Geriatrics : Alzheimer"s Disease

 Alzheimer's disease

Alzheimer's disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. 

In most people with the disease—those with the late-onset type—symptoms first appear in their mid-60s. 

Early-onset Alzheimer’s occurs between a person’s 30s and mid-60s and is very rare. 

Alzheimer’s disease is the most common cause of dementia among older adults.

Origins and history:

The disease is named after Dr. Alois Alzheimer. In 1906, 

Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. Her symptoms included memory loss, language problems, and unpredictable behavior. 

After she died, he examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary, or tau, tangles).

These plaques and tangles in the brain are still considered some of the main features of Alzheimer’s disease. 

Another feature is the loss of connections between nerve cells (neurons) in the brain.

 Neurons transmit messages between different parts of the brain, and from the brain to muscles and organs in the body. 

Many other complex brain changes are thought to play a role in Alzheimer’s, too.

This damage initially appears to take place in the hippocampus, the part of the brain essential in forming memories. 

As neurons die, additional parts of the brain are affected. By the final stage of Alzheimer’s, damage is widespread, and brain tissue has shrunk significantly.

Clinical Features:

Memory problems are typically one of the first signs of Alzheimer’s, though initial symptoms may vary from person to person. 

A decline in other aspects of thinking, such as finding the right words, vision/spatial issues, and impaired reasoning or judgment, may also signal the very early stages of Alzheimer’s disease. 

Mild cognitive impairment (MCI) is a condition that can be an early sign of Alzheimer’s, but not everyone with MCI will develop the disease.

People with Alzheimer’s have trouble doing everyday things like driving a car, cooking a meal, or paying bills. 

They may ask the same questions over and over, get lost easily, lose things or put them in odd places, and find even simple things confusing. 

As the disease progresses, some people become worried, angry, or violent.

How Long Can a Person Live with Alzheimer’s Disease?

The time from diagnosis to death varies—as little as 3 or 4 years if the person is older than 80 when diagnosed, to as long as 10 or more years if the person is younger.

Although treatment can help manage symptoms in some people, currently there is no cure for this devastating disease.

How Is Alzheimer's Disease Treated?

Alzheimer’s disease is complex, and it is unlikely that any one drug or other intervention will successfully treat it. 

Current approaches focus on helping people maintain mental function, manage behavioral symptoms, and slow down the symptoms of disease.

Treatment for Mild to Moderate Alzheimer’s

Medications called cholinesterase inhibitors are prescribed for mild to moderate Alzheimer’s disease. 

These drugs may help reduce some symptoms and help control some behavioral symptoms. 

The medications are Razadyne® (galantamine), Exelon® (rivastigmine), and Aricept® (donepezil).

Scientists do not yet fully understand how cholinesterase inhibitors work to treat Alzheimer’s disease, but research indicates that they prevent the breakdown of acetylcholine, a brain chemical believed to be important for memory and thinking. As Alzheimer’s progresses, the brain produces less and less acetylcholine; therefore, cholinesterase inhibitors may eventually lose their effect.

Treatment for Moderate to Severe Alzheimer’s

A medication known as Namenda® (memantine), an N-methyl D-aspartate (NMDA) antagonist, is prescribed to treat moderate to severe Alzheimer’s disease.

 This drug’s main effect is to decrease symptoms, which could allow some people to maintain certain daily functions a little longer than they would without the medication. 

For example, Namenda® may help a person in the later stages of the disease maintain his or her ability to use the bathroom independently for several more months, a benefit for both the person with Alzheimer's and caregivers.

The FDA has also approved Aricept®, the Exelon® patch, and Namzaric®, a combination of Namenda® and Aricept®, for the treatment of moderate to severe Alzheimer’s disease.

Namenda® is believed to work by regulating glutamate, an important brain chemical. When produced in excessive amounts, glutamate may lead to brain cell death. Because NMDA antagonists work differently from cholinesterase inhibitors, the two types of drugs can be prescribed in combination.