The purpose of the study is to see if daily use of nicotine patches will slow or reverse memory loss in participants with Mild cognitive impairment, an early stage of mental decline associated with Alzheimer's disease. Nicotine may mimic natural chemicals in the brain that play a crucial role in memory function, and previous studies have shown that nicotine may improve attention, learning, and memory. In this study, participants will receive either nicotine (up to 21mg/day, the standard dosage of a nicotine patch) or placebo for 2 years to see if these improvements in brain function can be observed over a longer period.

Two groups of former athletes (who competed in contact and not-contact sports) will undergo brain and heart assessments. Additionally, blood and urines samples will be collected in order to investigate potential markers of disease.

Neurological diseases are the leading cause of disability worldwide and a major contributor to health problems in children and adults. As the majority of these conditions result in lifelong disabilities, the implications for the family and for society is significant.

A significant number of adult and childhood neurological diseases have a genetic component and are caused by changes in our DNA and/or RNA leading to functional changes in the central nervous system. However, for many patients afflicted with these disorders, traditional genetic testing does not identify a clear genetic cause. The goal of this study will be to use newer genetic techniques to evaluate patients and families with neurological disorders to better understand the genetic basis of the disease.