Most preclinical data providing the rationales for clinical trials in SCI
are based on:
Effects on embryonic neurons and axon growth cones in cell culture,
which may not be a relevant model for regeneration of mature CNS
Effects on hemisection or contusion models of partial spinal cord injury,
in which assessment of regeneration is often ambiguous
Experiments in rodents, which may not provide the scale of required
regeneration distances to assess efficacy in humans
Nevertheless, after many years of basic research, clinical trials for
spinal cord repair are now under way.
Most trials are for neuroprotection.
Even when there is a
regeneration rationale, as in activated macrophages and Rho
inhibitors, the strongest evidence is still for neuroprotection.
Bioethics of highly invasive procedures are being addressed
vigorously in the scientific community.