Physiological Effects of N-Acetyl Cysteine in Patients With Multiple Sclerosis

Inclusion Criteria:

• Clinical diagnosis of relapsing remitting MS or progressive MS who do not plan tostart a medication during the study, or on stable disease modifying medication (interferon, glatiramer, dimethyl fumarate, teriflunomide).

• Age 18 years old to no upper limit

• Physically independent, ambulatory

• Women of childbearing potential will confirm a negative pregnancy test and mustpractice effective contraception during the period of pilot study. In addition, malesubjects who have a partner of childbearing age should practice effectivecontraception.

• Participants must be able to complete study procedures in the greater Philadelphiaarea.

Exclusion Criteria:

• Patients are excluded who have received treatment with intravenous steroids withinthe past 90 days for reasons other than MS

• Previous brain surgery that would interfere with determination of cerebralmetabolism or structure on the FDG PET-MRI.

• Score on Mini-Mental Status examination of 20 or lower.

• Wheelchair-bound or bed-ridden, non-ambulatory.

• Intracranial abnormalities that may complicate interpretation of the brain scans (e.g., stroke, tumor, vascular abnormality affecting the target area).

• History of head trauma with loss of consciousness > 48 hours.

• History of asthma requiring daily medications for adequate management.

• Any medical disorder or physical condition that could reasonably be expected tointerfere with the assessment of MS symptoms, or with any of the study assessmentsincluding the PET-MRI imaging.

• Patients with evidence of a significant psychiatric disorder by history/examinationthat would prevent completion of the study will not be allowed to participate.

• Patients with current alcohol or drug abuse

• Pregnant or lactating women.

• Enrollment in active clinical trial/ experimental therapy within the prior 30 days.

• Pending surgery during the course of the study.

• Patients taking medications that might interact with NAC involved in this study willbe evaluated on a case by case basis by the PI or study physician. These medicationsinclude: Medications for high blood pressure; Medications that slow blood clotting;Medications for diabetes; Nitroglycerin.

• Patients with history of pulmonary hypertension.

• Any neurological, psychiatric, or medical condition that might affect thedistribution of the radiopharmaceutical in the body or brain (as determined byInvestigator)

• Currently using medications that might alter the distribution ofradiopharmaceuticals in - -the body or brain (as determined by Investigator)

• Patient exceeds the weight limit of the table

• Claustrophobia that would prevent completion of imaging studies

• Glucose level that would interfere with the FDG PET scan

• Any additional contraindications for MRI; Has metallic objects (e.g., pacemakers) inthe body