ChordomaSpinal CordSpinal Cord InjuriesSpinal NeoplasmsSkull Base NeoplasmsSacrumSpinal Cord DiseasesSpinal Cord NeoplasmsCoccyxSpinal Cord CompressionSacrococcygeal RegionSpinal Cord IschemiaCranial Fossa, PosteriorInjections, SpinalChondrosarcomaParaplegiaSpinal Nerve RootsCervical VertebraeSkull NeoplasmsSpinal NervesThoracic VertebraeMotor NeuronsLaminectomySpinal Cord RegenerationChondromaSpinal CanalAnesthesia, SpinalQuadriplegiaMagnetic Resonance Imaging