Plasticity of the Dorsal Root Ganglion, Clinical Characteristics, and Treatment After Plexus Injury in Patients

Plexus injury occurs after traffic accidents mostly in male young working patients. It immensely affects the patients’ life in every aspect including work, career, social life, and emotional well-being. Dr. Rittner will review current treatment of plexus injury including physiotherapy, nerve grafting, and antineuropathic medication, although the latter is often ineffective. In her current study, she phenotyped patients after plexus injury and analyzed their avulsed dorsal root ganglia (DRG) shortly after injury (mean 4 m) and compared these to postmortem DRGs. Patients (80% males, mean age 33 y) suffered from moderate-high pain (mean NRS 4.4, max 7.3), substantially reduced function (DASH 73/100), but moderate scores for neuropathic pain (30/100). Analysis of DRGs documented a variable degree of neuronal loss – dependent on the extend and duration of injury. Immunoreactivity of GFAP and ApoJ was detected in FABP7+ satellite glia as a sign of glia activation. Iba1+ cells surrounding neurons pointed towards putative the novel population of macrophages. In rodents, in vitro reprogramming of adult DRG-derived glia achieved 30% sensory neurons with functional nociceptor properties. Manipulating non-neuronal cells like satellite glia e.g., by in situ reprogramming or other pathways could lead to novel avenues to function recovery after dorsal root injury.