Alzheimer’s disease is a progressive neurological disorder that affects the brain and results in cognitive impairments, such as impaired thinking, memory loss, and bizarre behavior. Alzheimer’s disease is the most common form of dementia and the fourth leading cause of death in adults.
What causes it
The cause of Alzheimer’s disease isn’t known; however, several factors appear to have some association with the disease. These include:
- deficiencies in the neurotransmitters acetylcholine, somatostatin, substance P, and norepinephrine
- repeated head trauma
- abnormalities on chromosomes 14 or 21
- deposits of beta amyloid protein.
The brain tissue of patients with Alzheimer’s disease has three distinguishing features:
- neurofibrillatory tangles (fibrous proteins)
- amyloid plaques (composed of degenerating axons and dendrites) granulovacuolar degeneration.
- Autopsy commonly reveals an atrophic brain that can weigh
1,000 g or less. Normal brain weight is 1,380 g.
What to look for
The onset of Alzheimer’s disease is insidious. Initial changes are almost imperceptible, but gradually progress to serious problems. Initial signs and symptoms include:
- forgetfulness and short-term memory loss
- difficulty learning and remembering new information
- inability to concentrate. Later signs and symptoms include:
- difficulty with abstract thinking and activities that require judgment
- progressive difficulty communicating
- severe deterioration in memory, language, and motor function
- repetitive actions or perseveration (a classic sign)
- nocturnal wakening, disorientation, and personality changes, such as restlessness and irritability.
What tests tell you
- Psychometric testing and neurologic examination can help establish the diagnosis.
- A PET scan measures the metabolic activity of the cerebral cortex and may help confirm an early diagnosis.
- EEG, CT scan, and MRI may help diagnose later stages of Alzheimer’s di sease.
- Testing for soluble amyloid beta protein precursor helps a ssess the extracellular deposits of amyloid beta-peptide, which is a major neuropathic sign of Alzheimer’s disease.
- Additional tests may help rule out other causes of dementia, such as vitamin B12 deficiency and hypothyroidism.
How it’s treated
Although there’s no known cure for Alzheimer’s disease, donepezil, tacrine, and rivastigmine have proven partially effective in improving mental performance. Drug therapy is also used to treat behavioral symptoms, such as aggression, paranoia, depression, and delusions. These drugs include:
- antipsychotics, such as haloperidol (Haldol), olanzapine ( Zyprexa), quetiapine (Seroquel), and risperidone (Risperdal)
- anxiolytics, such as alprazolam (Xanax), buspirone (BuSpar), diazepam (Valium), and lorazepam (Ativan)
- antidepressants, such as amitriptyline, bupropion (Wellbutrin), fluoxetine (Prozac), and paroxetine (Paxil).
What to do
- Establish an effective communication system with the patient and his family to help them adjust to his altered cognitive abilities.