[Anesthetic management of two patients with the history of SMON]

Patients of subacute myelo-optico-neuropathy (SMON) suffer from neurological disorders for a long time. The authors report anesthetic management of two patients with SMON. One patient was a 82-year-old woman suffering from SMON for 49 years. Sensory examination revealed numbness and hypesthesia in the both lower extremities. She underwent open reduction for femoral neck fracture. The other patient was a 91-year-old man suffered from SMON for 31 years. Sensory examination revealed weakness of leg muscles. He underwent transurethral resection of prostate. We chose general anesthesia for both patients instead of spinal anesthesia because of reported complications related to spinal anesthesia in patients with the disease. Intraoperative courses were uneventful and there were no neurological deteriorations postoperatively in both patients. One of the chief symptoms of patients with SMON is numbness of the lower extremity. Therefore patients of SMON may feel uncomfortable to the numbness by spinal or epidural anesthesia. This is the main reason we recommend general anesthesia for patients with SMON.