Senile dementia--Alzheimer's type

Causes and Risks:
Senile dementia/Alzheimer's type (SDAT) is the most common cause of intellectual decline with aging. The incidence is approximately 9 out of 10,000 people. This disorder affects women slightly more often than men and occurs primarily in older individuals.

The cause is unknown. Several factors are believed to be involved in the development of the disorder, but have not yet been proven. The neurochemical factors include lack of the substances used by the nerve cells to transmit nerve impulses (neurotransmitters), including acetylcholine, somatostatin, substance P, and norepinephrine . Environmental factors include exposure to aluminum, manganese, and other substances. The infectious factors include prion (virus-like organisms) infections that affect the brain and spinal cord ( central nervous system ). In some families (representing 5 to 10% of cases) there is an inherited predisposition to development of the disorder, but this does not follow strict (Mendelian) patterns of inheritance. The diagnosis is usually made by ruling out other causes of dementia .

Researchers have found that in families that have multiple members with Alzheimer's, there is a particular gene variation which is common to all of those with the disease. The gene, which produces a substance called apolipoprotein E4, is not said to cause the disease, it's presence simply increases the chances that the disease may eventually occur. There are many people who have the E4 gene and never become afflicted with Alzheimer's.

The onset is characterized by impaired memory , with progressive loss of intellectual function. There may be mood changes , changes in language capability, changes in gait , and other changes as the disorder progresses. There is a decrease in the size (atrophy) of the tissues of the brain, enlargement of the ventricles (the spaces within the brain), and deposits within the tissues of the brain.

The risk factors include age and family history of Alzheimer's disease.

Prevention:
There is no proven prevention at this time.

Symptoms:
  • awareness of intellectual decline, initially
  • apraxia : inability to perform purposeful movements (not caused by motor or sensory impairment); inability to use objects properly
  • difficulty with any previously learned, skilled sequential movement
  • trouble naming objects (anomia)
  • "word-finding" deficits in conversation
  • dementia, slowly progressive (progressive loss of many brain functions) including
    • gradual onset of intellectual decline
    • disrupted or wandering attention
    • inability to maintain goal directed, purposeful thinking or behavior
    • inability to concentrate
    • disorientation
    • confusion
    • memory losses, primarily short-term memory (at first)
    • withdrawal from social interaction
    • progressive difficulty interacting in social or personal situations
    • decreased ability to function in self care and daily living activities
    • lack of spontaneity
    • behavior that is inappropriate relative to the environment
    • judgment impairment
    • agitation or other affect/ mood changes that appear or worsen as the disorder progresses

+ sleep pattern changes ( sleep apnea is fairly common)



Signs and Tests:
The disorder is tentatively and/or provisionally diagnosed by the health care provider based in part on the history and progression of symptoms, and by ruling out other causes of dementia , including dementia due to metabolic causes . The history may show progressive decline in memory, judgment, and orientation , with changes in mood and behavior.

A neuromuscular examination shows inability to reproduce movements or perform skilled, coordinated movements. There may be a loss of ability to perform simple daily living activities such as eating, dressing, or toileting. Language and calculation abilities may be altered. Inappropriate reflexes, or increased or decreased action of normal reflexes, may be present. Psychologic studies and tests of sensation, cognitive function, and motor function may be abnormal.

Atrophy (shrinking) of the frontal or temporal lobes of the brain, generalized atrophy, and/or other "signal" changes in the white matter may appear on:

An EEG (electroencephalography) may show nonspecific changes. A lumbar puncture and cerebrospinal fluid (CSF) examination is normal.

Treatment:
There is no known definitive (proven to be effective) cure for SDAT (Alzheimer's). Treatment is aimed at relief of symptoms and protection from the effects of the deteriorating condition.

Tacrine and/or cognex may be used, and the results vary. Other treatments may be attempted, but most are considered experimental or have had variable results.

Stopping or changing medications that worsen confusion or that are not essential to the care of the person may improve cognitive function. This may include medications such as anticholinergics, analgesics , cimetidine, central nervous system depressants, and other medications.

Underlying disorders that contribute to confusion should be identified and treated as appropriate. These include heart failure , decreased oxygen ( hypoxia ), thyroid disorders , anemia , nutritional disorders, infections, and psychiatric conditions such as depression . The correction of coexisting medical and psychiatric disorders often greatly improves the patient's mental function.

Medications may be required to control aggressive or agitated behaviors or any behaviors that are dangerous to the person or to others. These are usually given in very low doses, with adjustment as required. Some of the medications that may be considered for use include the following:

  • anti-psychotics
  • serotonin-affecting drugs (lithium, trazodone, buspirone, clonazepam, etc.)
  • carbamazepine
  • cholinergic stimulators (such as tacrine phosphatidyl choline) have been effective for some persons with SDAT

An anticonvulsant medication may be needed for seizures .

The patient's sensory functions should be evaluated and augmented as needed with such things as hearing aids, glasses, and cataract surgery .

Psychotherapy is seldom effective because it may overload the patient's limited cognitive resources.

Eventually, 24-hour monitoring and assistance may be required to provide a safe environment, control aggressive or agitated behavior, and meet physiologic needs. This may include in-home care, boarding homes, adult day care, or convalescent homes.

General nutrition and health maintenance is important, but special diets or nutritional supplements are usually unnecessary. Exercise is important and should be encouraged.

Practical assistance early in the disorder may include frequent reminders, notes, lists of routine tasks, or directions for daily activities.

Behavior modification may be helpful for some people in controlling unacceptable or dangerous behaviors. This consists of rewarding appropriate or positive behaviors and ignoring inappropriate behaviors (within the bounds of safety ).

Reality orientation , with repeated reinforcement of environmental and other cues, may help reduce disorientation.

Family counseling may help in coping with the changes required for home care.

Visiting nurses or aides, volunteer services, homemakers, adult protective services, and other community resources may be helpful in caring for people with SDAT. In some communities, there may be access to support groups . See Alzheimer's - support group and elder care - support group .

Legal advice may be appropriate early in the course of the disorder. Advance directives, a power of attorney , and other legal actions may make it easier to make ethical decisions regarding the care of an SDAT patient.

Prognosis:
The probable outcome is poor. The disorder is usually not acute , but progresses steadily. Total disability is common. Death normally occurs within 15 years, usually from an infection or a failure of other body systems.

Complications:

  • loss of ability to function or care for self
  • complications caused by immobility
  • decubitus (bedsores)
  • broken bones
  • muscle contractures (loss of ability to move joints because of loss of muscle function)
  • loss of ability to interact
  • increased incidence of infections anywhere in the body
  • failure of body systems
  • reduced life span
  • abuse by an over-stressed caregiver
  • side effects of medications



Call Your Healthcare Provider:
Call your health care provider if someone close to you experiences symptoms of senile dementia/Alzheimer's type.

Call your health care provider if a person with this disorder experiences a sudden change in mental status (may indicate other illness).

Discuss the situation with your health care provider if you are caring for a person with this disorder and the condition deteriorates to the point where you can no longer care for the person in your home.