Decompression for botulinum toxin-exacerbated cervical myeloradiculopathy in the setting of congenital stenosis and Arnold-Chiari I malformation.

[INTRODUCTION] We present a case describing the management of a woman with severe, functionally limiting cervical myeloradiculopathy in the setting of congenital cervical canal stenosis and Arnold-Chiari I malformation.

[CASE PRESENTATION] The subject is a 57-year-old woman with prior anterior cervical discectomy and fusion who presented with left-sided neck pain associated with radiculopathy, migraine, gait incoordination, and cervical dystonia. Cervical stenosis and Chiari malformation were confirmed using MRI. Conservative management with botulinum toxin, oral muscle relaxants, and cervical brace led to gradual exacerbation of symptoms. Due to failure of conservative management, surgical decompression with C3-C6 posterior laminoplasty was performed, resulting in complete resolution of all symptoms and markedly improved quality of life.

[DISCUSSION] This case reports a severe and nonspecific presentation of cervical myeloradiculopathy. Surgery for cervical myeloradiculopathy is controversial, and conservative therapy is initially preferred. However, in this case, conservative treatments likely led to paraspinal weakness, cervical hypermobility, and biomechanical instability, resulting in exacerbation of symptoms. Stretch/shear forces have been postulated to accelerate cervical myelopathy, and excessive cervical instability and range of motion are significant predictors of deterioration. In this case, surgical decompression with posterior cervical laminoplasty after 1 year of conservative management yielded significant pain relief and functional restoration, indicating the utility of this procedure even in the presence of Arnold-Chiari I malformation. This case illustrates that decompression can be effective for refractory cervical myeloradiculopathy associated with Chiari malformation, congenital stenosis, and prior anterior instrumentation, and highlights the potential risks of prolonged conservative management.