Abstract
We observed a case of brainstem and cerebellar infarction that was thought to have been caused by methylpredonisolone suspension (Depo-Medrol®) used for cervical nerve block. The patient was a 57-year-old women. She was referred from a local clinic to our department for nerve root block due to increased radicular pain at the C6/C7 level caused by cervical intervertebral disk hernia (C5/6, C6/7). We attempted nerve root block under X-ray visualization. Since no vascular shadow was shown by contrast medium and the C6 nerve root sheath was depicted, 1 ml of a mixed solution of 0.75% ropivacaine plus 1 ml of methylprednisolone suspension (40 mg/ml) was injected. No abnormality was noted, and a further 0.5 ml was injected. However, within 30 seconds the patient lost consciousness and stopped breathing. Since magnetic resonance imaging performed 7 hours later showed an infarct of the cerebellum and brainstem and impending herniation, external and internal decompression and ventricular drainage were performed. Intraoperative findings and postoperative CT findings ruled out the possibility of a dissecting aneurysm. The infarct was thought to have been caused by complications arising from retrograde flow of the methylprednisolone suspension from the radicular artery into the left vertebral artery area. Therefore we think that corticosteroid suspensions should not be used for cervical nerve root block.
