Epidural and Subdural Infections
epidural & subdural spaces can be involved by bacterial or fungal infections, u as a consequence of direct local spread. Epidural abscesses arise from an adjacent focus of infection, such as sinusitis or osteomyelitis. When abscesses occur in the spinal epidural space, they may cause spinal cord compression and constitute a neurosurgical emergency. Infections of the skull or air sinuses may also spread to the subdural space, producing subdural empyema. The underlying arachnoid and subarachnoid spaces usually are unaffected, but a large subdural empyema may produce a mass effect. In addition, thrombophlebitis may develop in the bridging veins that cross the subdural space, resulting in venous occlusion and infarction of the brain. Most patients are febrile, with headache and neck stiffness, and if untreated may develop focal neurologic signs referable to the site of the infection, lethargy, and coma. With treatment, including surgical drainage, resolution of the empyema occurs from the dural side; if resolution is complete, a thickened dura may be the only residual finding. With prompt treatment, complete recovery is usual.