Pain with no gain: Allodynia following neural stem cell transplantation in spinal cord injury

Co-transplantation of autologous bone marrow mesenchymal stem cells and Schwann cells through cerebral spinal fluid for the treatment of patients with chronic spinal cord injury: safety and possible outcome

“…As mentioned above, this subject perhaps is related to severity and chronicity of the lesions, as well as the stability of the patients' condition after enrollment in the study (at least 2 years after Table 3 Subjective changes in patients from 6 months before to 24 months after transplantation (every 6 months) Studies have shown that the cell transplantation strategy increases the risk of neuropathic pain related to aberrant regeneration of axonal damage. 23,24 In our study, neuropathic pain and muscle spasm increased in 50% of the patients, which is more than what has been observed in our study and other previous studies. 5,18 In accordance with a small number of patients and lack of a control group, we could not say with confidence that intrathecal administration of this mixture of cells may increase the risk of neuropathic pain or muscle spasm development.…”

Possible role of spinal astrocytes in maintaining chronic pain sensitization: review of current evidence with focus on bFGF/JNK pathway

“…Are astrocytes sufficient and required for chronic pain sensitization?-Spinal astrocytes appear to be sufficient to produce persistent pain. Implantation of neural stem cells into the injured spinal cord improves motor recovery and causes allodynia-like hypersensitivity of the forepaws (Hofstetter et al, 2005;Macias et al, 2006). Because most of the stem cells that are implanted in the spinal cord become astrocytes, implantation-induced allodynia is likely to be attributed to the action of astrocytes.…”

Neural Stem/Progenitor Cell Clones as Models for Neural Development and Transplantation

“…When C17.2 NSCs were transplanted into injured spinal cord, they primarily differentiated into astrocytes, which may result in sprouting of dorsal horn nocioceptive neurons and in turn allodynia of the animals. GDNF, when overexpressed in transplanted C17.2 cells, reduced nocioceptive fiber sprouting and allodynia to a certain extent suggesting a protective or analgesic effect of GDNF on injury-induced neuropathic pain (Macias et al, 2006). We have isolated cortical GABAergic interneuron progenitor clones from rat embryonic forebrains and demonstrated their restricted interneuronal differentiation in culture.…”