Alzheimer's disease
Alzheimer’s disease, also called primary degenerative dementia, accounts for more than half of all dementias. It results in memory loss, confusion, impaired judgment, personality changes, disorientation, and loss of language skills; it essentially steals away the patient’s mind. Because this is a primary progressive dementia, the prognosis for a patient with this disease is poor.
Causes and incidence
The cause of Alzheimer’s disease is unknown; however, several factors are thought to be implicated in this disease. These include neurochemical factors, such as deficiencies in the neurotransmitter acetylcholine, somatostatin, substance P, and norepinephrine; environmental factors; and genetic immunologic factors. Genetic studies show that an autosomal dominant form of Alzheimer’s disease is associated with early onset and early death, accounting for about 100,000 deaths a year. A family history of Alzheimer’s disease and the presence of Down syndrome are two established risk factors.Alzheimer’s disease isn’t exclusive to the elder population; its onset begins in middle age in 1% to 10% of cases
The brain tissue of patients with Alzhei-mer’s disease has three hallmark features: neurofibrillary tangles, neuritic plaques, and granulovascular degeneration. Examination of the brain after death also finds that it’s atrophic, commonly weighing less than 1,000 g, compared with a normal brain weight of about 1,380 g.
About 360,000new cases of Alzheimer’s are diagnosed each year.
Signs and symptoms
Onset is insidious. Initially, the patient undergoes almost imperceptible changes, such as forgetfulness, recent memory loss, difficulty learning and remembering new information, deterioration in personal hygiene and appearance, and an inability to concentrate. Gradually, tasks that require abstract thinking and activities that require judgment become more difficult. Progressive difficulty in communication and severe deterioration in memory, language, and motor function result in a loss of coordination and an inability to write or speak. Personality changes (restlessness, irritability) and nocturnal awakenings are common.
Patients also exhibit loss of eye contact, a fearful look, wringing of the hands, and other signs of anxiety. When a patient with Alzheimer’s disease is overwhelmed with anxiety, he becomes dysfunctional, acutely confused, agitated, compulsive, or fearful.
Eventually, the patient becomes disoriented, and emotional lability and physical and intellectual disability progress. The patient becomes susceptible to infection and accidents. Usually, death results from infection.
Diagnosis
Early diagnosis of Alzheimer’s disease is difficult because the patient’s signs and symptoms are subtle. (See Organic brain syndrome, page 662.) Diagnosis relies on an accurate history from a reliable family member, mental status and neurologic examinations, and psychometric testing. A positron emission tomography scan measures the metabolic activity of the cerebral cortex and may help in early diagnosis. An EEG and a computed tomography scan may help in later diagnosis. Currently, the disease is diagnosed by exclusion; that is, tests are performed to rule out other disorders. The presence of Alzheimer’s can’t be confirmed until death, when pathologic findings are revealed at autopsy.
Treatment
Therapy consists of attempts to slow disease progression, manage behavioral problems, modify the home environment, and elicit family support. Some medications have proven helpful. Tacrine, a centrally acting anticholinesterase agent, is given to treat memory deficits. It has slowed progression of the disease and improved cognitive function in some patients. Other agents include donepezil and rivastigmine. Underlying disorders that contribute to the patient’s confusion, such as hypoxia, are also identified and treated.
Special considerations
Overall care is focused on supporting the patient’s remaining abilities and compensating for those he has lost.
❑Establish an effective communication system with the patient and his family to help them adjust to the patient’s altered cognitive abilities.
❑Offer emotional support to the patient and his family members. Behavior problems may be worsened by excess stimulation or change in established routine. Teach them about the disease, and refer them to social service and community resources for legal and financial advice and support.
❑Anxiety may cause the patient to become agitated or fearful. Intervene by helping him focus on another activity.
❑Provide the patient with a safe environment. Encourage him to exercise, as ordered, to help maintain mobility.
Pictures
Book Source Details
- Book Title: Professional Guide to Diseases (Eighth Edition)
- Author(s): Springhouse
- Year of Publication: 2005
- Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2005 Lippincott Williams & Wilkins.
Other Book Chapters Related to Amnesia
Read excerpts from these other book chapters related to Amnesia:
Medical Books Excerpts
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- "Handbook of Signs & Symptoms (Third Edition)" (2006)
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- "Handbook of Signs & Symptoms (Third Edition)" (2006)
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- Confusion
- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
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- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
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- Confusion
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
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- "Field Guide to Bedside Diagnosis" (2007)
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- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
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- Confusion
- "Nursing: Interpreting Signs and Symptoms" (2007)
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- Amnesia
- "Nursing: Interpreting Signs and Symptoms" (2007)
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- AMNESIA
- "Differential Diagnosis in Primary Care" (2007)
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Copyright Details: Professional Guide to Diseases (Eighth Edition), Copyright © 2008 Williams & Wilkins.
More About Causes of Amnesia
» Next page: Dissociative amnesia (Professional Guide to Diseases (Eighth Edition))
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