Alzheimer's Disease

Alzheimer's disease - also known as Alzheimer disease - is the most common form of dementia. It is a progressive and degenerative disease that eventually leads to death, and there is currently no known cure. It is best known for its effect of causing a marked decline in the cognitive and memory functions of individuals.

Alzheimer's disease is most often diagnosed in people aged over 65 years of age, although early-onset Alzheimer's can occur much earlier. It is predicted that by 2050, 1 in 85 people will be diagnosed with Alzheimer's disease. There are concerns in many countries that current infrastructure will not be adequate enough to deal with increasing numbers of Alzheimer's sufferers.

Very little is known about the cause and progression of Alzheimer's disease, although it is believed that plagues and tangles in the brain may be partially responsible for the condition. Research is ongoing, and there are more than 1000 clinical trials that have been or are being conducted to find a way to treat the disease, but it is currently not known if any of the developer treatments will work.

Signs and symptoms

Early signs of Alzheimer's are often mistaken as normal signs of old age, or stress-related ailments. Diagnosis of Alzheimer's in the early stages is uncommon, with most diagnosis occurring in the mid- to latter stages of the disease.

Due to the variable nature of Alzheimer's disease it can have a noticeably different effect on sufferers, which makes it very difficult to come up with a fixed set of symptoms. There is however some commonality between the basic signs and symptoms between sufferers. In addition to this Alzheimer's is can be fast or short in onset and progression, depending on the individual, which means it can easily go undiagnosed for years.

The average life expectancy for a person diagnosed with Alzheimer's is 7 years. Less than 3 percent of those diagnosed live more than 14 years after diagnosis.

The usual earliest sign of Alzheimer's is a marked difficulty in remembering recent events. As the disease progresses symptoms can manifest in a number of ways, which can include:

Confusion
Irritability and aggression
Mood swings
Trouble with language
Long-term memory loss.

This is often accompanied by a total or partial withdrawal from friends, family and society as a whole, including a loss of recognition and awareness. Control over bodily functions is gradually lost, ultimately leading to death.

Treatment

There is currently no known cures or effective treatments for Alzheimer's disease, although there are a number of proposed ways of managing the rate of progression and the effects of the disease in patients.

In the US, five different medications are currently approved for management of symptoms associated with Alzheimer's disease. These medications are:

• Tacrine
• Rivastigmine
• Glantamine
• Donepezil
• Memantine

None of these drugs have been shown to halt or delay the progression of the disease, and may offer limited effects on the symptoms of the disease. The first four are acetylcholinesterase inhibitors, and work by reducing the rate at which acetylcholine is broken down (which is accelareted in Alzheimer's patients due to the death of cholinergic neurons in the brain), increasing acetylcholine in the brain. Of these four, only donepezil is certified for use in late-stage Alzheimer's, whilst all five can be used for mild- to mid-stage Alzheimer's. Memantine works by preventing excitotoxicity in Alzheimer's patients by blocking the NMDA receptors, which inhibits their over-stimulation by glutomate.

Mental stimulation - such as regular games of chess -  along with physical exercise have been suggested as effective management techniques when applied properly and responsibly. There is some anecdotal evidence to suggest that engaging a patient suffering from Alzheimer's in particular forms of mental and physical activity can result in a noticeable improvement in that person's ability to function. There is currently no major studies that support this theory, although research into it is being conducted.