Diagnosis

Frontotemporal Dementia (FTD). Once considered rare, FTD is now considered to be the second most common cause of early-onset dementia. People who develop this condition tend to be in their mid-fifties although it can develop later on. It results in greater behavioral impairment (apathy, reduced empathy, poor self-care, unrestrained behavior) than with Alzheimer's disease. It may also be marked by speech problems and early incontinence. Brain imaging scans can help diagnose this problem.

Other Conditions that Cause Similar Symptoms. Some elderly people have a condition called mild cognitive impairment, which involves more severe memory loss than normal but no other symptoms of Alzheimer's. A number of conditions, including many medications, can produce symptoms similar to Alzheimer's:

• Severe depression
• Drug abuse
• Thyroid disease
• Severe vitamin B12 deficiency
• Blood clots
• Hydrocephalus (excessive accumulation of spinal fluid in the brain).
• Syphilis
• Huntington's disease
• Creutzfeldt-Jakob disease
• Brain tumors

It is important that the doctor recognize any treatable conditions that might be causing symptoms or worsening existing dementia caused by Alzheimer's or vascular abnormalities.

Psychological Testing

A number of psychologic tests are used or being developed to assess difficulties in attention, perception, and memory and problem-solving, social, and language skills. Experts are researching specific tests that may help identify early on people with mild memory impairment who are at high risk for Alzheimer's disease.

• Two commonly used tests that are very useful in identifying individuals who may be at risk for Alzheimer's are the Mini-Mental State Exam (MMSE) and the Mattis Dementia Rating Scale. Still, these tests have limitations.
• A clock drawing test is also a good test for Alzheimer's disease. The patient is given a piece of paper with a circle on it and is first asked to write the numbers in the face of a clock and then to show "10 minutes after 11." The score is based on spacing between the numbers and the positions of the hands.