Spinal DiseasesSpinal NeoplasmsIntervertebral Disc DegenerationSpondylitis, AnkylosingSpinal CordLumbar VertebraeSpinal Cord InjuriesSciatic NerveSpinal NervesPeripheral NervesSpinal Nerve RootsNerve FibersOptic NerveNerve RegenerationInjections, SpinalSpinal Cord DiseasesAnesthesia, SpinalNerve BlockSpinal Cord NeoplasmsSpinal CanalPeripheral Nerve InjuriesNerve EndingsSural NerveTibial NerveMedian NerveSpinal Cord CompressionNerve CrushFacial NerveUlnar NerveSpinal StenosisFemoral NerveSpinal FusionGanglia, SpinalMotor NeuronsNerve Growth FactorsPhrenic NerveTrigeminal NerveNerve Growth Factor