Autonomic DysreflexiaSpinal Cord InjuriesQuadriplegiaAutonomic Nervous System DiseasesReflex, AbnormalIntracranial Hemorrhage, HypertensiveParaplegiaAutonomic Fibers, PreganglionicReflexGalvanic Skin ResponseDoxazosinRectumUrodynamicsThoracic VertebraeAfferent PathwaysBlood PressureAdrenergic alpha-AntagonistsCervical VertebraeReceptors, Adrenergic, alphaColon