Page Outline
  1. Introduction
  2. Multi-infarct Dementia
  3. Parkinson’s Disease
  4. Huntington’s Disease
  5. Creutzfeldt-Jakob Disease
  6. Pick’s Disease
  7. Lewy Body Dementia
  8. Other Related Dementias

Introduction

Dementia is a loss of mental function in two or more areas such as language, memory, visual and spatial abilities, or judgment severe enough to interfere with daily life. Dementia itself is not a disease but a broader set of symptoms that accompanies certain diseases or physical conditions. Well-know diseases that cause dementia include Alzheimer’s disease, Multi-Infarct dementia, Parkinson’s disease, Huntington’s disease, Creutzfeldt-Jakob disease, Pick’s disease, and Lewy body dementia. Other physical conditions may cause or mimic dementia, such as depression, brain tumors, head injuries, nutritional deficiencies, hydrocephalus, infections (AIDS, meningitis, syphilis), drug reactions, and thyroid problems. Individuals experiencing dementia-like symptoms should undergo diagnostic testing as soon as possible. An early and accurate diagnosis helps to identify reversible conditions, gives patients a great chance of benefiting from existing treatments, and allows them and their families more time to plan for the future.

Alzheimer's disease accounts for 60 to 70 percent of cases of dementia. Other disorders that can cause memory loss, confusion and other symptoms associated with dementia are listed below.

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Multi-infarct Dementia

Multi-infarct dementia (MID), or vascular dementia, is a deterioration of mental capacity caused by multiple strokes (infarcts) in the brain. These events may be described as mini strokes, where small blood vessels in the brain become blocked by blood clots, causing the destruction of brain tissue. The onset of MID may seem relatively sudden, as it may take several strokes for symptoms to appear. These strokes may damage areas of the brain responsible for a specific function as well as produce general symptoms of dementia. As a result, MID is sometimes misdiagnosed as Alzheimer’s disease. MID is not reversible or curable, but detection of high blood pressure and other vascular risk factors can lead to a specific treatment that may modify MID’s progression. MID is usually diagnosed through neurological examination and brain scanning techniques, such as a computerized tomography (CT) scan or magnetic resonance imagining (MRI).

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Parkinson’s Disease

Parkinson’s disease (PD) is a progressive disorder of the central nervous system that affects over one million Americans. In PD certain brain cells deteriorate for reasons not yet known. These cells produce a substance called dopamine, which helps control muscle activity. PD is often characterized by tremors, stiffness in limbs and joints, speech difficulties, and difficulty initiating physical movement. Late in the course of the disease, some patients develop dementia, Alzheimer’s or some other dementia. Conversely, some Alzheimer’s patents develop symptoms of Parkinson’s. Medications such as levodopa, which converts dopamine inside the brain, and deprenyl, which prevents degeneration of dopamine-containing brain cells, are used to improve diminished or reduced motor symptoms in PD patients but do not correct the mental changes that occur.

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Huntington’s Disease

Huntington’s disease (HD) is an inherited, degenerative brain disease that causes both physical and mental disabilities and usually begins in mid-life. Early symptoms can vary from person to person but include involuntary movement of the limbs or facial muscles, difficulty concentrating, and depression. Other symptoms include personality change, memory disturbance, slurred speech, and impaired judgment. Children born to a person with HD have a 50% change of inheriting the gene that causes HD. Today a genetic test is available to confirm a diagnosis of HD and to identify carriers of the HD gene. It is recommended that anyone considering genetic testing talk first with family and/or appropriate medical and counseling professionals. There is no treatment to stop the progression of HD, but the movement disturbances and psychiatric symptoms can be treated with medication.

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Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob disease (CJD) is a rare, fatal brain disorder that causes rapid, progressive dementia and other neuromuscular disturbances. CJD is cause by a transmissible agent. Research suggests that the agent differs significantly from viruses and other conventional agents. This newly discovered pathogen is called a “prion”, short for “proteinaceous infectious particle,” because it consists of protein and transforms normal protein molecules into infectious ones. The disease can be inherited, but the majority of causes are not. Early symptoms of CJD include failing memory, changes in behavior, and lack of coordination. As the disease advances, usually very rapidly, mental deterioration becomes pronounced, involuntary movements (especially muscle jerks) appear, and the patient experiences severe difficulty with sight, muscular energy, and coordination. Like Alzheimer’s disease, a definitive diagnosis of CJD can be obtained only through examination of brain tissue at autopsy.

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Pick’s Disease

Pick’s disease (also know as Fronto-temporal dementia) is also a rare brain disorder, characterized by shrinkage of the tissues in the frontal and temporal lobes of the brain and by the presence of abnormal bodies (Pick’s bodies) in the nerve cells of the affected areas of the brain. Pick’s disease usually begins between the ages of 40 and 60. The symptoms are similar to Alzheimer’s disease, with a loss of language abilities, skilled movement, and the ability to recognize objects or people. Initial diagnosis is based on family history (Pick’s disease may be inherited), symptoms, tests, and ruling out other cause of dementia. A definitive diagnosis of Pick’s disease is usually obtained at autopsy.

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Lewy Body Dementia

Lewy body dementia (LBD) is an irreversible form of dementia associated with abnormal protein deposits in the brain called Lewy bodies. Symptoms of LBD are similar to Alzheimer symptoms and include memory loss, confusion, and difficulty communicating. Hallucinations and paranoia also become apparent in the earlier stages of the disease and often last throughout the disease process. Although initial symptoms of LBD may be mild, affected individuals eventually develop severe cognitive impairment. At this time, there is no treatment available for Lewy body dementia.

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Other Related Dementias

Read about other related dementias.

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