Chinese Medical Journal (Chin Med J 2003; 116(10)).

Decompression: To ensure that improvement was not merely due to surgery-associated decompression, patient MRIs had to indicate the absence of compression before surgery. In addition, the cord must have some structural continuity through the injury site, the situation for most individuals with SCI.

Patient Demographics: Huang’s study included 139 men and 32 women, of which 114 were quadriplegics and 57 paraplegics. Ages ranged from 2 to 64 (average 35) years, and the interval between injury and admission varied from 6 months to18 years.

Cell Transplantation: Olfactory-bulb OECs are grown in culture media for several weeks before transplantation. After the spinal cord has been exposed through a limited laminectomy, 500,000 cells are injected above and below the injury site. These cells presumably migrate to the injury site. Animal studies suggest that the OECs survive better when they are not directly injected into the injury site.

Functional Assessment: Function was assessed before and 2-8 weeks after surgery using the “gold standard” ASIA (American Spinal Injury Association) impairment scales, which include motor-function, light-touch, and pin-prick scores.

Results: Improvement was noted for each of these scores in five age categories (<20, 21-30, 31- 40, 41- 50, and >50). Interestingly, even though it is often assumed that regenerative potential is better in the young, pin-prick improvement was greatest for the 50+ category.

Possible Mechanisms:

Patients are often regaining some sensory and motor function soon after surgery. The study design specifically eliminated spinal-cord decompression as a possible cause for this rapid functional improvement. Improvement is also too fast to be caused by neuronal regeneration or axonal remyelination.

Huang speculates that OECs wakeup quiescent neurons that still transverse the injury site, perhaps by altering the injury site’s environment through secreting growth factors and producing adhesion and matrix molecules.