Anterior horn cell hyperintensity in Hirayama disease

(A) Abnormal kyphotic (straight) curvature of the cervical spine evidenced by dorsal aspects of the C3 through C6 vertebral bodies meeting a straight line (white) drawn from the dorsocaudal aspect of the C2 vertebral body to the dorsocaudal aspect of the vertebral body of C7. In addition, note the linear T2 intramedullary hyperintensity, representing atrophy and gliosis of the anterior horn cells (large arrow). (B) Transverse T2-weighted image demonstrating the owl eyes sign (hyperintensities in the anterior horns of gray matter), representing atrophy and gliosis of the anterior horn cells (white arrows)