// AD Fast Facts


  • 5.3 million Americans have Alzheimer’s disease.
  • It is the 7th leading cause of death.
  • There are 10.9 million unpaid caregivers.
  • The cost of providing care to Alzheimer’s patients in the U.S. is approximately $172 billion annually.
  • Research studies tell us that 5% of those over 65 have dementia, and this number increases with age.

Diagnosing Alzheimer’s Disease

  • The most common cause of a memory disorder is Alzheimer’s disease (AD). it is a slow and progressive illness that affects the brain impairing memory, thinking and behavior.
  • The diagnosis of a memory disorder usually requires a careful history taken by a internist, geriatrician, geriatric psychiatrist or neurologist, as well as memory testing (which may range from simple in office tests such as the Mini Mental (a 30 point test looking at orientation, memory, language, etc) to full neuropsychological testing (paper and pencil testing) which may take up to two hours or more.
  • The doctor usually will do a physical and neurologic exam, and ask about psychiatric issues such as depression.
  • Other tests that are often performed are blood tests looking for vitamin levels (B12, folate), thyroid function, exposure to syphilis (RPR). Special circumstances such as early age of onset or unusual presentations, may suggest other tests (for example heavy metal exposure, lyme exposure, etc.).
  • Imaging studies such as a CT scan or MRI of the brain are usually recommended. At times when the diagnosis is unclear, tests called functional imaging like a PET scan may be suggested.

Confirming the Diagnosis

There is no way currently to diagnose someone with Alzheimer’s disesase with 100% certainty while they are alive. This is why many families are interested in participating in a brain tissue donation program, where they can get a full, accurate autopsy diagnosis once their loved one has passed away.

There are two hallmark findings found on autopsy.

  • Amyloid-rich senile plaques
  • Neurofibrillary tangles

These abnormalities are visible under the microscope with special stains. They begin in the memory areas of the brain (called the hippocampus and entorhinal cortex) and then appear across the brain as the disease progresses.

Images courtesy of Daniel Perl, MD, Mount Sinai School of Medicine