Memory Disorders, Aging, and Forgetting - MCAT Social and Behavioral Sciences

Alzhemier's disease is the most common form of dementia. Nerve cells in the area of the brain associated with memory and cognition are disrupted by plaques and tangles. The disease begins with mild memory loss and progresses to a point where the patient is unable to perform necessary everyday tasks.

Parkinson's disease is associated with abnormal movements, tremors, and a shuffling gait. The symptoms of Parkinson's disease are caused by a lack of the neurotransmitter dopamine, which is caused by a degeneration of neurons.

Multiple sclerosis is a chronic, progressive disorder caused by the body's immune system attacking the myelin sheathes surrounding nerve fibers in the brain, spinal cord, and optic nerves. This damage leads to muscle weakness, numbness, and vision loss.

Amyotrophic lateral sclerosis, or Lou Gehrig disease, occurs when motor neurons progressively deteriorate. This leads to muscle weakness that can progress to paralysis.

A stroke, also called a cerebral vascular accident, occurs when the blood supply to the brain is suddenly interrupted and brain cells are deprived of oxygen. The symptoms of a stroke include sudden onset of weakness, especially on one side of the body, trouble speaking, and vision disturbrances.