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How Does Alzheimer’s Work In The Brain

What Causes Alzheimer’s Disease

Dementia & Brain Health: How Does Memory Work?

Alzheimer’s disease happens because of changes in the brain. Some of the symptoms may be related to a loss of chemical messengers in the brain, called neurotransmitters, that allow nerve cells in the brain to communicate properly.

People with Alzheimer’s disease have two things in the brain that are not normal: amyloid plaques and neurofibrillary tangles. Experts don’t know if amyloid plaques and neurofibrillary tangles are side effects of Alzheimer’s disease or part of the cause.

Granulovacuolar Degeneration And Neuropil Threads

Granulovacuolar degeneration occurs almost exclusively in the hippocampus. Neuropil threads are an array of dystrophic neurites diffusely distributed in the cortical neuropil, more or less independently of plaques and tangles. This lesion suggests neuropil alterations beyond those merely due to NFTs and SPs and indicates an even more widespread insult to the cortical circuitry than that visualized by studying only plaques and tangles.

Where Is Aduhelm Available

Following this approval, it would become available to patients within weeks.

However, many experts still feel the data around the drugs effectiveness is lacking, so this FDA approval came with a condition: Biogen and Eisai are free to market Aduhelm, the FDA said, but they must do another large placebo-controlled trial. If Aduhelm proves ineffective after that trial, the FDA could remove the drug from the market.

There are dozens of other disease-modifying drugs designed to treat Alzheimers currently in the pipeline.

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Support For Families And Alzheimer’s Disease Caregivers

Caring for a person with Alzheimers can have significant physical, emotional, and financial costs. The demands of day-to-day care, changes in family roles, and decisions about placement in a care facility can be difficult. NIA supports efforts to evaluate programs, strategies, approaches, and other research to improve the quality of care and life for those living with dementia and their caregivers.

Becoming well-informed about the disease is one important long-term strategy. Programs that teach families about the various stages of Alzheimers and about ways to deal with difficult behaviors and other caregiving challenges can help.

Good coping skills, a strong support network, and respite care are other things that may help caregivers handle the stress of caring for a loved one with Alzheimers. For example, staying physically active provides physical and emotional benefits.

Some caregivers have found that joining a support group is a critical lifeline. These support groups enable caregivers to find respite, express concerns, share experiences, get tips, and receive emotional comfort. Many organizations sponsor in-person and online support groups, including groups for people with early-stage Alzheimers and their families.

Read about this topic in Spanish. Lea sobre este tema en español.

Targeting Brain Waves With Light And Sound Therapy

Scientists develop brain scan to detect Alzheimers ...

This idea comes from a team of scientists at MIT that has been studying electrical pulses in the brain called gamma waves. These waves play a critical role in learning and memory.

The researchers noticed that these waves become weaker and less synchronized in people with Alzheimer’s. So they thought they might be able to slow down the disease by boosting gamma waves.

To find out, the team exposed mice to lights and sounds that caused the gamma waves in their brains to strengthen and synchronize, says Li-Huei Tsai, a professor of neuroscience at MIT and director of the Picower Institute for Learning and Memory.

“What really surprised us is that this approach produces profound benefits in mice engineered to model Alzheimer’s disease,” Tsai says.

After treatment, their brains started clearing out both amyloid and tau proteins, the brain’s immune cells began to function better, and the mice improved on tests of learning and memory.

The next step was to try the approach on humans, says Dr. Diane Chan, a neurologist at Massachusetts General Hospital who also works in Tsai’s lab. So the team built a portable device that could generate light and sound pulses at just the right frequency: 40 hz.

“We sent the device home with people who had mild Alzheimer’s dementia to let them use these devices an hour a day every day,” Chan says.

After three months, the team checked participants’ brains for signs of atrophy, which is usually found in people with Alzheimer’s.

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Two Common Classes Of Drugs Have Been Linked To Dementia Fortunately There Are Alternatives To Both

Image: Thinkstock

If you’re worried about developing dementia, you’ve probably memorized the list of things you should do to minimize your riskeating a healthy diet, exercising regularly, getting adequate sleep, and keeping your mind and soul engaged. In addition, some of the drugs you may be taking to help you accomplish those things could increase your risk of dementia. In two separate large population studies, both benzodiazepines and anticholinergics were associated with an increased risk of dementia in people who used them for longer than a few months. In both cases, the effect increased with the dose of the drug and the duration of use.

These findings didn’t come entirely as a surprise to doctors who treat older people. The Beer’s List published by the American Geriatrics Society has long recognized benzodiazepines, antihistamines, and tricyclic antidepressants as potentially inappropriate for older adults, given their side effects. Such drugs are on the list because they share troubling side effectsconfusion, clouded thinking, and memory lapsesthat can lead to falls, fractures, and auto accidents.

Montreal Cognitive Assessment Test For Dementia

The Montreal Cognitive Assessment is a brief 30-question test that takes around 10 to 12 minutes to complete and helps assess people for dementia. It was published in 2005 by a group at McGill University working for several years at memory clinics in Montreal.

Here’s a look at what the MoCA includes, how it’s scored and interpreted, and how it can assist in identifying dementia.

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Ps1 And Ps2 Mutations

Approximately 50-70% of early-onset autosomal-dominant AD cases appear to be associated with a locus mapped by genetic linkage to the long arm of chromosome 14 . Numerous missense mutations have been identified on a strong candidate gene, called PS1.

At the same time, another autosomal dominant locus responsible for early-onset AD was localized to chromosome 1. Two mutations were identified on the candidate gene, designated PS2. The physiological role of presenilins and the pathogenic effects of their mutations are not yet well understood.

How Is Alzheimer’s Different From Other Forms Of Dementia

How does the brain work?

Alzheimer’s disease is distinguished from other forms of dementia by characteristic changes in the brain that are visible only upon microscopic examination during autopsy. Brains affected by Alzheimer’s disease often show presence of the following:

  • Fiber tangles within nerve cells

  • Clusters of degenerating nerve endings

Another characteristic of Alzheimer’s disease is the reduced production of certain brain chemicals necessary for communication between nerve cells, especially acetylcholine, as well as norepinephrine, serotonin, and somatostatin.

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What Will The Doctor Do

It can be hard for a doctor to diagnose Alzheimer disease because many of its symptoms can be like those of other conditions affecting the brain. The doctor will talk to the patient, find out about any medical problems the person has, and will examine him or her.

The doctor can ask the person questions or have the person take a written test to see how well his or her memory is working. Doctors also can use medical tests to take a detailed picture of the brain. They can study these images and look for signs of Alzheimer disease.

When a person is diagnosed with Alzheimer disease, the doctor may prescribe medicine to help with memory and thinking. The doctor also might give the person medicine for other problems, such as depression . Unfortunately, the medicines that the doctors have can’t cure Alzheimer disease they just help slow it down.

How Do People Know They Have It

The first sign of Alzheimer disease is an ongoing pattern of forgetting things. This starts to affect a person’s daily life. He or she may forget where the grocery store is or the names of family and friends. This stage may last for some time or get worse quickly, causing more severe memory loss and forgetfulness.

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She Declined Very Slowly

Jim Taylor, husband of trial participant Geri Taylor, told Being Patient that before the aducanumab trial was interrupted, Geri had been on the drug for some three years, and during that time, her decline was very slow. We really thought the drug was helping. Of course, theres no way to know that, but her ability to maintain normal daily activities and live and take care of herself was really excellent. We traveled all the time and she managed all that well. During what I call the interregnum, the period when she wasnt getting the medication, she started to decline more quickly. Now that shes back on the drug, I kind of doubt its helpful. The benefit is really to get started as early as possible Shes in the stage in which decline is noticeable, and its much more rapid.

Medications To Maintain Mental Function In Alzheimer’s Disease

How your ears can cause brain shrinkage, dementia  St ...

Several medications are approved by the U.S. Food and Drug Administration to treat symptoms of Alzheimers. Donepezil, rivastigmine, and galantamine are used to treat the symptoms of mild to moderate Alzheimers. Donepezil, memantine, the rivastigmine patch, and a combination medication of memantine and donepezil are used to treat moderate to severe Alzheimers symptoms. All of these drugs work by regulating neurotransmitters, the chemicals that transmit messages between neurons. They may help reduce symptoms and help with certain behavioral problems. However, these drugs dont change the underlying disease process. They are effective for some but not all people and may help only for a limited time.

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What Are The Warning Signs Of Alzheimers Disease

Watch this video play circle solid iconMemory Loss is Not a Normal Part of Aging

Alzheimers disease is not a normal part of aging. Memory problems are typically one of the first warning signs of Alzheimers disease and related dementias.

In addition to memory problems, someone with symptoms of Alzheimers disease may experience one or more of the following:

  • Memory loss that disrupts daily life, such as getting lost in a familiar place or repeating questions.
  • Trouble handling money and paying bills.
  • Difficulty completing familiar tasks at home, at work or at leisure.
  • Misplacing things and being unable to retrace steps to find them.
  • Changes in mood, personality, or behavior.

Even if you or someone you know has several or even most of these signs, it doesnt mean its Alzheimers disease. Know the 10 warning signs .

Tangles And Cell Death

In normal brain tissue, a protein called tau stabilizes microtubules. Microtubules are key parts of cell structure.

In a diseased brain, protein strands, or threads, become tangled. As a result, the brain system of transporting cell nutrients along parallel structures which can be compared to railroad tracks falls apart.

Without these critical nutrients, brain cells die.

Memory and thinking depend on the transmission of signals across 100 billion neurons in the brain.

AD interferes with this cell signal transmission. It also affects the activity of brain chemicals called neurotransmitters.

The scrambled chemistry produces flawed signaling, so the brains messages are lost. This impacts the ability to learn, remember, and communicate.

Microglia are a type of cell that initiate immune responses in the brain and spinal cord. When AD is present, microglia interpret the beta-amyloid plaque as cell injury.

The microglia go into overdrive, stimulating inflammation that further damages brain cells.

Some AD research focuses on how this inflammatory response can be reduced or controlled.

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Structural Signs Of Dementia

Structural imaging of the brain consists of computed tomography and the popularly known magnetic resonance imaging scans. This kind of imaging focuses on the morphology as well as the structural details of the brain’s composition. It is a very physical kind of scan, searching for solid, visible signs of degeneration or abnormalities.

Degenerative dementia causes a number of visible physical signs in the brain in some patients, but is not always easy to detect. CT scans can usually observe some atrophy of the brain’s medial temporal lobe, but the CT scans’ lack of sensitivity can occasionally be problematic. MRI scans, of much higher resolution, can capture atrophy of the hippocampus in nearly 90 percent of all cases of Alzheimer’s disease.

What Is Alzheimer Disease

Your Amazing Brain – Dementia Explained – Alzheimer’s Research UK

Alzheimer disease, which affects some older people, is different from everyday forgetting. It is a condition that permanently affects the brain. Over time, the disease makes it harder to remember even basic stuff, like how to tie a shoe.

Eventually, the person may have trouble remembering the names and faces of family members or even who he or she is. This can be very sad for the person and his or her family.

It’s important to know that Alzheimer disease does not affect kids. It usually affects people over 65 years of age. Researchers have found medicines that seem to slow the disease down. And there’s hope that someday there will be a cure.

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How Does Aduhelm Work

In the brains of people with Alzheimers, a protein called beta-amyloid is believed to propagate and clump into plaques, choking up the brain and leading to cell death and atrophy, and resulting in the loss of cognitive abilities. Aduhelm is designed to treat Alzheimers in people at the very early stages of the disease by removing the beta-amyloid protein build-up in their brains.

Dr. Stephen Salloway, a principal investigator of the aducanumab clinical trial and the director of Butler Hospitals Memory and Aging Program, described the drugs origin story in a recent Being Patient BrainTalk.

The company that was developing it before Biogen looked at older people who lived a long life and either didnt get Alzheimers or had a very slow form, said Salloway, who in the past has consulted for Biogen and other pharmaceutical companies. The company surveyed these people and looked for antibodies that might be retarding that Alzheimers process in the brain. The lead drug they found was aducanumab.

According to Salloway, aducanumab enters the brain in very low concentrations and binds to the beta-amyloid plaques, then stimulating the immune system to help break up the plaques and remove them. It looks like it does this pretty well that it does lower the plaque build-up, Salloway told Being Patient based on his experience with the drugs clinical trials.

Stage : Severe Decline

As Alzheimer’s progresses, your loved one might recognize faces but forget names. They might also mistake a person for someone else, for instance, think their wife is their mother. Delusions might set in, such as thinking they need to go to work even though they no longer have a job.

You might need to help them go to the bathroom.

It might be hard to talk, but you can still connect with them through the senses. Many people with Alzheimer’s love hearing music, being read to, or looking over old photos.

At this stage, your loved one might struggle to:

  • Feed themselves

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What Happens To The Brain In Alzheimer’s Disease

The healthy human brain contains tens of billions of neuronsspecialized cells that process and transmit information via electrical and chemical signals. They send messages between different parts of the brain, and from the brain to the muscles and organs of the body. Alzheimers disease disrupts this communication among neurons, resulting in loss of function and cell death.

What Increases Your Risk


Certain things make getting a disease more likely. These are called risk factors. Risk factors for Alzheimer’s disease include:

  • Getting older. This is the main risk factor. People rarely have dementia before age 60.
  • A family history of Alzheimer’s disease, especially if one or more of your parents or siblings has the disease.
  • The presence of the apolipoprotein E-4 gene.
  • Having Down syndrome.
  • Injuries to the brain, especially more than one injury that caused you to pass out

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Check Out The Lilly Trial Guide

As Salloway put it: There are investigators like myself who have had a lot of experience and view this as beneficial to people, the opening of a new era for the treatment of Alzheimers. But you can also look the other way and say, Geez, Im not sure if the data is strong enough. Maybe we should wait and do more research.’

Alzheimers Disease Vs Other Types Of Dementia

Dementia is an umbrella term for a range of conditions that involve a loss of cognitive functioning.

Alzheimers disease is the most common type of dementia. It involves plaques and tangles forming in the brain. Symptoms start gradually and are most likely to include a decline in cognitive function and language ability.

To receive a diagnosis of Alzheimers, a person will be experiencing memory loss, cognitive decline, or behavioral changes that are affecting their ability to function in their daily life.

Friends and family may notice the symptoms of dementia before the person themselves.

There is no single test for Alzheimers disease. If a doctor suspects the presence of the condition, they will ask the person and sometimes their family or caregivers about their symptoms, experiences, and medical history.

The doctor may also carry out the following tests:

  • cognitive and memory tests, to assess the persons ability to think and remember
  • neurological function tests, to test their balance, senses, and reflexes
  • blood or urine tests
  • a CT scan or MRI scan of the brain
  • genetic testing

A number of assessment tools are available to assess cognitive function.

In some cases, genetic testing may be appropriate, as the symptoms of dementia can be related to an inherited condition such as Huntingtons disease.

Some forms of the APOE e4 gene are associated with a higher chance of developing Alzheimers disease.

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