The purpose of this study is to evaluate the long-term safety and effectiveness of the study drug, aducanumab in participants who have previously received aducanumab in the following previous clinical trials: Study 301 [ENGAGE]; Study 302 [EMERGE]; Study 103 [PRIME], and Study 205 [EVOLVE]. The study may last for about 2.5 years consisting of about 33 planned research clinic visits and 8 telephone safety contacts.

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.

Alzheimer's disease and Epilepsy may affect over 80% of individuals that have Down syndrome by the age of 60. Biomarkers found in the blood can enhance our understanding of the earliest changes linked to disease and may enhance clinical detection and healthy aging for individuals with Down syndrome.

The purpose of this study is to discover early neurobiological processes underlying the transition from healthy aging to disease. Our research team has developed technology that allows detection of small changes in the brain that get transferred to the blood.

We are recruiting individuals that either have or do not have Down syndrome for this biomarker study. Participants should be between the ages of 6 months and 85 years old and may include mothers and siblings of a child with Down syndrome. Infants and children will require consent form a parental or legal guardian.

Each participant will provide a blood sample for research purposes. We will also gather some basic health information about senses, habits, exercise level and smoking/vaping exposures.

Patients with Alzheimer Disease and patients with Heart failure (and a control group free from both the previous mentioned conditions) will be evaluated with cardiac and neuropsychological assessments, in order to investigate the relationship between the two conditions. 8 follow up visits will be repeated yearly, for 8 years.

Alcohol Use Disorder (AUD) is a risk factor for Alzheimer's Disease (AD), but more research is needed to identify the potential mechanisms underlying this risk. The present study will use fMRI to examine brain network profiles in mid-life AUD. The goal is to develop techniques to assess risk for Alzheimer's Disease and related dementias. Participation includes cognitive testing and MRI scanning.

Candidates for this study may or may not report disturbances in odor perception as their primary reason for seeking treatment at MUSC. This study is designed to collect long term, observational data from patients who are being treated with routine clinical care in health clinics at MUSC. Data from clinical questionnaires will be de-identified and stored in a database.

Traumatic Brain Injury is a risk factor for Alzheimer's Disease and other dementias. This study will use neuroimaging in Veterans and civilians with a history of TBI or without TBI to understand whether some of the brain changes that occur in Alzheimer's Disease are present in people with a history of TBI. The study is recruiting male and female military Veterans or civilians with or without TBI between the ages of 30 and 65.

The purpose of this study is to use neuroimaging to understand how networks in the brain change over time. Although the single most significant risk factor for developing Alzheimer's disease (AD) is age, the neurobiological processes underlying the transition from normal aging to AD are not well understood. Our group of researchers has developed ways to use MRI to detect small changes in certain parts of the brain. We will use neuroimaging to understand how the connections in the brain change over time in healthy aging. The goal is to discover which brain changes are present in healthy aging so that future studies can assess the risk for developing Alzheimer's Disease.

Participants will have two study visits (about 2 years apart) where they will undergo tests to assess mental function, fill out questionnaires, and undergo a blood draw, brain MRI and PET scan. At the second visit, participants will not repeat the blood draw and a PET scan.

Participants are required to have a Co-Participant accompany them for the first portion of each visit. This individual must be a reliable informant that has contact with the participant at least once per week.

This study will use neuroimaging to understand how the connections in the brain change in Alzheimer's Disease. Changes will also be examined in individuals with mild cognitive impairment and healthy aging. The goal is to discover which brain changes are present in healthy aging and MCI so that future studies can assess the risk for developing Alzheimer's Disease. The study involves blood draw, cognitive testing, MRI, PET scanning, and a 1-year follow-up visit to repeat cognitive testing and MRI scanning.

With this research study, we want to learn if methylphenidate (Ritalin® and others) helps people with Alzheimer's disease and apathy (lack of interest or concern for things that others find moving or exciting).