Surgical management of cervical spine manifestations of neurofibromatosis Type 1: long-term clinical and radiological follow-up in 22 cases

Expression analysis of NF1-mutated alleles in a rare compound heterozygous spinal NF1 patient by digital PCR

BACKGROUD

Neurofibromatosis type 1 (NF1) is a heterogeneous neurocutaneous disorder. Spinal neurofibromatosis (SNF) is a distinct clinical entity of NF1, characterized by bilateral neurofibromas involving all spinal nerve roots. Although both forms are caused by intragenic heterozygous variants of NF1, missense variants have been associated with SNF, according to a dominant inheritance model causing haploinsufficiency. Most patients carry pathogenic variants in one of the NF1 alleles; nevertheless, patients with both NF1-mutated copies have been described. Interestingly, all NF1 variants carried by the known SNF compound heterozygotes were missense/splicing variants or in-frame insertion-deletions.

AIMS

To investigate whether there is a differential expression of NF1 variant alleles in an NF1 compound heterozygous SNF patient possibly contributing to clinical phenotype.

MATERIALS & METHODS

We performed an allele-specific expression study, by chip-based digital PCR, in an SNF family carrying two NF1 missense variants. We evaluated the expression levels of the two NF1-mutated alleles both carried by the compound heterozygous SNF patient and his relatives.

RESULTS

Both alleles were expressed at comparable levels in the patient and hyper-expressed compared to the wild-type alleles of healthy controls.

DISCUSSION

Here we provide new insights into expression studies of NF1-mutated transcripts suggesting that a novel pathogenetic mechanism, caused by gain-of-function variants, could be associated with SNF.

CONCLUSIONS

Further studies should be performed in larger cohorts, opening new perspectives in the NF1 pathogenesis comprehension.

Case report: Bilateral spinal neurofibromatosis

Spinal neurofibromatosis (SNF) is a rare form of Neurofibromatosis in which neurofibromas exist bilaterally throughout all spinal roots. Despite previous attempts made to characterize and classify the disease as a separate clinical form of the disease, the low incidence rate of the disease and scarcity of previous reports calls for further studies and reports to elaborate this clinical entity. The patient in this report was a 36-year-old man presenting with lower limb weakness, unsteady gait, and paresthesia. The patient also presented with multiple cutaneous café-au-lait spots, cutaneous neurofibromas, and a large neurocutaneous neurofibroma of right facial nerve. Magnetic resonance imaging (MRI) of spine revealed bilateral spinal neurofibromas across all spinal cord roots. MRI study of head revealed no abnormalities in the brain and optic tract. The patient fulfilled both NIH criteria as well as revised criteria for NF1. Despite total spinal cord involvement, surgical intervention was withheld from the patient due to high propensity of recurrence as seen with previous attempts in removing peripheral neurofibromas, slow progression of symptoms, and lack of significant pain and impairment. SNF is often described as a form of disease with infrequent presentation of classical NF1 symptoms other than spinal tumors. The case presented here however, presented with several cutaneous neurofibromas and café-au-lait spots. Considering the positive outcome of surgical intervention in a few other reports, the decision to surgically intervene should be left to the clinical judgement of the participating surgeon, patient preference and socioeconomic background in a case-by-case manner.

Spinal manifestations of Neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) patients may present a wide spectrum of spinal pathologies. Osseous changes may lead to severe deformities with significant implications on growth and quality of life. Neurogenic tumors and soft tissue abnormalities may cause neuropathic pain and dysfunction ranging from minor paresthesias to profound motor and sensory deficits. Advanced imaging such as whole-body MRI, and volumetric tumor burden assessment have an evolving role in the evaluation and follow-up of patients with high spinal tumor load. Novel biological agents that target the hyperactivated ras pathway are currently under investigation and are reshaping current and future treatment paradigms. Surgical interventions for benign and malignant tumors, as well as deformity correction remain pivotal in treatment frameworks and require careful assessment by a dedicated multidisciplinary team.

PURPOSE

In this manuscript we review the various spinal manifestations of NF1 patients, indication for surgical intervention and oncological treatments.

Atlantoaxial Dislocation Associated with Type 1 Neurofibromatosis: Case Report and Review of the Literature

BACKGROUND

Neurofibromatosis type 1 (NF-1) is an autosomal dominant genetic condition in which spinal deformities are commonly involved. However, atlantoaxial dislocation in NF-1 is extremely rare. A review of the English literature has identified only 10 cases in 8 reports. We report a rare case involving NF-1 associated with severe atlantoaxial dislocation.

CASE DESCRIPTION

A 22-year-old woman with NF-1 presented with progressive numbness in her left upper and lower extremities and gait difficulty for 2 months. She was treated with skull traction and partial reduction was achieved. Initial surgical strategy was posterior fusion using a screw-rod-wire construct, but significant bleeding was encountered during the surgery. To shorten the procedure time, a single sublaminar wire of the atlas was tied to the spinous process of the axis to accomplish the reduction and fixation. C1-C2 fusion was performed using iliac crest autograft. The patient had significant improvement of neurologic deficit after surgery. Due to relatively poor fixation provided by the wire, she was requested to rest in bed for the first 3 months and to wear a cervical orthosis for the next 3 months. Solid bony fusion was confirmed by radiologic examination at 18-month follow-up.

CONCLUSIONS

Atlantoaxial dislocation is a rare complication in NF-1 patients. Surgical reduction combined with fusion is essential for a good outcome. Spine surgeons should also be knowledgeable about the possibility of significant hemorrhage before surgery.

Advanced pharmacological therapies for neurofibromatosis type 1-related tumors

Neurofibromatosis Type 1 (NF1) is an autosomal dominant tumor-predisposition disorder that is caused by a heterozygous loss of function variant in the NF1 gene, which encodes a protein called neurofibromin. The absence of neurofibromin causes increased activity in the Rat sarcoma protein (RAS) signalling pathway, which results in an increased growth and cell proliferation. As a result, both oncological and non-oncological comorbidities contribute to a high morbidity and mortality in these patients. Optic pathways gliomas, plexiform neurofibromas and malignant peripheral nerve sheath tumor (MPNST) are the most frequent NF1-associated tumors. The treatment of these complications is often challenging, since surgery may not be feasible due to the location, size, and infiltrative nature of these tumors, and standard chemotherapy or radiotherapy are burdened by significant toxicity and risk for secondary malignancies. For these reasons, following the novel discoveries of the pathophysiological mechanisms that lead to cell proliferation and tumorigenesis in NF1 patients, emerging drugs targeting specific signalling pathways (i.e. the MEK/ERK cascade), have been developed with promising results.

Clinical and neuroradiological characterisation of spinal lesions in adults with Neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) manifests itself in many ways in the spine. This study aims to report the types of spinal lesions, clinical and demographic data in a large cohort from a complex NF1 centre. The characteristics of those with spinal neurofibromatosis, where neurofibromas are present on every spinal nerve root, were sought for comparison with the wider group of NF1 patients. This is a retrospective review of MDT minutes of 303 patients from a UK NF1 centre and the largest reported series of NF1 patients based on radiological data. Prevalence of each symptom and lesion was calculated and statistically significant associations were established. The most reported findings were cutaneous lesions (44.9%) and neurological deficit (27.4%). 28.4% had dural ectasia, 52.5% had some form of spinal deformity. 57.8% had spinal nerve root tumours, the most common of which were at C2. The most progressive lesions were spinal nerve root tumours (29.1%). The only statistically significant association found was between dural ectasia and spinal deformity (P < 0.003), where dural ectasia is associated with a 32.6% increase in spinal deformity incidence. This is the largest descriptive study of spinal lesions in NF1. Spinal tumours and spinal deformity are prevalent in NF1. The predilection of spinal tumours for flexible spinal regions suggests that repetitive movement might be an important factor in pathogenesis. Physicians and patients should be alert to the observation that although many spinal neurofibromatosis patients display no neurological deficit, they often have significant lesions which require monitoring and sometimes surgery.

The MEK inhibitor selumetinib reduces spinal neurofibroma burden in patients with NF1 and plexiform neurofibromas

BACKGROUND

Spinal neurofibromas (SNFs) in neurofibromatosis type 1 (NF1) can cause progressive spinal cord compression and neurological dysfunction. The MEK inhibitor selumetinib shrinks the majority of plexiform neurofibromas (PNs) in patients with NF1. We assessed the effect of selumetinib on SNF.

METHODS

Pediatric and adult patients with NF1 and inoperable PN participating in phase 2 studies of selumetinib for PN were included in this analysis if they had SNF and serial spine magnetic resonance imaging (MRI). Selumetinib was administered orally at the recommended dose of 25 mg/m2/dose twice daily (max 50 mg b.i.d.; 1 cycle = 28 days). We qualitatively assessed the effect of selumetinib on SNF-related spinal canal distortion, cerebrospinal fluid distribution, and spinal cord deformity on MRI.

RESULTS

Twenty-four patients (18 male), median age 16.9 years (range, 6.2-60.3), had SNF, 22 of which were associated with the same nerves as the target PN assessed on the clinical trial. Twenty patients had spinal cord deformity. Twenty-three patients completed at least 12 treatment cycles to date. Eighteen patients showed subtle to a marked improvement in SNF burden, 5 remained stable, and no worsening was observed during treatment.

CONCLUSIONS

This is the first study describing the effect of selumetinib on SNF. Of 24 patients, 18 exhibited some improvement of SNF burden on imaging. These findings suggest that selumetinib may prevent the worsening of cord compression, potentially reducing the need for surgical interventions in select patients or benefitting patients who do not have a surgical option. Prospective evaluation of the clinical benefit of selumetinib for SNF is warranted.

Surgical Management of "Kissing" Spinal Plexiform Neurofibromas in Neurofibromatosis Type 1 Patients

BACKGROUND

"Kissing" neurofibromas (KNs) are a unique group of spinal tumors found in neurofibromatosis type 1 (NF1) patients. These are bilateral neurofibromas that approximate each other at the same level, with significant impingement compression of the cord or thecal sac. The best management options and surgical strategies for NF1 patients with KN have not been standardized.

METHODS

We conducted a retrospective study evaluating adult NF1 patients with KN. All patients are followed routinely at the Gilbert Israeli NF Center. Patients' files were reviewed for natural history, imaging features, surgical technique, and surgical outcome.

RESULTS

Twelve patients with at least 1 pair of KN were identified (6 females). Median age at spinal presentation was 24 (range 17-48). KNSs were located at the cervical (n = 8) and lumbar (n = 8) region, with no thoracic involvement. Seven of the 12 patients were operated; all underwent surgery due to cervical compression with progressive myelopathy. Four patients remained asymptomatic during the follow-up period. Three patients underwent multiple operations. Operative outcome was favorable in 71% of patients, with marked overall motor improvement or stabilization of neurologic deterioration. Two patients who entered surgery with a low functional reserve deteriorated after surgery.

CONCLUSIONS

In our series, KN caused progressive cord compression in 7 of the 8 patients with cervical tumors. No intervention was needed for lumbar tumors. Cervical tumors should be followed closely, with a low threshold for intervention. NF1 patients harboring KN should be followed both clinically and radiologically for life.

Need for arthrodesis following facetectomy for spinal peripheral nerve sheath tumors: an institutional experience and review of the current literature

OBJECTIVE

Spinal peripheral nerve sheath tumors (PNSTs) are a group of rare tumors originating from the nerve and its supporting structures. Standard surgical management typically entails laminectomy with or without facetectomy to gain adequate tumor exposure. Arthrodesis is occasionally performed to maintain spinal stability and mitigate the risk of postoperative deformity, pain, or neurological deficit. However, the factors associated with the need for instrumentation in addition to PNST resection in the same setting remain unclear.

METHODS

An institutional tumor registry at a tertiary care center was queried for patients treated surgically for a primary diagnosis of spinal PNST between 2002 and 2016. An analysis focused on patients in whom a facetectomy was performed during the resection. The addition of arthrodesis at the index procedure comprised the primary outcome. The authors also recorded baseline demographics, tumor characteristics, and surgery-related variables. Logistic regression was used to identify factors associated with increased risk of fusion surgery.

RESULTS

A total of 163 patients were identified, of which 56 (32 had facetectomy with fusion, 24 had facetectomy alone) were analyzed. The median age was 48 years, and 50% of the cohort was female. Age, sex, and race, as well as tumor histology and size, were evenly distributed between patients who received facetectomy alone and those who had facetectomy and fusion. On univariate analysis, total versus subtotal facetectomy (OR 9.0, 95% CI 2.01-64.2; p = 0.009) and cervicothoracic versus other spinal region (OR 9.0, 95% CI 1.51-172.9; p = 0.048) were significantly associated with increased odds of performing immediate fusion. On multivariable analysis, only the effect of total facetectomy remained statistically significant (OR 6.75, 95% CI 1.47-48.8; p = 0.025).

CONCLUSIONS

The authors found that total facetectomy and cervicothoracic involvement may be highly associated with the need for concomitant arthrodesis at the time of index surgery. These findings may help surgeons to determine the best surgical planning for patients with PNST.

Early and Midterm Outcomes of Surgical Correction for Severe Dystrophic Cervical Kyphosis in Patients with Neurofibromatosis Type 1: A Retrospective Multicenter Study

OBJECTIVE

To evaluate the early and midterm outcomes of surgical correction for severe dystrophic cervical kyphosis in patients with neurofibromatosis type 1 (NF-1) and analyze the pathomechanics and the influence on surgical efficacy of related systemic skeletal dystrophy.

METHODS

Ten patients who underwent surgical correction for NF-1-related severe dystrophic cervical kyphosis were reviewed. Radiographic parameters, including local and global Cobb angle, sagittal vertical axis, and T-1 slope, were measured. The visual analog scale score, Japanese Orthopaedic Association score, Neck Disability Index, Patient Satisfaction Index, and complications were evaluated.

RESULTS

The average follow-up was 50.6 months. The local and global Cobb angle improved from the preoperative average of 82.0° and 54.9° to an average of 35.6° and 29.8°, respectively, at the time of final follow-up. The C2-7 sagittal vertical axis averaged 5.8 mm before surgery and 8.9 mm at the final follow-up. The average T1 slope was -12.3° before surgery and -1.6° at the final follow-up. The visual analog scale score, Japanese Orthopaedic Association score, and Neck Disability Index improved significantly, and the overall satisfaction rate was 90.0%. One death and 4 instrumentation failures occurred, 3 patients showed progression of the kyphosis, and 2 fusion failures were observed.

CONCLUSIONS

Surgical correction, specifically the combined anteroposterior procedure, is essential and effective for management of NF-1-related severe dystrophic cervical kyphosis. However, high incidences of instrumentation failure, kyphosis progression, and fusion failure were observed. NF-1-related continuous skeletal dystrophy caused by multiple metabolic factors remarkably affected the midterm outcomes. Early prevention and targeted pharmacotherapy may be necessary.

Management of Cervical Instability as a Complication of Neurofibromatosis Type 1 in Children: A Historical Perspective With a 40-Year Experience

STUDY DESIGN

Literature review with supplementary case examples.

OBJECTIVES

The objective of this article was to review neurofibromatosis type 1 (NF1) and the associated spinal pathology with a focus on the disorder's manifestations in the immature cervical spine.

SUMMARY OF BACKGROUND DATA

NF1 is one of the most common inheritable genetic disorders. The disorder is associated with spinal deformities, long bone dysplasia, and osteoporosis. The manifestations of NF1 in the cervical spine commonly include instability secondary to kyphosis, neurofibromas, and dural ectasia.

METHODS

Literature relevant to the evaluation and management of NF1 in the cervical spine was reviewed using the PubMed/NCBI database with a focus on recent clinical studies. The review was supplemented with a historical perspective and patient cases.

RESULTS

The prevalence of NF1 cervical spine lesions is difficult to define because many patients may be asymptomatic. Symptoms of cervical kyphosis can include pain or nerve deficits but some have a surprisingly high tolerance for deformity and may have frank dislocation of one vertebral body over another (spondyloptosis) with few associated symptoms. Cervical radiographs should be obtained in patients requiring traction, surgery, or intubation, and those with neck pain or symptoms that suggest spinal neurofibromas. Patients with progressive symptoms should be offered surgery. Careful planning is required because many patients will have small, dysplastic vertebral bodies, thin posterior elements, plexiform neurofibromas, or dural ectasia. The decision to use preoperative traction will vary from patient to patient. Combined anterior-posterior fusion is recommended for most cases of severe symptomatic kyphosis, and the fusion should extend from parallel to parallel vertebrae (or six or more levels). Anterior or posterior fusion alone may be an alternative for skeletally mature patients with smaller, flexible curves.

CONCLUSIONS

Spinal deformity is the most common musculoskeletal manifestation of NF1. Cervical lesions are frequently asymptomatic, but patients with thoracolumbar scoliosis, dystrophic features, or a history of laminectomy should have the cervical spine carefully evaluated. For severe and progressive kyphotic deformities, most authors recommend a period of traction followed by a combined anterior-posterior fusion that is instrumented from parallel to parallel vertebra (or six or more levels). Close follow-up is very important because complications and progression are frequent.

C2 neurofibromas in neurofibromatosis type 1: genetic and imaging characteristics

OBJECTIVEC2 nerve root neurofibromas have been reported frequently in patients with neurofibromatosis type 1 (NF1), although their genetic and imaging characteristics are unexplored. The aim of this study was to characterize genetic and spinal imaging findings in a large cohort of NF1 patients with C2 neurofibromas.METHODSThe authors performed a review of national NF1 referrals between 2009 and 2016. Inclusion criteria were at least 1 C2 root neurofibroma and cervical-spine or whole-spine MRI scans available for analysis. Blinded imaging review was performed by a neuroradiologist with an interest in NF1.RESULTSFifty-four patients with 106 C2 neurofibromas were included. The median age was 32.5 years (range 15-61 years), and there were slightly more male patients (33 vs 21 female patients). Splice-site (30%) and missense (20%) variants were frequent. Spinal neurofibromas were distributed in all spine regions (65%) or in the cervical spine alone (22%). Most (93%) C2 neurofibromas were visible on MRI scans of the head. Intradural invasion and cord compression in the cervical spine included the C2 level in 95% and 80% of patients, respectively. Compared with all other cervical spine neurofibromas in these patients, C2 neurofibromas had higher rates of intraspinal extension (75% vs 32%; OR 6.20, 95% CI 3.85-9.97; p < 0.001), intradural invasion (53% vs 26%; OR 3.20, 95% CI 2.08-4.92; p < 0.001), and cord compression (25% vs 13%; OR 2.26, 95% CI 1.35-3.79; p = 0.002). However, C2 neurofibromas had lower rates of extraforaminal growth beyond the transverse process (12% vs 62%; OR 0.09, 95% CI 0.05-0.16; p < 0.001).CONCLUSIONSC2 neurofibromas are associated with an aggressive intraspinal phenotype, limited growth outside the spinal canal, and an uncommon genetic profile. These observations require future study.

Correction of Progressive Severe Cervical Kyphosis in a 21-Month-Old Patient With NF1: Surgical Technique and Review of Literature

BACKGROUND

Severe cervical kyphosis in the setting of neurofibromatosis type 1 (NF1) is a rare manifestation of the disease in the pediatric population. Dystrophic and immature bone complicate the placement of hardware necessary for surgical correction of alignment and a review of the literature yields 4 cases of pediatric patients with NF1 requiring surgical intervention in which the youngest patient was 10 yr old.

OBJECTIVE

To report the case of an 11-mo-old female with NF1 who presented with a plexiform cervical neurofibroma and focal cervical kyphosis. A comprehensive review of the literature and a detailed description of nonsurgical and surgical management for this patient population is described.

METHODS

A literature review was completed for article reviewing management of pediatric patients with cervical spine injuries and NF1. The patient's chart was reviewed and the patient was followed for a year to provide adequate follow-up. Institutional Review Board (IRB)/ethics committee approval and patient consent were neither required nor sought for this study.

RESULTS

The literature was reviewed, summarized, and utilized for operative planning and postoperative management. Postoperative imaging and 1-yr follow-up imaging showed anterior construct and lateral mass fusion, restoration of cervical alignment, and no neurological deficits.

CONCLUSION

This is the youngest reported patient to have surgical cervical kyphosis correction in the setting of NF1. A review of the literature helped develop a long-term plan and shape a novel same-day front-back-front approach to restore alignment that will be of use to teams managing these complex patients in the future.

Spinal and Paraspinal Plexiform Neurofibromas in Patients with Neurofibromatosis Type 1: A Novel Scoring System for Radiological-Clinical Correlation

BACKGROUND AND PURPOSE

Neurofibromatosis type 1 is a common tumor predisposition syndrome. The aim of this study was to characterize the radiologic presentation of patients with neurofibromatosis type 1 with widespread spinal disease and to correlate it to clinical presentation and outcome.

MATERIALS AND METHODS

We conducted a historical cohort study of adult patients with neurofibromatosis type 1 with spinal involvement. Longitudinal clinical evaluation included pain and neurologic deficits. Radiologically, spinal involvement was classified according to a novel classification system, and a radiologic risk score was calculated.

RESULTS

Two hundred fifty-seven adult patients with neurofibromatosis type 1 are followed in our center. Thirty-four of these patients qualified for inclusion in this study. Three independent factors were found to be associated with increased risk for neurologic deficit: 1) bilateral tumors at the same level in the cervical region that approximated each other, 2) paraspinal tumors at the lumbar region, and 3) intradural lesions. On the basis of these factors, we calculated a combined risk score for neurologic deficits for each patient. We found a clear correlation between patient status and the calculated radiologic risk score. Patients with neurologic deficits were found to have a higher risk score (9 ± 8.3) than patients without neurologic deficits (2.5 ± 2.9, P < .05). Patients who progressed during the follow-up period had significantly higher scores at presentation than patients with stable conditions (9.9 ± 8.73 versus 3.9 ± 5.3, respectively; P < .05).

CONCLUSIONS

In this series, neurologic deficit is correlated with tumor burden and subtype. We found no direct correlation with tumor burden and pain. Our novel radiologic classification scoring system may be used to predict increased risk for neurologic morbidity.

Cervical Scoliosis: Clinical and Radiographic Outcomes

Study Design Retrospective study. Objective Cervical scoliosis is a rare condition that can arise from various etiologies. Few reports on the surgical management of cervical scoliosis exist. Our objective was to evaluate clinical and radiographic outcomes following surgical management of cervical scoliosis. Methods We evaluated our cervical spine surgical database for patients with cervical scoliosis (Cobb angle > 10 degrees) from 2005 to 2010. Demographic data including age, gender, diagnoses, and primary versus revision surgery was collected. Surgical data including procedure (anterior versus posterior), estimated blood loss (EBL), length of surgery, length of hospitalization, and complications was recorded. Preoperative and postoperative Cobb angle measurements and Neck Disability Index (NDI) scores were recorded. Results Cervical scoliosis was identified in 18 patients. We excluded 5, leaving 5 men and 8 women with an average age of 50.7 (median 52, range 25 to 65). The average follow-up was 40 months (median 36.5, range 5 to 87). An anterior-only approach was used in 6 cases (average 4 levels fused), 5 cases were posterior-only approach (average 8.7 levels fused), and 2 cases were combined anterior-posterior approach. The EBL was an average of 286 mL (median 150, range 50 to 900), the average surgical time was 266 minutes (median 239, range 136 to 508), and the average hospital stay was 2.7 days (median 2, range 1 to 7). Complications occurred in 7 patients, and 2 developed adjacent segment pathology. The average coronal Cobb angle preoperatively was 35.1 degrees (median 31, range 13 to 63) and corrected was 15.7 degrees (median 10.5, range 2 to 59) postoperatively (p < 0.005). The average NDI preoperatively was 24.9 (median 26, range 6 to 37) and was reduced to 17.8 (median 18, range 7 to 30) postoperatively (p < 0.02). Conclusion Surgical management of cervical scoliosis can result in deformity correction and improvement in patient outcomes. Higher rates of complications may be encountered.

Hydrocephalus following bilateral dumbbell-shaped c2 spinal neurofibromas resection and postoperative cervical pseudomeningocele in a patient with neurofibromatosis type 1: a case report

Study Design Case report.

Objective To present a rare case of hydrocephalus following bilateral dumbbell-shaped C2 spinal neurofibromas resection and postoperative cervical pseudomeningocele in a patient with neurofibromatosis type 1 (NF1).

Methods The patient's clinical course is retrospectively reviewed. A 37-year-old man affected by NF1 referred to our department for progressive weakness of both lower extremities and gait disturbance. Radiological imaging showed bilateral dumbbell-shaped C2 spinal neurofibromas. After its resection, at the 1-month follow-up evaluation, the patient reported headache and nausea. A CT brain scan showed a postoperative cervical pseudomeningocele and an increase in the ventricular sizes, resulting in hydrocephalus.

Results A ventriculoperitoneal shunting was performed using a programmable valve opening pressure set to 120 mmH₂0. After surgery, the patient's neurological status markedly improved.

Conclusion Hydrocephalus must be considered a possible complication of cervical spine tumor resection.

Vascularized fibula strut graft used in neurofibromatosis type 1-related kyphosis: a case of almost complete reversal of deformity-induced tetraparesis

Study Design Case report.

Objective The aim of this study is to describe a case of vascularized fibula strut graft implanted in the cervicothoracic spine of a patient with neurofibromatosis type 1–related progressive kyphosis.

Methods A detailed history examination of the surgical procedures and the results of the follow-up after fibula strut graft implantation were performed. In addition, a review of the literature was conducted to access the incidence of similar cases with an almost complete reversal of a deformity-induced tetraparesis.

Results A 37-year-old man with severe type 1 neurofibromatosis causing a collapsing kyphosis of the cervicothoracic spine presented in 2006 with progressive low cervical tetraparesis. Intervention included posterior stabilization (C5 to T5) which was extended to C3–T9 in 2008; however, the kyphosis continued to worsen. In 2009, a vascularized fibula strut graft was implanted between the inferior and superior endplates of C3 and T9. Over the following months, the patient gradually recovered motor strength and improved functional use of all limbs. In March 2011, lower limb (bilateral) and right arm strength was grade 5, with left arm strength being grade 4+.

Conclusions This case report demonstrates the existence of a potential local option for the difficult problems of pseudoarthrosis, progressive spinal deformity, and cord compromise in patients with neurofibromatosis type 1–related kyphosis resulting in an almost complete reversal of deformity-induced tetraparesis.

Paraspinal chordoma mimicking a neurofibroma: a rare but important radiological pitfall

We present an unusual case of a chordoma presenting as an extradural spinal tumour with extension through an expanded intervertebral foramen to form a large paraspinal mass. The magnetic resonance imaging appearances closely mimicked a neurofibroma; however, pre-operative biopsy confirmed the diagnosis of chordoma. This is, to our knowledge, the tenth reported case of chordoma presenting as a mass expanding the intervertebral foramen. Thus, while it is a rare form of chordoma, it can lead to a recognised radiological pitfall. Making the distinction from neurofibroma before surgery is essential, as radical dissection of chordoma is required to reduce the risk of local recurrence.