Alzheimer and Dementias_BIO339_FS24_upload

Alzheimer’s disease is a progressive brain disorder that slowly destroys memory and thinking skills.
It is the most common form of dementia, contributing to 60-70% of cases.
Symptoms typically appear after age 60, but it is not considered a normal part of aging.

In the late 1890s, Auguste Deter, a woman in Germany, begins experiencing memory loss and cognitive decline.
These symptoms lead to her admission to a mental institution, highlighting the early case of Alzheimer’s disease.

Alois Alzheimer, a clinical psychiatrist and neuroanatomist, became involved with Auguste’s case post her admission in 1901.
He conducted interviews and cognitive tests to understand her decline. Auguste exhibited confusion and disorientation during these assessments.
On November 3, 1906, he presented findings at a psychiatric conference, detailing the disease process observed in Deter.

Alzheimer’s disease is marked by two primary pathological features:
- Beta-Amyloid Plaques: Abnormal clumps of protein that accumulate outside nerve cells.
- Neurofibrillary Tangles: Twisted fibers of protein build-up inside nerve cells disrupting their function.

The disease progresses through identifiable stages:
- Preclinical Stage: Early signs start in the entorhinal cortex; changes can occur 10-20 years prior to symptomatic onset.
- Mild to Moderate Stage: Increased memory loss, confusion, and practical difficulties manifest as the cerebral cortex declines.
- Severe Stage: Marked shrinkage of the brain and total dependence on caregivers; severe symptoms include weight loss and infection risk.

Alzheimer’s disease is a specific type of dementia. Dementia itself refers to a range of symptoms affecting memory and cognitive ability.
Other types of dementia include Lewy body dementia, vascular dementia, and frontotemporal dementia.

The adult human brain weighs about 3 pounds and contains approximately 86 billion neurons.
Major areas affected by Alzheimer’s include:
- Cerebral Hemispheres: Responsible for sensory processing and voluntary movement.
- Cerebellum: Coordinates balance and movement.
- Brain Stem: Controls basic autonomic functions.
- Hippocampus: Critical for memory formation.

Neurons must effectively communicate and repair themselves for proper function. Alzheimer’s disrupts these processes, leading to neuron death and cognitive decline.

Alzheimer’s diagnosis includes patient history, neurological exams, lab tests, and imaging techniques (CT, MRI).
Early diagnosis can lead to better management and planning for the future for patients and families.

Currently, there are no cures, but some medications such as Donepezil and Memantine can help manage symptoms.
Research is ongoing into the causes of Alzheimer’s, including genetic factors and lifestyle influences.

Genetic predispositions for Alzheimer’s include mutations in specific genes responsible for familial forms of early-onset Alzheimer’s. The APOE ε4 allele is a significant genetic risk factor for late-onset Alzheimer’s.

Recent research focuses on identifying effective treatments and understanding the underlying biology of Alzheimer’s disease to develop disease-modifying therapies.