors
  • ↑ Stiffness of vessels → ↑ BP
  • Thickening and calcification of heart valves
  • Impaired diastolic function
• Pulmonary function:
  • ↓ Elastic tissue → ↓ elastic recoil → enlarged alveolar ducts → loss of ⅓ of surface area per volume of lung tissue → ↑ anatomic dead space
  • ↑ Chest wall Chest wall The chest wall consists of skin, fat, muscles, bones, and cartilage. The bony structure of the chest wall is composed of the ribs, sternum, and thoracic vertebrae. The chest wall serves as armor for the vital intrathoracic organs and provides the stability necessary for the movement of the shoulders and arms. Chest Wall stiffness
  • ↓ Functional reserves
    • ↑ Residual volume and FRC
    • ↓ Forced vital capacity
  • ↑ Alveolar-arterial (A-a) oxygen gradient and V/Q mismatch
• GI function:
  • ↓ Esophageal muscle strength and coordination → dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming "stuck." Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia
  • ↑ In reflux esophagitis Esophagitis Esophagitis is the inflammation or irritation of the esophagus. The major types of esophagitis are medication-induced, infectious, eosinophilic, corrosive, and acid reflux. Patients typically present with odynophagia, dysphagia, and retrosternal chest pain. Esophagitis, due to altered contractions and sphincter tone
  • ↓ Transit time → ↑ in constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation
• Renal function:
  • ↓ Renal mass and ↑ fibrosis
  • ↓ Renal blood flow
  • ↓ Renal function
  • ↓ Creatinine clearance
• Immune function: 
  • ↓ Immune response
  • ↑ Susceptibility to infection and malignancy
• Skin:
  • Epidermal thinning
  • ↓ Elasticity
  • ↑ Fragility

Body mass and metabolism

• ↓ Lean muscle mass 
• ↑ Body fat
• ↓ Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones density 
• ↓ Basal metabolic rate
• ↓ Caloric consumption needs

Sexual changes

• Men:
  • Slower erection and ejaculation
  • Longer refractory period
• Women: vaginal atrophy, thinning, and dryness (due to ↓ in estrogen)

Pathologic Cognitive Decline

While some changes in cognition are observed in normal aging, some patients may experience more cognitive impairment than expected, which affects intellectual performance or daily functioning. This unexpected impairment should prompt an evaluation.

Clinical presentation

• Memory lapses and forgetfulness
• Inability to focus
• Difficulty finding words
• Inability to complete tasks independently
• Decline in reasoning and judgment
• Personality changes
• Mood changes

Screening for cognitive decline

• Recommended only if clinical suspicion is present
• Mini–Mental State Examination (MMSE): 
  • 30-point questionnaire 
  • Used extensively in clinical settings to measure cognitive impairment
  • Includes the following:
    • Orientation to time  
    • Orientation to place 
    • Registration 
    • Attention and calculation 
    • Recall 
    • Language 
    • Repetition
    • Complex commands
  • Interpretation:
    • ≥ 24 points is considered normal.
    • 19–23 points indicates mild dementia.
    • 10–18 points indicates moderate dementia.
    • ≤ 9 points indicates severe dementia. 
• Mini–cognitive test has 89% specificity for dementia, involving the following: 
  • 3-item recall
  • Clock draw test

Evaluation

• Review medications.
• Screen for depression.
• Laboratory evaluation:
  • TSH → hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto's disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism
  • Vitamin B₁₂ and CBC → vitamin B₁₂ deficiency
  • Rapid plasma reagin → tertiary syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis
• Neuroimaging (CT or MRI) to evaluate for:
  • Cerebrovascular disease
  • Normal-pressure hydrocephalus
  • Subdural hematoma
  • Mass lesion
• Neuropsychological testing (in-depth cognitive testing)

Differentiating mild versus more severe neurocognitive changes

• Mild neurocognitive decline:
  • Mild decline in ≥ 1 cognitive domain
  • Normal functioning in all daily activities 
• Major neurocognitive decline (dementia):
  • Severe decline in ≥ 1 cognitive domain
  • Significant irreversible decline in all daily activities 
  • Marked functional impairment

Differential Diagnosis

• Major depressive disorder Major depressive disorder Major depressive disorder (MDD), commonly called depression, is a unipolar mood disorder characterized by persistent low mood and loss of interest in association with somatic symptoms for a duration of ≥ 2 weeks. Major depressive disorder has the highest lifetime prevalence among all psychiatric disorders. Major Depressive Disorder: mood disorder marked by depressed mood, sleep Sleep Sleep is a reversible phase of diminished responsiveness, motor activity, and metabolism. This process is a complex and dynamic phenomenon, occurring in 4-5 cycles a night, and generally divided into non-rapid eye movement (NREM) sleep and REM sleep stages. Physiology of Sleep disturbances, anhedonia, feelings of guilt or worthlessness, loss of energy, low concentration, weight or appetite changes, psychomotor retardation or agitation, and suicidal ideation. In elderly patients, pseudodementia may also be present. Diagnosis is clinical but requires ruling out other potential diagnoses. Treatment options include pharmacotherapy, psychotherapy Psychotherapy Psychotherapy is interpersonal treatment based on the understanding of psychological principles and mechanisms of mental disease. The treatment approach is often individualized, depending on the psychiatric condition(s) or circumstance. Psychotherapy, and electroconvulsive therapy.
• Alzheimer disease Alzheimer disease As the most common cause of dementia, Alzheimer disease affects not only many individuals but also their families. Alzheimer disease is a progressive neurodegenerative disease that causes brain atrophy and presents with a decline in memory, cognition, and social skills. Alzheimer Disease: chronic neurodegenerative disease. Alzheimer disease Alzheimer disease As the most common cause of dementia, Alzheimer disease affects not only many individuals but also their families. Alzheimer disease is a progressive neurodegenerative disease that causes brain atrophy and presents with a decline in memory, cognition, and social skills. Alzheimer Disease is the most common cause of dementia. The etiology of this disease is unclear but is thought to be multifactorial. Alzheimer disease Alzheimer disease As the most common cause of dementia, Alzheimer disease affects not only many individuals but also their families. Alzheimer disease is a progressive neurodegenerative disease that causes brain atrophy and presents with a decline in memory, cognition, and social skills. Alzheimer Disease causes a decline in memory, thought processes, behavior, and functional abilities. Diagnostic considerations involve history, exam, imaging, lab test, and neuropsychological testing; however, definitive diagnosis is made only postmortem with evidence of amyloid plaques and neurofibrillary tangles at autopsy. There is no cure.
• Vascular dementia: declines in mental function caused by brain damage after insufficient or impaired blood supply to the brain. This type of dementia characteristically causes stepwise progression of decline in thought processes, executive functioning, and daily functional abilities. Exact symptoms vary by area of the brain impacted by impaired blood flow. Diagnosis is aided by imaging studies. Management is focused on control of risk factors and conditions such as hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, dyslipidemia, and diabetes.
• Frontotemporal dementia: group of rare brain disorders, including Pick disease, associated with atrophy in the frontal and temporal lobes of the brain. This atrophy leads to personality and behavioral changes, as well as diminished thought processes and language abilities. Diagnosis is made clinically in combination with imaging, neuropsychological tests, and other tests to rule out other conditions. Management involves antipsychotics and antidepressants, as well as speech therapy.
• Lewy body dementia: 2nd most common progressive dementia. Lewy body dementia develops because of abnormal deposition of Lewy bodies in the nerve cells of the brain, leading to impaired mental functions related to thinking, movement, behavior, and mood. Patients will also have visual hallucinations, Parkinson’s disease–like movement abnormalities, and fluctuating cognition. The diagnosis is made clinically and through imaging and testing to rule out other conditions. There is no cure, but medications may help manage symptoms. 
• Normal-pressure hydrocephalus: abnormal accumulation of CSF inside the ventricles of the brain, typically due to a blockage in the drainage pathway. This accumulation causes pressure and stretching of the periventricular white matter, Normal-pressure hydrocephalus is marked by gait abnormalities, incontinence, and dementia. Imaging of the brain Imaging of the brain Today, CT and MRI, especially the latter, are the preferred imaging methods for the study of the cranial vault and its contents. In conditions where emergent management is decided on the basis of presentation and imaging, CT has the advantage of rapid scan time and wider availability. Imaging of the Head and Brain, lumbar puncture, and intracranial pressure monitoring help make the diagnosis. Management involves placing a shunt in the brain to drain the CSF. 
• Prion diseases: also known as transmissible spongiform encephalopathies Transmissible Spongiform Encephalopathies Transmissible spongiform encephalopathies (TSEs) are diseases caused by prions. Prions differ from viruses in that they are small, infectious pathogens that do not contain nucleic acid. Recognized TSEs include Creutzfeldt-Jakob Disease (CJD), variant Creutzfeldt-Jakob Disease (vCJD), Kuru, fatal familial insomnia (FFI), and Gerstmann-Straussler syndrome (GSS). Transmissible Spongiform Encephalopathies. Prion diseases are a large group of rare, progressive neurodegenerative diseases that can affect both humans and animals. Symptoms include behavioral changes, ataxia, myoclonus, and seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures. Unfortunately, these diseases are associated with long incubation periods (≥ 20 years), and once symptoms occur, progression to death is rapid. Diagnosis is often made on postmortem brain biopsy. 
• Vitamin B₁₂ deficiency: potential cause of reversible cognitive decline. Low levels of vitamin B₁₂ can be due to a decline in absorption with increasing age, poor diet, alcoholism, and pernicious anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview. Clinical manifestations include fatigue, psychotic symptoms, and decline in concentration, visual-spatial tasks, and executive functioning. Diagnosis is made via vitamin B₁₂ blood testing and neuropsychological evaluation. Management involves vitamin B₁₂ replacement.