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The natural history of untreated sporadic vestibular schwannomas: a comprehensive review of hearing outcomes

J Neurosurg 112:163–167, 2010.(DOI: 10.3171/2009.4.JNS08895)

Observation is an important consideration when discussing management options for patients with vestibular schwannoma (VS). Most data regarding clinical outcomes after conservative management come from modestsized series performed at individual centers. The authors performed an analysis of the published literature on the natural history of VSs with respect to hearing outcome. Their objective was to provide a comprehensive and unbiased description of outcomes in patients whose disease was managed conservatively. Methods. The authors identified a total of 34 published studies containing hearing outcome data in patients with VSs < 25 mm in largest diameter who underwent observation management. The effects of initial tumor size and tumor growth rate on hearing function at latest follow-up were analyzed. Data from individual and aggregated cases were extracted from each study. Patients with poorer hearing (American Association of Otolaryngology–Head and Neck Surgery Classes C or D, or Gardner-Robertson Classes III, IV, or V) at the time of presentation were excluded.

Results. A total of 982 patients met the inclusion criteria for this analysis, with a mean initial tumor size of 11.3 ± 0.68 mm. The mean growth rate was 2.9 ± 1.2 mm/year. The length of follow-up for these studies ranged from 26 to 52 months. Patients with preserved hearing at latest follow-up had a statistically larger initial tumor size than those whose hearing declined during the observation period (11.5 ± 2.3 mm vs 9.3 ± 2.7 mm, p < 0.0001), but the 2-mm difference of means was at the limit of imaging resolution and observer reliability. In contrast, patients with lower rates of tumor growth (≤ 2.5 mm/year) had markedly higher rates of hearing preservation (75 vs 32%, p < 0.0001) compared with patients with higher tumor growth rates. Interestingly, the authors’ analysis found no difference in the rate of reported intervention for patients in either group (16 vs 18%, p = not significant).

Conclusions. These data suggest that a growth rate of > 2.5 mm/year is a better predictor of hearing loss than the initial tumor size for patients undergoing observation management of VSs < 25 mm in largest diameter.


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Aceclofenac–tizanidine in the treatment of acute low back pain: a double-blind, double-dummy, randomized, multicentric, comparative study against aceclofenac alone

Eur Spine J (2009) 18:1836–1842DOI 10.1007/s00586-009-1019-4

Tizanidine and aceclofenac individually have shown efficacy in the treatment of low back pain. The efficacy and tolerability of the combination have not yet been established.

The objective of the study was to evaluate the efficacy and safety of aceclofenac-tizanidine fixed dose combination against aceclofenac alone in patients with acute low back pain.

This double-blind, double-dummy, randomized, comparative, multicentric, parallel group study enrolled 197 patients of either sex in the age range of 18–70 years with acute low back pain. The patients were randomized to receive either aceclofenac (100 mg)–tizanidine (2 mg) b.i.d or aceclofenac (100 mg) alone b.i.d for 7 days. The primary efficacy outcomes were pain intensity (on movement, at rest and at night; on VAS scale) and pain relief (on a 5-point verbal rating scale). The secondary efficacy outcomes measures included functional impairment (modified Schober’s test and lateral body bending test) and patient’s and investigator’s global efficacy assessment.

Aceclofenac–tizanidine was significantly superior to aceclofenac for pain intensity (on movement, at rest and at night; P < 0.05) and pain relief (P = 0.00) on days 3 and 7. There was significant increase in spinal flexion in both the groups from baseline on days 3 and 7 with significant difference in favour of the combination group (P < 0.05). There were significantly more number of patients with excellent to good response for the aceclofenac–tizanidine treatment as compared to aceclofenac alone (P = 0.00). Both the treatments were well tolerated.

In this study, aceclofenac–tizanidine combination was more effective than aceclofenac alone and had a favourable safety profile in the treatment of acute low back pain.

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The Efficacy of Plate Construct Augmentation Versus Cage Alone in Anterior Cervical Fusion

Spine 2009 Dec 15;34(26):2886-92.DOI: 10.1097/BRS.0b013e3181b64f2c

Study Design. Retrospective study.
Objective. To compare the efficacy of anterior cervical discectomy and fusion with cage alone (ACDF-CA) with cage and plate construct (ACDF-CPC) in regards to fusion rate, radiologic and clinical outcomes.
Summary of Background Data. ACDF-CA has shown good results; however, debate exists regarding the high rate of complications such as pseudarthrosis, subsidence, and local kyphosis. In an attempt to avoid these complications, the authors have performed ACDF with cage and plate construct (ACDF-CPC).
Methods. A total of 78 consecutive patients who underwent 1- or 2-level ACDF-CA or ACDF-CPC suffering from cervical radiculopathy were divided into 2 groups; Group A (n = 38) underwent ACDF-CA; Group B (n = 40) underwent ACDF-CPC. Fusion rate, segmental kyphosis, disc height, and subsidence rate were assessed by radiographs. Clinical outcomes were assessed using Robinson criteria.
Results. Solid fusion was achieved in 78.9% (30/38) of subjects in group A compared to 97.5% (39/40) of subjects in group B (P = 0.01). Segmental kyphosis was noted in 42.1% (16/38) in group A compared with 10% (4/40) in group B (P < 0.01). There was a significant decrease in disc height in group A compared to group B (P < 0.05). Subsidence occurred in 32.3% (19/59 levels) of group A compared with 9.7% (6/62 levels) of group B (P < 0.01). Clinical outcomes were similar for both treatment groups. The pseudarthrosis rate in group A was higher than that in group B (P = 0.01). Revision surgery was required in 10.5% (4/38) of group A, whereas none of group B required reoperation (P < 0.01).
Conclusion. The use of cage and plate construct in 1- or 2-level ACDF results in a more lordotic alignment, an increased disc height, a higher fusion rate, a lower subsidence rate, and a lower complication rate than that of cage alone; however, there is no significant difference in clinical outcome between groups

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Understanding inconsistencies in patient-reported outcomes after spine treatment: response shift phenomena

Not uncommonly, spine surgeons and physiatrists note a mismatch between patient-reported outcome measures, where one measure might indicate a good outcome and another indicates an inferior outcome after spine treatment. This may be the result of patient characteristics that lead to changes in internal standards, values, and conceptualization of their own health-related quality of life. This can result in a ‘‘moving goal post’’ when a self-report outcome measure is used for prepost comparisons. These ‘‘response shifts’’ may obfuscate relevant changes of interest to clinicians and are meaningful and worthy of study in and of themselves.

PURPOSE: To provide a background on response shift with an emphasis on distinctions relevant to spinal interventions, both surgical and nonsurgical. To describe current methods for detecting and investigating response shift phenomena, and to propose specific hypotheses that can be tested in collaborative research. METHODS AND RESULTS: Two types of methods will be briefly described: methods that require new data collection; and methods that use recent statistical and technical advances to implement secondary analysis of existing data. Two specific testable hypotheses for spinal disorders are suggested along with suggested methods for testing these hypotheses. CONCLUSIONS: A response shift will cause the patient to use the same functional outcome report measure differently pre- and posttreatment. Response shift phenomena are likely to affect the measurement properties of standard spine outcome measures and to obfuscate differences between treatments in clinical trials and cost-effectiveness studies. They point to a need for developing strategies in clinical practice to manage response shifts so that they enhance patient well-being.

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Is Preoperative Functional Magnetic Resonance Imaging Reliable for Language Areas Mapping in Brain Tumor Surgery? Review of Language Functional Magnetic Resonance Imaging and Direct Cortical Stimulation Correlation Studies

doi: 10.1227/01.NEU.0000360392.15450.C9

OBJECTIVE: Language functional magnetic resonance imaging (fMRI) has been used extensively in the past decade for both clinical and research purposes. Its integration in the preoperative imaging assessment of brain lesions involving eloquent areas is progressively more diffused in neurosurgical practice. Nevertheless, the reliability of language fMRI is unclear. To understand the reliability of preoperative language fMRI in patients operated on for brain tumors, the surgical studies that compared language fMRI with direct cortical stimulation (DCS) were reviewed.

METHODS: Articles comparing language fMRI with DCS of language areas were reviewed with attention to the lesion pathology, the magnetic field, the language tasks used pre- and intraoperatively, and the validation modalities adopted to establish the reliability of language fMRI. We tried to explore the effectiveness of language fMRI in gliomas.

RESULTS: Nine language brain mapping studies compared the findings of fMRI with those of DCS. The studies are not homogeneous for tumor types, magnetic fields, pre- and intraoperative language tasks, intraoperative matching criteria, and results. Sensitivity and specificity were calculated in 5 studies (respectively ranging from 59% to 100% and from 0% to 97%).

CONCLUSION: The contradictory results of these studies do not allow consideration of language fMRI as an alternative tool to DCS in brain lesions located in language areas, especially in gliomas because of the pattern of growth of these tumors. However, language fMRI conducted with high magnet fields is a promising brain mapping tool that must be validated by DCS in methodological robust studies.

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Gamma knife radiosurgery for arteriovenous malformations of basal ganglia, thalamus and brainstem—a retrospective study comparing the results with that for AVMs at other intracranial locations

Objective The objective of this retrospective study was to study the outcome in patients with basal ganglia, thalamus and brainstem (central/deep) arteriovenous malformations (AVMs) treated with gamma knife radiosurgery (GKS) and to compare the results with that for AVMs at other intracranial locations.
Methods and results The results of 53 patients with central AVMs and 255 patients with AVMs at other locations treated with GKS at our center between April 1997 and March 2005 with minimum follow-up of 1 year were analyzed.
Central AVMs Forty of these 53 AVMs were Spetzler-Martin grade III, 11 were grade IV, and 2 were grade V. The mean AVM volume was 4.3 cm3 (range 0.1–36.6 cm3). The mean marginal dose given was 23.3 Gy (range 16–25 Gy). The mean follow-up was 28 months (range 12–96 months). Check angiograms were advised at 2 years after GKS and yearly thereafter in the presence of residual AVM till 4 years. Presence of a residual AVM on an angiogram at 4 years after radiosurgery was considered as radiosurgical failure. Complete obliteration of the AVM was documented in 14 (74%) of the 19 patients with complete angiographic follow-up. Significantly lower obliteration rates (37% vs. 100%) were seen in larger AVMs (>3 cm3) and AVMs of higher (IV and V) Spetzler-Martin grades (28% vs. 100%). The 3- and 4-year actuarial rates of nidus obliteration were 68% and 74%, respectively. Eight patients (15%) developed radiation edema with a statistically significantly higher incidence in patients with AVM volume >3 cm3 and in patients with Spetzler-Martin grade IV and V AVMs. Five patients (9.4%) had hemorrhage in the period of latency.
Comparison of results with AVMs at other locations Patients with central AVMs presented at a younger age (mean age 22.7 years vs. 29 years), with a very high proportion (81% vs. 63%) presenting with hemorrhage. Significantly higher incidence of radiation edema (15% vs. 5%) and lower obliteration rates (74% vs. 93%) were seen in patients with central AVMs.
Conclusions GKS is an effective modality of treatment for central AVMs, though relatively lower obliteration rates and higher complication rates are seen compared to AVMs at other locations.
Key words: Basal ganglia – Brainstem – Central arteriovenous malformations – Deep brain arteriovenous malformations – Gamma knife – Thalamus
DOI 10.1007/s00701-009-0335-0

Acta Neurochirugica December 2009.

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An evidence-based clinical guideline for the use of antithrombotic therapies in spine surgery

The Spine Journal 9 (2009) 1046–1051

BACKGROUND CONTEXT: The objective of the NorthAmerican Spine Society (NASS) Evidence- Based Clinical Guideline on antithrombotic therapies in spine surgery was to provide evidence-based recommendations to address key clinical questions surrounding the use of antithrombotic therapies in spine surgery. The guideline is intended to address these questions based on the highest quality clinical literature available on this subject as of February 2008. The goal of the guideline recommendations was to assist in delivering optimum, efficacious treatment with the goal of preventing thromboembolic events.

PURPOSE: To provide an evidence-based, educational tool to assist spine surgeons in minimizing the risk of deep venous thrombosis (DVT) and pulmonary embolism (PE).

STUDY DESIGN: Systematic review and evidence-based clinical guideline.

METHODS: This report is from the Antithrombotic Therapies Work Group of the NASS Evidence- Based Guideline Development Committee. The work group was composed of multidisciplinary spine care specialists, all of whom were trained in the principles of evidence-based analysis. Each member of the group was involved in formatting a series of clinical questions to be addressed by the group. The final questions agreed on by the group are the subject of this report. A literature search addressing each question and using a specific search protocol was performed on English language references found in MEDLINE, EMBASE (Drugs and Pharmacology), and four additional evidence-based databases. The relevant literature was then independently rated by at least three reviewers using the NASS-adopted standardized levels of evidence. An evidentiary table was created for each of the questions. Final grades of recommendation for the answers to each clinical question were arrived at via Web casts among members of the work group using standardized grades of recommendation. When Level I to IV evidence was insufficient to support a recommendation to answer a specific clinical question, expert consensus was arrived at by the work group through the modified nominal group technique and is clearly identified as such in the guideline.

RESULTS: Fourteen clinical questions were formulated, addressing issues of incidence of DVT and PE in spine surgery and recommendations regarding utilization of mechanical prophylaxis and chemoprophylaxis in spine surgery. The answers to these 14 clinical questions are summarized in this article. The respective recommendations were graded by the strength of the supporting literature that was stratified by levels of evidence. CONCLUSIONS: A clinical guideline addressing the use of antithrombotic therapies in spine surgery has been created using the techniques of evidence-based medicine and using the best available evidence as a tool to assist spine surgeons in minimizing the risk of DVT and PE. The entire guideline document, including the evidentiary tables, suggestions for future research, and all references, is available electronically at the NASS Web site (www.spine.org) and will remain updated on a timely schedule


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Prediction of early secondary complications in patients with spontaneous subarachnoid hemorrhage based on accelerated sympathovagal ratios

Acta Neurochir (2009) 151:1631–1637 DOI 10.1007/s00701-009-0517-9

Purpose The development of secondary complications following spontaneous subarachnoid hemorrhage (SAH) largely depends on sympathetic overexcitation. The roles of vagal activities, however, are poorly defined. Because both components of the autonomic nervous system can be explored in the frequency domain of heart rate variability (HRV), the present study aimed to determine the dynamic evolution of autonomic activities and to identify patients at high risk for complications following hemorrhage. Methods Thirty patients with SAH were enrolled in our study. Those who suffered from symptomatic vasospasm, cerebral infarction, neurogenic pulmonary edema, or early mortality within 1 week of ictus were categorized into the complication group. Spectral analysis of HRV explored three important indices of sympathetic and vagal modu- lations: low-frequency (LF), high-frequency (HF), and LF/HF ratios. Patterns of HRV dynamics within the first 3 days were compared between complication and non complication groups. The group trends, estimated by the slopes of HRV changes, were determined for further univariate and multivariate analysis. Results Our study showed that daily HRV in the complica- tion group exhibited an approximately 2.7-fold increase of sympathovagal ratio (denoted by LF/HF). This resulted from reciprocal changes of sympathoexcitation (LF) and vagal withdrawal (HF). Multivariate analysis revealed that LF/HF slope, an indicator of the trend of sympathovagal change, was an independent variable significantly associat- ed with the development of complications.

Conclusions This study confirmed that during early SAH period, patients with and without complications presented different patterns of sympathovagal changes. LF/HF slope during the first 3 days was a significant predictor of secondary complications after SAH.

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Single-center experience with the Neuroform stent for endovascular treatment of wide-necked intracranial aneurysms

Surgical Neurology 72 (2009) 612–619. DOI:10.1016/j.surneu.2009.03.038

Background: Stent-assisted coiling is an accepted endovascular treatment (EVT) for wide-necked intracranial aneurysms. The Neuroform stent (Target Therapeutics, Fremont, Calif) is a flexible nitinol self-expandable stent that was designed to potentially overcome the limitations of balloon expandable coronary stents in the intracranial circulation. The aim of this study was to reenforce the use of this stent for EVT of wide-necked cerebral aneurysms.

Methods: Between March 2005 and March 2008, 24 patients harboring wide-necked cerebral aneurysms were treated with stent reconstruction of the aneurysm neck. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate postprocedure angiography studies were performed to determine successful coil occlusion of the aneurysm as well as patency of the parent vessel. We assessed the clinical history, aneurysm dimensions, and technical detail of the procedures, including any difficulties with stent placement and deployment, degree of aneurysm occlusion, and complications. Clinical outcome was assessed with the Glasgow Outcome Scale (GOS).

Results: The stent was easily navigated and precisely positioned in 24 of 26 cases. However, technical difficulties occurred in 9 patients, including difficulties in crossing the stents interstice in 6 cases, inadvertent stent delivery (n = 1), and incapacity of stent delivery (n = 1) and incapacity of crossing the neck (n = 1). These latter 2 cases were classified as failures of the stent-assisted technique. A single procedural complication occurred, involving transient nonocclusive intrastent thrombus formation, which was treated uneventfully with abciximab. Seventeen patients experienced excellent clinical outcomes (GOS 5), with good outcomes (GOS 4) in 5 patients and a poor outcome (GOS 3) in 2 patients. There were no treatment-related deaths or neurologic complications (mean clinical follow-up, 12 months). Angiographic results consisted of 17 complete occlusions, 4 neck remnants, and 3 incomplete occlusions.

Conclusions: The Neuroform stent is very useful for EVT of wide-necked intracranial aneurysms because it is easy to navigate and to deploy accurately. In most cases, the stent can be deployed precisely, even in very tortuous carotid siphons. Although in some cases delivery and deployment was challenging, clinically significant complications were not observed.

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Non-audiofacial morbidity after Gamma Knife surgery for vestibular schwannoma

Neurosurg Focus 27 (6):E4, 2009. (DOI: 10.3171/2009.9.FOCUS09198)

Object. While many studies have been published outlining morbidity following radiosurgical treatment of ves- tibular schwannomas, significant interpractitioner and institutional variability still exists. For this reason, the authors conducted a systematic review of the literature for non-audiofacial-related morbidity after the treatment of vestibular schwannoma with radiosurgery.

Methods. The authors performed a comprehensive search of the English-language literature to identify studies that published outcome data of patients undergoing radiosurgery treatment for vestibular schwannomas. In total, 254 articles were found that described more than 50,000 patients and were analyzed for satisfying the authors’ inclusion criteria. Patients from these studies were then separated into 2 cohorts based on the marginal dose of radiation: ≤ 13 Gy and > 13 Gy. All tumors included in this study were < 25 mm in their largest diameter.

Results. A total of 63 articles met the criteria of the established search protocol, which combined for a total of 5631 patients. Patients receiving > 13 Gy were significantly more likely to develop trigeminal nerve neuropathy than those receiving < 13 Gy (p < 0.001). While we found no relationship between radiation dose and the rate of developing hydrocephalus (0.6% for both cohorts), patients with hydrocephalus who received doses > 13 Gy appeared to have a higher rate of symptomatic hydrocephalus requiring shunt treatment (96% [> 13 Gy] vs 56% [≤ 13 Gy], p < 0.001). The rates of vertigo or balance disturbance (1.1% [> 13 Gy] vs 1.8% [≤ 13 Gy], p = 0.001) and tinnitus (0.1% [> 13 Gy] vs 0.7% [≤ 13 Gy], p = 0.001) were significantly higher in the lower dose cohort than those in the higher dose cohort.

Conclusions. The results of our review of the literature provide a systematic summary of the published rates of nonaudiofacial morbidity following radiosurgery for vestibular schwannoma.

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Effective lordosis: analysis of sagittal spinal canal alignment in cervical spondylotic myelopathy

J Neurosurg Spine 11:667–672, 2009. (DOI: 10.3171/2009.7.SPINE08656)

Object. Analysis of cervical sagittal deformity in patients with cervical spondylotic myelopathy (CSM) requires a thorough clinical and radiographic evaluation to select the most appropriate surgical approach. Angular radiographic measurements, which are commonly used to define sagittal deformity, may not be the most appropriate to use for surgical planning. The authors present a simple straight-line method to measure effective spinal canal lordosis and analyze its reliability. Furthermore, comparisons of this measurement to traditional angular measurements of sagittal cervical alignment are made in regards to surgical planning in patients with CSM.

Methods. Twenty preoperative lateral cervical digital radiographs of patients with CSM were analyzed by 3 independent observers on 3 separate occasions using a software measurement program. Sagittal measurements included C2–7 angles utilizing the Cobb and posterior tangent methods, as well as a straight-line method to measure effective spinal canal lordosis from the dorsal-caudal aspect of the C2–7 vertebral bodies. Analysis of variance for repeated measures or Cohen 3-way (kappa) correlation coefficient analysis was performed as appropriate to calculate the intra and interobserver reliability for each parameter. Discrepancies in angular and effective lordosis measurements were analyzed.

Results. Intra and interobserver reliability was excellent (intraclass coefficient > 0.75, kappa > 0.90) utilizing all 3 techniques. Four discrepancies between angular and effective lordotic measurements occurred in which images with a lordotic angular measurement did not have lordosis within the ventral spinal canal. These discrepancies were caused by either spondylolisthesis or dorsally projecting osteophytes in all cases.

Conclusions. Although they are reliable, traditional methods used to make angular measurements of sagittal cervical spine alignment do not take into account ventral obstructions to the spinal cord. The effective lordosis measurement method provides a simple and reliable means of determining clinically significant lordosis because it accounts for both overall alignment of the cervical spine as well as impinging structures ventral to the spinal cord. This method should be considered for use in the treatment of patients with CSM.


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The role of platybasia in trigeminal neuralgia

REV NEUROL 2009; 49: 630-2

Introduction. The vascular compression of a nerve is known to be the most important cause of idiopathic trigeminal neuralgia (ITN) by most authors. However, several cases of skull base deformities in patients with ITN have been reported in our bibliographic review. Aim. To compare the existence of platybasia between a group of patients with ITN and a randomized control group.

Subjects and methods. Twenty-five patients with ITN and twenty-five control subjects were X-rayed and their basal angles were measured and compared.

Results. The basal angle measured to investigate the existence of platybasia is significantly greater in the ITN group than in the control group. Platybasia was found in 10 patients with ITN. However, only two cases of platybasia were reported in the control group. Therefore in our study we have found that the incidence of platybasia in patients with ITN is significantly increased.

Conclusion. Our data demonstrated that platybasia has an important role in the pathogenesis of the ITN by altering the normal anatomy of the nerves and vessels within the posterior fossa

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Is All “Communicating” Hydrocephalus Really Communicating? Prospective Study on the Value of 3D-Constructive Interference in Steady State Sequence at 3T

Am J Neuroradiol 30:1898 –906.DOI 10.3174/ajnr.A1726

BACKGROUND AND PURPOSE: 3D-constructive interference in steady state (3D-CISS) sequence has been used to assess the CSF pathways. The aim of this study was to investigate the additive value of 3D-CISS compared with conventional sequences in the diagnosis of obstructive membranes in hydrocephalus.

MATERIALS AND METHODS: A total of 134 patients with hydrocephalus underwent MR imaging examination with a 3T unit consisting of turbo spin-echo, 3D-CISS, and cine phase-contrast (cine PC) sequences. 3D-CISS was used to assess obstructive membranes in CSF pathways compared with other sequences. Cine PC, follow-up imaging, and surgical findings were used to confirm obstructive membranes.

RESULTS: Comparing the number of noncommunicating cases by using the conventional and 3D-CISS images, we found 26 new cases (19.4%) of 134 cases that were previously misdiagnosed as communicating hydrocephalus by conventional images. 3D-CISS sequence identified obstructive membranes invisible in other sequences, which facilitated selection of neuroendoscopy in the treatment of 31 patients (23.1%) in total who would have been otherwise treated with shunt insertion. These patients included 26 newly diagnosed noncommunicating cases after demonstration of intraventricular and/or fourth ventricular outlet membranes and 5 cases of communicating hydrocephalus with obstructing cisternal membranes. There were obstructions of the foramina of Luschka in 22 of 26 newly found noncommunicating cases.

CONCLUSIONS: Conventional sequences are insensitive to obstructive membranes in CSF pathways, especially in the fourth ventricular exit foramina and the basal cisterns. 3D-CISS sequence, revealing these obstructive membranes, can alter patient treatment and prognosis.

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Sinus pericranii in children: report of 16 patients and preoperative evaluation of surgical risk

J Neurosurg Pediatrics 4:050360–500420, 2009.(DOI: 10.3171/2009.7.PEDS0994)

Sinus pericranii (SP) is a rare venous varix in an extracranial location connected to the intracranial venous system. The aim of this retrospective study was to report on 16 pediatric cases of SP with consideration of the preoperative evaluation of surgical risk.

Methods. The study population consisted of 10 patients who had undergone surgery for SP and 6 patients with concomitant craniosynostosis and SP. The mean age of the patients at presentation was 3.7 years. To identify characteristics of SP with high operative risk, 8 cases in this report and 11 previously reported cases of SP with sufficient information were categorized on the basis of the number and size of SP, the number and size of transcranial channels, the venous drainage type, and the amount of blood loss. Hemorrhage amounts were classified into 3 grades based on the description of intraoperative blood loss.

Results. Sinus pericranii not associated with craniosynostosis were resected without any postoperative morbidity. Sinus pericranii associated with craniosynostosis were preserved. After craniofacial reconstruction, 2 cases of SP with craniosynostosis regressed, completely in one patient and partially in another. These 2 patients with SP were confirmed to have compromised intracranial sinus before craniofacial reconstruction. Among a total of 19 patients, multiplicity or size (> 6 cm) of SP (p = 0.036) and multiplicity (> 3) or size (> 3 mm) of transcranial channels (p = 0.004) was associated with more severe hemorrhage grade. Sinus pericranii with peripheral venous drainage (drainer type) was not associated with hemorrhage grade after classification into 3 grades (p = 0.192). However, all 3 cases of SP with massive Grade 3 hemorrhage were the drainer type. Hemorrhage grade was correlated with the number of risk factors for SP (r = 0.793, p < 0.001).

Conclusions. Three risk factors of SP and the presence of compromised intracranial sinus are markers for high-risk SP. “Squeezed-out sinus syndrome” is suggested as a concept for SP associated with compromised intracranial sinus, mainly caused by craniosynostosis. Sinus pericranii in squeezed-out sinus syndrome probably serves as a crucial alternative to venous drainage of the brain with intracranial venous compromise. Conservative treatment for such patients with SP is recommended.


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Deep brain stimulation of the subcallosal cingulate gyrus for depression

J Neurosurg 111:1209–1215, 2009.(DOI: 10.3171/2008.10.JNS08763)

Object. Deep brain stimulation (DBS) of the subcallosal cingulate gyrus (SCG), including Brodmann area 25, is currently being investigated for the treatment of major depressive disorder (MDD). As a potential emerging therapy, optimal target selection within the SCG has still to be determined. The authors compared the location of the electrode contacts in responders and nonresponders to DBS of the SCG and correlated the results with clinical outcome to help in identifying the optimal target within the region. Based on the location of the active contacts used for long-term stimulation in responders, the authors suggest a standardized method of targeting the SCG in patients with MDD.

Methods. Postoperative MR imaging studies of 20 patients with MDD treated with DBS of the SCG were ana- lyzed. The authors assessed the location of the active contacts relative to the midcommissural point and in relation to anatomical landmarks within the medial aspect of the frontal lobe. For this, a grid with 2 main lines was designed, with 1 line in the anterior-posterior and 1 line in the dorsal-ventral axis. Each of these lines was divided into 100 units, and data were converted into percentages. The anterior-posterior line extended from the anterior commissure (AC) to the projection of the anterior aspect of the corpus callosum (CCa). The dorsal-ventral line extended from the inferior portion of the CC (CCi) to the most ventral aspect of the frontal lobe (abbreviated “Fr” for the formula).

Results. Because the surgical technique did not vary across patients, differences in stereotactic coordinates between responders and nonresponders did not exceed 1.5 mm in any axis (x, y, or z). In patients who responded to the procedure, contacts used for long-term stimulation were in close approximation within the SCG. In the anterior- posterior line, these contacts were located within a 73.2 ± 7.7 percentile distance from the AC (with the AC center being 0% and the line crossing the CCa being 100%). In the dorsal-ventral line, active contacts in responders were located within a 26.2 ± 13.8 percentile distance from the CCi (with the CCi edge being 0% and the Fr inferior limit being 100%). In the medial-lateral plane, most electrode tips were in the transition between the gray and white matter of SCG.

Conclusions. Active contacts in patients who responded to DBS were relatively clustered within the SCG. Be- cause of the anatomical variability in the size and shape of the SCG, the authors developed a method to standardize the targeting of this region.


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Classification of trigeminal neuralgia: clinical, therapeutic, and prognostic implications in a series of 144 patients undergoing microvascular decompression

Journal of Neurosurgery, Dec 2009, Vol. 111, No. 6, Pages 1231-1234. DOI: 10.3171/2008.6.17604
Trigeminal neuralgia (TN) presents a diagnostic challenge because of the variety of symptoms, findings during microvascular decompression (MVD), and postsurgical outcomes observed among patients who suffer from this disorder. Recently, a new paradigm for classification of TN was proposed, based on the quality of pain. This study represents the first clinical analysis of this paradigm.
Methods
The authors analyzed 144 consecutive cases involving patients who underwent MVD for TN. Preoperative symptoms were classified into 1 of 2 categories based on the preponderance of shocklike (Type 1 TN) or constant (Type 2 TN) pain. Analysis of clinical characteristics, neurovascular pathology, and postoperative outcome was performed.
Results
Compared with Type 2 TN, Type 1 TN patients were older, were more likely to have right-sided symptoms, and reported a shorter duration of symptoms prior to evaluation. Previous treatment by percutaneous or radiosurgical procedures was not a predictor of symptoms, surgical findings, or outcome (p = 0.48). Type 1 TN was significantly more likely to be associated with arterial compression. Venous or no compression was more common among Type 2 TN patients (p < 0.01). Type 1 TN patients were also more likely to be pain-free immediately after surgery, and less likely to have a recurrence of pain within 2 years (p < 0.05). Although a subset of patients progressed from Type 1 to Type 2 TN over time, their pathological and prognostic profiles nevertheless resembled those of Type 1 TN.
Conclusions
Type 1 and Type 2 TN represent distinct clinical, pathological, and prognostic entities. Classification of patients according to this paradigm should be helpful to determine how best to treat patients with this disorder.

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Cerebral Hemodynamic Changes in Severe Head Injury Patients Undergoing Decompressive Craniectomy

J Neurosurg Anesthesiol 2009;21:339–345

Objective: To assess the intracranial hemodynamic modifica- tions induced by a decompressive craniectomy (DC) after severe traumatic brain injury (TBI), using transcranial Doppler (TCD) ultrasonography and intracranial pressure (ICP) sensor. Mor- tality rate and neurological outcomes were also evaluated after this procedure.

Design: A prospective study was carried out on 26 TBI patients, measuring transcranial Doppler and ICP before, immediately after, and 48 hours after the DC, allowing for statistical analysis of hemodynamic changes. The mortality rate and the neuro- logical outcomes were assessed.

Measurements and Results: After DC, ICP decreased from 37±17 to 20±13mm Hg (P=0.0003). The global cerebral blood flow was modified with diastolic velocities rising from 23±15 to 31±13cm/s (P=0.0038) and a pulsatility index decreasing from 1.70±0.66 to 1.18±0.37 (P=0.0012). This normalization of the global cerebral hemodynamics after the DC was immediate, symmetric, and constant during the first 48 hours. Outcome was evaluated at 6 months: good recovery or moderate disability was observed in 11 patients (42%), persistent vegetative state in 7 patients (27%), and 8 patients died (31%).

Conclusions: The DC results in a significant, immediate, and durable improvement of ICP associated with a normalization of cerebral blood flow velocities in most TBI patients with refractory intracranial hypertension.


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External ventricular drain insertion accuracy: is there a need for change in practice?

Neurosurgery 65:1197–1201, 2009.DOI: 10.1227/01.NEU.0000356973.39913.0B

OBJECTIVE: Free-hand insertion of an external ventricular drain (EVD) is a common emergency neurosurgical procedure, mostly performed for critically ill patients. Although EVD complications have been studied thoroughly, the accuracy of EVD positioning has been audited only occasionally.

METHODS: Post-EVD insertion computed tomographic scans performed in our unit over a 2-year period were analyzed for EVD tip location and intracranial catheter length.

RESULTS: A total of 183 post-EVD insertion scans were reviewed. Of those, 73 EVD tips (39.9%) were in the ipsilateral frontal horn of the lateral ventricle (the desired tar- get); of those, 18 (25%) required EVD revision/reinsertion. Of the others, 35 (19.1%) were in the third ventricle, 33 (18%) in the body of the lateral ventricle, 19 (10.4%) in the sub- arachnoid space, 5 (2.7%) in the contralateral frontal horn, and 18 (9.8%) within the brain parenchyma. When the EVD tip was outside the desired target, 44 of the patients (40%) required EVD revision/reinsertion procedure (P = 0.0383).

CONCLUSION: Free-hand insertion of an EVD is an inaccurate procedure, and further studies are required to assess the accuracy and feasibility of the routine use of neuro- navigation, ultrasonography, or other guidance techniques and the possible implication of the decreasing revision rate, complications, and length of hospital stay.

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Wound healing after craniotomy: a randomized trial comparing scalp clips to artery forceps for scalp hemostasis

J Neurosurg 111:1175–1178, 2009.(DOI: 10.3171/2009.5.JNS081481)

Object. In this prospective randomized clinical trial, investigators looked at wound healing after craniotomy. The hypothesis was that the self-closing plastic scalp clips used for hemostasis on the skin edge might lead to local  ized microscopic tissue damage and subsequent delayed wound healing.

Methods. The trial consisted of 2 arms in which different methods were used to secure scalp hemostasis: 1) the routinely­used­plastic­clips (Scalpfix,­Aesculap); and 2)­the older method of artery forceps placed on the galea. Participants were restricted to those > 16 years of age undergoing craniotomies expected to last > 2 hours. Repeat operations were not included. One hundred fifty patients were enrolled.­They were visited at 3 and 6 weeks postoperativel by an observer blinded to the method used, and the wounds were assessed for macroscopic epithelial closure, signs of­infection, and hair regrowth by using a predefined assessment scale.

Results.­The results showed no significant difference in wound healing between the 2 groups at either 3 weeks (OR 0.55, 95% CI 0.27–1.11; p = 0.09) or 6 weeks (OR 0.79, 95% CI 0.39–1.58; p = 0.50). The length of operation was found to be a significant factor affecting wound healing at 6 weeks (OR/hour 0.68,­95%­CI 0.51–0.92; p­=0.01)

Conclusions.­The use of Aesculap Scalpfix self-retaining plastic scalp clips on the skin edge during craniotomy surgery does not appear to affect wound healing significantly to the postoperative 6 week mark.


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No effect of traction in patients with low back pain: a single centre, single blind, randomized controlled trial of Intervertebral Differential Dynamics Therapy

Eur Spine J (2009) 18:1843–1850 DOI 10.1007/s00586-009-1044-3

Low back pain (LBP) poses a significant problem to society. Although initial conservative therapy may be beneficial, persisting chronic LBP still frequently leads to expensive invasive intervention. A novel non- invasive therapy that focuses on discogenic LBP is Intervertebral Differential Dynamics Therapy (IDD Therapy, North American Medical Corp. Reg U.S.). IDD Therapy consists of intermittent traction sessions in the Accu-SPINA device (Steadfast Corporation Ltd, Essex, UK), an FDA approved, class II medical device. The intervertebral disc and facet joints are unloaded through axial distraction, positioning and relaxation cycles. The purpose of this study is to investigate the effect of IDD Therapy when added to a standard graded activity program for chronic LBP patients. In a single blind, single centre, randomized controlled trial; 60 consecutive patients were assigned to either the SHAM or the IDD Therapy. All subjects received the standard conservative therapeutic care (graded activity) and 20 sessions in the Accu-SPINA device. The traction weight in the IDD Therapy was systematically increased until 50% of a person’s body weight plus 4.45 kg (10 lb) was reached. The SHAM group received a non-therapeutic traction weight of 4.45 kg in all sessions. The main outcome was assessed using a 100-mm visual analogue scale (VAS) for LBP. Secondary outcomes were VAS scores for leg pain, Oswestry Disability Index (ODI), Short-Form 36 (SF-36). All parameters were measured before and 2, 6 and 14 weeks after start of the treatment. Fear of (re)injury due to movement or activities (Tampa Scale for Kinesiophobia), coping strategies (Utrecht Coping List) and use of pain medication were recorded before and at 14 weeks. A repeated measures analysis was performed. The two groups were comparable at baseline in terms of demographic, clinical and psychological characteristics, indicating that the random allocation had succeeded. VAS low back pain improved significantly from 61 (±25) to 32 (±27) with the IDD protocol and 53 (±26) to 36 (±27) in the SHAM protocol. Moreover, leg pain, ODI and SF-36 scores improved significantly but in both groups. The use of pain medication decreased significantly, whereas scores for kinesiophobia and coping remained at the same non-pathological level. None of the parameters showed a difference between both protocols. Both treatment regimes had a significant beneficial effect on LBP, leg pain, functional status and quality of life after 14 weeks. The added axial, intermittent, mechanical traction of IDD Therapy to a standard graded activity program has been shown not to be effective.

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