Alzheimer's Disease

Introduction
Alzheimer disease is the most common and important degenerative disease of the brain. Alzheimer disease is the commonest cause for dementia. The incidence of Alzheimer disease in the age group above 60 years is 123 cases per 100,000 annually. There are approximately 2 million people with Alzheimer's disease in United States. The familial occurrence of Alzheimer's disease is less than 1 percent of all cases.

What are the changes in the brain in a patient with Alzheimer's disease?
With the onset of Alzheimer's disease the brain may start shrinking in size with associated loss of weight of the brain. In severe cases of Alzheimer's disease there may be as much as 20 percent or more reduction of the weight of brain compared to normal brain. The hippocampus of the brain -- which is involved in learning, memory and conversion of short-term memory to long-term memory -- may show extreme atrophy and may be visualized in MRI scans. The following pathological changes are present in brain in a patient with Alzheimer's disease.

The following pathological changes are usually present in the brain of patients with Alzheimer's disease.

• The cholinergic neurons of the nucleus basalis of Meynert and locus ceruleus are greatly reduced in number.
• Presence of Alzheimer's tangles. This contains hyperphosphorylated form of microtubular protein tau.
• Presence of senile plaques containing amyloid through out the brain.

What are the symptoms present in a patient with Alzheimer's disease?
The onset of mental changes in patients with Alzheimer's disease is usually very slow that neither the family nor the patient can date the time of its beginning. Sometimes the mental changes may be precipitated by an acute episode like febrile illness, surgery, mild head injury or intake of some drugs. Some patients with Alzheimer's disease may complaint of dizziness, headache or other vague symptoms.

Forgetfulness is the major problem in patients with Alzheimer's disease. Patients with Alzheimer's disease may have difficulty in remembering small day-to-day events. Appointments may be forgotten and things are misplaced. Alzheimer's disease patients may ask the same question again and again. Sometimes the patients make up their own stories to fill up the gap caused by memory loss.

Patients with Alzheimer's disease often have difficulty in speaking because they often forgets the words to use and this may result in sudden halt in speech.The comprehension of speech may be lost. Patients with Alzheimer's disease may develop lack of attentiveness. They may repeat every spoken phrase after the speaker (echolalia). Patients with Alzheimer's disease may have difficulty in naming objects. There may be difficulty in performing calculation (acalculia). The patient may not be able to manage his ore her own personal finances and may even have difficulty in purchasing items from a grocery store. Patients may have difficulty in getting inside the car and sometimes they may lose his way back to home and wander.

Later as the disease worsens, the patients may forget the use common things like holding a razor or pen. Patients with advanced Alzheimer's disease may lose control over the bladder and may have urinary incontinence. Later these patients may not be able to stand and walk and finally bedridden needing some one's help to take care of him.

How do you diagnose Alzheimer's disease?
MRI and CT scan are used as ancillary tests in diagnosis of Alzheimer disease. Neuropsychological tests show deterioration in memory and verbal access skills. The following conditions, which mimic like Alzheimer's disease, should be ruled out:

• Multi infarct dementia
• Dementia of normal pressure hydrocephalus
• Chronic subdural hematoma
• Brain tumour
• Chronic drug intoxication.

What are the treatments available for Alzheimer's disease?
Trazodone, haloperidol, thioridazine, rivastigmine, resperidone and related drugs may suppress some of the aberrant behavior and hallucinations, making life more comfortable for both patient and the family. Small dose of diazepam is useful, if sleep is severely disturbed.
Questions asked by the patient's family must be answered patiently and sensitively. Common questions asked are:

• Should I argue with the patient? (No)
• Must I there be constantly? (depends on the situation and severity of dementia)
• Will a change of environment or a trip help? (Generally not)
• Can he drive? (Best thing is not to drive)
• What shall we do about the patient's fear at night and his hallucinations? (Medications under supervision will help)

Visiting nurses, social agencies, live-in-health care aids, day care settings and respite care to relieve families from the constant burden of caring for the patient should all be used in managing of a patient with Alzheimer's disease.

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Did you know
Alzheimer disease is the most common and important degenerative disease of the brain. Alzheimer disease is the commonest cause for dementia. The incidence of Alzheimer disease in the age group above 60 years is 123 cases per 100,000 annually. There are approximately 2 million people with Alzheimer's disease in United States.