Neuropsychology of Memory: Alzheimer's and Dementia

Overview

**Topics Covered: **
- Definition of dementia
- Four types of dementia
- Warning signs and risk factors of Alzheimer's
- Neural substrates of Alzheimer's
- Memory impairments in Alzheimer's
- Diagnosis and treatment of Alzheimer's

Definition: Symptoms from brain disease, often progressive and age-related.
**Types of Dementia: **
- Alzheimer's Disease: Most common, 60-80% of cases. Progressive decline in cognitive and functional abilities.
- Vascular Dementia: Caused by reduced oxygen to the brain, often post-stroke. Progressive cognitive decline.
- Dementia with Lewy Bodies: Linked to Parkinson's disease. Symptoms include motor, memory, visual deficits, hallucinations.
- Frontotemporal Dementia: Affects frontal and temporal lobes, results in personality changes, language and behavioral difficulties.
- Semantic Dementia: Loss of semantic memory, difficulty in comprehending words and pictures.

Memory Loss: Difficulty performing job skills and familiar tasks.
Language Problems: Difficulty retrieving common words, sometimes substituting incorrect words.
Disorientation: Difficulty with time and place, missing appointments.
Misplacing Items: Difficulty finding everyday objects, like keys or a purse.
Behavioral Changes: Mood swings, personality changes, poor judgment, decreased initiative.

Age: Greatest risk factor; risk increases after age 65, up to 33% risk after age 85.
Family History: Higher risk if close relatives have Alzheimer's.
Head Injury: Traumatic brain injuries increase risk.
Heart Health: Conditions like heart disease, diabetes, stroke, high BP, high cholesterol increase risk.

Plaques and Tangles: Beta-amyloid plaques and neurofibrillary tangles disrupt neural communication and cell function.
**Affected Areas: **
- Interhinal Cortex: Early affected area, related to memory, navigation, and perception of time.
- Hippocampus: Critical for memory formation.
- Cerebral Cortex: Later stages affect cognitive functions.
Stages of Alzheimer's:
- Preclinical: Changes begin in interhinal cortex and hippocampus, 10-20 years before symptoms.
- Mild: Memory loss, confusion, mild cognitive impairments.
- Moderate: Increased memory loss, confusion, language difficulties, anxiety.
- Severe: Extensive brain atrophy, complete dependence, occurs after 85, involves involuntary functions, leading to death.

Episodic Memory: Earliest affected, difficulty with daily episodes like appointments, keys, bills.
Semantic Memory: Difficulty naming objects, using correct words, conceptual knowledge breaks down.
Implicit Memory: Mixed results, some learning intact, disruption in more complex tasks.
Working Memory: Deficits in digit span tasks, visual-spatial sketchpad tasks, especially under articulatory suppression.

Cognitive Status Tests: Assess memory, thinking, problem solving.
Common Tests:
- MMSE: Mini Mental State Exam, score <12 indicates severe dementia.
- Mini-Cog Test: Recalling objects, drawing clock face; used to evaluate cognitive decline.

Pharmacological Treatments:
- Disease-Modifying: Aducanumab targets amyloid plaques.
- Symptom-Relieving: Cholinesterase inhibitors, glutamate regulators to improve cognition.
Non-Pharmacological Interventions:
- External aids, Reality Orientation Training, Reminiscence Therapy using environmental cues and familiar objects.

External Memory Aids: Message boards, calendars.
Reality Orientation Training: Using calendars, weather info, environmental cues.
Reminiscence Therapy: Scrapbooks with old photos, reconstructing environments to look like past decades, playing period music.

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