Fibrocartilaginous embolism of the posterior spinal artery: A case report regarding the responsible intervertebral disc on magnetic resonance imaging.

INTRODUCTION: Fibrocartilaginous embolism (FCE) of the spinal cord is an ischemic myelopathy caused by rupture of the intervertebral disc and subsequent entrance of the nucleus polposus material into the nearby vasculature. However, responsible disc lesions frequently cannot be determined, which may cause diagnostic difficulty.

CASE PRESENTATION: A 63-year-old man suddenly felt a strange sensation in the lower limbs and noticed that he could not walk. The patient was brought to our hospital, where he was hospitalized. On neurological examination, his proprioception and vibratory sense were disturbed in the lower limbs. Spine magnetic resonance imaging (MRI) revealed a hyperintense cord lesion located at the C4-5 vertebral level of the posterior spinal artery region on diffusion-weighted sequence. He was diagnosed as having spinal cord infarction and treated with antiplatelet medication. Follow-up MRI was performed 5 days later, which displayed a collapsed C3/4 disc and a defected C4 vertebral body that were not evident on earlier MRI. These findings suggested the disc lesion was active and responsible for the infarction, leading to the diagnosis of FCE. The patient gradually improved and had no gait difficulty at the time of discharge.

DISCUSSION: In the presented case, MRI did not reveal the responsible disc lesion when the diagnosis of spinal cord infarction was made; however, it became evident 5 days later. Although such a disc signal change within several days has not been described as a clue suggesting FCE, follow-up MRI with a relatively short interval may elucidate the responsible lesion and correct diagnosis.