Dr Silver addresses the importance of applying strict inclusion criteria to investigate a homogeneous group of patients.

In our study, acute ischaemia of the spinal cord was based on an acute neurological deficit attributable to a non-traumatic spinal cord lesion and spinal computed tomography or magnetic resonance imaging findings that were typical for ischaemic lesions such as extrinsic or intrinsic cord compression. In addition, other possible causes were ruled out with CSF examinations.1

However, the diagnosis acute spinal cord ischaemia is often made when other causes are ruled out.2, 3 Unfortunately, as Silver already pointed out, a substantial number of patients with ischaemic SCI have an idiopathic origin.2, 4, 5, 6 Although other authors have pointed out that ischaemic myelopathy of idiopathic origin may have a more favourable evolution than other types,7, 8 this has not been confirmed in other studies.2, 4

Although we believe that idiopathic cases should not have been excluded in our study, we suggest that more studies are necessary to identify further possible causes for acute myelopathies.9 Based on these studies, stricter inclusion criteria for patients with acute spinal cord ischaemia can be adopted.