Brain imaging helps to diagnose and understand Alzheimer’s disease. For instance:
- Magnetic resonance imaging (MRI) can show brain shrinkage (atrophy).
- FDG PET scans can show lower brain metabolism. (FDG is the tracer
molecule used to show how well your tissues and organs are working.)
- Amyloid PET scans show higher levels of amyloid protein in the brain.
How does Alzheimer’s disease progress (get worse)?
The progression of Alzheimer’s disease can be broken down into stages:
- No symptoms with Alzheimer’s present in the brain
- Mild symptoms, with Alzheimer’s changes in the brain. This is called
prodromal AD and is the phase before Alzheimer’s dementia.
- Alzheimer’s dementia
- Alzheimer’s dementia (mild), in which daily function is beginning to be impaired
- Alzheimer’s dementia (moderate), in which thinking and memory skills are
getting worse. Changes in behavior are common in this stage.
- Alzheimer’s dementia (severe) is linked to very serious impairment.
People in this stage often have trouble walking and experience incontinence.
How do changes in the brain happen because of Alzheimer’s disease?
Key changes in the brain in AD include:
- Brain shrinkage. This is called atrophy.
- The loss of nerve cells
- The presence of neuritic amyloid plaques (protein deposits that
collect between nerve cells, or neurons)
- The presence of neurofibrillary tangles (twisted fibers in the
nerve cells, thought to contribute to cell breakdown)
- Brain inflammation (swelling)
Which medicines are used to treat Alzheimer’s disease?
The medicines used to treat AD include the
cholinesterase inhibitors (donepezil, rivastigmine and galantamine), and the
NMDA antagonist memantine.
Cholinesterase inhibitors
These drugs work by slowing the breakdown of
acetylcholine, the chemical that helps nerves communicate. The medications do
not cure AD or stop the progression of the disease. They do help relieve some
memory problems and reduce some behavioral symptoms. The most common side
effects of these drugs are nausea, vomiting and diarrhea. Some people may have
loss of appetite, insomnia or bad dreams.
Memantine
Memantine blocks a brain receptor that is thought to
add to the cellular harm associated with AD. Side effects include drowsiness,
headache and dizziness.
Patients can help develop new and better treatments
for AD by participating in clinical trials. Cleveland Clinic Lou Ruvo Center for
Brain Health is conducting several trials of promising drugs.
What is the outlook for people with Alzheimer’s disease?
Alzheimer’s disease gets worse over time and is
ultimately fatal. The course of the disease varies from person to person.
What research is being done on Alzheimer’s disease?
Researchers continue to study medications to treat AD.
Carefully designed and conducted studies are needed to give a clear picture of
safety and effectiveness before any approval might be considered.
References
American Health Assistance Foundation. Alzheimer’s Disease Research.
www.ahaf.org
Accessed 4/21/2011
Alzheimer’s Association. www.alz.org Accessed 4/21/2011
National Institute on Aging. Alzheimer’s Disease Education and Referral Center.
www.nia.nih.gov Accessed 4/21/2011