Spinal neurofibromatosis

Radiographic/MR Imaging Correlation of Spinal Bony Outlines

The human spine is a highly specialized structure that protects the neuraxis and supports the body during movement, but its complex structure is a challenge for imaging. Radiographs can provide fine bony detail, but lack soft tissue definition and can be complicated by overlying structures. MR imaging allow(s) excellent soft tissue contrast, but some bony abnormalities can be difficult to discern. This makes the 2 modalities highly complementary. In this article, the authors discuss the correlation between radiographic and MR imaging appearances focusing first on disease affecting the vertebral body itself, its surrounding structures, and finally global spinal alignment.

Spinal neurofibromatosis with NF1 mutation in a classic neurofibromatosis type 1 family: A case report and literature review

Background

Spinal neurofibromatosis (SNF) is a related form of Neurofibromatosis type 1 (NF1) with a low incidence. Here, we report a SNF patient with NF1 (OMIM *613113) mutation in a classic NF1 family to enrich the case data.

Methods

We presented the clinical data of a 27‐year‐old female suffered from SNF. Two NF1 individuals (the mother and the brother) in the patient's family were also described. In the SNF patient, tumors in cervical were removed by surgical operation after the spinal MRI evaluation. Hematoxylin‐eosin staining and immunohistochemistry were performed to better characterize the excised tumors. NF1 exons of the patient and her NF1 families were further sequenced by the next‐generation sequencing technology.

Results

The patient developed irregular café‐au‐lait macules, multi‐subcutaneous nodules, recurrent numbness, and weakness of both lower extremities. Multiple neurofibromas were found in the whole spine by spinal MRI. Tumor‐like cells and hyperplasia of ganglion cells were found in the excised tissue by H&E staining and immunohistochemistry, respectively. One‐year follow‐up on the SNF patient showed that after the surgery lower limb pain, numbness and convulsion were completely relieved. A common germ‐line pathogenic mutation (NM_000267.3:c.1721 + 3A>G) was found in both the SNF patient and her classic NF1 families.

Conclusion

A case of SNF with classic NF1 mutation in a classic NF1 family was identified for the first time, indicating that SNF may share the same gene mutation with NF1, while the different manifestation of NF1 and SNF may be related to gene modification.

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

Object

Patients with neurofibromatosis Type 1 (NF-1) at the cervical spine present significant surgical challenges due to neural compression, multiplicity of tumors, and complex spinal deformities. Iatrogenic instability following resection of tumors is underappreciated in the literature. The focus of this study was to understand the indications for stabilization in this specific group of patients.

Methods

The authors performed a retrospective review of 20 cases involving NF-1 patients with symptomatic cervical spine neurofibromas who underwent surgical decompression and tumor resection, with or without instrumentation, between 1991 and 2008. They also included 2 additional cases involving patients treated before 1991. Imaging findings and data pertaining to clinical presentation, intraoperative management, and postoperative assessment were compiled to clarify the indications for stabilization. An ordinal pain scale based on patient self-assessment was used. Neurological function was evaluated using American Spinal Injury Association Impairment Scale scores.

Results

The patient group comprised 13 men and 9 women. Their median age at presentation was 42.5 years; their median age at initial diagnosis of NF-1 was 30 years (range 8–74 years). The median duration of follow-up (since presentation) was 7 years (range 1–32 years). Progressive myelopathy was the main presenting symptom. Spinal cord compression was identified in 13 patients on presentation. Complete removal of the symptomatic tumors was performed in 11 patients. Ten patients underwent instrumented fusion during their first surgery. Six of these 10 required a second surgery—with fixation in 4 cases and without in 2. Of the 12 patients who did not receive instrumented fusion in their first surgery, 8 required a second surgery—with fixation in 5 cases and without in 3. Neurological deterioration due to progressive deformity was the indication for the second surgery in 3 of the 5 patients who required instrumented fusion only in their second surgery; the other 2 patients presented with neurological deterioration secondary to tumor progression. Four patients needed a third operation and instrumented fusion: 3 for deformity-related deficit and 1 for tumor progression. Based on the latest follow-up, 21 patients were stable clinically and radiologically, and 1 patient had died.

Conclusions

This specific group of patients represents a significant surgical challenge. In this retrospective analysis, emphasis is placed on early stabilization of the cervical spine to prevent late deformity as part of the comprehensive management of patients with NF-1.

Dural ectasia as a cause of widening of the internal auditory canals in neurofibromatosis

Patients with neurofibromatosis have an increased incidence of acoustic neuroma, which is often bilateral. We present three patients with neurofibromatosis and enlarged internal auditory canals secondary to dural ectasia, without associated acoustic neuromata. Air CT cisternography and Metrizamide CT cisternography was needed in differentiating dural ectasia from acoustic neuroma in two patients.