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Diagnosing Alzheimer's Disease

  • By Meg Marinis, Director of Medical Research
Diagnosing Alzheimer's Disease
"You know what's really fun and not at all depressing? Alzheimer's research."

Yep. Derek said it. And as the researcher on this show, I'm right there with him. And I'm sure for those of you who are familiar with Alzheimer's Disease, you completely agree. And so that's why we research. We research for the estimated 35.6 million people worldwide reported to be living with dementia in 2010. According to the Alzheimer's Association, that number is estimated to increase to 65.7 million in 2030, and to 115.4 million by 2050.

We've got a serious problem on our hands... So, we research.

In Episode 713, "Don't Deceive Me (Please Don't Go)," Dr. Derek Shepherd initiates the beginning of his Alzheimer's NGF (Nerve Growth Factor) Clinical Trial. His experiment involves a minimally invasive neurosurgery in which he precisely drills two tiny burr holes into his patient's skull to inject either a drug or placebo solution into the brain. His hypothesis claims that this drug will send a message to the patient's brain cells to make more Nerve Growth Factor to help protect nerve cells from dying. The goal would be to stop or slow down the progression of the disease.

Now in order to be accepted into Derek's clinical trial, the patient must fit the criteria. To be eligible for the study, participants must be in good general health, have a reliable study partner to accompany all study visits, be on standard of care medications, and... have mild to moderate Alzheimer's Disease.

How does one know if it's not just normal aging?

First of all, aging is not a disease. Normal aging should not be associated with memory loss. Look at Jack Lalanne, who worked until his death at age 96, and Betty White, who's still working and winning awards at age 89. That's normal aging. It may take longer to retrieve a memory, but it shouldn't be forgotten. According to the Alzheimer's Association, there are ten warning signs of Alzheimer's Disease.

- Memory changes that disrupt daily life.
- Challenges in planning or solving problems.
- Difficulty completing familiar tasks at home, at work, or at leisure.
- Confusion with time or place.
- Trouble understanding visual images and spatial relationships.
- New problems with words in speaking or writing.
- Misplacing things and losing the ability to retrace steps.
- Decreased or poor judgment.
- Withdrawal from work or social activities.
- Changes in mood or personality.

So, what are the steps to diagnosis?

First thing's first. See the doctor. If a loved one seems to be exhibiting worrisome symptoms (when changes in memory and thinking begin to affect daily life), he or she should see someone who is well informed about Alzheimer's Disease. If one's primary care physician does not have experience with the disease, they can refer the patient to the right doctor.

Now, there's not one single test that confirms a diagnosis of Alzheimer's Disease. Diagnostic steps include a thorough work-up to evaluate one's general health and identify any other conditions that might be affecting one's memory or cognitive behavior. The physician will usually begin with a patient interview (typically along with a family member) to gather information about current and past illnesses. Patients are encouraged to bring a list of all medications they might be taking as well as have the knowledge of their family's medical history on hand.

Mental status tests

Next, the doctor will begin mental status testing to gain an idea of whether the patient is aware of their symptoms, knows the date/time/location, and can remember a short list of words, follow instructions, and do simple calculations. One of the more commonly used tests is called the Mini-mental state exam (MMSE). Examples of questions include:

- State the year, season, day of the week and date
- Remember and repeat (minutes later) the names of three common objects.
- Count backward from 100 by 7s or spell "world" backwards.
- Name two familiar objects present in the office as the doctor points to them.
- Identify the location of the doctor's office (state, city, street, floor).
- Repeat a common phrase or saying after the doctor.
- Copy a picture of two interlocking shapes.
- Follow a three-part instruction, such as: take a piece of paper in your right hand, fold it in half, and place it on the floor.

Another test frequently used is the "mini-cog" which entails two tasks: First, the doctor will ask the patient to remember the names of three common objects and repeat them later; and secondly, the patient will be asked to draw a face of a clock showing all twelve numbers in the right places and a time specified by the doctor.

Physical exam and diagnostic tests

The doctor will evaluate the patient's diet, nutrition, use of alcohol, check medications and do a thorough physical exam as well as lab tests. The patient's blood pressure, temperature, and pulse will be taken.

These tests will rule out anything else that may be causing the patient's dementia. Other conditions that may mimic Alzheimer's-type symptoms include: anemia, malnutrition, vitamin deficiencies, excess use of alcohol, medication side effects, certain infections, diabetes, kidney or liver disease, thyroid abnormalities, and problems with the heart, lung, or blood vessels.

Also, confusion exists on the difference between Alzheimer's and dementia—many people use the terms interchangeably, which is incorrect—they are two distinct conditions. Dementia describes a set of symptoms, not the disease itself, such as language difficulty, loss of recent memory, or poor judgment. After a complete evaluation, many physicians can accurately diagnose the cause of dementia symptoms in 90% of cases.

Other disorders that cause dementia are: Vascular dementia, Parkinson's Disease, dementia with Lewy Bodies, and Frontotemporal dementia. For example, in dementia with Lewy Bodies, rather than forgetfulness, early disease signs usually are lowered attention span, visual hallucinations, and a fluctuation between periods of lucidity followed by periods of confusion.

Latest advances in diagnostic techniques

Right now, the only definitive way to diagnose Alzheimer's is at autopsy. Pathologists see amyloid plaques and can officially say Alzheimer's. They are looking for ways to make diagnosis more certain earlier.

Doctors do include structural imaging with MRI or CT in the standard evaluation for Alzheimer's Disease. These scans help rule out any tumors, evidence of strokes, damage from head trauma, or a fluid build-up. But most recently, and the research is currently still being carried out right now, an advisory panel has recommended to the FDA a new chemical that can actually illuminate the signs of the disease in brain scans. The imaging agent, known as Amyvid (florbetapir), is injected into patients who then undergo a PET scan. The Amyvid is supposed to highlight amyloid plaques in the brain on the scan, an indicator lately considered to be a sign of Alzheimer's. A negative result would help rule out a diagnosis of Alzheimer's Disease while a positive result could lead to an earlier diagnosis and allow patients and their families to plan ahead.

The majority of the research has focused on earlier diagnosis in order to concentrate on the patient receiving treatment before symptoms have taken over their lives.

For more information on diagnosing the disease, please visit:

http://www.nia.nih.gov/Alzheimers/AlzheimersInformation/Diagnosis/


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