Study Settings

Enrollment occurred sequentially, in three cohorts of six patients each. Given the hazard of iatrogenic damage, a risk‐escalation paradigm was adopted ¹² for the number of injections and the amount of potential damage leading to neurological side effects. The first group comprised patients with severe lower limb disability (not‐ambulatory), that is, subjects with a lower risk of exacerbated weakness caused by the procedure: Given that the patients in this group showed no signs of iatrogenic damage following the transplant ⁸, the relevant regulatory bodies approved the recruitment of patients that displayed fair functional autonomy (i.e., ambulatory patients) into the second and third groups. A psychologist assessed the fitness of each patient soon after recruitment. A clinical interview and Minnesota multiphasic personality inventory 2 tests were used to ensure that the participants fully understood that this was a safety trial and that they were aware of all risks associated with the overall procedure.