Dementia, the loss of the ability to think and reason, is a devastating disease, no matter what the cause. Dementia is characterized by difficulties with reasoning, memory loss, speech difficulties and loss of motor abilities. Around 5 percent of people 65 to 74 and 40 percent of those over 85 have some type of dementia, the Merck Manual states. There are many types of dementia; treatment can sometimes help slow the acceleration of symptoms.
Alzheimer's Disease
Alzheimer's is the most common cause of dementia, according to the Alzheimer's Association. Although people often refer to Alzheimer's as if everyone with memory loss has the disease, Alzheimer's is a specific disease. Alzheimer's is responsible for 50 to 70 percent of all cases of dementia, according to the Alzheimer's Association. Alzheimer's is caused by the buildup of proteins, called plaques and tangles, in and between the nerve cells. While everyone develops plaque and tangles to some degree as they age, people with Alzheimer's have more than normal. They affect the areas of the brain responsible for learning and memory first, which is why people so often associate the disease with memory loss.
As Alzheimer's disease progresses, people have trouble with normal daily activities, forgetting how to use familiar objects. They may not be able to recall the names of people or common household items. Suspicion and delusions are common as the disease progresses. Motor disturbances occur late in Alzheimer's. Gradually, people with the disease become unable to care for themselves altogether and are bedridden.
Vascular Dementia
Vascular dementia is the second most common type of dementia, the Alzheimer's Association states. Vascular dementia is caused by decreased blood flow to the brain from small clots that block blood vessels. Symptoms may start suddenly, after a stroke or heart attack. Memory loss and confusion are symptoms of vascular dementia; motor difficulties can also affect people with vascular dementia early in the disease. Treating the underlying disease may help prevent further damage.
Lewy Body Dementia
Lewy body dementia affects only 1 percent of people over age 65, the Mayo Clinic states. Lewy bodies are round structures that grow in the areas of the brain responsible for thinking and movement. They contain proteins similar to those found in Parkinson's disease, a disease that causes muscle tremors and stiffness. The tangles and plaques found in Alzheimer's are also often seen in Lewy body dementia. People with Lewy body dementia often have severe hallucinations, delusions and sleep disorders in addition to memory loss, confusion and difficulty moving. Medications similar to those used to treat Alzheimer's and Parkinson's disease may help improve symptoms.
Frontotemporal Dementia
Frontotemporal dementia (FTD) is also known as Pick's disease. Pick's disease causes confusion and personality changes before memory loss occurs. FTD is caused by shrinking of the frontal and temporal lobes of the brain. The disease is more common in those with a family history of FTD. There are two variants of FTD; some people have pronounced personality changes, and others have speech difficulties. Personality changes include disinterest in other people, inappropriate behavior and decreased energy. Behavior modification techniques and antidepressants may help with the symptoms of FTD, but prognosis is poor. FTD usually affects those between the ages of 40 and 65.
