Managing the cervical spine in multiple myeloma patients.

Discuss the relevant literature on surgical and nonsurgical treatments for multiple myeloma (MM) and their complementary effects on overall treatment. Existing surgical algorithms designed for neoplasia of the spine may not suit the management of spinal myeloma. Less than a fifth of metastatic, including myelomatous lesions, occur in the cervical spine but have a poorer prognosis and surgery in this area carries a higher morbidity. With the advances of chemotherapy, early access to radiotherapy, early orthosis management, and high definition imaging, including CT and MRI, surgical indications in MM have changed. Medical decompression (or oncolysis), including in the presence of neurological deficit and orthotic stabilization, are proving viable nonsurgical options to manage MM. A key to decision making is the assessment and monitoring of biomechanical spinal stability as part of a multidisciplinary approach.

Cervical dural calcification and cervical myelopathy in X-linked hypophosphataemic rickets: a case report and review of the literature.

X-linked hypophosphataemic rickets (XLHR) is a genetic disorder resulting from a genetic mutation in the PHEX gene. This may cause ossification of soft tissue structures risking spinal cord compression. We present the first known case of cervical dural calcification secondary to XLHR to cause myelopathic symptoms due to cord compression.

Osteosarcoma of the spine: dismal past, any hope for the future?

PURPOSE: The purpose of this study was to analyse all cases of spinal osteosarcoma (OS) treated in a regional bone tumour unit over the last 27 years. We were primarily interested in overall survival following tumour surgery, and if there is a difference in the survival of patients undergoing en bloc resection versus non-en bloc surgery. METHODS: Prospectively maintained tumour databases were searched in a regional bone tumour unit. All cases of surgically managed spinal OS were extracted and inpatient notes, imaging (including staging), histological margin status, and outcomes (neurological deficit and survival curves) were reviewed. RESULTS: Twenty-six patients were identified between 1985 and 2012. The median age was 26.5 years (range 6-78 y). Overall Kaplan-Meier survival was 69.5% (95% CI: 46.3-84.2%) and 10.8% (95% CI: 1.8-29.0%) at 1 and 5 years, respectively. There appears to be improved survival associated with primary spinal OS compared to that of metastatic disease, but this does not reach statistical significance (p = 0.29, Cox proportional hazards analysis). En bloc resection results in a significantly improved survival time compared to non-en bloc (biopsy and debulking): 44.1% alive at 2 years compared to 9.4%, respectively, p = 0.009. CONCLUSIONS: En bloc resection for primary spinal OS is associated with improved survival; there have been major changes in both surgical treatment and chemo/radiotherapy regimens over the period studied, potentially confounding the interpretation.

Osteochondroma of C1 causing vertebral artery occlusion.

Spinal osteochondromas constitute a small percentage of all intraspinal tumours, and are a rare cause of neurological symptoms. We describe a patient with a vertebral artery occlusion secondary to an osteochondroma of the C1 vertebra presenting with symptoms of cerebral ischaemia. This case is reported because of its extreme rarity.

Malignant PEComa of the lumbar vertebra: a rare bone tumour.

We describe the case of a 26-year-old patient with a perivascular epithelioid cell tumour (PEComa) involving the 5th lumbar vertebra. Radiological findings, pathological features and treatment are presented. We conclude that PEComas should be considered in the differential diagnosis of vertebral lesions.

The Relative Merits of Posterior Surgical Treatments for Multi-Level Degenerative Cervical Myelopathy Remain Uncertain: Findings from a Systematic Review.

OBJECTIVES: To assess the reporting of study design and characteristics in multi-level degenerative cervical myelopathy (DCM) treated by posterior surgical approaches, and perform a comparison of clinical and radiographic outcomes between different approaches. METHODS: A literature search was performed in Embase and MEDLINE between 1995-2019 using a sensitive search string combination. Studies were selected by predefined selection criteria: Full text articles in English, with >10 patients (prospective) or >50 patients (retrospective), reporting outcomes of multi-level DCM treated by posterior surgical approach. RESULTS: A total of 75 studies involving 19,510 patients, conducted worldwide, were identified. Laminoplasty was described in 56 studies (75%), followed by laminectomy with (36%) and without fusion (16%). The majority of studies were conducted in Asia (84%), in the period of 2016-2019 (51%), of which laminoplasty was studied predominantly. Twelve (16%) prospective studies and 63 (84%) retrospective studies were identified. The vast majority of studies were conducted in a single centre (95%) with clear inclusion/exclusion criteria and explicit cause of DCM. Eleven studies (15%) included patients with ossification of the posterior longitudinal ligament exclusively with cohorts of 57 to 252. The clinical and radiographic outcomes were reported with heterogeneity when comparing laminoplasty, laminectomy with and without fusion. CONCLUSIONS: Heterogeneity in the reporting of study and sample characteristics exists, as well as in clinical and radiographic outcomes, with a paucity of studies with a higher level of evidence. Future studies are needed to elucidate the clinical effectiveness of posterior surgical treatments.

Non-dysraphic intradural spinal cord lipoma: case series, literature review and guidelines for management.

PURPOSE: Non-dysraphic intradural spinal cord lipomas are rare lesions and the management remains controversial. We present our experience with five cases and propose guidelines for their management. METHODS: Five patients who underwent surgery for non-dysraphic spinal cord lipomas between January 2004 and April 2009 were retrospectively reviewed. All had varying degrees of neurological symptoms at the time of surgery with characteristic features on magnetic resonance imaging (MRI). All patients underwent decompression with a laminectomy/laminoplasty and debulking. The dura was primarily closed in one patient. The literature was also extensively reviewed regarding these rare lesions and optimum management guidelines proposed. RESULTS: The age at presentation ranged from 17 to 52 years (mean 32.2). Minimum follow-up was 8 months and maximum follow-up was 5 years. There was neurological improvement following surgery in all cases. Post-operative MRI scan showed evidence of significant residual tumour in all patients. CONCLUSION: The extent of surgical resection does not necessarily correlate with clinical outcome. The aim of surgery should, therefore, be adequate decompression with preservation of neural structures. Aggressive debulking should be avoided. Onset of any neurological symptoms/signs, bowel or bladder symptoms or intractable local symptoms should be an indication for surgery.

Anterior cervical corpectomy: review and comparison of results using titanium mesh cages and carbon fibre reinforced polymer cages.

Different types of cages have recently become available for reconstruction following anterior cervical corpectomy. We review the results using titanium mesh cages (TMC) and stackable CFRP (carbon fibre reinforced polymer) cages. Forty-two patients who underwent anterior cervical corpectomy between November 2001 and September 2008 were retrospectively reviewed. Pathologies included cervical spondylotic myelopathy (CSM), cervical radiculopathy, OPLL (ossified posterior longitudinal ligament), metastasis/primary bone tumour, rheumatoid arthritis and deformity correction. All patients were evaluated clinically and radiologically. Outcome was assessed on the basis of the Odom's criteria, neck disability index (NDI) and myelopathy disability index (MDI). Mean age was 60 years and mean follow-up was 1½ years. Majority of the patients had single-level corpectomy. Twenty-three patients had TMC cages while 19 patients had CFRP cages. The mean subsidence noted with TMC cage was 1.91 mm, while with the stackable CFRP cage it was 0.5 mm. This difference was statistically significant (p < 0.05). However, there was no statistically significant correlation noted between subsidence and clinical outcome (p > 0.05) or between subsidence and post-operative sagittal alignment (p > 0.05) in either of the groups. Three patients had significant subsidence (> 3 mm), one of whom was symptomatic. There were no hardware-related complications. On the basis of the Odom's criterion, 9 patients (21.4%) had an excellent outcome, 14 patients (33.3%) had a good outcome, 9 patients (21.4%) had a fair outcome and 5 patients (11.9%) had a poor outcome, i.e. symptoms and signs unchanged or exacerbated. Mean post-operative NDI was 26.27% and mean post-operative MDI was 19.31%. Fusion was noted in all 42 cases. Both TMC and stackable CFRP cages provide solid anterior column reconstruction with good outcome following anterior cervical corpectomy. However, more subsidence is noted with TMC cages though this might not significantly alter the clinical outcome unless the subsidence is significant (>3 mm).

Analysis of axonal regeneration in the central and peripheral nervous systems of the NG2-deficient mouse.

BACKGROUND: The chondroitin sulphate proteoglycan NG2 blocks neurite outgrowth in vitro and has been proposed as a major inhibitor of axonal regeneration in the CNS. Although a substantial body of evidence underpins this hypothesis, it is challenged by recent findings including strong expression of NG2 in regenerating peripheral nerve. RESULTS: We studied axonal regeneration in the PNS and CNS of genetically engineered mice that do not express NG2, and in sex and age matched wild-type controls. In the CNS, we used anterograde tracing with BDA to study corticospinal tract (CST) axons after spinal cord injury and transganglionic labelling with CT-HRP to trace ascending sensory dorsal column (DC) axons after DC lesions and a conditioning lesion of the sciatic nerve. Injury to these fibre tracts resulted in no difference between knockout and wild-type mice in the ability of CST axons or DC axons to enter or cross the lesion site. Similarly, after dorsal root injury (with conditioning lesion), most regenerating dorsal root axons failed to grow across the dorsal root entry zone in both transgenic and wild-type mice. Following sciatic nerve injuries, functional recovery was assessed by analysis of the toe-spreading reflex and cutaneous sensitivity to Von Frey hairs. Anatomical correlates of regeneration were assessed by: retrograde labelling of regenerating dorsal root ganglion (DRG) cells with DiAsp; immunostaining with PGP 9.5 to visualise sensory reinnervation of plantar hindpaws; electron microscopic analysis of regenerating axons in tibial and digital nerves; and by silver-cholinesterase histochemical study of motor end plate reinnervation. We also examined functional and anatomical correlates of regeneration after injury of the facial nerve by assessing the time taken for whisker movements and corneal reflexes to recover and by retrograde labelling of regenerated axons with Fluorogold and DiAsp. None of the anatomical or functional analyses revealed significant differences between wild-type and knockout mice. CONCLUSION: These findings show that NG2 is unlikely to be a major inhibitor of axonal regeneration after injury to the CNS, and, further, that NG2 is unlikely to be necessary for regeneration or functional recovery following peripheral nerve injury.

Is a persistent central canal a risk factor for neurological injury in patients undergoing surgical correction of scoliosis?

BACKGROUND: Scoliosis patients with associated syringomyelia are at an increased risk of neurological injury during surgical deformity correction. The syrinx is therefore often addressed surgically prior to scoliosis correction to minimize this risk. It remains unclear if the presence of a persistent central canal (PCC) within the spinal cord also poses a similar risk. The aim of this study is to determine whether there is any evidence to suggest that patients with a PCC are also at a higher risk of neurological injury during surgical scoliosis correction. METHODS: Eleven patients with a PCC identified on pre-operative magnetic resonance imaging who had undergone correction of adolescent idiopathic scoliosis (AIS) over a 7-year study period at our institution were retrospectively identified. The incidence of abnormal intra-operative spinal cord monitoring (SCM) traces in this group was in turn compared against 44 randomly selected age- and sex-matched controls with no PCC who had also undergone surgical correction of AIS during the study period. Fisher's exact test was applied to determine whether there was a significant difference in the incidence of abnormal intra-operative SCM traces between the two groups. RESULTS: Statistical analysis demonstrated no significant difference in the incidence of abnormal intra-operative SCM signal traces between the PCC group and the control group. CONCLUSIONS: This study demonstrates no evidence to suggest a PCC increases the risk of neurological complications during scoliosis correction. We therefore suggest that surgical correction of scoliosis in patients with a PCC can be carried out safely with routine precautions.

Spinal meningocele due to iatrogenic dural puncture during epidural analgesia for childbirth: 5-year history of headache with a spinal etiology.

Patients undergoing epidural injection for labor pains occasionally sustain iatrogenic inadvertent puncture of the dura with or without damage to the underlying neurological structures. This may be associated with CSF leakage, headache, neurological deficit, and infection. Rarely, the headache persists for years. To the authors' knowledge, chronic headache due to acquired spinal meningocele featuring as a duplicated dural sac, as a sequela of traumatic inadvertent dural puncture, has not been previously reported. The authors report a case of a 20-year-old woman with persistent headaches following an epidural injection. Five years later, the persistent headache was found to be due to a large acquired spinal meningocele. The operative removal of the meningocele led to resolution of headaches. This report highlights the importance of considering a spinal condition as a culprit for chronic headache and postulates a mechanism for the formation of the acquired spinal meningocele appearing as a duplicated dural sac. The authors recommend early MR imaging of the spine for any persisting headache that has a history of attempted spinal access. If an acquired spinal meningocele collection is found, exploration with a view to complete removal of the sac should be considered. To the authors' knowledge, this is the first case report depicting a rare, treatable cause of chronic spinal hypotension resulting in headaches.

Cushing's disease in children and adolescents: 20 years of experience in a single neurosurgical center.

OBJECTIVE: This is a retrospective analysis of 25 consecutive pediatric patients with Cushing's disease who underwent transsphenoidal surgery performed by a single neurosurgeon in a specialist center during a 20-year period. This article discusses the presentation of Cushing's disease, the endocrinological investigation with particular reference to bilateral inferior petrosal sinus sampling (BIPSS), the operative management with reference to specific pediatric difficulties of the transsphenoidal approach and the use of intraoperative image guidance, and the analysis of these cases as regards postoperative complications and outcomes of this rare condition in young patients. METHODS: All patients underwent detailed endocrine investigation and imaging in the form of computed tomography and/or magnetic resonance imaging. BIPSS was performed in 19 patients (76%), with successful lateralization of the side of the microadenoma in 14 (74%) and prediction of a central tumor in four (94% total prediction rate). Surgical removal was via the sublabial, paraseptal, transsphenoidal route. RESULTS: There were 15 male and 10 female patients, with a mean age of 13.4 years (range, 6.6-17.8 yr). Weight gain was the most common presentation (100%), and then growth impairment (96%), fatigue and skin changes (64%), and hypertension (32%). Postoperative complications included growth hormone deficiency (36%), transient diabetes insipidus (12%), panhypopituitarism (4%), and transient cerebrospinal fluid rhinorrhea (4%). The median follow-up period was 59.5 months (range, 6-126 mo). Overall, 15 patients (60%) achieved surgical cure or remission, of which 14 outcomes were obtained using the results of BIPSS. Ten patients (40%) required postoperative radiotherapy to achieve "remission." There were no cases of meningitis, no neurological deficits, no reoperations, and no mortality. CONCLUSION: Cushing's disease in children and adolescents is a rare illness. The accurate preoperative localization of the adenoma is essential for achieving good results. In this series, BIPSS was far more accurate in localizing the adenoma than computed tomography or magnetic resonance imaging. Imaging, however, is useful for the exclusion of other intracranial problems. Transsphenoidal surgery was safe and efficacious in achieving cure in the majority of cases. The challenge of transsphenoidal surgery in this age group is the small pituitary fossa and the absence of sphenoid sinus aeration in some cases. We found the use of intraoperative neuronavigation to be an excellent aid in overcoming such anatomic difficulties.

NG2 proteoglycan expression in the peripheral nervous system: upregulation following injury and comparison with CNS lesions.

The chondroitin sulphate proteoglycan NG2 blocks neurite outgrowth in vitro and thus may be able to inhibit axonal regeneration in the CNS. We have used immunohistochemistry to compare the expression of NG2 in the PNS, where axons regenerate, and the spinal cord, where regeneration fails. NG2 is expressed by satellite cells in dorsal root ganglia (DRG) and in the perineurium and endoneurium of intact sciatic nerves of adult rats. Endoneurial NG2-positive cells were S100-negative. Injury to dorsal roots, ventral rami or sciatic nerves had no effect on NG2 expression in DRG but sciatic nerve section or crush caused an upregulation of NG2 in the damaged nerve. Strongly NG2-positive cells in damaged nerves were S100-negative. The proximal stump of severed nerves was capped by dense NG2, which surrounded bundles of regenerating axons. The distal stump, into which axons regenerated, also contained many NG2-positive/S100-negative cells. Immunoelectron microscopy revealed that most NG2-positive cells in distal stumps had perineurial or fibroblast-like morphologies, with NG2 being concentrated at the poles of the cells in regions exhibiting microvillus-like protrusions or caveolae. Compression and partial transection injuries to the spinal cord also caused an upregulation of NG2, and NG2-positive cells and processes invaded the lesion sites. Transganglionically labelled ascending dorsal column fibres, stimulated to sprout by a conditioning sciatic nerve injury, ended in the borders of lesions among many NG2-positive processes. Thus, NG2 upregulation is a feature of the response to injury in peripheral nerves and in the spinal cord, but it does not appear to limit regeneration in the sciatic nerve.