Allogenic Human Cord Tissue Derived Mesenchymal Stromal Cells(CBR Systems)

The purpose of this research study is to test the safety and benefit of a human cord blood derived stem cell infusion as a treatment for individuals with post COVID-19 neurological problems. Participants in the study will have 6 clinic visits over a 12 to 14 mo. period with each visit lasting 2 to 6 hours. Participants will receive 1 stem cell infusion at study visit #3. Participants will have a brain PET and MRI scan at the baseline and 6mo. post-infusion visits. Follow-up safety assessments will be conducted at 6mo. and 1yr. after the stem cell infusion.