Fig. 2

A Cervical alignment types (modified Toyama method [16]): A line connecting the midpoints of the inferior margin of C2 and the superior margin of C7 was constructed. Lordotic group: all centroids are anterior to the line and the distance between at least one centroid and the line is ≥2 mm; Straight group: the distance between the line and each centroid is less than 2 mm; Sigmoid group: some centroids are anterior to and some posterior to the line and the distance between the line and at least one centroid is ≥2 mm; Kyphotic group: all the centroids are posterior to the line and the distance between at least one centroid and the line is ≥2 mm. B The distribution of patients with DCM presenting different changes in DSSEPs in each cervical alignment type