Diagnosis by a professional is particularly important, because a number of other ailments -- many of which are treatable -- share symptoms associated with Alzheimer's disease. These include infections, inadequate nutrition, vitamin B-12 deficiency, anemia, hypothyroidism, hypoglycemia (low blood sugar), depression, and cerebral vascular insufficiency (decreased blood flow to the brain due to constricted or obstructed arteries).
Also, a medication side effect or a harmful combination of medicines can sometimes cause Alzheimer's-like symptoms. Other diseases and conditions sometimes confused with Alzheimer's disease are Parkinson's disease, stroke, thyroid problems, brain tumors, advanced syphilis, and Huntington's disease (an inherited degenerative nerve disease).
To check for Alzheimer's disease, the doctor will probably begin with physical and psychological tests designed to eliminate other possible causes of mental impairment.
Verbal tests and interviews of the family are the usual next steps, but they will not produce a definitive diagnosis.
MRI of the brain is helpful in excluding other causes of dementia such as strokes or clots.
Positron emission tomography (PET) brain scans can help diagnose Alzheimer's. Doctors can give a radioactive drug that attaches to beta amyloid -- a protein in the brain that can signal the disease. If the PET scan shows beta amyloid, it increases the chance the person has Alzheimer's but can't diagnose it for sure.
The only absolute proof of Alzheimer's disease currently available is to examine brain tissue, usually done only after death. The brain tissue of Alzheimer patients shows evidence of nerve tangles, protein plaques, and general brain shrinkage from cell death.
What Is the Treatment for Alzheimer's Disease?
Alzheimer's disease is incurable: Nothing can halt or reverse it. However, certain medications seem to slow its general progress to some degree in the early stages and others can help with mood changes and other specific behavioral problems of the disease:
Cognex. In 1993, Cognex became the first drug approved by the FDA for treatment of Alzheimer's disease. The drug works by slowing the breakdown of acetylcholine, a chemical that helps nerve cells in the brain communicate. Because this drug caused liver damage it is rarely used, but other drugs in this same category, cholinesterase inhibitors, are used today, such as:
Donepezil (Aricept), rivastigmine (Exelon), and galantamine (Razadyne, formerly known as Reminyl). These medications work by the same mechanism as Cognex, but are better tolerated. They may improve mental functioning in early cases and delay worsening of symptoms.
Memantine (Namenda). This is a newer drug that works by blocking a substance called glutamate, which may be overactive in someone with Alzheimer's disease. The drug appears to protect against nerve damage and has fewer side effects than the cholinesterase inhibitors. It may improve mental function and delay worsening of moderate to severe symptoms. In severe Alzheimer's disease, patients may be on both Namenda and a cholinesterase inhibitor.