Cervicothoracic Kyphosis and Spinal Cord Compression in Hurler Syndrome.

Abstract

Introduction: Hurler syndrome is characterized by significant spinal abnormalities, including cervical instability, odontoid dysplasia, and spinal cord compression. Spinal compression and kyphosis at the cervicothoracic (C-T) junction are also observed but less commonly reported. The present study was conducted to determine the prevalence of C-T kyphosis and spinal cord compression at the C-T junction in patients with Hurler syndrome. In addition, we aimed to evaluate the significance of C-T kyphosis and spinal cord compression in these patients in terms of clinical symptoms or neuromonitoring changes in nonspine surgery.

Method: This retrospective case series examines patients with Hurler syndrome at a single pediatric institution from 2009 to 2023, with 47 included based on available spinal MRIs. Radiographic assessments included the C6-T4 kyphosis, maximal C-T kyphosis, and spinal cord compression using Kang grading for stenosis. Follow-up MRIs tracked changes in C-T kyphosis and new spinal cord compression. The value of C-T kyphosis associated with spinal cord compression (Kang grades 2 and 3) was determined using receiver operating characteristic (ROC) analysis. IONM data, including SSEP and TcMEP, were reviewed for significant changes during surgeries unrelated to the spine.

Results: This study involved 47 patients with an average age of 5 years and 57% male. Initial MRI showed a mean C-T kyphosis of 17 degrees, primarily affecting C7-T3. Follow-up MRIs revealed progressive C-T kyphosis and spinal cord compression. A C-T kyphosis >20 degrees was associated with Kang grade 2 spinal cord compression. IONM during nonspine surgeries identified significant changes in 3 patients. One patient developed postoperative paraplegia following hip surgery performed without IONM. A retrospective review of a prior airway MRI showed a C-T kyphosis of 49 degrees along with spinal canal stenosis.

Conclusions: The manuscript sheds light on the intricate nature of C-T kyphosis in individuals with Hurler syndrome. While the clinical significance and optimal management of this condition are still under discussion, the study underscores the importance of evaluating C-T kyphosis to guide surgical planning and reduce the risk of spinal cord injury in affected patients.

Level of evidence: Case series, Level IV.