Alzheimer's Disease

What is Alzheimer's disease?

From: MedlinePlus, National Library of Medicine

Alzheimer's disease (AD) is the most common form of dementia among older people. Dementia is a brain disorder that seriously affects thinking and memory skills. If you have AD, it can impair your ability to reason or learn new skills until it becomes difficult to complete daily activities.

AD begins slowly over many years. It first involves the parts of the brain that control thought, memory, and language. It may be mistaken for normal memory changes with aging. However, AD is not a normal part of aging. The brain changes from the disease lead to symptoms that get worse over time.

What are the symptoms of Alzheimer's disease?

From: MedlinePlus, National Library of Medicine

People with AD may have trouble remembering recent events or the names of people they know. Behavior may vary from person to person and day to day. AD progresses in stages. Late-onset AD occurs in adults aged 65 and older, which is when most people develop the disease. Early-onset AD happens before age 65, which is not common.

Some symptoms of AD can include:

• Getting lost in familiar places
• Repeating the same question
• Not recognizing family members
• Having trouble speaking, reading, or writing
• Not taking care of yourself, such as not bathing or eating poorly

In AD, over time, symptoms get worse. Later on, people with AD may become anxious or aggressive or wander away from home. Eventually, they need total care. This can cause great stress for family members who must care for them.

Who is more likely to develop Alzheimer's disease?

From: MedlinePlus, National Library of Medicine

Researchers don't fully understand what causes AD. Age is the biggest risk factor. Your risk is also higher if a family member has had the disease. Although people who develop Alzheimer's don't always have a history of the disease in their families.

Researchers believe the causes of AD may be a combination of age-related changes in the brain, along with genetic, health, and lifestyle factors. Some medical conditions that are associated with a higher risk of AD include:

• Hearing loss
• Depression
• Mild cognitive impairment
• Concussion or other traumatic brain injury (TBI)

A related problem, mild cognitive impairment (MCI), causes more memory problems than normal for people of the same age. Many, but not all, people with MCI will develop AD.

How is Alzheimer's disease diagnosed?

From: MedlinePlus, National Library of Medicine

Some health conditions can cause memory loss or symptoms like AD. Talk with your health care provider if you're having noticeable changes in your memory. To determine if your symptoms are related to AD and not normal aging or another health condition, your provider may:

• Review your medical history and any medicines you're taking
• Conduct tests to check your memory, thinking, and problem-solving skills
• Ask about changes in behavior or personality
• Do tests to rule out any medical or mental health conditions
• Refer you to a provider that specializes in caring for older adults
• Recommend a neurologist, a doctor who specializes in treating diseases of the brain and nervous system

What are the treatments for Alzheimer's disease?

From: MedlinePlus, National Library of Medicine

No treatment can stop the disease. However, some medicines may help keep symptoms from getting worse for a limited time.

Can Alzheimer's disease be prevented?

From: MedlinePlus, National Library of Medicine

You can't change some risk factors, like your age. But changing certain lifestyle factors may promote your brain health and help you live a healthier lifestyle overall. This can include to:

• Manage chronic health issues such as high blood pressure or hearing loss
• Get regular physical activity
• Eat a healthy diet
• Quit smoking (or don't start)
• Get enough sleep
• Develop strong social connections

Genetic causes described in the linked summary

From: MedlinePlus Genetics

Some cases of early-onset Alzheimer's disease are caused by gene variants (also called mutations) that can be passed from parent to child. This results in what is known as early-onset familial Alzheimer's disease (FAD). Researchers have found that this form of the disorder can result from variants in the APP, PSEN1, or PSEN2 genes. When any of these genes is altered, large amounts of a toxic protein fragment called amyloid beta peptide are produced in the brain. This peptide can build up in the brain to form clumps called amyloid plaques, which are characteristic of Alzheimer's disease. A buildup of toxic amyloid beta peptide and amyloid plaques may lead to the death of nerve cells and the progressive signs and symptoms of this disorder. Other cases of early-onset Alzheimer's disease may be associated with changes in different genes, some of which have not been identified.

Some evidence indicates that people with Down syndrome have an increased risk of developing Alzheimer's disease. Down syndrome, a condition characterized by intellectual disability and other health problems, occurs when a person is born with an extra copy of chromosome 21 in each cell. As a result, people with Down syndrome have three copies of many genes in each cell, including the APP gene, instead of the usual two copies. Although the connection between Down syndrome and Alzheimer's disease is unclear, the production of excess amyloid beta peptide in cells may account for the increased risk. People with Down syndrome account for less than 1 percent of all cases of Alzheimer's disease. This type of Alzheimer's disease is not inherited.

The causes of late-onset Alzheimer's disease are less clear. The late-onset form does not clearly run in families, although clusters of cases have been reported in some families. Alzheimer's disease is probably related to variations in one or more genes in combination with lifestyle and environmental factors. A gene called APOE has been studied extensively as a risk factor for the disease. In particular, a variant of this gene called the e4 allele seems to increase an individual's risk for developing late-onset Alzheimer's disease.

Many more genes have been associated with Alzheimer's disease, and researchers are investigating the role that additional genes may play in Alzheimer's disease risk.

Inheritance described in the linked summary

From: MedlinePlus Genetics

Early-onset familial Alzheimer's disease is inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person inherits the altered gene from one affected parent.

The inheritance pattern of late-onset Alzheimer's disease is uncertain. People who inherit one copy of the APOE e4 allele have an increased chance of developing the disease; those who inherit two copies of the allele are at even greater risk. It is important to note that people with the APOE e4 allele inherit an increased risk of developing Alzheimer's disease, not the disease itself. Not all people with Alzheimer's disease have the e4 allele, and not all people who have the e4 allele will develop the disease.

Which doctor should you see?

The suggested department for discussing Alzheimer's Disease is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.