What is Alzheimer’s Disease?

Alzheimer’s disease (AD) is a slow, progressive, degenerative brain disease resulting from damaged neurons in parts of the brain that control cognitive function. It is characterized by memory loss and deterioration in intellectual ability.1,2 Healthy brains have approximately 100 billion neurons connected by 100 trillion synapses (circuits). Signals flows through the synapses via tiny bursts of chemicals. A brain with AD typically has an accumulation of beta-amyloid plaques outside the neuron and tau tangles inside the neuron, which are believed to cause neuron damage.1 As the number of damaged neurons increase, signal flow through the synapses is impaired. Individuals with AD experience a decline in memory, language, walking, swallowing, problem solving, and other cognitive skills required to complete activities of daily living.1,2 Autopsy specimens of brains of individuals with AD have “dramatic shrinkage from cell loss and widespread debris from dead and dying neurons.”1