The "hard" cervical disc, a bony ridge resulting from periosteal activity, usually occurs in the patient with a previous neck injury. The "soft" disc is the bulging or extruded disc itself, often manifested by acute radicular pain in the younger patient. Causes of spondylotic myelopathy include a congenitally narrow spinal canal, disc degeneration and impaired vascularity. Disc syndromes include dysphagia and vertebral artery compression.