Alzheimer’s disease is the cause of 50 to 70 percent of cases of dementia. Other disorders that can cause memory loss, confusion and other symptoms associated with dementia include:
Mild cognitive impairment (MCI)
Sometimes a person can have problems with memory or other cognitive abilities that are not serious enough to appear in medical tests or interfere with everyday life. This is called mild cognitive impairment (MCI).
Research has shown that individuals with MCI have an increased risk of progressing to Alzheimer’s disease over the next few years, especially when their main area of difficulty involves memory. But a diagnosis of MCI does not always mean the person will develop Alzheimer’s.
This type of dementia is caused by reduced blood-flow to parts of the brain. Vascular dementia is considered the second-most-common form of dementia.
One type of vascular dementia can occur after a single stroke blocks the flow of blood to a large part of the brain.
In one type of vascular dementia, a series of very small strokes block small arteries. Individually, these strokes are too small to cause major symptoms, but over time their combined effect becomes noticeable.
Symptoms of vascular dementia can be similar to Alzheimer’s disease. They include problems with memory, confusion and difficulty following instructions. In some cases, the impairment associated with vascular dementia can be more rapid and marked. Alzheimer’s advances slowly.
In this condition, Alzheimer’s disease and vascular dementia occur together. Some experts believe that this combination is very common.
This disease affects control of movement, resulting in tremors, stiffness and impaired speech. Many individuals with Parkinson’s also develop dementia in the final stages of the disease.
Dementia with Lewy bodies
This disease often starts with wide variations in attention and alertness. Individuals affected by this illness often experience visual hallucinations as well as muscle rigidity and tremors similar to those associated with Parkinson’s disease.
Physical injury to the brain
An automobile accident or other significant trauma can damage or destroy brain cells and cause symptoms of dementia, such as behavioral changes, memory loss and other cognitive difficulties.
This is an inherited, progressive disorder that causes irregular movements of the arms, legs and facial muscles; personality changes; and a decline in the ability to think clearly.
Creutzfeldt-Jakob disease (CJD) (CROYZ-felt YAH-kob)
A rare, rapidly fatal disorder that impairs memory and coordination and causes behavior changes. Recently, “variant Creutzfeldt-Jakob disease (vCJD)” was identified as the human disorder believed to be caused by eating meat from cattle affected by “mad cow disease.”
Frontotemporal dementia or Pick’s disease
Another rare disorder that may sometimes be hard to distinguish from Alzheimer’s. Personality changes and disorientation often occur before memory loss.
Normal pressure hydrocephalus (NPH)
This is caused by a buildup of fluid in the brain. The cause of most cases is unknown. Symptoms include difficulty walking, memory loss and inability to control urine. NPH can sometimes be corrected with surgery to drain the excess brain fluid.