Admission doctors detected only 1 of 15 cases of delirium - contributes to a high death rate for older people with delirium
Alzheimer’s Disease and Other Neurocognitive Disorders
Neurocognitive Disorder: A disorder marked by a significant decline in at least one area of cognitive functioning
Major Neurocognitive Disorder: When the decline in cognitive functioning is substantial and interferes with a person’s ability to be independent
Mild Neurocognitive Disorder: When the decline in cognitive functioning is modest and doesn’t interfere with a person’s ability to be independent
Alzheimer’s disease: The most common type of neurocognitive disorder, usually occurring after the age of 65, marked most prominently by memory impairment
Early onset: When Alzheimer’s disease appears in middle age
Late onset: When Alzheimer’s disease appears after the age of 65
11% of all people over 65 have Alzheimer’s
African Americans and Hispanic Americans are twice as likely to develop this disease
Gradually progressive disease in which memory impairment is the most prominent cognitive dysfunction
Time between onset and death is typically 3-8 yrs
Usually begins with mild memory problems, lapses of attention, and difficulties in language and communication
17% develop major depressive disorder
Usually remain in fairly good health until the later stages of the disease
Responsible for almost 94,000 deaths each year in the US
6th leading cause of death in the country
3rd leading cause of death in the elderly
Can only be diagnosed with certainty after death, when structural changes in the person’s brain can be examined
Senile Plaques: Sphere-shaped deposits of beta-amyloid protein that form in the spaces between certain neurons and in certain blood vessels of the brain as people age
Exceptionally high in people with Alzheimer’s
Neurofibrillary Tangles: Twisted protein fibers found within the neurons of the hippocampus and certain other brain structures
Extraordinary among in people with Alzheimer’s
Genetic Causes
Many plaques formed by the beta-amyloid proteins also causes tau proteins within neurons to start breaking down, resulting in tangles and the death of many neurons
Abnormal activity by the beta-amyloid protein causes the repeated formation of plaques
Abnormal activity by the tau protein causes the excessive formation of tangles
Early-Onset Alzheimer’s
Caused by abnormalities in genes responsible for the production of the beta-amyloid precursor protein and the presenilin protein
Some families transmit mutations of one or both genes
Leads to abnormal amyloid-protein buildups
Leads to plaque formations
Late-Onset Alzheimer’s
Doesn’t typically run in families
Results from a combination of genetic, environmental, and lifestyle factors
ApoE gene
Located on chromosome 19
Normally responsible for the production of a protein that helps carry various fats into the bloodstream
ApoE-4 gene
30% of the population
Promotes the excessive formation of beta-amyloid proteins
Makes people particularly vulnerable to the development of Alzheimer’s disease
Not everyone with this form of the gene develops the disease
Alternative Genetic Theory
Abnormal tau protein activity is not always the result of these abnormal beta-amyloid protein buildups
Multiple genetic causes for the formation of numerous tangle formations
Gene forms that promote beta-amyloid protein formations and plaques
Gene forms that more directly promote tau protein abnormalities and tangle formations
Brain Structure and Biochemical Changes
Prefrontal Cortex: Part of the brain that enables humans to hold info temporarily and continue working with the info as long as it’s needed
Temporal lobes and diencephalon help in transforming short-term memory into long-term memory
Deficient activity levels of certain brain chemicals can prevent the formation of memories
Other Explanations
High levels of zinc in the brains of some Alzheimer’s patients
Lead may contribute to the development of Alzheimer’s
Autoimmune Theory: Changes in aging brain cells may trigger an autoimmune response that helps lead to the disease
Viral Theory: A virus may cause Alzheimer’s, especially in cases of particularly fast-moving forms
Assessing and Predicting Alzheimer’s
Diagnosticians are usually able to build a very strong circumstantial case and arrive at an accurate diagnosis
Biomarkers: Biochemical, molecular, genetic, or structural characteristics that usually accompany a disease
Large number of beta-amyloid proteins
Large number of tau proteins
Many biomarkers appear in the brain long before the obvious onset of the disease
Certain combinations of biomarkers can predict cases of Alzheimer’s
Other Types of Neurocognitive Disorders
Vascular Neurocognitive Disorder: Blood flow to specific areas of the brain is cut off after a stroke, damaging the areas
Progressive
Symptoms begin suddenly rather than gradually
Cognitive functioning may continue to be normal in areas of the brain not affected by the stroke
Frontotemporal neurocognitive disorder: Rare disorder that affects the frontal and temporal lobes
Neurocognitive disorder due to prion disease
Caused by a slow-acting virus that may live in the body for years before the disease develops
Symptoms that include spasms of the body
Rapid course once launched
Neurocognitive disorder due to Huntington’s disease
Inherited progressive disease in which memory problems, personality changes, and mood difficulties worsen over time
Movement problems - severe twitching and spasms
Children of ppl with Huntington’s have a 50% chance of developing it
Parkinson’s disease: Slowly progressive neurological disorder marked by tremors, rigidity, and unsteadiness
Can result in neurocognitive disorder due to Parkinson’s disease
Similar to neurocognitive disorder due to Lewy body disease
Involves the buildup of clumps of protein deposits
Progressive cognitive problems
Significant movement difficulties, visual hallucinations, and sleep disturbances
Second most common neurocognitive disorder
Other neurocognitive disorder causes
HIV infections
Traumatic brain injuries
Substance abuse
Various medical conditions
Meningitis
Advanced syphilis
Treatments
Drug Treatment
Designed to affect acetylcholine and glutamate, the neurotransmitters that play important roles in memory
Short-term memory and reasoning ability improves slightly
Benefits of drugs are limited and their side effects can be problematic
Greatest use to ppl in the early, mild stage of Alzheimer’s
Vitamin E will may slow down some cognitive difficulties
Drugs for preventing or delaying the onset of Alzheimer’s