A rare cause of neurological deterioration to complete paraplegia after surgery for thoracic myelopathy: a case report

INTRODUCTION: Progressive deterioration of neurological status post-thoracic myelopathy surgery after a clinically stable period is rare and can pose a diagnostic dilemma. We present our experience with such a case where all known etiologies were ruled out and the cause of deterioration could not be conclusively identified. The course was found to be similar to sub-acute post-traumatic ascending myelopathy (SPAM). However, the condition has only been described for traumatic injuries so far. CASE PRESENTATION: Our patient presented a history of back pain and associated gait instability for one and a half months. There was no history of trauma. Investigations suggested an Anderson-like lesion at T11–T12 with cord edema at the same level suggestive of instability. She underwent posterior stabilization T9 to L2 and laminectomy of T11 as well as T12 under neuromonitoring. The postoperative sequence of events included an episode of pyrexia on the fifth day of surgery, neurological deterioration from the seventh day of surgery proceeding to complete paraplegia by the fourteenth day, no response to steroid treatment and no signs of recovery till two years post surgery. MRI findings were suggestive of SPAM, and there was no evidence of infection. DISCUSSION: Ascending myelopathy is a potential but rare cause of delayed deterioration in neurological status after surgical intervention. MRI findings of cord edema extending more than four levels above the involved segments is a characteristic finding of the condition. Ascending myelopathy may lead to complete cord injury. The precise cause of the condition is unknown and prognosis remains poor.