Tuesday, September 28, 2010
when dementia takes over
It is normally required to be present for at least 6 months to be diagnosed; cognitive dysfunction that has been seen only over shorter times, in particular less than weeks, must be termed delirium. In all types of general cognitive dysfunction, higher mental functions are affected first in the process.
Especially in the later stages of the condition, affected persons may be disoriented in time (not knowing what day of the week, day of the month, or even what year it is), in place (not knowing where they are), and in person (not knowing who they are or others around them). Dementia, though often treatable to some degree, is usually due to causes that are progressive and incurable.
Symptoms of dementia can be classified as either reversible or irreversible, depending upon the etiology of the disease. Less than 10% of cases of dementia are due to causes that may presently be reversed with treatment.
Causes include many different specific disease processes, in the same way that symptoms of organ dysfunction such as shortness of breath, jaundice, or pain are attributable to many etiologies.
Without careful assessment of history, the short-term syndrome of delirium (often lasting days to weeks) can easily be confused with dementia, because they have all symptoms in common, save duration, and the fact that delirium is often associated with over-activity of the sympathetic nervous system.
Some mental illnesses, including depression and psychosis, may also produce symptoms that must be differentiated from both delirium and dementia.
Chronic use of substances such as alcohol can also predispose the patient to cognitive changes suggestive of dementia,although moderate intake may have a protective effect.