Alzheimer’s Disease

Disease information

Alzheimer’s disease is a neurodegenerative disease which is the most important cause of dementia. It is pretty common in the elderly with the prevalence doubling every five years after the age of 65. About 30 percent of all individuals over 90 suffer from the disease.

Alzheimer’s disease involves irreversible deterioration of cognitive abilities. The course of the disease is divided into 3 stages: preclinical, MCI (mild cognitive impairment) and then dementia. Patients with Alzheimer’s disease have hyperphosphorylated tau proteins accumulate in the form of neurofibrillary tangles in the nerve cells. Tau proteins are responsible for stabilizing the microtubules of the neuronal cytoskeletal framework. Hyper-phosphorylation of these proteins results in the disease pathology. The regions typically affected are the brain cortex and limbic regions.

Outside of nerve cells, there is accumulation of beta amyloid plaques. These peptides are produced by the processing of membrane bound amyloid precursor protein (APP). Normally, this precursor protein undergoes alpha breakdown. During Alzheimer’s, the processing is impaired such that it undergoes beta cleavage and yields beta amyloid plaques.