Spinal DiseasesSpinal Cord InjuriesSpinal NeoplasmsIntervertebral Disc DegenerationSpondylitis, AnkylosingSpinal CordLumbar VertebraeCordotomyMuscle SpasticityChronic DiseaseInjections, SpinalAnterior Horn CellsSpasmParaplegiaQuadriplegiaReflex, AbnormalElectromyographyDecerebrate StateSpinal Cord DiseasesSpinal Nerve RootsMotor NeuronsReflexZygapophyseal JointSpineSacrumUrinationThoracic VertebraeUrinary BladderLocomotionBack PainWheelchairsSpinal NervesCatsAnesthesia, SpinalCervical VertebraeTailLumbosacral RegionUrinary Bladder, NeurogenicInjections, EpiduralSpinal Cord NeoplasmsRats, Sprague-DawleySpinal CanalPain ManagementMononeuropathiesSpinal Cord CompressionRecovery of FunctionElectric StimulationElectric Stimulation TherapyHindlimbSpinal StenosisSpinal FusionNerve Block5-HydroxytryptophanPain