Researchers at the Medical University of South Carolina are studying speech and language in people with Parkinson's disease (PD), progressive supranuclear palsy (PSP), and multiple system atrophy (MSA), and in healthy adult volunteers. These conditions can change how a person speaks and uses language, and the changes may differ from one condition to another. The study uses a tablet-based set of short speech and language tasks, called SLANG, together with computer software that measures features of the recorded speech, such as pitch, timing, and word choice. Participants also complete standard speech, language, and thinking tests and a brief exam by a neurologist, which researchers compare against the tablet measurements. The purpose of this study is to gather early research data: to build a database of these measurements across the groups, to check whether the tablet captures them reliably, and to explore whether they differ between conditions. SLANG is not used to diagnose participants or to guide their medical care in this study. The long-term goal of this research is to develop a tool that could someday help clinicians recognize and tell these conditions apart earlier, but testing such a tool for diagnosis is beyond the scope of the current study.

This study aims to create a long-term Ehlers-Danlos syndrome (EDS) biorepository and clinical research database to support gene and biomolecular discovery. The repository will serve as a sustainable resource for advancing EDS-related research by collecting both clinical data and biological samples. Participants who consent will be included in the EDS registry, which stores demographic and operative information, contact details, and biological specimens for current and future studies. Enrolled patients may also choose to be recontacted for future research opportunities. The database will link participants across specialties using identifiers such as name, date of birth, and medical record number. Data collected will include information from electronic health records, such as clinical notes, diagnoses, medications, labs, imaging, anthropometric measures, and procedure reports.

In this study, we are testing whether a higher dose of a non-invasive brain stimulation technique, called transcranial direct current stimulation (tDCS), can be safely used in people with depression. Participants will come to the Brain Stimulation Lab and receive mild electrical stimulation through electrodes placed on their scalp.

The study begins with a safety run-in, where the first few participants will receive stimulation at gradually increasing levels (2, 4, and 6 milliamps) while being closely monitored. If no serious side effects are found, later participants will receive repeated 6 milliamp sessions for 5 days total. We will check skin comfort, mood, and overall tolerability after each session.

Individuals with chronic cervical spinal cord injury will complete a 10-week training protocol where they receive non-invasive brain stimulation and feedback on the size of the corresponding muscle response (wrist extensor). We will assess the impact of the brain stimulation training on 1) the brain-to-spinal cord-to-muscle connection and 2) motor functions of the arm and hand. Also, brain and spine magnetic resonance imaging will be collected before and after the training. The imaging measurements will tell us about how spinal damage, brain function, and brain structure relate to motor presentation and the response to the training.

Adherence to home exercise is important to achieve upper limb recovery after stroke. However, adherence is typically low. Therefore, a new home exercise program with an Apple Watch and iPhone app was created to improve adherence to upper limb exercises for stroke survivors at home. Participants will come to our lab to experience the new home exercise program. Participants who opt for home use will bring the device home to try the new home exercise program at home. The purpose of this study is for researchers to examine usability and feasibility of participants using the new home exercise program.

Persistent smell loss that can include diminished or distorted smell function is a common symptom of long COVID syndrome. There are limited treatment options for long COVID-related smell loss. Our study aims to determine the efficacy of two at-home treatments, smell training and non-invasive trigeminal nerve stimulation. This study requires participants to conduct daily at-home treatment sessions, attend three in-person study visits at the MUSC Department of Psychiatry and Behavioral Sciences, and complete electronic questionnaires over the 12-week trial, and again at the six-month timepoint. Participants in this trial may benefit directly with an improvement in sense of smell. However, participation may also help society more generally, as this study will provide new information about long COVID-related smell loss and its treatment.

EEG Substudy:

Long COVID syndrome has been associated with cognitive impairment and may be related to affected emotional regulation. This study will use a electroencephalography (EEG) to examine how the body and brain responses to emotional cues in participants who are currently undergoing treatment for COVID-related smell loss. Participation will aid in the understanding of how emotional processing in long COVID is impacted by treatment for related smell loss.

Blood Analysis Substudy:
Alzheimer's Disease can be precedented by other clinical disorders or neuropsychiatric symptoms. Due to the cognitive deficits that can affect those with Long COVID, this sub study will use a blood sample to investigate if there are blood based biomarkers for Alzheimer's in those who report Long COVID symptoms.

This study will examine how marijuana use can affect oral bacteria and brain health in people with HIV and without HIV. Early studies show that marijuana users have more oral bacteria than non-marijuana users. The increase in bacteria is believed to affect brain health. Participation in the study will be one visit. The visit will take approximately 120 minutes.

The purpose of this study is to develop and test if upper limb task practice and muscle activity training improve upper limb function in stroke survivors. Participants will be asked to come to the laboratory 3 times a week for 6 weeks to receive upper limb task practice and/or muscle activity training. Participants will also come to the laboratory for additional 3 visits for assessments of upper extremity function. The total duration of the study will be 2.5 months.

The purpose of this study is to examine the relationship between reflexes in the leg and the presence of neuropathic pain. The researchers are recruiting 30 individuals with spinal cord injury (SCI) total, 15 individuals with neuropathic pain due to SCI and 15 individuals without neuropathic pain. For this portion of the study, there are 2 visits. The first visit will examine cutaneous reflexes in the leg. During the second visit, the study team will assess sensation in the leg and administer questionnaires about pain, functioning, and quality of life.

The purpose of the second part of the study is to examine the effect of reflex training in the leg to decrease neuropathic pain. For this, the researchers are recruiting 15 individuals with neuropathic pain due to spinal cord injury to participate in the reflex training procedure. The study involves approximately 50 visits with a total study duration of about 6.5 months (3 months for baseline and training phases followed by 1 month and 3 month follow-up visits).

The purpose of this study is to examine the relationship between common clinical assessments and measurements of the function of brain-spinal cord-muscle connections. For examining brain-to-muscle pathways, we use a transcranial magnetic stimulator. This stimulator produces a magnetic field for a very short period of time and indirectly stimulates brain cells with little or no discomfort. We hope that the results of this training study will help us in developing therapy strategies for individuals, better understanding clinical assessments, and understanding treatments that aim to improve function recovery in people with SCI.

There are 2 aims for this study. The purpose of the first is to examine the relationship between assessments commonly used in therapy and doctor's offices (clinical assessments) and measurements of the function of brain-spinal cord- muscle connections. This will require 2 visits, and each visit will last approximately 2 hours.

The purpose of the second aim is to examine the effects of training on brain-spinal cord-muscle response. This will require 30 visits, and each visit will last approximately 1.5 hours.