CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study.

BACKGROUND: The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to treat pituitary adenoma and related sellar pathologies. The recently adopted expanded endonasal approach (EEA) has improved access to the ventral skull base whilst retaining the principles of minimally invasive surgery. Despite the advantages these approaches offer, cerebrospinal fluid (CSF) rhinorrhoea remains a common complication. There is currently a lack of comparative evidence to guide the best choice of skull base reconstruction, resulting in considerable heterogeneity of current practice. This study aims to determine: (1) the scope of the methods of skull base repair; and (2) the corresponding rates of postoperative CSF rhinorrhoea in contemporary neurosurgical practice in the UK and Ireland. METHODS: We will adopt a multicentre, prospective, observational cohort design. All neurosurgical units in the UK and Ireland performing the relevant surgeries (TSA and EEA) will be eligible to participate. Eligible cases will be prospectively recruited over 6 months with 6 months of postoperative follow-up. Data points collected will include: demographics, tumour characteristics, operative data), and postoperative outcomes. Primary outcomes include skull base repair technique and CSF rhinorrhoea (biochemically confirmed and/or requiring intervention) rates. Pooled data will be analysed using descriptive statistics. All skull base repair methods used and CSF leak rates for TSA and EEA will be compared against rates listed in the literature. ETHICS AND DISSEMINATION: Formal institutional ethical board review was not required owing to the nature of the study - this was confirmed with the Health Research Authority, UK. CONCLUSIONS: The need for this multicentre, prospective, observational study is highlighted by the relative paucity of literature and the resultant lack of consensus on the topic. It is hoped that the results will give insight into contemporary practice in the UK and Ireland and will inform future studies.

A Case of Cervical Radiculopathy Presenting as Dystonic Tremor.

BACKGROUND: To our knowledge, this is the first case report of a cervical disc prolapse and foraminal stenosis presenting with dystonic tremor in addition to brachialgia. CASE DESCRIPTION: A 54-year-old, right-handed man presented with a dystonic tremor and aching throughout his right upper limb. Magnetic resonance imaging of the cervical spine revealed a disc osteophyte complex at C5/6 causing C6 foraminal impingement bilaterally in addition to a disc osteophyte complex at C6/C7 causing severe bilateral foraminal narrowing. Electromyography showed neurogenic changes consistent with chronic C6/7 radiculopathy. There was no response to numerous medical treatments for his dystonia or brachialgia. Computed tomography-guided right C6 and C7 root block led to complete but temporary resolution of all symptoms, including the dystonic tremor. Definitive treatment consisting of a C5/6 and C6/7 anterior cervical discectomy and fusion led to a complete, immediate, and continued resolution of his right-sided brachialgia and dystonic tremor. CONCLUSIONS: This case highlights the potential of cervical disc prolapse to present with dystonic tremor with the likely mechanism being secondary to the painful radiculopathy and highlights the potential benefits of surgical decompression with this atypical presentation.

Predicting post-operative cerebrospinal fluid (CSF) leak following endoscopic transnasal pituitary and anterior skull base surgery: a multivariate analysis.

BACKGROUND: Post-operative CSF leak is the major source of morbidity following endoscopic transsphenoidal surgery. The purpose of this study was to identify factors associated with post-operative CSF leak in patients undergoing this surgery and facilitate the prospective identification of patients at higher risk of this complication. METHODS: A review of a prospectively maintained database containing details of 270 endoscopic transsphenoidal operations performed by the senior author over a 9-year period was performed. Univariate analysis was performed using the Chi-squared and Fisher's exact tests, as appropriate. A logistic regression model was constructed for multivariate analysis. RESULTS: The rate of post-operative CSF leak in this series was 9%. On univariate analysis, previous surgery, resection of craniopharyngiomas, adenomas causing Cushing's disease and intra-operative CSF leaks were associated with an increased risk of post-operative CSF leak. The use of a vascularised nasoseptal flap and increasing surgical experience were associated with a decreased rate of CSF leak. On multivariate analysis, a resection of tumour for Cushing's disease (OR 5.79, 95% CI 1.53-21.95, p = 0.01) and an intra-operative CSF leak (OR 4.56, 95% CI 1.56-13.32, p = 0.006) were associated with an increased risk of post-operative CSF leak. Increasing surgical experience (OR 0.14, 95% CI 0.04-0.46, p = 0.001) was strongly associated with a decreased risk of post-operative CSF leak. CONCLUSIONS: Increasing surgical experience is a strong predictor of a decreased risk of developing post-operative CSF leak following endoscopic transsphenoidal surgery. Patients with Cushing's disease and those who develop an intra-operative CSF leak should be managed with meticulous skull base repair and close observation for signs of CSF leak post-operatively.

Reoperative endoscopic endonasal surgery for residual or recurrent pituitary adenomas.

OBJECTIVE Regrowth of the lesion after surgical removal of pituitary adenomas is uncommon unless subtotal resection was originally achieved in the first surgery. Treatment for recurrent tumor can involve surgery or radiotherapy. Locations of residual tumor may vary based on the original approach. The authors evaluated the specific sites of residual or recurrent tumor after different transsphenoidal approaches and describe the surgical outcome of endoscopic endonasal transsphenoidal reoperation. METHODS The authors analyzed a prospectively collected database of a consecutive series of patients who had undergone endoscopic endonasal surgeries for residual or recurrent pituitary adenomas after an original transsphenoidal microscopic or endoscopic surgery. The site of the recurrent tumor and outcome after reoperation were noted and correlated with the primary surgical approach. The chi-square or Fisher exact test was used to compare categorical variables, and the Mann-Whitney U-test was used to compare continuous variables between surgical groups. RESULTS Forty-one patients underwent surgery for residual/recurrent pituitary adenoma from 2004 to 2015 at Weill Cornell Medical College. The previous treatment was a transsphenoidal microscopic (n = 22) and endoscopic endonasal (n = 19) surgery. In 83.3% patients (n = 30/36) there was postoperative residual tumor after the initial surgery. A residual tumor following endonasal endoscopic surgery was less common in the sphenoid sinus (10.5%; 2/19) than it was after microscopic transsphenoidal surgery (72.7%; n =16/22; p = 0.004). Gross-total resection (GTR) was achieved in 58.5%, and either GTR or near-total resection was achieved in 92.7%. Across all cases, the average extent of resection was 93.7%. The rate of GTR was lower in patients with Knosp-Steiner Grade 3-4 invasion (p < 0.0005). Postoperative CSF leak was seen in only one case (2.4%), which stopped with lumbar drainage. Visual fields improved in 52.9% (n = 9/17) of patients and were stable in 47% (n = 8/17). Endocrine remission was achieved in 77.8% (n = 14/18) of cases, 12 by surgery alone and 2 by adjuvant medical (n = 1) and radiation (n = 1) therapy. New diabetes insipidus occurred in 4.9% (n = 2/41) of patients-in one of whom an additional single anterior hormonal axis was compromised-and 9.7% (n = 4/41) of patients had a new anterior pituitary hormonal insufficiency. CONCLUSIONS Endonasal endoscopic reoperation is extremely effective at removing recurrent or residual pituitary adenomas that remain after a prior surgery, and it may be preferable to radiation therapy particularly in symptomatic patients. Achievement of GTR is less common when lateral cavernous sinus invasion is present. The locations of residual/recurrent tumor were more likely sphenoidal and parasellar following a prior microscopic transsphenoidal surgery and sellar following a prior endonasal endoscopic surgery.

Management of Giant Calcified Thoracic Disks and Description of the Trench Vertebrectomy Technique.

STUDY DESIGN: Case series and review of the literature. OBJECTIVE: To review the management of giant calcified disks in our large cohort and compare with the existing literature. We discuss our surgical technique. METHODS: Twenty-nine cases of herniated thoracic disk between 2000 and 2013 were reviewed. Eighteen patients were identified as having giant calcified thoracic disks, defined as diffusely calcified disks occupying at least 40% of the spinal canal. Demographic data was collected in addition to presentation, imaging findings, operative details, and outcomes using the modified Japanese Orthopaedic Association (mJOA) scale. RESULTS: Giant calcified thoracic disks (GCTDs) are unique clinical entities that require special neurosurgical consideration owing to significant (≥40%) involvement of the spinal canal and compression of the spinal cord, often leading to myelopathy. The median age at diagnosis was 51.2 years (range 37 to 70) with the mean duration of presenting symptoms being 9.9 months (range 2 weeks to 3 years). Seventeen (94.4%) patients presented with at least one sign of myelopathy (hyperreflexia, hypertonia, bladder or bowel dysfunction) with the remaining 1 (5.6%) patient presenting with symptoms in keeping with radiculopathy. Thoracotomy was performed on 17 (94.4%) patients, and 1 (5.6%) patient had a costotransverse approach. Mean follow-up was 19.8 months (range 7 months to 2 years). mJOA score improved in 15 (83.3%) patients. mJOA scores in the other patients remained stable. CONCLUSIONS: GCTDs are difficult neurosurgical challenges owing to their size, degree of spinal cord compression, and consistency. We recommend a trench vertebrectomy via a thoracotomy in their surgical management. This procedure safely allows the identification of normal dura on either side of the compressed segment prior to performing a diskectomy. Excellent fusion rates were achieved with insertion of rib head autograft in the trench.

Long-Term Outcomes of Endoscopic Third Ventriculostomy in Adults.

OBJECTIVE: To describe long-term outcomes of endoscopic third ventriculostomy (ETV) in adults with hydrocephalus. METHODS: Single-institution retrospective review of adults treated with ETV between 1998 and 2006. Patient demographic, treatment, and follow-up data were collected. The patients were divided into 2 groups: primary ETV for patients with previously untreated or newly diagnosed hydrocephalus and secondary ETV for patients with a previous shunt presenting with shunt malfunction. ETV outcome was deemed successful if the patient remained shunt-free after ETV. Multivariate analysis was performed using Cox regression. RESULTS: The study population comprised 190 patients, with a median age of 43 years (range, 16-79 years). The median duration of follow-up was 112 months (range, 1-190 months). The primary ETV group contained 129 patients; the secondary ETV group, 61 patients. Operative complications occurred in 11 patients (6%). A successful outcome was obtained in 139 patients (73%). ETV failure occurred in 51 patients, with a median time to failure of 2 months (range, 0-124 months). Although the majority (86%) of ETV failures occurred within 2 years postoperatively, failure was noted in 3 cases between 5 and 10 years after intervention, including in 1 patient at a 124-month follow-up. In multivariate analysis, only previous shunt was found to influence outcomes (P = 0.021), with shorter ETV survival noted in patients with a previous shunt. Age, indication, and ETV success did not influence outcome. CONCLUSIONS: ETV is a safe procedure with excellent rates of long-term efficacy; however, late failure can occur, and patients should be instructed to seek medical advice if symptoms recur. A previous shunt is associated with a higher ETV failure rate.

Outcome of microsurgical excision of unruptured brain arteriovenous malformations in ARUBA-eligible patients.

OBJECTIVES: To determine the outcome of microsurgical excision of selected unruptured brain arteriovenous malformations (AVMs), and to compare the results with those of the ARUBA trial. METHODS: Prospective data collection for all patients undergoing microsurgical excision of unruptured brain AVMs by two neurovascular surgeons. Outcome measures similar to those assessed in the ARUBA trial (death and stroke) as well as modified Rankin scores (mRS) at 6 months were assessed. RESULTS: Between September 2004 and September 2014, 45 patients with unruptured brain AVMs underwent microsurgical excision. 11 patients (eight children and three with mRS >2 at presentation) were excluded to match ARUBA eligibility criteria. 34 patients were included in this study. AVM characteristics closely matched those in the ARUBA trial with 70.5% Spetzler-Martin (SM) grade I or II AVMs, 68% AVM size <3 cm. However, compared to ARUBA, a larger proportion of our patients presented with seizures, and a lower proportion with headaches. 8(23%) had preoperative embolization. There were no deaths and no strokes (as defined in ARUBA). 5 (14.7%) had permanent neurological deficit related to surgery within/near eloquent cortex. At 6 months follow-up, 32 (94%) had mRS score of 0-1. Two (6%) had mRS 2 and none had mRS> 2. Postoperative digital DSA confirmed complete AVM excision in all cases. None of the patients have suffered intracranial hemorrhage during the follow-up period of 6-126 (median 69) months. CONCLUSIONS: Microsurgical excision of unruptured brain AVMs can be performed with low morbidity in selected cases. Our study has limitations particularly the small number of patients with selected AVMs for microsurgical excision. However, our results suggest that ARUBA results may not be applicable to microsurgical excision when cases are appropriately selected for this treatment modality.

Management of Typical and Atypical Hangman's Fractures.

Study Design Retrospective study of a prospectively maintained database. Objective Our aim was to retrospectively review management and outcomes of patients with low-grade hangman's fractures, specifically looking at differences in outcomes between collars and halo immobilization. We also studied fracture patterns and their treatment outcomes. Methods Forty-one patients with hangman's fractures were identified from 105 patients with axis fractures between 2007 and 2013. Typical hangman's fractures were defined as traumatic spondylolisthesis of the axis causing a bilateral pars interarticularis fracture. Fractures involving the posterior cortex of C2 on one or both sides or an asymmetrical pattern were defined as atypical. Results There were 41 patients with a mean age of 59 years, with 13 (31.7%) typical and 28 (68.2%) atypical fractures. There were 22 (53.6%) type 1 fractures, 7 (41.4%) type 2 fractures, and 2 (4.9%) type 2a fractures in this series. Cervical collars were used to manage 11 patients (27% of all patients with hangman's fractures) and halo orthosis was used in 27 (65.8%). Three (7.3%) patients underwent surgical fixation of the fracture. Bony union was achieved in all patients on radiologic follow-up. Permanent neurologic deficit occurred in one patient due to associated injuries. Neck pain and stiffness were reported more commonly in the atypical group, but this finding was not statistically significant. Conclusions The majority of hangman type fractures can be treated nonoperatively. We found no difference in outcomes between a rigid collar or halo immobilization for treatment of low-grade fractures. Radiologic follow-up is essential to identify cases of nonunion.

The Role of Conservative Management in Incidental Os Odontoideum.

BACKGROUND: Os odontoideum is a relatively rare but significant condition of the cervical spine that has potentially life-threatening complications, including vertebral artery dissection, leading to permanent neurologic disability and even death. Unfortunately, the literature is not clear as to the best management approach for os odontoideum. As such, clinicians and their patients are still left with difficult and uncertain treatment decisions in the absence of a clinical consensus. CASE DESCRIPTION: A 20-year-old male was brought in after an assault and found to have os odontoideum on routine investigation. He was informed of management options and elected to undergo a conservative management approach with radiologic surveillance. The patient subsequently became symptomatic and required surgical fixation. CONCLUSIONS: This case illustrates that in the event an asymptomatic case of os odontoideum with radiological instability is managed conservatively, careful clinical and radiologic follow-up is essential as such cases can become symptomatic.

Twiddler's syndrome in spinal cord stimulation.

BACKGROUND: The aims are to present a case series of Twiddler's syndrome in spinal cord stimulators with analysis of the possible mechanism of this syndrome and discuss how this phenomenon can be prevented. METHOD: Data were collected retrospectively between 2007 and 2013 for all patients presenting with failure of spinal cord stimulators. The diagnostic criterion for Twiddler's syndrome is radiological evidence of twisting of wires in the presence of failure of spinal cord stimulation. RESULTS: Our unit implants on average 110 spinal cord stimulators a year. Over the 5-year study period, all consecutive cases of spinal cord stimulation failure were studied. Three patients with Twiddler's syndrome were identified. Presentation ranged from 4 to 228 weeks after implantation. Imaging revealed repeated rotations and twisting of the wires of the spinal cord stimulators leading to hardware failure. CONCLUSIONS: To the best of our knowledge this is the first reported series of Twiddler's syndrome with implantable pulse generators (IPGs) for spinal cord stimulation. Hardware failure is not uncommon in spinal cord stimulation. Awareness and identification of Twiddler's syndrome may help prevent its occurrence and further revisions. This may be achieved by implanting the IPG in the lumbar region subcutaneously above the belt line. Psychological intervention may have a preventative role for those who are deemed at high risk of Twiddler's syndrome from initial psychological screening.

Migrating intrathecal high-velocity projectile.

Bullet injuries to the spine can cause significant damage to surrounding tissues and cause serious neurological sequelae. These cases are often associated with neurological deficits. We present a case of a gunshot injury to the spine with a migrating intrathecal bullet which subsequently developed neurological deficits. Initially, the patient did not exhibit any neurological symptoms when first assessed soon after the injury. Subsequently, the patient developed signs of neurological injury as a result of spinal intrathecal migration of the projectile.

Conservative management of type II and III odontoid fractures in the elderly at a regional spine centre: A prospective and retrospective cohort study.

BACKGROUND: The optimal management of odontoid fractures in the elderly population is unclear and management of this group of patients is complicated by multiple co-morbidities. This study aimed to determine the outcomes after conservative management strategies were applied in this patient group. METHODS: We carried out retrospective and prospective analyses of all patients with axial cervical spine injuries, at a single centre. We included patients aged over 60 years with type II and III odontoid fractures. Information was gathered on demographics, ASA grading-associated injuries and complications. The outcome measures were rates and type of union, pain and neurological functions, specifically ambulation. RESULTS: Fifty-seven adult patients with a median age of 78 years (range 60-92 years) were included. There were 42 type II and 15 type III odontoid fractures. Three patients required surgical fixation due to displaced fractures, which could not be reduced with manual traction. Twenty-four (41%) patients were managed with a rigid pinned halo orthosis to obtain adequate reduction and immobilisation. The remaining 30 (53%) were managed in a hard cervical collar. Patients managed with a halo were significantly younger and had more associated injuries than patients managed in a collar (age: t-test=4.05, p<0.01, associated injuries: Chi-square=4.38, p<0.05). At a mean follow-up of 25 weeks, 87% of type II and 100% of type III fractures had achieved bony union or stable, fibrous non-union. There were no statistical differences in fracture type, follow-up or neurological outcomes between the halo and collar groups. However, overall more patients managed in a collar developed stable fibrous non-union than bony fusion (Fisher's exact test, p<0.05), although this was not significant when analysed by each fracture type individually. A regression model was constructed and identified fracture type as the only independent predictor of time to union, with type III fractures healing faster than type II. CONCLUSIONS: High rates of bony union and stable fibrous non-union with a good functional outcome can be achieved in the elderly population sustaining type II or III odontoid fractures, when managed non-surgically. Halo orthosis may not offer any clear advantage over hard collar in this group. Close follow-up is needed for late complications and there must be a willingness to perform surgery if conservative measures fail.

Surgical disconnection of the cortical venous reflux for high-grade intracranial dural arteriovenous fistulas.

OBJECTIVES: To assess the clinical outcome, complications, and angiographic outcomes after surgical disconnection of intracranial dural arteriovenous fistulas (DAVFs). METHODS: Analysis of prospectively collected data, including clinical presentation, preoperative angiographic findings, postoperative complications, clinical, and angiographic outcomes. RESULTS: Between January 2002 and January 2012, 25 patients underwent surgery for DAVFs. The anatomical locations included tentorial (8), ethmoidal (8), foramen magnum (5), middle fossa (2), torcular (1), and parafalcine (1). All had cortical venous reflux (CVR) and all were treated with craniotomy and disconnection of CVR. Two patients required repeat surgery for residual CVR. One patient had a postoperative seizure. There were no other complications. All patients had complete disconnection of CVR confirmed by digital subtraction angiography. None of the patients have had hemorrhage or recurrence of CVR on follow-up. CONCLUSIONS: Surgical disconnection of CVR for high-grade intracranial DAVFs is highly effective and can be performed with very low complication rates. Where embolization cannot be performed safely, surgical disconnection (rather than stereotactic radiosurgery) is the treatment of choice for high grade DAVFs.

Applications of the ultrasonic bone cutter in spinal surgery--our preliminary experience.

OBJECTIVE: To present our experience with the Misonix Ultrasonic Bone scalpel in spinal surgery, highlighting its potential applications and advantages. METHODS: Between March and December 2011, a total of 937 spinal cases were performed at a single centre. The Misonix Bone Scalpel (MBS) was used in 62 of these cases. Data were collected prospectively using the Spine Tango registry. Patient demographics, disease type, surgery performed and complications were all recorded along with pre- and post-operative core measures outcome index (COMI). RESULTS: The majority of cases were for spinal degenerative disorders, in particular, revision cases. The bone cutter was also used to achieve laminotomies for access to intradural tumours, corpectomies and a mixture of other pathologies. Of the 62 patients only 1 (1.6%) experienced a blood loss greater than 500 ml, and there was only 1 dural tear (1.6%) as a direct result of the MBS. Four illustrative cases are discussed. CONCLUSIONS: The MBS is a useful adjunct in spinal surgery with particular value in revision cases where scar tissue distorts the normal anatomy. There was a low complication rate with a trend to reduced blood loss. This was most apparent to the senior authors during cervical and thoracic corpectomies.

Proposal for a prospective multi-centre audit of chronic subdural haematoma management in the United Kingdom and Ireland.

BACKGROUND. Chronic subdural haematoma (CSDH) is a common condition that increases in incidence with rising age. Evacuation of a CSDH is one of the commonest neurosurgical procedures; however the optimal peri-operative management, surgical technique, post-operative care and the role of adjuvant therapies remain controversial. AIM. We propose a prospective multi-centre audit in order to establish current practices, outcomes and national benchmarks for future studies. METHODS. Neurosurgical units (NSU) in the United Kingdom and Ireland will be invited to enrol patients to this audit. All adult patients aged 16 years and over with a primary or recurrent CSDH will be eligible for inclusion. OUTCOME MEASURES AND ANALYSIS. The proposed outcome measures are (1) clinical recurrence requiring re-operation within 60 days; (2) modified Rankin scale (mRS) score at discharge from NSU; (3) morbidity and mortality in the NSU; (4) destination at discharge from NSU and (5) length of stay in the NSU. Audit standards have been derived from published systematic reviews and a recent randomised trial. The proposed standards are clinical recurrence rate < 20%; unfavourable mRS (4-6) at discharge from NSU < 30%; mortality rate in NSU < 5%; morbidity rate in NSU < 10%. Data will be submitted directly into a secure online database and analysed by the study's management group. CONCLUSIONS. The audit will determine the contemporary management and outcomes of patients with CSDH in the United Kingdom and Ireland. It will inform national guidelines, clinical practice and future studies in order to improve the outcome of patients with CSDH.

A rare case of primary sellar lymphoma presenting a diagnostic challenge.

Primary sellar lymphoma (PSL) is an exceptional diagnosis, among the most unusual causes of a sellar mass. Distinguishing PSL from other sellar lesions is often difficult as clinical and radiological features are typically non-specific. We present a case in which unusual presentation and previous medical history made diagnosis particularly challenging.