What is early-onset Alzheimer's disease, or EOAD? It's the phrase used in cases where Alzheimer's strikes a person under the age of 65, and it's becoming more common in the 21st century.

Alzheimer’s disease does not affect just the elderly—sometimes it can attack people in their 50s, 40s, and even 30s. And when it does, the effects can be devastating. So what is early-onset Alzheimer’s disease (EOAD)?

Simply put, EOAD involves the onset of Alzheimer’s before the age of 65, when it will have serious implications for an individual’s ability to work and earn money in the prime of his or her life—not to mention impact on family. (Some refer to it as younger-onset Alzheimer’s.)

Estimates suggest that 15 to 35 people per 100,000 are living with early-onset Alzheimer’s. It is responsible for less than 10 percent of all Alzheimer’s disease (AD) cases but, worryingly, it is on the rise. According to the Centers for Disease Control and Prevention (CDC), Alzheimer’s disease is “a type of dementia—an irreversible, progressive brain disease that affects an estimated 5.4 million Americans.”

What Causes Early-Onset Alzheimer’s Disease?

When it comes to Alzheimer’s, 95 percent of cases are sporadic (not-inherited) and 5 percent are genetic (inherited or familial).

• Sporadic AD has been shown in research to be associated with the following risk factors:
  • Advancing age
  • Obesity
  • Metabolic syndrome and diabetes
  • Cardiovascular disease
  • High cholesterol
  • Hypertension
  • Inflammation
  • Down syndrome
  • Traumatic brain injury
  • Smoking
  • Estrogen decline after menopause

Other possible risk factors include aluminum exposure, previous depression, and psychological distress.

• Genetic or familial AD, which accounts for less than 5 percent of cases, is almost exclusively early-onset AD. At least three family members are affected in two or more generations, with two of the individuals being first-degree relatives. Three gene mutations are commonly seen:
  • Amyloid precursor protein (APP)
  • Presenilin-1 (PS1)
  • Presenilin-2 (PS2)

All three forms of genetic early-onset Alzheimer’s lead to excessive production of sticky proteins in the brain. It is estimated that these are implicated in about 60 to 70 percent of early-onset AD and only 1 percent of all AD. (To learn more about the genetics of dementia, see our post “Is Dementia Hereditary?”)

Genetic Counseling

If you have a strong family history of early-onset AD, you may wish to consider genetic counseling. The counselor will discuss the benefits and pitfalls of testing:
The benefits include planning—you can prepare yourself and your family should symptoms appear, and you may be able to change your lifestyle to reduce your risk.
The pitfalls include the uncertainty and distress caused by knowing you are at risk of a disease, that you may or may not develop. Your eligibility for life, long-term care, and disability insurance may also be affected.

Diagnosing Early-Onset Alzheimer’s Disease

If you start to experience symptoms—including memory problems, cognitive decline, or trouble doing everyday tasks—see your doctor. Early diagnosis and treatment usually improve outcomes. There are several other possible causes of early onset memory loss and cognitive decline, other than AD, so clinical evaluation is essential to provide accurate diagnosis.

Other conditions that may mimic early-onset AD include: alcohol or drug abuse, depression, vitamin B12 deficiency, vascular dementia, hearing or visual loss, metabolic disorders such as low sodium and thyroid disorders, medication side effects, dehydration, Lyme disease, Parkinson’s disease, Lewy body dementia, and Wernicke-Korsakoff Syndrome (thiamine deficiency). Some of these conditions may be reversed with appropriate treatment, so early diagnosis is essential.

Planning for Life with Early-Onset Alzheimer’s Disease

Diagnosis of the condition allows you to prepare yourself and your family in the following ways:

• Family. You will want to discuss your diagnosis with your family and make plans for your care as the disease progresses. You may also want to educate your family and friends on your diagnosis, as many people are unaware that Alzheimer’s can affect younger people.
• Finances. You will need to carefully consider and plan for the financial implications of your diagnosis and perhaps get help from a financial expert with experience in the field. You may wish to research benefits you can claim, such as The Americans with Disabilities Act, Family and Medical Leave Act, and COBRA.
• Legal. Legal issues to be considered include financial and medical power of attorney, a living will, and end-life wills. As your illness develops, you may be deemed unfit to complete these legal documents, so take action as soon as you can.
• Work. If you work, your employer may be able to adapt your workload or schedule to help you cope better.
• Counseling. You and your family may benefit from psychological counseling, following your diagnosis. This will help you come to terms with your diagnosis and plan for your future.

The Alzheimer’s Association offers great advice on all of these issues.

Protect Yourself Against AD

While you may not be able to change your genetic risk for Alzheimer’s, there are lifestyle strategies you can take that may reduce your risk.

• Diet. Diets high in fish, fruit and vegetables are rich in antioxidants, and healthy fats may reduce the risk of developing EOAD. (See our article on the Mediterranean diet.)
• Exercise. Some evidence suggests that regular exercise may have a protective effect against AD.
• Brain training. Higher levels of education and brain training may have a protective effect against AD, due to the brain’s remarkable ability to rewire itself when it is challenged.

Resources

For more information on living with early-onset Alzheimer’s disease, visit:

• The Alzheimer’s Association: The Alzheimer’s Association works on a global, national and local level to provide care and support for all those affected by Alzheimer’s and other dementias. Helpline, available 24 hours: 800-272-3900.
• The National Institute on Aging: The NIA, part of the National Institutes of Health, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life.