Sometimes, it is necessary to re-learn a previously learned movement behavior, for example, a bad posture during the golf drive or while playing the piano. Unlearning or relearning an intensively trained behavior is particularly important if the behavior is hampering recovery, for example, in chronic pain or after a stroke. With this study, we experimentally test the brain mechanisms that control the change of pre-existing stable memories of a motor skill with electroencephalography (EEG). We will then use non-invasive brain stimulation to modulate these brain mechanisms and test if it is possible to change the pre-existing motor memory and the learning of a new motor skill.

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.

This study is for patients with recurrent/progressive medulloblastoma, which is a type of childhood brain tumor. Participants in this study will receive intravenous (IV, into the veins) bevacizumab and intrathecal (into the spinal fluid) or intraventricular (into the fluid surrounding the brain) etoposide and cytarabine in combination with five oral (taken by mouth) chemotherapy drugs as a possible treatment for recurrent/progressive medulloblastoma. Total study duration is about 1 year and depending on how well a participant tolerates the medications and the response of the disease, the patient may continue the treatment after the first year.

The purpose of the first portion of this study is to gather feedback from clinicians on the usability of the current system and procedure, so the researchers can make reflex training more useful and usable for improving recovery after spinal cord injury or other nervous system injuries and diseases. The researchers are recruiting 20 therapists who have been actively practicing physical medicine and 30 adults with no known neurological conditions to test system usability and the reflex operant conditioning protocol. For this portion of the study, there are 5 visits. We will also recruit 15 adults with no neurological injuries, 15 adults with neuropathic pain, and 15 adults with non-neuropathic pain to participate in one visit to provide feedback on sensation caused by stimulating electrodes.

The purpose of the second part of the study is to validate the capacity of the system to change the size of the targeted reflex. For this the researchers are recruiting 25 individuals with chronic incomplete SCI who have spasticity in the leg to participate in the reflex training procedure. The study involves approximately 45 visits with a total study duration of about 6 months.

The study team is recruiting 20 adults with spasticity due to chronic stroke and 20 adults with no neurological injuries for a 4 day study over 1 week. In people with chronic stroke, one of the most common and disabling problems is spasticity (increased muscle tone or muscle stiffness). The purpose of this research study is to examine effects of dry needling on the nervous system (pathways between the muscle, spinal cord, and brain) in people with spasticity due to chronic stroke. Dry needling is a procedure in which a thin, stainless steel needle is inserted into your skin to produce a muscle twitch response. It is intended to release a knot in your muscle and relieve pain.

The total study duration is 4 visits over one week. The first visit will take about 1.5 hours, during which the study team will determine the best electrode placement and create a removeable cast of your arm or leg to aid in placing electrodes in the next visits. The second visit will take about 3 hours, during which dry needling will take place, and the fourth and fifth visits will take about 1.5 hour. During all visits you will be asked to participate in examinations of reflexes (muscle responses to non-invasive nerve stimulation) and arm/leg function.

We are currently recruiting volunteers who are interested in participating in a brain-spinal cord-muscle response training study that aims to better understand the changes that take place in the nervous system as a result of this type of training. After spinal cord injury, brain-to-muscle connections are often interrupted. Because these connections are important in movement control, when they are not working well, movements may be disturbed. Researchers have found that people can learn to strengthen these connections through training. Strengthening these connections may be able to improve movement control and recovery after injuries.

Research participants will be asked to stand, sit, and walk during the study sessions. Electrodes are placed on the skin over leg muscles for monitoring muscle activity. For examining brain-to-muscle connections, we use transcranial magnetic stimulation. The stimulation is applied over the head and will indirectly stimulate brain cells with little or no discomfort.

Participation in this study requires approximately three sessions per week for four months, followed by two to three sessions over another three months. Each session lasts approximately 1 hour. Participants will receive a mileage reimbursement.

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.

Older adults typically have trouble identifying the speech they hear, especially in noisy environments. Fortunately, compared to younger adults, older adults are better able to compensate for difficulties identifying the speech they hear by recruiting the visual system. However, the extent to which older adults can benefit from visual input, and how this influence relates to age-related changes in brain structure and function, have not been thoroughly investigated. The general purpose of this study is to determine how age-related changes in brain structure and function affect how well people hear and see. This study seeks participants with normal hearing to mild hearing loss, who also have normal or corrected-to-normal vision.