Dementia is a general term, which indicates that a noticeable brain decline has taken place and that the individual’s mind is no longer as good as it used to be.  These changes might be noticed by the individual or by those who know the individual well enough to detect that he or she is suffering from diminished mental and physical abilities.
         There are as many types of dementia, as there are diseases that cause dementia, and the manifestations of dementia vary greatly, depending on the individual’s age, education, health condition, social situation, and support systems.  With few exceptions, dementias tend to be progressive with age, starting after fifty and becoming more prevalent with each decade.  Current estimates suggest that 10% of individuals over 70 and up to 40% over 85 have enough memory loss that could progress to dementia with attendant declines in language skills, visual-spatial perceptions, mathematical calculations, problem solving, and mood stability.  Destabilized emotions might lead to delusions, agitation, anger, insomnia, and lack of inhibitions, which could result in reckless behavior.
         Recent memory often becomes impaired long before distant memory.  This paradox—the individual has problems recalling recent events while still exhibiting excellent recall of distant events—is rather typical of most types of dementia.  With time, however, dementia leads to global brain dysfunction with oblivion of self, family, and surroundings, and impairments in the skills of daily living such as dressing, grooming, eating, washing, and using the toilet.
         The four commonest types of dementia are: 1) Alzheimer’s disease—responsible for >50% of cases; 2) Multiple small strokes— responsible for 10 to 20% of cases; 3) Parkinson’s disease and other brain degenerating conditions and 4) Alcoholism or other drug effects and addictions.  A skilled clinician can diagnose these four types and can also rule out the other, less common, brain-undermining conditions that may present as pseudo-dementias and are potentially treatable.
         As a rule most dementias that are progressive are untreatable.  The existing treatments merely help memory during the early but not during the advanced stages.  There are no proven treatments that halt the progression of dementia.  There are, however, reversible causes of dementia (pseudo-dementias) that need to be ruled out during the dementia workup.  Depression, alcoholism, low thyroid, low vitamin B12, hydrocephalus (high water pressure around the brain), certain poisonings, and many other disorders can masquerade as dementia, are potentially treatable, and should not be missed.
         The most important risk factors for dementia are increasing age, genetic (or familial) predispositions, conditions that cause hardening of the arteries (such as high blood pressure, cholesterol, diabetes, and smoking), brain infections (encephalitis), severe mental illnesses, and brain concussions.  Failing memory, however, may be a normal consequence of aging; at 85 a person can remember only half of the vocabulary he or she had at age 18.  But failing memory is also an important precursor of dementia because 12% of those who are experiencing memory failure transition to dementia every year and 75% of dementia patients herald their disease with memory symptoms.
         There are new, sophisticated tests that can detect dementia at an early stage but we still lack the medical treatments necessary to arrest or reverse the disease.  Because of that, making a very early diagnosis is seldom important except in situations where patients may wish to put their affairs in order based on the recognition that they would not be able to do so as their disease progresses.  The natural course of Alzheimer’s disease from diagnosis till death is 8 to 10 years but some may die after one year if their disease is exceptionally rapid while others may linger on for 25 years if their disease is exceptionally slow.
         The Mini-Mental State Examination is a useful screening test for dementia but is not sensitive enough to detect the very early stages.  A score > 25 = normal; 21-24 = mild; 10-20 = moderate; and <9 = severe.

Orientation:  Name season/date/day/month/year = 5 points.
                    Name building, floor, town, state, country = 5 points.
Regulation:  Identify three objects by name then ask the patient to repeat
                    those three names (e.g. shoe, clock, jacket) = 3 points.
Attention and Calculation:  Subtract 7 from 100 seven times and call
                    each number (i.e. 93, 86, 79, 72, 65) = 5 points.
Recall:  Recall the three objects presented earlier
                    (i.e. shoe, clock, jacket) = 3 points.
Language:   Name pencil and watch = 2 points.        
                  Repeat “No ifs, ands, and buts.” = 1 point.
                  Follow a 3-step command (e.g. “Take the paper, fold it in half, and
                    place it on the table.”) = 3 points.
Write “close your eyes” and ask the patient to obey the written
                    command = 1 point.
Ask the patient to write a complete sentence = 1 point.
Ask the patient to copy a complex design (e.g. intersecting pentagons) = 1 point.

Total = 30 points.