In-depth analysis of Alzheimer’s disease: type, challenges and new progresses KellyOnTech
What is the only disease among the top ten leading causes of death worldwide that lacks an effective treatment?
It is Alzheimer’s disease. Here, “effective treatment” refers to any drug or method that can slightly improve symptoms, and this standard is already alarmingly low. This issue talks about the new progress in the treatment of Alzheimer’s disease.
Cognitive decline is a significant global health issue, with someone diagnosed with cognitive decline every three seconds. In 2020, over 55 million people worldwide had Alzheimer’s disease. This figure is expected to double every 20 years, potentially reaching 78 million by 2030 and 139 million by 2050. The countries experiencing the fastest growth in elderly populations are China, India, and their neighbouring regions in South Asia and the West Pacific.
Alzheimer’s disease is not only fatal; it gradually robs patients of their memory, cognitive abilities, and self-care skills over the years or decades following its onset. Ultimately, it strips them of their basic human rights and dignity. The heartbreaking story of Alice, a linguistic professor in the 2014 film Still Alice, powerfully illustrates the impact of this disease.
Why Is Alzheimer’s Disease Difficult to Treat?
Alzheimer’s disease is difficult to treat due to its complex causes. Unlike diseases caused by abnormal cell growth, like cancer, or blocked blood vessels, as in heart disease, Alzheimer’s stems from the rapid decline of the brain’s vast synaptic network. In Alzheimer’s patients, this natural reduction occurs too quickly, leading to a loss of normal brain function.
Three Types of Alzheimer’s Disease
Alzheimer’s disease is actually the brain’s protective response to certain threats. The issue arises when these threats are continuous, repetitive, and strong, causing the brain’s defense mechanisms to become persistent and overly intense. Over time, this excessive protection crosses the line and becomes harmful. The disease can be categorized into three main types according to the world well-renowned expert Dr. Dale Bredesen:
Type I: Inflammatory/thermal type
This form of Alzheimer’s is more common in people with one or two ApoE4 alleles, often with a family history of the disease. Alzheimer’s has long been considered part of the human genetic disease spectrum. Inflammation, the immune system’s response to invading pathogens, plays a significant role here. In this type of Alzheimer’s, patients typically begin by losing the ability to store new information, affecting short-term memory while long-term memory, speech, and cognitive functions like calculation and writing remain intact. Over time, however, long-term memory is gradually lost.
Type II: Atrophic/cold type
This form of Alzheimer’s often affects individuals with one or two copies of the ApoE4 gene and typically develops around ten years later than the inflammatory type. Unlike Type I, patients with Type II show no signs of inflammation in physical exams, and inflammatory markers may even be lower than normal. However, the brain’s resources to support synapses and neurons are depleted. Common indicators include low hormone levels, reduced vitamin D, insulin resistance or low insulin levels, and high homocysteine levels. It’s also possible for Type I inflammatory and Type II atrophic Alzheimer’s to occur together in the same person.
Type III: Toxic/malignant type
This form of Alzheimer’s typically affects people with the common ApoE3 allele, not ApoE4, and often occurs without a family history. Toxic Alzheimer’s usually begins at a younger age, often in the 40s to 60s, and is often triggered by intense stress or stimulation. It starts with cognitive challenges, such as difficulty with numerical reasoning or verbal organization. Patients not only struggle with forming new memories but also lose old ones, including both episodic (life events) and procedural memories (like complex skills such as playing bridge). They may also have trouble with simple arithmetic, taking longer to calculate bills or tips. Additionally, symptoms of mental disorders like depression or attention deficit are common in this type of Alzheimer’s.
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Since we cannot pinpoint the specific triggers affecting each patient or fully understand which factors are attacking the brain, there is currently no single treatment that effectively addresses Alzheimer’s disease.
The key is to identify the main causes of Alzheimer’s onset in each individual and develop a tailored plan that addresses these factors. Relying on just one drug or treatment is unlikely to be effective.
New Progress in Alzheimer’s Disease
The diagnosis of Alzheimer’s disease is a complex process that involves cognitive tests, neuroimaging examinations, and ultimately confirming the diagnosis by detecting the presence of beta-amyloid and tau proteins.
Beta-amyloid, an abnormal substance discovered by neuropathologist Alois Alzheimer in 1906 during his first brain autopsy of an elderly dementia patient, is a key indicator of the disease. Another abnormal protein, tau, was also identified, manifesting as long strands that entangle to form neurofibrillary tangles.
Current treatment strategies focus on reducing the accumulation of harmful substances like beta-amyloid and tau. One promising approach under investigation is a non-drug method that promotes the flow of cerebrospinal fluid in the brain. This fluid flow aids in removing harmful proteins and metabolic waste, potentially delaying or alleviating the symptoms of Alzheimer’s disease.
Cerebrospinal fluid (CSF) is a clear, colourless liquid that surrounds the brain and spinal cord. Its main functions include:
In addition, various companies are developing Alzheimer’s risk diagnosis algorithms using big data and artificial intelligence technologies. These innovations are expected to provide more accurate tools for early detection and prevention of Alzheimer’s disease, ultimately improving patients’ quality of life.
According to recent research from Cedars-Sinai Medical Centre, a leading teaching hospital and research centre, individuals can continue to produce new brain cells well into their sixties, seventies, and eighties. Stay tuned for practical ways to boost brain activity and slow cognitive decline.