Severe cervical kyphosis in a complex child with NF1, case report and literature review

Abstract

Purpose: We faced and herein report a detailed description of pre-operative assessment, management, and post-operative follow-up of a 2-year and 10-month-old girl with neurofibromatosis 1 (NF1) who presented with severe, dystrophic, cervical kyphosis (170 degrees) associated with extensive pre- and para-vertebral plexiform neurofibromas, who also went under MEK inhibitors therapy. Cervical kyphosis in NF1 is particularly rare, and there is no extensive literature available on the subject in terms of clinico-radiological features, surgical approach, and outcomes. We therefore also performed a comprehensive review of the available literature on the topic.

Methods: The clinical report was made through the retrospective review of all medical documents and imaging of the patient. The systematic review was performed based on the inclusion and exclusion criteria set by the authors on surgical management of cervical kyphosis in NF1 patients according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Results: Our patient underwent a first-stage halo-gravity traction followed by a single-stage occipito-cervical posterior fusion. The six-week traction resulted in a reduction of the deformity from 170 to 90°. A further amelioration was obtained by surgery with a final 60% correction of the curvature (69° at last post-operative X-ray). No complications were observed at 1-and-a-half-year follow-up. The plexiform neurofibromas were treated with MEK inhibitors: trametinib for 1 year and 11 months until performing halo traction, and with selumetinib after surgery. We just found 19 papers suitable according to our selection criteria.

Conclusion: Combined anterior and posterior fusion (CAP) is generally the best treatment option, although it is not always feasible. When plexiform, symptomatic, inoperable neurofibromas coexist, surgery can be preceded or followed by MEK inhibitor treatment for better control or a volumetric reduction of the tumors. The best therapeutic choice should always be the result of a multidisciplinary, expert approach and patient-tailored design.

Keywords: IMEK; Kypho-scoliosis; Neurofibromatosis type 1; Plexiform neurofibroma.

Fig. 1

Imaging of the patient. A Pre-operative lateral view of the cervical spine. A severe kyphosis is demonstrated centered at C3. B CT scan reconstruction confirms the presence of dystrophic changes of the cervical vertebrae. C CT scan view of the right-sided facet joints shows dystrophic changes but no dislocation of the facets. D CT angiogram shows normal representation of the two vertebral arteries. E CT scan 3-D reconstruction of cervical spine deformity. F MRI scan shows tenting of the spinal cord around the kyphosis apex; the patient had no neurological deficits before surgery. G Axial image of the MRI confirms tenting and compression of the spinal cord at the apex of the kyphosis. H MRI axial image showing the extensive pre-vertebral neurofibromas (red arrow) encasing major blood vessels of the neck. The extensive neurofibromas present in the front of the spine made the anterior approach not feasible in this patient. I MRI sagittal view confirms the presence of extensive pre-vertebral neurofibromas (red arrow)

Fig. 2

Progressive correction of the deformity. X-ray of the column before traction (A); soon after the traction procedure, an immediate reduction of the kyphosis was achieved (B); 6 weeks after traction (C). The patient is in traction on the surgical bed (D). Further traction under anaesthesia showed further improvement and correction of the kyphosis (E). Post-operative radiological X-ray (F)

Fig. 3

Literature review