Spinal Nerve RootsSpinal NervesPeripheral Nervous System NeoplasmsNerve Compression SyndromesSpinal CordLumbosacral RegionRadiculopathyLumbar VertebraeSpinal CanalNeuralgiaSpinal Cord InjuriesInjections, SpinalMagnetic Resonance ImagingSemicircular CanalsSciatic NerveSciaticaPeripheral Nerve InjuriesLigationPeripheral NervesLumbosacral PlexusEar CanalGanglia, SpinalHyperalgesiaPeripheral Nervous System DiseasesCauda EquinaIntervertebral Disc DisplacementNerve FibersRoot Canal PreparationNerve BlockSpinal StenosisSpinal Cord NeoplasmsCervical VertebraeRats, Sprague-DawleyPainSacrumMyelographyTooth RootPain MeasurementSpinal Cord CompressionEpidural SpaceRoot Canal IrrigantsLaminectomyPain ThresholdSpinal DiseasesSpinal Cord DiseasesOptic NerveDental Pulp CavityNerve RegenerationRoot Canal Filling MaterialsCervical PlexusMononeuropathiesSpinal NeoplasmsRhizotomyNeurons, AfferentLow Back Pain