Pain and spinal cysts in paraplegia: treatment by drainage and DREZ operation

About 10% of paraplegics suffer from intractable pain. The onset of pain may be immediate or delayed for months to several years after the injury. The delayed onset of pain is highly suggestive of the development of a spinal cyst. This is a report of 18 paraplegics who developed a delayed onset of intractable pain who were found at the time of surgery to have associated spinal cord cysts. Treatment consisted of the dorsal root entry zone (DREZ) operation in addition to evacuation of the cyst. Burning pain was the most common complaint occurring years after the trauma. In this study we compared the relationship between the onset and character of the pain, the time of the spinal injury, the operative findings, and the results of the DREZ procedure and evacuation of the traumatic spinal cyst. We believe that the combination of paraplegia, pain and spinal cyst has not been emphasized in the neurosurgical literature although it is well known that cystic formation can follow spinal trauma. Two patients developed spinal cysts with nontraumatic lesions of the spinal cord. A single cyst was found in 14 patients while four had two separate cysts. The diagnosis was made on the basis of history and clinical examination with radiographic confirmation using delayed CT scan and myelography and more recently magnetic resonance imaging. Intraoperative ultrasound was employed in the study of some patients. All patients were treated with combined DREZ lesions and evacuation of the cysts with good pain relief in 77.7%.