Read my last newsletter about the history of coronavirus here.
History - Dr. Alois Alzheimer
In 1903, Dr. Alois Alzheimer, a German pathologist and researcher, opened a brain research clinic in Munich, Germany alongside Dr. Emil Kraepelin. Three years later in 1906, Dr. Alzheimer gave a famous speech to the 37th Congress of Psychiatrists of Southern Germany describing “an unusual disease of the cerebral cortex” he found in one of his patients, who is famously known as Auguste D. Her symptoms included profound memory loss, hallucinations, and disorientation. She would later die from this unusual disease at age 50. After analyzing her brain at autopsy, Dr. Alzheimer found significant signs of shrinkage and amyloid plaques*.
*Amyloid plaques are polymorphous beta protein deposits in the grey matter of the brain.
Dr. Alzheimer died in 1915, without any official diagnosis of this peculiar disease. Nevertheless, he sparked an international research effort.
Before Alzheimer’s death in 1910, Dr. Kraepelin coined the term “Alzheimer’s disease.”
Dementia & Alzheimer’s disease: What’s the difference?
Dementia is a general term used for the collective signs of memory loss, cognitive impairments, communication deficits, and other behavioral impairments that interfere with one’s daily activities. Sometimes dementia and Alzheimer’s disease are used interchangeably, however they are completely different. Dementia is not a single disease rather it is a term that encapsulates a variety of medical conditions, including Alzheimer’s. Alzheimer’s disease is the most common cause of dementia among older adults, accounting for 60-80% of cases.
Alzheimer’s disease is a type of dementia that affects memory, thinking, and behavior. It worsens over time, and there is no cure. The greatest risk factor is increasing age; most people with Alzheimer’s disease are over the age of 65; however, early-onset Alzheimer’s can occur in younger individuals. It is the 6th leading cause of death in the United States, but more recent data suggests it may actually be the third leading cause of death, behind heart disease and cancer.
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Biological changes in the brain
Scientists are still trying to completely understand the incredibly complex changes in the brain due to Alzheimer’s, but it is known that these biological changes can happen a decade before phenotypic symptoms appear. During this time, abnormal amounts of protein—amyloid plaques & tau tangles*—are building up in the brain.
*Tau is a protein within the axon of the nerve cell. They help form microtubules that transport nutrients to the brain. In a healthy brain, the tau protein helps the microtubules remain strong and straight, but in one with Alzheimer’s, the tau collapses and forms tangles, preventing the transport of nutrients and other essential substances.
Additionally, neurons begin to lose function, losing connection with other neurons, and die. These biological changes initially take place in the hippocampus and entorhinal cortex, parts of the brain that are essential in forming memories. As more neurons experience a loss of function, the disease impacts other parts of the brain, causing severe shrinkage.
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Etiological factors of Alzheimer’s
There is no specific cause of Alzheimer’s; the etiology of this disease is still widely unknown, but doctors have concluded that it can be genetic or a combination of age-related changes to the brain, genetic, environmental, and lifestyle factors. There are two types of Alzheimer’s disease—early-onset and late-onset.
Late-onset Alzheimer’s disease is characterized by having symptoms appear around age 60. It is the most common type and may involve a certain gene known as apolipoprotein E (APOE). This gene is known to heighten one’s risk of developing Alzheimer’s, but even if one does have this gene, it does not mean they will definitely develop it. Some with the APOE gene do not develop Alzheimer’s, and some with Alzheimer’s do not have the APOE gene.
Early-onset Alzheimer’s is a very rare occurrence and appears between a person’s 30’s to mid-60’s. Some cases include changes in the genes or other genetic components.
To conclude, there is no definitive cause of Alzheimer’s.
Treatment
There are many medications that help with the overall complications that arise with Alzheimer’s—memory loss, cognitive impairments, etc. However, on June 7th, 2021, the FDA approved the first ever biologically targeted treatment specifically for Alzheimer’s. Aducanumab (brand name: Aduhelm) reduces the amount of amyloid deposits in the brain which is highly believed to cause cognitive dysfunction and memory loss. There has been some controversy regarding this drug due to its severe side effects (brain swelling and bleeding) and doubts due to its true clinical benefits. This is NOT a cure for Alzheimer’s and will not reverse progression of the disease if one already has symptoms.
Prevention
Just recently, as of November 16th, 2021, the first human trials of an Alzheimer’s nasal vaccine are starting to begin at Boston’s Brigham and Women’s Hospital. They will start to test the safety and efficacy of a nasal vaccine that will prevent the onset and progression of Alzheimer’s disease. Similar to Aducanumab, this vaccine directly targets the hallmark of Alzheimer’s: amyloid plaques. After two decades of research, doctors and scientists hope for a nontoxic treatment for those with early symptoms of the disease and those who pose a high risk of developing it.
Suggestions
The Alzheimer’s Association uses interactive tools to illustrate the pathophysiology of the disease in the brain, check it out here.
Still Alice, starring Julianne Moore, shines a light on those living with Alzheimer’s, hopefully encouraging the scientific and political communities to support finding a cure for this disease.
Disclaimer: All information in my newsletters are for educational purposes only and should not be substituted as medical advice. Please consult with your doctor or a healthcare professional if you have concerns or questions about Alzheimer’s disease.
Thank you so much for reading, and happy Thanksgiving!
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As always, please email me at reemlfawaz@gmail.com with any questions.