Risk factors and surgical treatment of craniovertebral stenosis in patients with Maroteaux-Lamy syndrome (Mucopolysaccharidosis type VI)

Abstract

Introduction. Atlantoaxial instability with the outcome of myelopathy and spastic tetraparesis are commonly described in patients with MPS VI type. The accumulation of glycosaminoglycans behind the odontoid process leads to a gradual development of the spinal canal stenosis and compression of the spinal cord in the cervical spine. These lesions lead to neurological disorders and loss of quality of life. Methods. Nine patients with MPS type VI. Of them 3 males and 6 females aged 14 to 35 years (mean age 20.8 years). All patients presented with craniovertebral stenosis of some degree and underwent posterior spinal canal decompression with cervical fusion. Neurological symptoms were observed in 7 of all cases preoperatively. Functional assessment and evaluation of neurological status was conducted in all cases. CT and MRI evaluation was performed at the atlantoaxial level before surgery and at follow-up. Results. The average follow-up period was 2.9 years. Seven of the nine patients demonstrated regression of neurological symptoms. In two patients the neurological status was unchanged. Solid fusion was achieved in 6 cases. Complications from surgery we observed in 3 patients. One patient died one year after surgery due to unrelated causes, there was one case of pseudarthrosis one case of implant instability and one case of early postoperative wound suppuration. Conclusion. The majority of patients with type VI MPS present with some degree of spinal stenosis at the atlantoaxial level. Based on our experience, these patients require close neurological and radiographic monitoring as early as possible. In our view, surgical treatment of patients with type VI MPS should be considered before the onset and progression of neurological symptoms.