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.

This study is collecting information to determine if there is a genetic factor contributing to the development of Parkinson's disease. Adults with Parkinson's disease or individuals that have family members with Parkinson's disease may qualify to participate in this study. All participants that qualify to enroll will have their medical history recorded, a brief neurological examination will be performed and blood will be drawn for genetic analysis. All information collected will be coded to protect participants privacy. No other procedures are involved in this study because it is not a treatment study.

Transcranial direct current stimulation (tDCS) has shown the potential to improve symptoms in patients with movement deficits, such as Parkinson's disease and chronic stroke. However, the effects of tDCS have so far not been proven on a wider scale due to lack of knowledge regarding exactly how tDCS works. This has limited the adoption of this potentially useful therapy for patients with Parkinson's disease, chronic stroke and other conditions affecting movement. We think that by studying the effect of tDCS on brain signals while subjects perform a virtual reality task that requires integration of visual and motor information we can separate out exactly what occurs in the brain when tDCS is turned on. We expect this approach to broaden our understanding of tDCS application in conditions affecting movement and possibly lead to therapeutic advances in this population.

This registry is designed for patients with Parkinson's Disease (PD) who are being considered for treatment with deep brain stimulation (DBS). A registry is a type of observational study that collects information about patients' medical conditions and/or treatments to better understand how a condition or treatment affects patients in the real world.The purpose of the research is to create a list of patients with Parkinson Disease who are all receiving DBS to learn more about the effects of DBS on their PD symptoms

IPX203 is an investigational extended-release (i.e. releases drug more slowly) capsule formulation of carbidopa-levodopa (CD-LD) administered orally (by mouth). "Investigational" means that IPX203 is being tested and has not been approved for marketing.

IPX203 is being investigated to determine whether the drug is safe and potentially has a better effect than currently approved IR CD-LD. If successful, the drug could possibly improve the daily control of motor symptoms in people with Parkinson's disease.

IPX203 is provided as a capsule containing 140 mg LD and 35 mg CD. The study doctor may adjust the IPX203 dosing regimen based on your response to the study drug during the 4 week dose conversion period. Your study doctor will instruct you on the dose of IPX203 or IPX203 placebo that you will receive during the 13-week portion of the study.

Your total participation time in the study will be approximately 24 weeks (6 months), which includes 4 weeks for your initial assessment (screening) period to determine if the trial is suitable for you.

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.

Transcranial direct current stimulation (tDCS) has shown the potential to improve symptoms in patients with motor deficits, however its effects have not been consistent in randomized studies to date, limiting widespread adoption of this technology. A critical gap in our knowledge is a detailed understanding of how tDCS affects motor areas in the brain. We propose using tDCS while recording directly from motor cortex using subdural electrocorticography (sECoG) in patients undergoing deep brain stimulation surgery. We expect this novel approach to broaden our understanding of tDCS application and possibly lead to therapeutic advances in this population.

An investigator initiated pilot study of transcutaneous auricular vagal nerve stimulation (taVNS) in mild to moderate Parkinson's disease (PD).

We will assess whether nerve stimulation done on the surface of the skin, (called transcutaneous vagus nerve stimulation (taVNS)) is safe and effective in people with Parkinson's Disease (PD). A small electrical stimulator will be used to deliver electric pulses to a small portion of the left ear of the study participants. Participants will be assigned by chance to either 2 weeks of treatment with real taVNS, or a sham stimulation. The investigator will rate PD motor and cognitive symptoms before, during, and after the 2-week cycle. The investigators will also perform a number of blood and eye movement tests to check for the effectiveness of the stimulation, and perform regular safety checks.

This is an exploratory study and the information obtained may lead to new findings regarding the inflammatory and neurodegenerative mechanisms in the progression of PD and help to develop new drugs to halt the disease progression. The study simply involves a one time blood draw.

We will ask 80 patients with Parkinson's disease, representing the full spectrum of motor and cognitive symptoms, to participate. Participation will include measurement of eye movements using two methods: the new computer-based saccade battery and the best available video-based eye-tracking equipment. The evaluation will be repeated about 30 days later. Data will be analyzed to determine whether the computer-based tasks are reliable and able to provide the same quality of information as the gold standard in eye-tracking. A comparison sample of 80 healthy older adults will also complete the behavioral saccade tests in order to establish normative data that will enable application in clinical settings.