Dementia often occurs in the elderly but it can also affect young adults though rarely. If the condition starts before the age of 65 it is called presenile dementia. The senile type, on the other hand, occurs after 65.

Depending on its cause, dementia may either be primary or secondary. Primary dementia is found in about 80 to 90 percent of cases and is caused by pathological changes in the brain cells or cerebral vessels. While these changes are also apparent in secondary dementia, these are the result of other diseases. This is true in 10 to 20 percent of cases.

Secondary dementia usually follows diseases alike brain tumors or multiple head injuries that can lead to subdural hematoma (the accumulation of blood in the skull). Not a few boxers have died because of this. An unrecognized infection can also cause secondary dementia. Formerly, the culprit here was syphilis but now all eyes are on Lyme disease - a frequent cause of dementia.

Diabetes and an underactive thyroid are other possible causes of secondary dementia. So are nutritional, deficiencies, particularly those involving vitamin B12 and folic acid. Heavy metal poisoning, excessive alcohol intake and an overdose of sleeping pills, tranqui1izers, and narcotics can also affect brain function and eventually result in secondary dementia.

Sometimes the problem may be brought about by loneliness or depression. But this is properly labeled "pseudodementia" since there is no underlying cerebral deterioration. It may, however, lead others to think that the patient has the real thing. Thus, the doctor should take the pain of ruling out any underlying disorder to make an accurate diagnosis of dementia.

"Before you conclude that an older relative or friend who's behaving 'strangely' has irreversible dementia, ask the doctor whether other disorders have been considered and excluded," said Dr. Isadore Rosenfeld of the New York Hospital Memorial Sloan-Kettering Cancer Center in The Best Treatment.

If your relative has any of the above conditions, don't panic. They are reversible and respond well to treatment. The irreversible forms of dementia fall under the primary type. The most common forms of primary dementia include Alzheimer's disease and multi-infarct dementia (MID).

Alzheimer's disease is named after the German neurologist Alois Alzheimer who first described the condition in November 1906. But the disease was known as long as 140 years ago and descriptions of it were made as early as 1838.

Alzheimer's patient was a 51-year-old woman who was jealous of her husband, didn't trust her doctor, and believed that people were out to murder her.

"On admission, she was helpless, disoriented, could not understand anything, was confused and lost. She seemed to have auditory hallucinations, and would scream for hours on end. She had perception disorders, forgetting the names of common objects. Reading, writing, and conversation were impaired: often she would stop talking completely. However she still walked normally and had full use of her hands, and had normally reacting pupils, Any focal symptoms were mild and transient." according to Dr. Siegfried Kanowski of Freie University in Berlin who talked about Alzheimer's first case at the 9th International Bayer Pharma Press Seminar in Vienna.

"Mental regression advanced steadily and she died four and a half years after she was first seen. At the end, she was completely apathetic, confined to bed in a fetal position and incontinent." he added.

This wasn't the last time doctors heard about this mysterious disorder. Over four million Americans have Alzheimer's disease which is the most common cause of dementia in western countries. Although the disease may begin as early as age 4O, it usually strikes the aged with devastating results.

"The disease occurs in approximately 4 percent of persons 65 to 74 years old, 10 percent of those 75 to 84 years, and 17 percent of those 85 years or older. Alzheimer's disease is extremely rare in young people and is uncommon in middle age," said Dr. David E. Larson, editor-in-chief of the Mayo Clinic Family Health Book.

Is there a connection between the use of aluminum pots and pans and Alzheimer's disease? Find out in the third part of this series. To enhance your memory and support healthy brain function, take Neurovar. For more information on this powerful supplement, go to