PMC5498211_01
Cervical CT reconstruction images (lateral view [a] and anterior view [b]). The cervical vertebrae were twisted, and scoliosis, kyphosis, and disc-space narrowing of the C2/3, C3/4, C5/6, and C6/7 were evident. A coronal cervical MRI T2-weighted image (c) and sagittal cervical T1-weighted images (d, e). The cervical spine was rotated, and the spinal cord was compressed at the level of C3-C4.
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C2 to C6 vertebral levels with kyphotic deformity. Coronal and sagittal computed tomography (CT) reconstruction images of the cervical spine showed cervical scoliosis, kyphosis, and disc space narrowing at the C2/3, C3/4, C5/6, and C6/7 intervertebral levels (Fig. 1a and b). Magnetic resonance imaging (MRI) performed under sedation revealed cervical scoliosis with severe focal compression of the cord at the C3-4 vertebral level (Fig. 1c, d and e).
The external appearance of the cervical spinal cord (ventral view [a] and dorsal view [b]). Oblique indentation was observed on the ventral surface of the cord at the lower C4 segment (arrow), and a dent was also observed on the right dorsolateral side (arrowhead). The ventral roots of the right C4, bilateral C5 and the dorsal roots of the right C4 appeared atrophic and brownish in color.
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After the removal of the cervical vertebrae, the external appearance of the ventral surface of the cervical cord revealed a linear indentation, running obliquely at the level between the C4 and C5 segments (Fig. 2). The ventral roots of the right C4, bilateral C5 and the dorsal roots of the right C4 appeared atrophic and brownish in color (Fig. 2).
A cross-section of the spinal cord at the upper C4, C4, upper C5, lower C5, C6, T5 and L4 segments. The C4 segment showed marked ventral indentation and a decrease in both the sagittal and transverse diameters. In this section, the atrophy of the gray matter was more prominent than the atrophy of the white matter, and anterior horn cells were almost completely absent. The lateral funiculi were severely damaged; the degree of damage was greater on the right side than on the left. The bilateral corticospinal tracts showed more marked secondary descending degeneration down to the lumbar segments on the right side than on the left. The right dorsal root showed pallor at the level of the indentation (arrow). At the upper C4 segment, above the most severely affected segment, the bilateral cuneate fasciculi showed pallor, which was considered to be secondary ascending degeneration caused by the primary lesions of the dorsal horn and dorsal roots at the lower segments (Kluver-Barrera staining, scale bar=1 mm).
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At the C4 segment, which showed severe indentation, the spinal cord was deformed and atrophic, and was surrounded by dense fibrous tissue (Fig. 3). At the upper C4 segment, above the most severely affected segment, the bilateral cuneate fasciculi showed pallor, which was considered to represent secondary ascending degeneration due to the primary lesions of the dorsal horn and dorsal roots at the lower segments (Fig. 3).
The histological findings of the right lateral funiculus at the C4 segment. The right lateral funiculus was severely damaged with reactive gliosis and capillary proliferation (a). Clusters of oligodendrocytes were conspicuous, as demonstrated by immunohistochemical staining (a, inset). An epon-embedded semi-thin section stained with toluidine blue (the area corresponds to panel a) revealed a marked decrease in the population of myelinated fibers and clusters of oligodendrocytes were often associated with small myelinated axons. Thinly myelinated fibers were also observed (arrows). a: Hematoxylin and Eosin staining, scale bar=100 microm, inset; Olig-2 immunohistochemical staining, scale bar=20 microm. b: An epon-embedded semi-thin section stained with toluidine blue, scale bar=10 microm.
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Numerous clusters of oligodendrocytes were demonstrated immunohistochemically by Olig-2 in the affected lateral funiculus (Fig. 4a). The epon-embedded semi-thin sections showed markedly decreased numbers of myelinated fibers and thinly myelinated axons around the damaged region (Fig. 4b).