Alzheimer's Disease and Related Disorders

What is Dementia?

Dementia is the loss of intellectual functions (such as thinking, remembering and reasoning) of sufficient severity to interfere with a person's daily functioning. It is not a disease in itself, but rather a group of symptoms that may accompany certain diseases or physical conditions. The cause and rate of progression of dementias vary. Some of the better known diseases that produce dementia include Alzheimer's disease, vascular dementia, Huntington's disease, Frontal Lobe Dementia, Lewy Body disease, Creutzfeldt-Jakob disease, and Parkinson's disease. Other conditions which may cause or mimic dementia include depression, brain tumors, nutritional deficiencies, head injuries, hydrocephalus, infections (AIDS, meningitis, syphilis), drug reactions and thyroid problems. It is imperative that all persons experiencing memory deficits or confusion undergo a thorough diagnostic work-up. This requires examination by a physician experienced in the diagnosis of dementing disorders and detailed laboratory testing. The examination should include a reevaluation of all medications. This process will help the patient obtain treatment for reversible conditions, aid the patient and family in planning future care, and provide important medical information for future generations.

What is Alzheimer's Disease?

Alzheimer's disease is the most common of the dementing disorders, affecting as many as 4 million Americans. Alzheimer's disease is a progressive, degenerative disease that attacks the brain and results in impaired memory, thinking and behavior. Symptoms of Alzheimer's disease include a gradual memory loss, decline in ability to perform routine tasks, disorientation in time and space, impairment of judgment, personality change, difficulty in learning, and loss of language and communication skills. As with all dementias, the rate of progression in Alzheimer's patients varies from case to case. From the onset of symptoms, the life span of an Alzheimer victim can range anywhere from 3 to 20 or more years. The disease eventually leaves its victims unable to care for themselves. While a definitive diagnosis of Alzheimer's disease is possible only through the examination of brain tissue, which is usually done at autopsy, it is important for a person suffering from any symptoms of dementia to undergo a thorough clinical examination. In fact, after such an evaluation, approximately 20% of suspected Alzheimer's cases prove to be a medical condition other than Alzheimer's, sometimes treatable.

What is Vascular Dementia?

Vascular dementia, or multi-infarct dementia, is a deterioration of mental capabilities caused by multiple strokes (infarcts) in the brain. The onset of vascular dementia may be relatively sudden as many strokes can occur before symptoms appear. These strokes may damage areas of the brain responsible for a specific function as well as produce generalized symptoms of dementia. As result, vascular dementia may appear similar to Alzheimer's disease. This dementia is not reversible or curable, but recognition of an underlying condition (high blood pressure) often leads to a specific treatment that may modify the progression of that disorder. Vascular dementia is usually diagnosed through neurological examination and brain scanning techniques, such as computerized tomography (CT scan) or magnetic resonance imaging (MRI), in order to identify strokes in the brain.

Parkinson's Disease

Parkinson's disease (PD) is a progressive disorder of the central nervous system that affects more than one million Americans. Individuals with PD lack the substance dopamine, which is important for the central nervous system's control of muscle activity. Parkinson's disease is often characterized by tremors, stiffness in limbs and joints, speech impediments and difficulty in initiating physical movement. Late in the course of the disease, some patients develop dementia and eventually Alzheimer's disease. Conversely, some Alzheimer patients develop symptoms of Parkinson's disease. Medications such as levodopa, which converts itself into dopamine once inside the brain and depreynl, which prevents degeneration of dopamine-containing neurons, are used to improve diminished or reduced motor symptoms in PD patients but do not correct the mental changes that occur.

Lewy Body Dementia

Lewy Body Dementia consists of both cognitive problems (similar to Alzheimer¹s) and motor impairments (as seen in Parkinson¹s Disease). One area may be dominant but both must be present. In addition, many who have Lewy Body Dementia experience vivid visual hallucinations. Parkinson drugs can improve steadiness and muscle control. Cholinesterase-inhibitor agents, such as Aricept and Exelon, may be beneficial for cognition and hallucinations. Certain neuroleptic drugs, such as Haldol, should be avoided due to negative responses. [more information]

Huntington's Disease

Huntington's disease is an inherited, degenerative brain disease that affects the mind and body. The disease usually begins during midlife, and is characterized by intellectual decline, and irregular and involuntary movements of the limbs or facial muscles. Other symptoms of Huntington's disease include personality change, memory disturbance, slurred speech, impaired judgment and psychiatric problems. Huntington's disease currently affects more than 25,000 Americans. The diagnostic process for Huntington's disease includes an evaluation of family medical history, recognition of typical movement disorders and CAT brain scanning. A genetic marker linked to Huntington's disease has been identified on chromosome 4 and researchers are working on locating the gene itself. Although there is no treatment available to stop to progression of the disease, the movement disorders and psychiatric symptoms can be controlled by drugs.

Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob Disease (CJD) is a rare, fatal brain disorder caused by a transmissible infectious organism, probably a virus. Early symptoms of CJD include failing memory, changes in behavior, and a lack of coordination. As the disease progresses, usually very rapidly, mental deterioration becomes pronounced, involuntary movements (especially muscle jerks) appear, and the patient may become blind, develop weakness in the arms or legs, and ultimately lapse into a coma. The death of CJD patients is usually caused by infections in the bedridden, unconscious patient. Like Alzheimer's disease, a definitive diagnosis of CJD can be obtained only through an examination of brain tissue, usually at autopsy.

Frontal Lobe Dementia

Frontal Lobe Dementia is also a rare brain disorder that like Alzheimer's disease is usually difficult to diagnose. Disturbances in personality, behavior and orientation may precede and initially be more severe than memory defects. Like Alzheimer's disease, a definitive diagnosis is usually obtained at autopsy.

Normal Pressure Hydrocephalus

Normal pressure hydrocephalus; is an uncommon disorder which involves an obstruction in the normal flow of cerebrospinal fluid. This blockage causes a buildup of cerebrospinal fluid on the brain. Symptoms of normal pressure hydrocephalus; include dementia, urinary incontinence and difficulty in walking. Presently, the most useful diagnostic tools are the neuroimaging techniques (i.e., MRI). Normal pressure hydrocephalus may be caused by any of several factors including meningitis, encephalitis and head injuries. In addition to treatment of the underlying cause, the condition may be corrected by a neurosurgical procedure (insertion of a shunt) to divert the fluid away from the brain.

Depression

Depression is a psychiatric disorder marked by sadness, inactivity, difficulty in thinking and concentration, hopelessness, and sometimes suicidal tendencies. Many severely depressed patients will have some mental deficits including poor concentration and attention. When dementia and depression are present together, intellectual deterioration may be exaggerated. Depression, whether present alone or in combination with dementia, can be reversed with proper treatment.

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