[Long-term gadolinium-enhancement of cauda equina on MRI in a case of spinal cord infarction after epidural anesthesia].

A 49-year-old woman developed paraplegia 26 hours after appendectomy under epidural and general anesthesia. Systolic blood pressure fell to 85 mmHg for 25 minutes after epidural anesthesia, which was performed at the level of the L1/2 intravertebral space. Neurological examination revealed paraplegia and superficial sensory impairment below the level of the L 1 spinal cord. The bladder was atonic by cystometry. MRI showed gadolinium enhancement of the cauda equina extending over a long period (3 months) and spinal cord infarction. The infarction was at the level of 10th thoracic spinal vertebra to conus and was limited to the gray matter of the spinal cord. We consider that the reason for spinal cord infarction was prolonged hypotension of the patient, who was diabetic, hypertensive and hypercoagulopathic. The blood supply to the gray matter is mainly from the central artery which is derived from the anterior spinal artery, and the gray matter is particularly vulnerable to hypotension. Our hypotheses concerning gadolinium enhancement of the cauda equina are the following: 1) enhancement of the cauda equina was seen due to collateral formation after spinal cord infarction, and 2) long-term enhancement of the cauda equina was observed due to an ischemic lesion involving a large area.