1480. Anterior Cervical Discectomy and Fusion for Hirayama Disease: A Case Report and Literature Review

Authors: Yi-Hsuan Kuo, MD; Chao-Hung Kuo; Jau-Ching Wu; Wen-Cheng Huang (Taipei, Taiwan)

Introduction: Hirayama disease, a juvenile muscular atrophy of the distal upper extremity, is a rare form of cervical flexion myelopathy characterized by insidiously progressive weakness of the hands and forearm muscles. The pathognomonic finding is a markedly forward-shifted spinal cord during neck flexion, demonstrated by dynamic magnetic resonance images (MRIs). Methods: In this report, we describe a 31-year-old man who had classic radiological and clinical presentations of Hirayama disease. He underwent multi-level instrumented anterior cervical discectomy and fusion (ACDF) to keep his sub-axial cervical spine slightly-lordotic (non-flexion). Results: His motor evoked potential (MEP) amplitude improved immediately intra-operation, and there were improvements of myelopathy at 1-year post-operation. The postoperative dynamic cervical spine MRIs also demonstrated minimal cord compression and elimination of the venous plexus engorgement dorsal to the thecal sac. Conclusion: Although Hirayama disease is benign in nature and frequently self-limiting, multi-level instrumented ACDF could be a reasonable option of management.