Upper cervical myelopathy due to arachnoiditis and spinal cord tethering from adjacent C-2 osteomyelitis. Case report and review of the literature.

Myelopathy caused by a spinal cord infection is typically related to an adjacent compressive lesion such as an epidural abscess. The authors report a case of progressive high cervical myelopathy from spinal cord tethering caused by arachnoiditis related to an adjacent C-2 osteomyelitis. This 70-year-old woman initially presented with a methicillin-sensitive Staphylococcus aureus osteomyelitis involving the C-2 odontoid process. She was treated with appropriate antibiotic therapy but, over the course of 4 weeks, she developed progressive quadriparesis. A magnetic resonance image revealed near-complete resolution of the C-2 osteomyelitis, but new ventral tethering of the cord was observed at the level of the odontoid tip. She subsequently underwent open surgical decompression and cord detethering. Postoperatively she experienced improvement in her symptoms and deficits, which continued to improve 1 year after her surgery. To the authors' knowledge, this is the first reported case of progressive upper cervical myelopathy due to arachnoiditis and cord tethering from an adjacent methicillin-sensitive S. aureus C-2 osteomyelitis.