Alzheimer’s disease 101
Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and thinking skills, and eventually even the ability to carry out the simplest tasks. In most people with Alzheimer’s, symptoms first appear after age 65. In Early onset cases the symptoms can appear in the 40’s and 50’s. Estimates vary, but experts suggest that as many as 5.5 million Americans may have Alzheimer’s disease. The older one gets the greater the chance of developing Alzheimer’s disease.
There are many types of dementia, all caused by a different process occurring with the brain. Alzheimer’s disease is the most common cause of dementia among older people accounting upwards of 80% of the cases over the age of 65. Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities, to such an extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living.
Alzheimer’s 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. Upon her death Dr. Alzheimer examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles). The plaques are made up of beta amyloid fibrils that ‘clump’ in the brain and ultimately kill neurons. The tangles occur when the tau protein molecule destabalizes within the neuron itself, become ‘tangled’ and also contribute to the progression of the disease.