What is Dementia?
Dementia is a progressive brain disorder that causes the loss of multiple intellectual functions (e.g. memory, judgment, language, planning) and produces severe impairment in social and occupational functioning. Dementia may also be associated with depression, anxiety, behavior and personality changes.
Numerous diseases can cause dementia including Alzheimer’s disease ( the most common cause), Vascular dementia, Parkinson’s disease, Lewy Body dementia, Huntington’s disease and frontotemporal dementia. Other medical disorders may cause dementia or dementia-like syndromes including thyroid disorders, depression, vitamin B12 or folic acid deficiencies, alcoholism, HIV infection, meningitis, head trauma, neurosyphilis and hypercalcemia.
People with symptoms of dementia need to have a comprehensive assessment including history and physical examination by an MD (preferably someone with experience in the diagnosis of dementia), psychological testing and specific blood chemistries and radiological studies of the brain. This diagnostic assessment will clarify if there are reversible (treatable) causes for dementia and allow the patient and family plan for the future.
Types of Dementia
Alzheimer’s Disease (AD) is the most common cause of dementia in older people. It is estimated that four million Americans currently suffer from AD or a related form of dementia. Nearly 10 percent of all people over age 65 and up to half of those over age 85 are thought to have AD or another form of dementia.
LEWY BODY DEMENTIA
Increasingly being recognized as a distinct form of dementia. Similar to Alzheimer’s disease, however some symptoms are typically different with people more often experiencing visual hallucination, Parkinson’s like movement problems and fluctuating impairments in cognitive functioning. Lewy bodies are microscopic, round deposits which contain damaged nerve cells which are found in the brain after death. Researchers believe that Lewy bodies are produced by brain and nerve cells trying to protect themselves from attack.
VASCULAR DEMENTIA (a.k.a. Multi-infarct Dementia)
Caused by occurs when blood clots block small blood vessels in the brain that produce multiple strokes or infarcts. These strokes or infarcts destroy vital brain tissue. Vascular dementia is particularly common African American and Hispanic elderly and is highly correlated with hypertension and advanced age.
FRONTOTEMPORAL DEMENTIA (FTD)
Primarily involves the front part of the brain. FTD has a different age of onset, symptoms, brain pathology and course of illness than other types of dementia such as Alzheimer’s disease or Parkinson’s related dementia, Patients with FTD show significant changes in personality, behavior and some thought processes. Early in the course of the illness patients will demonstrate loss of inhibition resulting in socially inappropriate behavior, apathy, social withdrawal, and compulsive behaviors. In the later stages of FTD patient will become immobile and unable to speak or show emotional expressions. CT scans or neuro imaging studies of the brain will show structural changes in the frontal and temporal areas of the brain.
A severe reduction of a brain chemical called dopamine which is responsible for modulating muscle activity. People with Parkinson’s often have tremors, slowed speech, labored body movements and difficulty walking. In the more advanced stages of the Parkinson’s disease, many people will develop a form of dementia.