Month: May 2015

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Radiosurgery for symptomatic cavernous malformations: A multi‑institutional retrospective study in Japan

Gamma knife radiosurgery for brainstem cavernous malformations- should a patient wait for the rebleed?

Surg Neurol Int 2015;6:S249-57

A group study for symptomatic cavernous malformation (CM) treated with gamma knife (GK) surgery was performed.

Methods: A total of 298 cases collected from 23 GK centers across Japan were included. Hemorrhage was the most common manifestation, followed by seizures and neurological deficits. Most of the lesions were located in the brainstem and basal ganglia, followed by the cerebral or cerebellar hemispheres. The CMs, which had a mean diameter of 14.8 mm, were treated using GK surgery with a mean marginal dose of 14.6 Gy.

Results: In terms of hemorrhage‑free survival (HFS), a marked dissociation was confirmed between the hemorrhage and seizure groups, while no obvious difference was noted between sexes. Superficial CMs located in cerebellum or lobar regions responded to the treatment better than deeply located CMs in the basal ganglia or brainstem. No significant difference of dose‑dependent response was seen for three different ranges of marginal dose: Less than 15 Gy, between 15 and 20 Gy, and more than 20 Gy. Complications were more frequent after a marginal dose of over 15 Gy and in patients with lesions more than 15 mm in diameter. The rates of annual hemorrhage were estimated to be 7.4% during the first 2 years after radiosurgery and 2.8% thereafter. The overall hemorrhage rate after radiosurgery was 4.4%/year/patient.

Conclusion: The risk of hemorrhage is considerably reduced after GK treatment. The HFS as well as annual hemorrhage rate after GK treatment was apparently superior to that after conservative treatment for symptomatic CMs. To optimize the success of GK treatment, it is important to reduce the incidence of complications.

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Clinical factors associated with venous thromboembolism risk in patients undergoing craniotomy

Awake craniotomy for gliomas in a high-field intraoperative magnetic resonance imaging suite

J Neurosurg 122:1004–1011, 2015

Patients undergoing craniotomy are at risk for developing venous thromboembolism (VTE). The safety of anticoagulation in these patients is not clear. The authors sought to identify risk factors predictive of VTE in patients undergoing craniotomy.

METHODS The authors reviewed a national surgical quality database, the American College of Surgeons National Surgical Quality Improvement Program. Craniotomy patients were identified by current procedural terminology code. Clinical factors were analyzed to identify associations with VTE.

RESULTS Four thousand eight hundred forty-four adult patients who underwent craniotomy were identified. The rate of VTE in the cohort was 3.5%, including pulmonary embolism in 1.4% and deep venous thrombosis in 2.6%. A number of factors were found to be statistically significant in multivariate binary logistic regression analysis, including craniotomy for tumor, transfer from acute care hospital, age ≥ 60 years, dependent functional status, tumor involving the CNS, sepsis, emergency surgery, surgery time ≥ 4 hours, postoperative urinary tract infection, postoperative pneumonia, on ventilator ≥ 48 hours postoperatively, and return to the operating room. Patients were assigned a score based on how many of these factors they had (minimum score 0, maximum score 12). Increasing score was predictive of increased VTE incidence, as well as risk of mortality, and time from surgery to discharge.

CONCLUSIONS Patients undergoing craniotomy are at low risk of developing VTE, but this risk is increased by preoperative medical comorbidities and postoperative complications. The presence of more of these clinical factors is associated with progressively increased VTE risk; patients possessing a VTE Risk Score of ≥ 5 had a greater than 20-fold increased risk of VTE compared with patients with a VTE score of 0.

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Long-term Functional Outcomes and Predictors of Shunt-Dependent Hydrocephalus After Treatment of Ruptured Intracranial Aneurysms in the BRAT Trial: Revisiting the Clip vs Coil Debate

Hydrocephalus

Neurosurgery 76:608–615, 2015

Acute hydrocephalus is a well-known sequela of aneurysmal subarachnoid hemorrhage (SAH). Controversy exists about whether open microsurgical methods serve to reduce shunt dependency compared with endovascular techniques.

OBJECTIVE: To determine predictors of shunt-dependent hydrocephalus and functional outcomes after aneurysmal SAH.

METHODS: A total of 471 patients who were part of a prospective, randomized, controlled trial from 2003 to 2007 were retrospectively reviewed. All variables including demographic data, medical history, treatment, imaging, and functional outcomes were included as part of the trial. No additional variables were retrospectively collected.

RESULTS: Ultimately, 147 patients (31.2%) required a ventriculoperitoneal shunt (VPS) in our series. Age, dissecting aneurysm type, ruptured vertebrobasilar aneurysm, Fisher grade, Hunt and Hess grade, admission intraventricular hemorrhage, admission intraparenchymal hemorrhage, blood in the fourth ventricle on admission, perioperative ventriculostomy, and hemicraniectomy were significant risk factors (P < .05) associated with shunt-dependent hydrocephalus on univariate analysis. On multivariate analysis, intraventricular hemorrhage and intraparenchymal hemorrhage were independent risk factors for shunt dependency (P< .05). Clipping vs coiling treatment was not statistically associated with VPS after SAH on both univariate and multivariate analyses. Patients who did not receive a VPS at discharge had higher Glasgow Outcome Scale and Barthel Index scores and were more likely to be functionally independent and to return to work 72 months after surgery (P < .05).

CONCLUSION: There is no difference in shunt dependency after SAH among patients treated by endovascular or microsurgical means. Patients in whom shunt-dependent hydrocephalus does not develop after SAH tend to have improved long-term functional outcomes.

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Infections in patients undergoing craniotomy: risk factors associated with post-craniotomy meningitis

awake craniotomy

J Neurosurg 122:1113–1119, 2015

The authors performed a prospective study to define the prevalence and microbiological characteristics of infections in patients undergoing craniotomy and to clarify the risk factors for post-craniotomy meningitis.

Methods Patients older than 18 years who underwent nonstereotactic craniotomies between January 2006 and December 2008 were included. Demographic, clinical, laboratory, and microbiological data were systemically recorded. Patient characteristics, craniotomy type, and pre- and postoperative variables were evaluated as risk factors for meningitis

Results Three hundred thirty-four procedures were analyzed (65.6% involving male patients). Traumatic brain injury was the most common reason for craniotomy. Almost 40% of the patients developed at least 1 infection. Ventilatorassociated pneumonia (VAP) was the most common infection recorded (22.5%) and Acinetobacter spp. were isolated in 44% of the cases. Meningitis was encountered in 16 procedures (4.8%), and CSF cultures were positive for microbial growth in 100% of these cases. Gram-negative pathogens (Acinetobacter spp., Klebsiella spp., Pseudomonas aeruginosa, Enterobacter cloaceae, Proteus mirabilis) represented 88% of the pathogens. Acinetobacter and Klebsiella spp. demonstrated a high percentage of resistance in several antibiotic classes. In multivariate analysis, the risk for meningitis was independently associated with perioperative steroid use (OR 11.55, p = 0.005), CSF leak (OR 48.03, p < 0.001), and ventricular drainage (OR 70.52, p < 0.001).

Conclusions: Device-related postoperative communication between the CSF and the environment, CSF leak, and perioperative steroid use were defined as risk factors for meningitis in this study. Ventilator-associated pneumonia was the most common infection overall. The offending pathogens presented a high level of resistance to several antibiotics.

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Treatment Outcomes of Unruptured Arteriovenous Malformations With a Subgroup Analysis of ARUBA Eligible Patients

AVM

Neurosurgery 76:563–570, 2015

The design and conclusions of A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA) trial are controversial, and its structure limits analysis of patients who could potentially benefit from treatment.

OBJECTIVE: To analyze the results of a consecutive series of patients with unruptured brain arteriovenous malformations (BAVMs), including a subgroup analysis of ARUBAeligible patients.

METHODS: One hundred five patients with unruptured BAVMs were treated over an 8-year period. From this series, 90 adult patients and a subgroup of 61 patients determined to be ARUBA eligible were retrospectively reviewed. A subgroup analysis for Spetzler-Martin grades I/II, III, and IV/V was performed. The modified Rankin Scale was used to assess functional outcome.

RESULTS: Persistent deficits, modified Rankin Scale score deterioration, and impaired functional outcome occurred less frequently in ARUBA-eligible grade I/II patients compared with grade III to V patients combined (P = .04, P = .04, P = .03, respectively). Twenty-two of 39 patients (56%) unruptured grade I and II BAVMs were treated with surgery without and with preoperative embolization, and all had a modified Rankin Scale score of 0 to 1 at the last follow-up. All patients treated with surgery without and with preoperative embolization had radiographic cure at the last follow-up.

CONCLUSION: The results of ARUBA-eligible and unruptured grade I/II patients overall show that excellent outcomes can be obtained in this subgroup of patients, especially with surgical management. Functional outcomes for ARUBA-eligible patients were similar to those of patients who were randomized to medical management in ARUBA. On the basis of these data, in appropriately selected patients, we recommend treatment for low-grade BAVMs.

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The cranial orbital buttress technique for nonsyndromic unicoronal and metopic craniosynostosis

The cranial orbital buttress technique for nonsyndromic unicoronal and metopic craniosynostosis

Neurosurg Focus 38 (5):E4, 2015

Current craniosynostosis procedures can result in complications due to absorbable plates and screws or other specialized expensive hardware. The authors propose the cranial orbital buttress (COB) technique of frontoorbital remodeling for metopic and unicoronal synostoses, wherein no plates or screws are used. They hypothesize that, with this technique, aesthetically acceptable outcomes for unicoronal and metopic synostosis can be achieved. In this article, they present this technique and compare the results with current frontoorbital remodeling practices.

METHODS The authors conducted a retrospective chart review of cases in which patients with nonsyndromic unicoronal or metopic synostosis underwent cranio-orbital surgery at their institution from 1985 through 2009. Operative parameters, surgical variations, and complications were analyzed. The COB technique uses a 1-piece switch, hemiforeheads, or multiple pieces for forehead remodeling. The supraorbital bar is reconstructed in patients with metopic synostosis using a double wedge or greenstick fracture technique, and in patients with unicoronal synostosis a hinge procedure based on a 1.5-orbital osteotomy is used. The supraorbital bar is advanced and supported in place by bone graft(s) inserted at the lateral aspect(s) of the orbit(s) to form a buttress, with fixation done using absorbable sutures.

RESULTS A total of 79 cases met the criteria for inclusion in the study. Twenty-nine patients had metopic synostosis, 3 had combined metopic and sagittal synostoses, and 47 had unicoronal synostosis. The patients’ mean age at surgery was 11.4 ± 10.1 months and the mean operative time was 183.4 ± 41.0 minutes. The mean length of hospital stay was 3.7 ± 1.2 days. The mean blood loss was 150.0 ± 125.6 ml, and 33% of patients required a blood transfusion (mean volume 206.9 ± 102.3 ml). In metopic synostosis, hemiforeheads were used most often (24/29, 83%), and the supraorbital bar was remodeled using a bilateral intracranial orbital osteotomy followed by a double wedge modification (23/29,79%) or a greenstick fracture (4/29 14%) for milder cases. Forehead remodeling for unicoronal synostosis was by a forehead switch (39/47, 83%) and the supraorbital bar was remodeled using a 1.5-orbital intracranial orbital osteotomy (34/47, 72%) such that the bar was advanced on the abnormal side and hinged at the midline of the normal orbit. Perioperative complications occurred in 19% of cases and included dural tears (16%), inconsequential subdural hematoma (1.3%), and nasal greenstick fracture (1.3%). The total reoperation rate was 7.6% (cranioplasties for irregular contours, 6.3%; scar revision, 1.3%).

CONCLUSIONS The COB remodeling technique is simple and efficient, gives acceptable outcomes, and is less resource intensive than previous techniques reported in the literature.

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Long-term Outcomes of the US FDA IDE Prospective, Randomized Controlled Clinical Trial Comparing PCM Cervical Disc Arthroplasty With Anterior Cervical Discectomy and Fusion”

PCM vs ACDF

Spine 2015;40:674–683

Study Design. Prospective, multicenter, randomized clinical trial.

Objective. To evaluate the long-term safety and effectiveness of the PCM Cervical Disc compared with anterior cervical discectomy and fusion (ACDF) in treatment of patients with symptomatic single- level degenerative spondylosis between C3–C4 and C7–T1 with or without prior cervical fusion.

Summary of Background Data. The 2-year results of the PCM Cervical Disc trial have been reported previously. The current study reports the long-term results of the same trial.

Methods. Patients with single-level cervical spondylosis and radiculopathy with or without myelopathy unresponsive to nonoperative treatment were enrolled. The per protocol patient sample at 5 years included 293 patients (163 PCM, 130 ACDF). Adverse events and secondary surgical procedures are reported on the cohorts through current follow-up, which include 110 patients (68 PCM, 42 ACDF) at 7 years.

Results. At 5 years postoperative, all patient-reported outcomes— neck and arm pain visual analogue scale score, neck disability index, and general health (36-Item Short Form Health Survey physical and mental component scores: physical component summary, mental component summary)—were significantly improved from baselines in both groups, and mean scores were significantly better in the PCM group for neck disability index (P = 0.001), neck pain (P = 0.002), general health (Pphysical component summary= 0.014; P mental component summary= 0.004), and patient satisfaction (P = 0.005).
PCM patients trended toward fewer 2- to 7-year device-related
serious adverse events (1/214, 0.5% PCM; 2/190, 1.1% ACDF) and secondary surgical procedures (7/211, 3.3% PCM; 14/290, 7.6% ACDF). Adjacent-level degeneration was radiographically more frequent after ACDF (33.1% PCM, 50.9% ACDF; P = 0.006) and was the primary indication for the increase in late-term secondary surgical procedures after ACDF.

Conclusion. The long-term results show good clinical outcomes after ACDF and PCM arthroplasty. PCM patients showed greater improvement in neck disability index and neck pain scores with a lower rate of radiographical adjacent-level degeneration and a trend toward fewer secondary surgical procedures. These data support PCM arthroplasty to be a viable and sustainable alternative to ACDF.
Level of Evidence: 1

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Adjacent Segment Pathology Requiring Reoperation After Anterior Cervical Arthrodesis

Outcomes After Anterior Cervical Discectomy and Fusion in Professional AthletesSpine 2015;40:E571–E577

Study Design. A retrospective study.

Objective. The purpose of this study was to determine, using survivorship analysis, the rate of adjacent segment pathology (ASP) development and to identify the risk factors for reoperation.

Summary of Background Data. The study of Hilibrand defi ned “adjacent segment disease” as symptomatic radiculopathy or myelopathy due to an adjacent segment documented on 2 consecutive offi ce visits. In addition to being somewhat subjective, their criterion is not as practical as identifying the rate of adjacent pathology by the need for reoperation.

Methods. This was a retrospective analysis of 1038 consecutive patients who underwent primary anterior cervical spine arthrodesis for radiculopathy and/or myelopathy by 1 surgeon. Annual incidence and prevalence of ASP requiring surgery were calculated and survivorship was determined. We used the Cox regression for risk factor analysis.

Results. Secondary surgery on adjacent segments occurred at a relatively constant rate of 2.4% per year (95% confi dence interval, 1.9–3.0). The Kaplan-Meier analysis predicted that 22.2% of patients would need reoperation at adjacent segments by 10 years postoperatively. Factors increasing the risk were smoking, female sex, and the number of arthrodesis segments. One or 2-segment arthrodesis had an 1.8 times greater risk than arthrodesis involving 3 or more segments. Age, neurological diagnosis, diabetes, Klippel- Feil syndrome, and noncontiguous segmental-type ossifi cation of posterior longitudinal ligament were not signifi cant risks.

Conclusion. Patients treated with 1- or 2-segment anterior cervical arthrodesis are more likely to develop ASP than those treated with arthrodesis involving 3 or more segments. Smokers and women had a higher ASP reoperation rate. Our series, the largest in the literature, predicts that 22.2% of patients will require reoperation for ASP within 10 years, substantially higher than the Hilibrand study.

Level of Evidence: 3

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Silent Arteriovenous Malformation Hemorrhage and the Recognition of “Unruptured” Arteriovenous Malformation Patients Who Benefit From Surgical Intervention

Silent Arteriovenous Malformation Hemorrhage and the Recognition of “Unruptured” Arteriovenous Malformation Patients Who Benefit From Surgical Intervention

Neurosurgery 76:592–600, 201

Arteriovenous malformation (AVM) patients present in 4 ways relative to hemorrhage: (1) unruptured, without a history or radiographic evidence of old hemorrhage (EOOH); (2) silent hemorrhage, without a bleeding history but with EOOH; (3) ruptured, with acute bleeding but without EOOH; and (4) reruptured, with acute bleeding and EOOH. OBJECTIVE: We hypothesized that characteristics and outcomes in the unrecognized group of silent hemorrhage patients may differ from those of unruptured patients.

METHODS: Two hundred forty-two patients operated-on since 1997 were categorized by hemorrhage status and hemosiderin positivity in this cohort study: unruptured (group 1), silent hemorrhage (group 2), and ruptured/reruptured (group 3/4). Group 3/4 was combined because hemosiderin cannot distinguish acute hemorrhage from older silent hemorrhage.

RESULTS: Hemosiderin was found in 45% of specimens. Seventy-five patients (31.0%) had unruptured AVMs, 30 (12.4%) had silent hemorrhage, and 137 (56.6%) had ruptured/ reruptured AVMs. Deep drainage, posterior fossa location, preoperative modified Rankin Scale (mRS) score, outcome, and macrophage score were different across groups. Only the macrophage score was different between the groups without clinical hemorrhage. Outcomes were better in silent hemorrhage patients than in those with frank rupture (mean mRS scores of 1.2 and 1.7, respectively).

CONCLUSION: One-third of patients present with silent AVM hemorrhage. No clinical or anatomic features differentiate these patients from unruptured patients, except the presence of hemosiderin and macrophages. Silent hemorrhage can be diagnosed using magnetic resonance imaging with iron-sensitive imaging. Silent hemorrhage portends an aggressive natural history, and surgery halts progression to rerupture. Good final mRS outcomes and better outcomes than in those with frank rupture support surgery for silent hemorrhage patients, despite the findings of ARUBA.

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Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation

Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation

J Neurosurg 122:1068–1075, 2015

The authors completed a prospective, institutional review board–approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed.

Methods Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. All patients underwent complete T1, T2, and cine MRI studies in the supine position preoperatively as a baseline. After the patient was placed prone with the neck flexed in position for surgery, iMRI was performed. The patient then underwent a bone decompression of the foramen magnum and arch of C-1, and the MRI was repeated. If obstruction was still present, then in a stepwise fashion the patient underwent dural splitting, duraplasty, and coagulation of the tonsils, with an iMRI study performed after each step guiding the decision to proceed further.

Results Eighteen patients underwent PFD for Chiari I malformations between November 2011 and February 2013; 15 prone preincision iMRIs were performed. Fourteen of these patients (93%) demonstrated significant improvement of CSF flow through the foramen magnum dorsal to the tonsils with positioning only. This improvement was so notable that changes in CSF flow as a result of the bone decompression were difficult to discern.

Conclusions The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is positioned for surgery.

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Endovascular and Surgical Treatment of Internal Carotid Bifurcation Aneurysms: Comparison of Results, Outcome, and Mid-Term Follow-up

Categorization of aneurysms by their origin and projection

Neurosurgery 76:540–551, 2015

Aneurysms of the internal carotid artery (ICA) bifurcation are rare, and no studies have compared patient outcomes after endovascular vs surgical treatment.

OBJECTIVE: To report the safety, efficacy, and follow-up outcome of these 2 treatment options for patients with ICA bifurcation aneurysms.

METHODS: Patient and aneurysm characteristics, treatment results, and follow-up outcomes (at 30 months) were analyzed from patient records and review of imaging findings.

RESULTS: A total of 58 patients with ICA bifurcation aneurysms were treated. By interdisciplinary consensus, 30 aneurysms were assigned for coiling and 28 for clipping. Patients who underwent surgical clipping were younger and had larger aneurysms. More patients were assigned to coiling if their aneurysms originated only from the ICA bifurcation or projected superiorly. For the combined angiographic endpoint, complete and nearly complete occlusion (Raymond-Roy I + II), similar rates of 96% (coiling) or 100% (clipping) could be achieved. Raymond-Roy I occlusion occurred more often after clipping (79% vs 41% coiling). Follow-up of the endovascular group showed minor recanalization of the aneurysm neck (Raymond-Roy II) in 42%. One patient (4%) showed a major recanalization (Raymond-Roy III) and needed re-treatment. For incidental findings, no bleeding complications or new persistent neurological deficits occurred during follow-up.

CONCLUSION: Treatment of ICA bifurcation aneurysms after interdisciplinary assignment to clipping or coiling is effective and safe. Despite significantly more minor recanalizations after coiling, the re-treatment rate was very low, and no bleeding was observed during follow-up. Multivariate analysis revealed that origin only from the ICA bifurcation was an independent predictor of aneurysm recanalization after endovascular treatment.

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Deep brain stimulation versus anterior capsulotomy for obsessive-compulsive disorder: a review of the literature

DBS

J Neurosurg 122:1028–1037, 2015

Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric condition. Traditionally, anterior capsulotomy (AC) was an established procedure for treatment of patients with refractory OCD. Over recent decades, deep brain stimulation (DBS) has gained popularity.

In this paper the authors review the published literature and compare the outcome of AC and DBS targeting of the area of the ventral capsule/ventral striatum (VC/VS) and nucleus accumbens (NAcc). Patients in published cases were grouped according to whether they received AC or DBS and according to their preoperative scores on the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and then separated according to outcome measures: remission (YBOCS score < 8); response (≥ 35% improvement in YBOCS score); nonresponse (< 35% improvement in YBOCS score); and unfavorable (i.e., worsening of the baseline YBOCS score).

Twenty studies were identified reporting on 170 patients; 62 patients underwent DBS of the VC/VS or the NAcc (mean age 38 years, follow-up 19 months, baseline YBOCS score of 33), and 108 patients underwent AC (mean age 36 years, follow-up 61 months, baseline YBOCS score of 30). In patients treated with DBS there was a 40% decrease in YBOCS score, compared with a 51% decrease for those who underwent AC (p = 0.004). Patients who underwent AC were 9% more likely to go into remission than patients treated with DBS (p = 0.02). No difference in complication rates was noted.

Anterior capsulotomy is an efficient procedure for refractory OCD. Deep brain stimulation in the VC/VS and NAcc area is an emerging and promising therapy. The current popularity of DBS over ablative surgery for OCD is not due to nonefficacy of AC, but possibly because DBS is perceived as more acceptable by clinicians and patients.

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Atlantoaxial instability in acute odontoid fractures is associated with nonunion and mortality

Atlantoaxial-instability-in-acute-odontoid-fractures-is-associated-with-nonunion-and-mortality_2015_The-Spine-Journal

The Spine Journal 15 (2015) 910–917

Odontoid fractures are the most common geriatric cervical spine fractures. Nonunion rates have been reported to be up to 40% and mortality up to 35%, and poor functional outcomes are common. Atlantoaxial instability (AAI) is a plausible prognostic factor, but its role has not been previously examined.

PURPOSE: To determine the effect of severe AAI on the outcomes of nonunion and mortality in patients with acute odontoid fractures.

STUDY DESIGN: Retrospective cohort/single institution.

PATIENT SAMPLE: One hundred twenty-four consecutive patients with acute odontoid fractures.

OUTCOME MEASURES: Rates of nonunion and mortality.

METHODS: Two independent blinded reviewers measured AAI using postinjury computed tomography scans. Patients were classified as having ‘‘severe’’ or ‘‘minimal’’ AAI on the basis of greater versus less than or equal to 50% mean subluxation across each C1–C2 facet joint. Rates of nonunion and mortality were compared using independent samples t tests and adjusted for age, displacement, and subtype using binary logistic regression.

RESULTS: One hundred seven patients had minimal AAI and 17 had severe AAI. Mean follow-up was 4.4 months (standard deviation54.6). Patients with severe AAI were more likely to experience nonunion (29% vs. 10%, respectively; p5.03) and mortality (35% vs. 14%, respectively; p5.03) regardless of treatment modality. Fracture displacement correlated with AAI (r250.65). When adjusted for patient age, the odds ratio of nonunion with severe AAI approached significance at 3.3 (95% confidence interval [CI]: 0.9–11.7). Mortality prediction with AAI approached a twofold increased risk (odds ratio52.1; 95% CI: 0.6–6.8). In patients with Type-II fractures, the odds of mortality with severe AAI approached a threefold higher risk (odds ratio53.3; 95% CI: 0.9–12.3).

CONCLUSIONS: Patients with acute odontoid fractures and severe AAI may be more likely to experience nonunion and mortality, suggesting the possibility that aggressive management could be warranted. Further investigation with a large prospective study including patient-important functional outcomes is justified. 

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Does Navigated Transcranial Stimulation Increase the Accuracy of Tractography?

Does Navigated Transcranial Stimulation Increase the Accuracy of Tractography?

Neurosurgery 0:1–10, 2015

Tractography based on diffusion tensor imaging has become a popular tool for delineating white matter tracts for neurosurgical procedures.

OBJECTIVE: To explore whether navigated transcranial magnetic stimulation (nTMS) might increase the accuracy of fiber tracking.

METHODS: Tractography was performed according to both anatomic delineation of the motor cortex (n = 14) and nTMS results (n = 9). After implantation of the definitive electrode, stimulation via the electrode was performed, defining a stimulation threshold for eliciting motor evoked potentials recorded during deep brain stimulation surgery. Others have shown that of arm and leg muscles. This threshold was correlated with the shortest distance between the active electrode contact and both fiber tracks. Results were evaluated by correlation to motor evoked potential monitoring during deep brain stimulation, a surgical procedure causing hardly any brain shift.

RESULTS: Distances to fiber tracks clearly correlated with motor evoked potential thresholds. Tracks based on nTMS had a higher predictive value than tracks based on anatomic motor cortex definition (P < .001 and P = .005, respectively). However, target site, hemisphere, and active electrode contact did not influence this correlation.

CONCLUSION: The implementation of tractography based on nTMS increases the accuracy of fiber tracking. Moreover, this combination of methods has the potential to become a supplemental tool for guiding electrode implantation.

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Birth desires and intentions of women diagnosed with a meningioma

Petroclival meningioma outcomes

J Neurosurg 122:1151–1156, 2015

To the authors’ knowledge, no previous study has examined the impact of meningioma diagnosis on women’s birth desires and intentions. In an exploratory study, the authors surveyed women affected by meningioma to determine their attitudes toward childbearing and the influences, including physician recommendations, on this major life decision and compared their responses to those of women in the general population.

Methods Meningioma survivors from the Meningioma Mommas online support group participated in an online survey that included questions on their birth desires and intentions, whether the risk of disease recurrence influenced their reproductive decisions, and risks communicated to them by their physicians. Using chi-square and rank-sum tests, the authors compared the survey participants’ responses with those of the general population as assessed by the 2006– 2010 National Survey of Family Growth. Logistic regression was used to adjust for differences in age, race, ethnicity, education, parity, pregnancy status, and infertility status in these populations.

Results Respondents with meningioma were more likely than those in the general population to report wanting a baby (70% vs 54%, respectively), intending to have a baby (27% vs 12%, respectively), and being very sure about this intention (10% vs 2%, respectively). More than half (32 of 61) of the women of childbearing age reported being advised by a physician about potential risk factors for recurrence of the meningioma, and pregnancy was the most commonly cited risk factor (26 of 61). The most common factor influencing birth desires and intentions was risk of the meningioma returning and requiring more treatment, which was reported by nearly two-thirds of the women in their childbearing years.

Conclusions A majority of the meningioma survivors of childbearing age who completed the survey reported a desire for children, although concern about the risk of meningioma recurrence was an important factor for these women when making reproductive decisions. Physicians are in a position to educate their patients on potential risk factors for recurrence and to provide contact information for services such as counseling and family planning.

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Comparison of language cortex reorganization patterns between cerebral arteriovenous malformations and gliomas: a functional MRI study

Comparison of language cortex reorganization patterns between cerebral arteriovenous malformations and gliomas- a functional MRI study

J Neurosurg 122:996–1003, 2015

Cerebral arteriovenous malformations (AVMs) are congenital malformations that may grow in the language cortex but usually do not lead to aphasia. In contrast, language dysfunction is a common presentation for patients with a glioma that involves language areas. The authors attempted to demonstrate the difference in patterns of language cortex reorganization between cerebral AVMs and gliomas by blood oxygen level–dependent (BOLD) functional MRI (fMRI) evaluation.

Methods The authors retrospectively reviewed clinical and imaging data of 63 patients with an unruptured cerebral AVM (AVM group) and 38 patients with a glioma (glioma group) who underwent fMRI. All the patients were right handed, and all their lesions were located in the left cerebral hemisphere. Patients were further categorized into 1 of the 2 following subgroups according to their lesion location: the BA subgroup (overlying or adjacent to the inferior frontal or the middle frontal gyri [the Broca area]) and the WA subgroup (overlying or adjacent to the supramarginal, angular, or superior temporal gyri [the Wernicke area]). Lateralization indices of BOLD signal activations were calculated separately for the Broca and Wernicke areas. Statistical analysis was performed to identify the difference in patterns of language cortex reorganization between the 2 groups.

Results In the AVM group, right-sided lateralization of BOLD signal activations was observed in 23 patients (36.5%), including 6 with right-sided lateralization in the Broca area alone, 12 in the Wernicke area alone, and 5 in both areas. More specifically, in the 34 patients in the AVM-BA subgroup, right-sided lateralization of the Broca area was detected in 9 patients (26.5%), and right-sided lateralization of the Wernicke area was detected in 4 (11.8%); in the 29 patients in the AVM-WA subgroup, 2 (6.9%) had right-sided lateralization of the Broca area, and 13 (44.8%) had right-sided lateralization of the Wernicke area. In the glioma group, 6 patients (15.8%) showed right-sided lateralization of the Wernicke area, including 2 patients in the glioma-BA subgroup and 4 patients in the glioma-WA subgroup. No patient showed right-sided lateralization of the Broca area. Moreover, although the incidence of right-sided lateralization was higher in cases of low-grade gliomas (5 in 26 [19.2%]) than in high-grade gliomas (1 in 12 [8.3%]), no significant difference was detected between them (p = 0.643). Compared with the AVM group, the incidence of aphasia was significantly higher (p < 0.001), and right-sided lateralization of language areas was significantly rarer (p = 0.026) in the glioma group.

Conclusions Right-sided lateralization of BOLD signal activations was observed in patients with a cerebral AVM and in those with a glioma, suggesting that language cortex reorganization may occur with both diseases. However, the potential of reorganization in patients with gliomas seems to be insufficient compared with patients AVMs, which is suggested by clinical manifestations and the fMRI findings. Moreover, this study seems to indicate that in patients with an AVM, a nidus near the Broca area mainly leads to right-sided lateralization of the Broca area, and a nidus near the Wernicke area mainly leads to right-sided lateralization of the Wernicke area.

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A Pilot Cost-Effectiveness Analysis of Treatments in Newly Diagnosed High-Grade Gliomas: The Example of 5-Aminolevulinic Acid Compared With White-Light Surgery

5-ALA-induced fluorescence behavior of reactive tissue changes following glioblastoma treatment with radiation and chemotherapy

Neurosurgery 76:552–562, 2015

High-grade gliomas are aggressive, incurable tumors characterized by extensive diffuse invasion of the normal brain parenchyma. Novel therapies at best prolong survival; their costs are formidable and benefit is marginal. Economic restrictions thus require knowledge of the cost-effectiveness of treatments. Here, we show the cost-effectiveness of enhanced resections in malignant glioma surgery using a well-characterized tool for intraoperative tumor visualization, 5-aminolevulinic acid (5-ALA).

OBJECTIVE: To evaluate the cost-effectiveness of 5-ALA fluorescence-guided neurosurgery compared with white-light surgery in adult patients with newly diagnosed high-grade glioma, adopting the perspective of the Portuguese National Health Service.

METHODS: We used a Markov model (cohort simulation). Transition probabilities were estimated with the use of data from 1 randomized clinical trial and 1 noninterventional prospective study. Utility values and resource use were obtained from published literature and expert opinion. Unit costs were taken from official Portuguese reimbursement lists (2012 values). The health outcomes considered were quality-adjusted life-years, lifeyears, and progression-free life-years. Extensive 1-way and probabilistic sensitivity analyses were performed.

RESULTS: The incremental cost-effectiveness ratios are below €10 000 in all evaluated outcomes, being around €9100 per quality-adjusted life-year gained, €6700 per life-year gained, and €8800 per progression-free life-year gained. The probability of 5-ALA fluorescence-guided surgery cost-effectiveness at a threshold of €20000 is 96.0% for quality-adjusted life-year, 99.6% for life-year, and 98.8% for progression-free life-year.

CONCLUSION: 5-ALA fluorescence-guided surgery appears to be cost-effective in newly diagnosed high-grade gliomas compared with white-light surgery. This example demonstrates cost-effectiveness analyses for malignant glioma surgery to be feasible on the basis of existing data.

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Deep brain stimulation versus anterior capsulotomy for obsessive-compulsive disorder: a review of the literature

brain-ocd-treatment

J Neurosurg 122:1028–1037, 2015

Obsessive-compulsive disorder (OCD) is a chronic and debilitating psychiatric condition. Traditionally, anterior capsulotomy (AC) was an established procedure for treatment of patients with refractory OCD. Over recent decades, deep brain stimulation (DBS) has gained popularity.

In this paper the authors review the published literature and compare the outcome of AC and DBS targeting of the area of the ventral capsule/ventral striatum (VC/VS) and nucleus accumbens (NAcc).

Patients in published cases were grouped according to whether they received AC or DBS and according to their preoperative scores on the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and then separated according to outcome measures: remission (YBOCS score < 8); response (≥ 35% improvement in YBOCS score); nonresponse (< 35% improvement in YBOCS score); and unfavorable (i.e., worsening of the baseline YBOCS score).

Twenty studies were identified reporting on 170 patients; 62 patients underwent DBS of the VC/VS or the NAcc (mean age 38 years, follow-up 19 months, baseline YBOCS score of 33), and 108 patients underwent AC (mean age 36 years, follow-up 61 months, baseline YBOCS score of 30). In patients treated with DBS there was a 40% decrease in YBOCS score, compared with a 51% decrease for those who underwent AC (p = 0.004). Patients who underwent AC were 9% more likely to go into remission than patients treated with DBS (p = 0.02). No difference in complication rates was noted.

Anterior capsulotomy is an efficient procedure for refractory OCD. Deep brain stimulation in the VC/VS and NAcc area is an emerging and promising therapy. The current popularity of DBS over ablative surgery for OCD is not due to nonefficacy of AC, but possibly because DBS is perceived as more acceptable by clinicians and patients.

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Cerebral Venous Sinus Thrombosis on Unenhanced CT

Cerebral Venous Sinus Thrombosis on Unenhanced CT

Neurosurg Q 2015;25:154–160

The aim of the study was to investigate computed tomography (CT) signs of cerebral venous sinus thrombosis (CVST), so as to increase clinicians’ awareness of CVST and improve the sensitivity of the diagnosis.

Materials and Methods: We retrospectively analyzed all the CVST cases primary diagnosed by CT and confirmed further by magnetic resonance imaging (MRI) or other clinical methods within the past 4 years in our institution. In total, 11 cases including 6 male and 5 female patients with a mean age of 31.0 years were studied. All patients had emergency CT examination for complaints of headache. The initial CT examinations were performed within 7 days after the onset in 7 cases and over 7 days in the other 4 cases. Six cases had continuous follow-up CT examinations, twice in 4 and 3 times in 2. The analysis items focus on the density change by measuring the CT values of involved venous sinuses in different phases, as well as indirect signs including venous infarction and hemorrhage. As a comparison, we measured CT values of normal venous sinuses in 40 healthy people with age ranging from 20 to 60 years.

Results: Of the patients with CT examinations performed within a week after the onset, 6 cases displayed uniform high density in related venous sinuses with a mean value of 72 HU. One week later, the densities declined slightly or reached isodensity with a mean value of 58 HU. The follow-up CT demonstrated the density changes of sinuses with the extension of the course of CVST, from high density gradually attenuating into mixed density, and into isodensity at last. During 7 to 10 days after the onset in 3 cases, the involved sinuses showed central high density with peripheral isodensity. A change of involved sinuses from high-density to isodensity occurring in different sites was found in 1 case on follow-up CT. Cortical vein thrombosis with secondary hemorrhage in 2 cases and CVST with subarachnoid hemorrhage in 2 cases were revealed in our study.

Conclusions: On CT, the CVST presented as the attenuation of the sinuses from high to isodensity with its resolution course. In the first week, the involved sinuses mainly appear as high density, then in 7 to 10 days decrease to mixed density as central high density and peripheral isodensity, and gradually to uniform isodensity at last. The secondary infarction and hemorrhage are important indirect signs of CVST. Understanding the abnormal density change of venous sinuses and intracerebral indirect signs on CT could improve our diagnostic sensitivity for CVST.

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Craniocervical Instability in the Setting of Os Odontoideum

Craniocervical Instability in the Setting of Os Odontoideum

Neurosurgery 76:514–521, 2015

Our clinical understanding of os odontoideum (OO) remains incomplete. Congenital and traumatic causes have been proposed and advocated. Clinical presentations range from asymptomatic to axial pain to myelopathy or vertebral-basilar ischemia. A consensus for surgical management exists for those found to have an unstable atlantoaxial complex or symptomatic cranial-vertebral junction compression.

OBJECTIVE: To evaluate the clinical presentation and surgical outcomes of patients with OO and an unstable atlantoaxial complex or symptomatic cranial-vertebral junction compression.

METHODS: Patients with a diagnosis of OO who underwent surgical management were included. Patients were excluded on the basis of previous C2 fracture, Fielding diagnostic criteria, and inadequate follow-up. History of trauma and presenting symptoms were assessed. Clinical and neurological improvements were measured with the use of patient satisfaction scores and the Japanese Orthopaedic Association scores. Fusion status was documented with the use of radiographs and computed tomographic imaging.

RESULTS: Of 279 patients, 112 reported a history of cranial-vertebral junction trauma, whereas 28 were diagnosed with congenital malformations. Clinically, 84.9% of patients presented with myelopathy, with pain presented in 42.6%. Atlantoaxial fixation was performed in 240 patients, occiput-to-C2 fixation in 35 patients, and extended occipitocervical fixation in 4 patients. Mean follow-up was 40.3 months. Complications were reported in 2.4% of patients. Japanese Orthopaedic Association scores improved from a preoperative mean of 12.4 to 14.8. Two hundred thirty-five patients (77.7%) improved, with 30 patients experiencing no change in symptoms and 14 patients deteriorating. Fusion was achieved in 96.8% of patients.

CONCLUSION: Our data reveal that surgical treatment for OO using the indications and techniques delineated is associated with high satisfaction rates, improved functional scores, and high fusion rates with low complication rates.

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