Some aspects of Alzheimer’s disease are still unknown to medicine as it is a neurodegenerative disease with no cure. Its cause, diagnosis, and treatment are not always conclusive, making it necessary to talk more about the condition. That’s why, September 21 is declared World Alzheimer’s Day.
At least 1.2 million people live with some form of dementia in Brazil, and 100,000 new cases are diagnosed each year. The number reaches 55 million, with 10 million new cases per year worldwide, according to the World Health Organization (WHO).
Alzheimer’s Disease International estimates that due to the aging of the population, the number of people affected by the disease could reach 74.7 million in 2030 and 131.5 million in 2050.
What is Alzheimer’s?
Alzheimer’s is a neurodegenerative, progressive and still incurable disease that generally affects people over the age of 65 and is the most common type of dementia in the elderly, said psychiatrist Adiel Rios, a researcher at the University of São Paulo Institute of Psychiatry. USP).
The disease begins when the processing of certain proteins in the central nervous system begins to fail. As a result, toxic protein fragments appear inside neurons and in the spaces between them. This toxicity causes progressive neuronal loss in certain areas of the brain, such as the hippocampus, which controls memory, and the cerebral cortex, which is essential for language, reasoning, memory, recognizing sensory stimuli, and abstract thinking.
“Studies show that the disease is related to the buildup of plaques in the brain formed by beta-amyloid protein. Its agglutination between neurons impairs all neural activity by preventing the transmission of signals,” says Rios.
The term dementia is used to describe a range of symptoms that include memory loss, thinking difficulties and language impairment, among others. Although it is the most common cause of dementia, Alzheimer’s disease is not the only one. There are other types of neurodegenerative and cerebrovascular dementia, says Natally Santiago, a neurosurgeon at Hospital San Gennaro.
“In contrast to normal brain aging, pathological changes occur in brain tissue with protein deposition (proteinopathy) and neuronal loss in Alzheimer’s disease,” explains Santiago.
Causes of Alzheimer’s
It is not yet known what actually causes Alzheimer’s, but it is believed to be genetically determined. According to Santiago, heredity can be considered a risk factor, but there is no direct genetic transmission to all generations.
“It is believed that transmission of a predisposition occurs along with external (environmental) factors that may or may not trigger the disease,” he said.
According to the neurologist, memory loss and behavioral changes are the first signs of the disease. A warning sign, he says, is when memory loss interferes with personal activities, becomes repetitive, and jeopardizes an individual’s routine.
“With the evolution of the disease, memory is significantly compromised due to the inability of family members to recognize, to have autobiographical memories. Behavioral changes also tend to get worse,” she says. Diagnosis is clinical, made by medical evaluation. The neurologist explains that there are no markers for the disease and that blood tests and imaging help rule out other possible causes of dementia.
In the early stages of Alzheimer’s, progressive memory failures related to recent events are the most striking symptoms. Old memories tend to be preserved, according to Rios. “A person can remember in detail events that happened 50 years ago, but do not remember anything that happened yesterday or a few hours ago,” the psychiatrist explains.
With the progression of the disease, problems such as difficulty in adapting to time and place, such as not being able to remember the way home, begin to appear. Other symptoms are sleep disturbances, restlessness or apathy, and even psychotic states, explains the psychiatrist.
In the final stage of the disease, the patient loses the ability to express himself, cannot even recognize family members and can no longer take care of himself, and demands full-time caregivers,” says Rios.
Psychiatrist shows how the main symptoms of Alzheimer’s are.:
- Loss of memory
- Reduced capacity for judgment and criticism
- difficulty reasoning
- Putting objects in an inappropriate place
- Frequent changes in mood and behavior
- Personality changes and loss of initiative to carry out tasks
Risk Factors for Alzheimer’s
The disease was named after the doctor alzheimer’s. In 1906, a neuropathologist autopsied the brain of a woman who died after suffering language problems, unpredictable behavior, and memory loss.
Dr. Alzheimer’s discovered amyloid plaques and neurofibrillary tangles, which are considered hallmarks of the disease. Know some of the factors that can contribute to its development:
Age: probability of development Alzheimer’s It doubles every 5 years after the age of 65. For most people, symptoms first appear after age 60. Early-onset Alzheimer’s is a rare form of dementia that affects people under the age of 65 and often has an inherited factor.
Family history: Genetics play an important role in an individual’s risk of contracting the disease.
Head trauma: There is a possible link between illness and repeated trauma or loss of consciousness.
Heart health: Heart problems such as high blood pressure, high cholesterol, and diabetes increase the risk of vascular dementia.
Because Alzheimer’s is still an incurable disease, some drugs have been shown to stabilize or reduce the rate of disease progression, providing more time for symptom relief, and better quality of life for patients and their families, says Santiago.
The use of the experimental drug aducanumab, indicated for the early stages of the disease, was approved by the Food and Drug Administration (FDA), the US regulatory agency equivalent to Anvisa, in June 2021. The agency has not approved a new drug for Alzheimer’s. since 2003.
The drug was developed for patients with mild cognitive impairment and aims to not only alleviate symptoms but slow the progression of the disease. Pharmaceutical company Biogen and its Japanese partner Eisai have developed aducanumab, which is given by intravenous infusion to treat early Alzheimer’s disease. In July 2020, Biogen completed its application to the FDA and has been pending approval ever since.
This is the first empowerment to change the perspective of treatment. Alzheimer’s. “The drug acts on the damaged protein in the brain of people who already have the disease,” says Jerusa Smid, coordinator of the Brazilian Academy of Neurology (ABN) Scientific Cognitive Neurology and Aging Department.
However, there are controversial factors about aducanumab that still need to be clarified. According to the neurologist, they include clinical consequences and side effects that need to be clarified in phase 4 of the trial (testing the drugs on a larger group of people).
“In addition to the fact that the drug shows cerebral hemorrhage as a side effect that is considered serious, there is a lack of data proving the patient’s clinical improvement,” says Jerusa.
Other drugs are being investigated. In March 2021, the New England Journal of Medicine published a study showing that Eli Lilly and Company’s experimental intravenous drug donanemab can slow cognitive decline in people with the disease.
On July 25, 2018, additional results from the first clinical trial for an experimental drug, the antibody BAN2401, showed that it improved cognition and reduced clinical manifestations. Alzheimer’s. Details on immunotherapy were announced at a press conference during the Alzheimer’s Association’s International Conference that same year.
The first drug to be used on a large scale and approved by regulatory agencies was tacrine in 1993. However, this drug became obsolete with the advent of new drugs, due to the difficulty of administration and the risk of complications and side effects.
According to the Brazilian Alzheimer’s Association (Abraz), drugs that act on acetylcholine and are approved for use in Brazil for mild to moderate dementia are rivastigmine, donepezil and galantamine (known as acetylcholinesterase inhibitors or anticholinesterases). “They’re all available in the Unified Health System,” says the ABN neurologist.
“Preventive measures and the use of these drugs tend to improve symptoms and slow disease progression, but they certainly do not cure the disease. Alzheimer’s”, Confirmation Smid.
How to prevent Alzheimer’s
To date, medicine has not discovered what really causes the disease. Alzheimer’s disease, Smid explains that measures considered preventative tend to delay it, not prevent it.
Prevention measures are listed in two meta-analyses (reviews of several studies) published in 2020 in The Lancet and Journal of Neurology, Neurosurgery & Psychiatry, which analyze studies specifically on prevention, treatment, and care in cases of dementia. Alzheimer’s.
According to the publication, the main risk factors are excessive alcohol consumption, sedentary lifestyle, smoking and a nutrient-poor diet, which increase the risk of obesity, diabetes and hypertension.
According to experts, these factors need to be avoided with social and educational measures to improve the lives of these groups. “These actions require public health programs and individualized interventions,” the researchers from University College London and the University of Plymouth, both based in the United Kingdom, who signed the study concluded.
The authors concluded that two-thirds of the most promising interventions focus on lifestyle changes for healthy living and avoiding risk factors for cardiovascular disease, such as high blood pressure and cholesterol levels.
The main preventive activities (by individuals or public authorities) identified by the two meta-analyses included:
- Keeping proper blood sugar and weight under control to prevent diabetes
- Keeping your weight at a healthy level, typically below a Body Mass Index (BMI) of 25
- Get as much schooling as possible from childhood.
- Avoid head trauma (such as concussion)
- Staying cognitively active by reading and learning new things
- Prevent or control depression
- stress Management
- Treat “orthostatic hypotension” (recurrent dizziness when standing up)
- Keeping blood pressure under control from the age of 40
- Examine lifetime risk of hearing loss and use a hearing aid if needed (hearing loss is associated with damage to the brain region associated with memory)
- Avoid high levels of homocysteine, an amino acid that can contribute to clot formation in blood vessels and damage to arteries (prevention is based on supplementation of B vitamins with medical advice)
- Do physical exercises
- Manage atrial fibrillation, a fast and irregular heart rate due to chaotic electrical signals in the heart (with regular medical monitoring)
- Eat foods containing vitamin C or take supplements (citrus fruits such as oranges and acerola; vegetables such as carrots, yellow peppers and red peppers, and vegetables such as cabbage and broccoli)
- Reduce exposure to air pollution and secondhand tobacco smoke
- avoid alcohol abuse
- avoid or smoke
- quality sleep
- Avoid postmenopausal estrogen replacement therapy (this does not apply in cases of early menopause or perimenopause)
- avoiding the use of dementia medications as prevention
- Fighting poverty and racial discrimination