Can Preoperative Imaging Predict Tumor Involvement of the Anterior Clinoid in Clinoid Region Meningiomas?

Can Preoperative Imaging Predict Tumor Involvement of the Anterior Clinoid in Clinoid Region Meningiomas?

Neurosurgery 77:525–530, 2015

Anterior clinoid region meningiomas may infiltrate the bone over which they arise, therefore requiring an anterior clinoidectomy to achieve a Simpson grade 1 resection. A clinoidectomy, however, is not without risks.

OBJECTIVE: We performed a study of diagnostic accuracy investigating whether preoperative imaging could predict tumor involvement of the clinoid, and thereby tailor the degree of bony removal.

METHODS: Patients having undergone resection of a clinoid region meningioma between 2001 and 2011 were identified. Included in further analysis were those patients in whom a clinoidectomy was performed with subsequent pathologically confirmed presence or absence of tumor in the clinoid process on decalcified specimens. Two neuroradiologists, blinded to pathology results, independently reviewed available preoperative imaging and stated whether or not they anticipated the clinoid to be involved by tumor. Interobserver agreement and the ability to accurately predict tumor involvement of the clinoid were then analyzed.

RESULTS: Sixty-two patients were included in the final analysis. Interobserver agreement was 100%. Sensitivity and specificity of preoperative imaging to predict tumor involvement was 89% and 52%, respectively, with positive and negative likelihood ratios of 1.85 and 0.20. Positive and negative predictive values were 73% and 76%, respectively.

CONCLUSION: Preoperative imaging of clinoid region meningiomas can accurately predict the presence or absence of tumor involvement of the clinoid in only approximately 75% of cases. In light of the fact that a quarter of patients with radiographically negative clinoids will have tumor present on pathological analysis, we recommend a clinoidectomy for all clinoid region meningiomas.

Minimally Invasive Spinal Surgery in the Elderly: Does It Make Sense?

Minimally Invasive Spinal Surgery in the Elderly- Does It Make Sense

Neurosurgery 77:S108–S115, 2015

Lumbar degenerative disease can have varied pathoanatomy, with stenosis, spondylolisthesis, and scoliosis contributing to significant pain and disability. Among appropriately selected patients, surgical intervention can treat both back pain and leg pain and improve quality of life in a cost-effective manner with an acceptable safety profile. The evolution of minimally invasive surgical (MIS) techniques offers the potential to decrease the physiological impact of surgery and to improve the complication profile while achieving the same spine surgical objectives. The utility of such techniques among elderly patients >65 years of age has not been rigorously evaluated, and this systematic review sought to define the utility and safety of MIS spinal surgery for decompression, interbody fusion, and deformity correction in this population.

Review of 2 studies for MIS lumbar decompression reveals that the majority of elderly patients exhibit significant improvements in pain (change in visual analog score for leg pain, 3.4 points) and disability (change in Oswestry Disability Index, 19 points), with inadvertent durotomy in 3% of patients. Review of 4 studies for MIS lumbar interbody fusion reveals robust improvement in pain (change in visual analog score for leg pain, 3.4 points; change in visual analog score for back pain, 7.2 points), with inadvertent durotomy in 5% of patients.

Narrative review was performed for adult degenerative deformity correction, revealing that MIS techniques are feasible for managing such patients with acceptable rates of osseous union and complication. On the basis of largely low-quality, retrospective evidence, we recommend that elderly patients should not be excluded from MIS interventions for symptomatic lumbar degenerative spinal disease.

Feasibility of radiological markers in idiopathic normal pressure hydrocephalus

Feasibility of radiological markers in idiopathic normal pressure hydrocephalus

Acta Neurochir (2015) 157:1709–1719

Various radiological markers have been proposed for diagnostics in idiopathic normal pressure hydrocephalus (iNPH).We examined the usefulness of radiological markers in the diagnostics and prediction of shunt response in iNPH.

Method In this retrospective cohort study, we evaluated brain CTor MRI scans of 390 patients with suspected iNPH. Based on a 24-h intraventricular pressure monitoring session, patients were classified into a non-NPH (n=161) or probable iNPH (n=229) group. Volumes of cerebrospinal fluid compartments (lateral ventricles, sylvian and suprasylvian subarachnoid spaces and basal cisterns) were visually assessed. Disproportionally enlarged subarachnoid spaces, flow void, white matter changes, medial temporal lobe atrophy and focally dilated sulci were evaluated. Moreover, we measured quantitative markers: Evans’ index (EI), the modified cella media index, mean width of the temporal horns and callosal angle.

Results iNPH was more likely in patients with severe volumetric disproportion between the suprasylvian and sylvian subarachnoid spaces than in those without disproportion (OR 7.5, CI 95 % 4.0–14.1, P<0.0001). Mild disproportion (OR 2.6, CI 95 % 1.4–4.6, P=0.001) and narrow temporal horns (OR per 1mm0.91, CI 95%0.84–0.98, P=0.014)were also associated with an iNPH diagnosis. Other radiological markers had little association with the iNPH diagnosis in the final combined multivariate model. Interestingly, EI was higher in non-NPH than iNPH patients (0.40 vs. 0.38, P= 0.039). Preoperative radiological markers were not associated with shunt response.

Conclusions Visually evaluated disproportion was the most useful radiological marker in iNPH diagnostics. Narrower temporal horns also supported an iNPH diagnosis, possibly since atrophy was more pronounced in the non-NPH than iNPH group.

Endoscopic hematoma evacuation for acute and subacute subdural hematoma in elderly patients

Endoscopic hematoma evacuation for acute and subacute subdural hematoma in elderly patients

J Neurosurg 123:1065–1069, 2015

Endoscopic surgery was performed for acute or subacute subdural hematoma (SDH), and its effectiveness and safety in elderly patients were evaluated.

Methods Between September 2007 and November 2013, endoscopic surgery was performed in 11 elderly patients with acute SDH (8 patients) and subacute SDH (3 patients). The criteria for surgery were as follows: 1) the presence of clinical symptoms; 2) age older than 70 years; 3) no brain injury (intracerebral hematoma, brain contusion); 4) absence of an enlarging SDH; and 5) no high risk of bleeding. Hematoma evacuation was performed with a 4-mm rigid endoscope with a 0° lens and a malleable irrigation suction cannula.

Results Endoscopic surgery was performed under local anesthesia. The mean age of the patients was 82.6 years (range 73–91 years). There were 5 female and 6 male patients. The mean preoperative Glasgow Coma Scale score was 12, and 5 patients had been receiving antithrombotic drug therapy. The mean operation time was 85 minutes. Only 1 patient had rebleeding, and reoperation with the same technique was performed uneventfully in this individual. A total of 7 patients had a good recovery (modified Rankin Scale Score 0–2) at discharge.

Conclusions Endoscopic hematoma evacuation of acute and subacute SDH is a safe and effective method of clot removal that minimizes operative complications. This technique may be a less invasive method for treating elderly patients with acute and subacute SDHs.

Subcortical anatomy as an anatomical and functional landmark in insulo-opercular gliomas

Subcortical anatomy as an anatomical and functional landmark in insulo-opercular gliomas

J Neurosurg 123:1081–1092, 2015

Little attention has been given to the functional challenges of the insular approach to the resection of gliomas, despite the potential damage of essential neural networks that underlie the insula. The object of this study is to analyze the subcortical anatomy of the insular region when infiltrated by gliomas, and compare it with the normal anatomy in nontumoral hemispheres.

Methods Ten postmortem human hemispheres were dissected, with isolation of the inferior fronto-occipital fasciculus (IFOF) and the uncinate fasciculus. Probabilistic diffusion tensor imaging (DTI) tractography was used to analyze the subcortical anatomy of the insular region in 10 healthy volunteers and in 22 patients with insular Grade II and Grade III gliomas. The subcortical anatomy of the insular region in these 22 insular gliomas was compared with the normal anatomy in 20 nontumoral hemispheres.

Results In tumoral hemispheres, the distances between the peri-insular sulci and the lateral surface of the IFOF and uncinate fasciculus were enlarged (p < 0.05). Also in tumoral hemispheres, the IFOF was identified in 10 (90.9%) of 11 patients with an extent of resection less than 80%, and in 4 (36.4%) of 11 patients with an extent of resection equal to or greater than 80% (multivariate analysis: p = 0.03).

Conclusions Insular gliomas grow in the space between the lateral surface of the IFOF and uncinate fasciculus and the insular surface, displacing and compressing the tracts medially. Moreover, these tracts may be completely infiltrated by the tumor, with a total disruption of the bundles. In the current study, the identification of the IFOF with DTI tractography was significantly associated with the extent of tumor resection. If the IFOF is not identified preoperatively, there is a high probability of achieving a resection greater than 80%.

Transvenous Approach to Intracranial Arteriovenous Malformations

Transvenous Approach to Intracranial Arteriovenous Malformations

Neurosurgery 77:644–652, 2015

A compartmental conceptualization of intracranial arteriovenous malformations (AVMs) allows recognition of feeding arteries, an intervening plexiform nidus, and draining veins. AVM therapy involves eliminating the nidus, which is the source of hemorrhage, without compromising normal arterial and venous drainage of the brain. Traditional methods of AVM therapy through microsurgery and endovascular embolization involve arterial devascularization, with preservation of AVM venous drainage, until the nidus is excluded.

The transvenous approach in treating vascular malformations was popularized by successful treatment models for dural arteriovenous fistulas. More recently, high-flow intracranial AVMs are being managed with transvenous endovascular approaches, although this novel technique has its challenges and perils.

We review the current literature on transvenous AVM therapy and highlight its role for AVM therapy in the present day.

What You See Is What You Get: Lead Location Within Deep Brain Structures Is Accurately Depicted by Stereotactic Magnetic Resonance Imaging

What You See Is What You Get- Lead Location Within Deep Brain Structures Is Accurately Depicted by Stereotactic Magnetic Resonance Imaging

Operative Neurosurgery 11:412–419, 2015

Magnetic resonance imaging (MRI)-verified deep brain stimulation relies on the correct interpretation of stereotactic imaging documenting lead location in relation to visible anatomic target. However, it has been suggested that local signal distortion from the lead itself renders its depiction on MRI unreliable.

OBJECTIVE: To compare lead location on stereotactic MRI with subsequent location of its brain track after removal.

METHODS: Patients underwent deep brain stimulation with the use of MRI-guided and MRI-verified Leksell frame approach. Infection or suboptimal efficacy required lead removal and subsequent reimplantation by using the same technique. Postimplantation stereotactic MR images were analyzed. Lateral (x) and anteroposterior (y) distances from midcommissural point to center of the lead hypointensity were recorded at the anterior commissure-posterior commissure plane (pallidal electrode) or z = 24 (subthalamic electrode). Stereotactic MRI before the second procedure, x and y distances from the center of the visible lead track hypointensity to midcommissural point were independently recorded. Vectorial distance from center of the lead hypointensity to the center of its track was calculated.

RESULTS: Sixteen electrode tracks were studied in 10 patients. Mean differences between lead artifact location and lead track location were: x coordinate 0.4 mm 6 0.2; y coordinate 0.6 mm 6 0.3. Mean vectorial distance was 0.7 mm 6 0.2.

CONCLUSION: Stereotactic distance between lead location and subsequent brain track location on MRI was small. The mean discrepancy was approximately half the deep brain stimulation lead width. This suggests that lead hypointensity seen on postimplantation MRI is indeed an accurate representation of its real location within deep brain structures.

The lateral infratrigeminal transpontine window to deep pontine lesions

The lateral infratrigeminal transpontine window to deep pontine lesions

J Neurosurg 123:699–710, 2015

Surgery of brainstem lesions is increasingly performed despite the fact that surgical indications and techniques continue to be debated. The deep pons, in particular, continues to be a critical area in which the specific risks related to different surgical strategies continue to be examined. With the intention of bringing new knowledge into this important arena, the authors systematically examined the results of brainstem surgeries that have been performed through the lateral infratrigeminal transpontine window.

Methods Between 1990 and 2013, 29 consecutive patients underwent surgery through this window for either biopsy sampling or for removal of a deep pontine lesion. All of this work was performed at the Department of Neurosurgery of the Istituto Nazionale Neurologico “Carlo Besta”, in Milan, Italy. A retrospective analysis of the findings was conducted with the intention of bringing further clarity to this important surgical strategy.

Results The lateral infratrigeminal transpontine window was exposed through 4 different approaches: 1) classic retrosigmoid (15 cases), 2) minimally invasive keyhole retrosigmoid (10 cases), 3) translabyrinthine (1 case), and 4) combined petrosal (3 cases). No deaths occurred during the entire clinical study. The surgical complications that were observed included hydrocephalus (2 cases) and CSF leakage (1 case). In 6 (20.7%) of 29 patients the authors encountered new neurological deficits during the immediate postoperative period. All 6 of these patients had undergone lesion removal. In only 2 of these 6 patients were permanent sequelae observed at 3 months follow-up. These findings show that 93% of the patients studied did not report any permanent worsening of their neurological condition after this surgical intervention.

Conclusions This retrospective study supports the idea that the lateral infratrigeminal transpontine window is both a low-risk and safe corridor for either biopsy sampling or for removal of deep pontine lesions.

Effect of Prior Embolization on Cerebral Arteriovenous Malformation Radiosurgery Outcomes

AVM

Neurosurgery 77:406–417, 2015

Embolization before stereotactic radiosurgery (SRS) for cerebral arteriovenous malformations (AVM) has been shown to negatively affect obliteration rates, but its impact on the risks of radiosurgery-induced complications and latency period hemorrhage is poorly defined.

OBJECTIVE: To determine, in a case-control study, the effect of prior embolization on AVM SRS outcomes.

METHODS: We evaluated a database of AVM patients who underwent SRS. Propensity score analysis was used to match the case (embolized nidi) and control (nonembolized nidi) cohorts. AVM angioarchitectural complexity was defined as the sum of the number of major feeding arteries and draining veins to the nidus. Multivariate Cox proportional hazards regression analyses were performed on the overall study population to determine independent predictors of obliteration and radiation-induced changes.

RESULTS: The matching process yielded 242 patients in each cohort. The actuarial obliteration rates were significantly lower in the embolized (31%, 49% at 5, 10 years, respectively) compared with the nonembolized (48%, 64% at 5, 10 years, respectively) cohort (P = .003). In the multivariate analysis for obliteration, lower angioarchitectural complexity (P , .001) and radiologically evident radiation-induced changes (P = .016) were independent predictors, but embolization was not significant (P = .744). In the multivariate analysis for radiologic radiation-induced changes, lack of prior embolization (P = .009) and fewer draining veins (P = .011) were independent predictors.

CONCLUSION: The effect of prior embolization on AVM obliteration after SRS may be significantly confounded by nidus angioarchitectural complexity. Additionally, embolization could reduce the risk of radiation-induced changes. Thus, combined embolization and SRS may be warranted for appropriately selected nidi.

A single thalamic target for deep brain stimulation to treat hemi-body pain syndrome

A single thalamic target

Acta Neurochir (2015) 157:1519–1523

Patients experiencing hemi-body pain represent a difficult problem when using the thalamus as a DBS target given its anatomical topology.
Methods A 50-year-old HIV positive male underwent a right unilateral thalamic DBS to treat his severe left hemi-body central post-stroke pain following years of unsuccessful medication therapy.
Results The final active contact of the electrode corresponded to stimulation of the nucleus ventrocaudalis parvocellularis internis, which has provided prolonged pain relief.
Conclusion To our knowledge this was the first time this pattern of pain was treated by a single thalamic DBS electrode, suggesting stimulation in this region may be a feasible target for achieving relief from chronic severe hemi-body pain.

Feasibility study for brain biopsies performed with the use of a head-mounted robot

Feasibility study for brain biopsies performed with the use of a head-mounted robotJ Neurosurg 123:737–742, 2015

Frame-based stereotactic interventions are considered the gold standard for brain biopsies, but they have limitations with regard to flexibility and patient comfort because of the bulky head ring attached to the patient. Frameless image guidance systems that use scalp fiducial markers offer more flexibility and patient comfort but provide less stability and accuracy during drilling and biopsy needle positioning. Head-mounted robot–guided biopsies could provide the advantages of these 2 techniques without the downsides. The goal of this study was to evaluate the feasibility and safety of a robotic guidance device, affixed to the patient’s skull through a small mounting platform, for use in brain biopsy procedures.

Methods This was a retrospective study of 37 consecutive patients who presented with supratentorial lesions and underwent brain biopsy procedures in which a surgical guidance robot was used to determine clinical outcomes and technical procedural operability.

Results The portable head-mounted device was well tolerated by the patients and enabled stable drilling and needle positioning during surgery. Flexible adjustments of predefined paths and selection of new trajectories were successfully performed intraoperatively without the need for manual settings and fixations. The patients experienced no permanent deficits or infections after surgery.

Conclusions The head-mounted robot–guided approach presented here combines the stability of a bone-mounted set-up with the flexibility and tolerability of frameless systems. By reducing human interference (i.e., manual parameter settings, calibrations, and adjustments), this technology might be particularly useful in neurosurgical interventions that necessitate multiple trajectories.

Spontaneous subarachnoid hemorrhage and negative initial vascular imaging—should further investigation depend upon the pattern of hemorrhage on the presenting CT?

Spontaneous subarachnoid hemorrhage and negative initial vascular imaging—should further investigation depend upon the pattern of hemorrhage on the presenting CT?

Acta Neurochir (2015) 157:1477–1484

Multiple investigations are usually performed in patients with spontaneous SAH who have negative initial angiography. This study aimed to evaluate the most appropriate use of additional imaging studies and how this may be influenced by the findings of the initial CT.

Methods A retrospective analysis was performed on a prospectively collected cohort of patients referred with spontaneous SAH and negative initial angiography. The patients were divided into four categories based upon the distribution of blood on the initial CT: perimesencephalic (pSAH), diffuse (dSAH), sulcal (sSAH) and CT negative (CSF positive for xanthochromia) (nCT-pLP). The number and nature of the subsequent imaging investigations were reviewed, and the results were correlated with the findings of the presenting CT.

Results One hundred fourteen patients were included in the study. Repeat imaging found five relevant abnormalities. Three cases of vasculitis were diagnosed on the first DSA following a negative CTA. A case of dissecting aneurysm was revealed on the third neurovascular study. A hemorrhagic spinal tumor presented with xanthochromia. No subsequent abnormality was found on the third DSA or MRI head. No case of pSAH had a subsequent positive finding if the initial CTA was negative.

Conclusions Certain patterns of SAH are associated with a low yield of abnormalities on repeat imaging if the initial angiography is normal. The authors believe that the pattern of hemorrhage on the presenting CT should be used to guide the most appropriate use of further imaging modalities and present a diagnostic algorithm for this purpose.

Transient aphasias after left hemisphere resective surgery

Transient aphasias after left hemisphere resective surgery

J Neurosurg 123:581–593, 2015

Transient aphasias are often observed in the first few days after a patient has undergone resection in the language- dominant hemisphere. The aims of this prospective study were to characterize the incidence and nature of these aphasias and to determine whether there are relationships between location of the surgical site and deficits in specific language domains.

Methods One hundred ten patients undergoing resection to the language-dominant hemisphere participated in the study. Language was evaluated prior to surgery and 2–3 days and 1 month postsurgery using the Western Aphasia Battery and the Boston Naming Test. Voxel-based lesion-symptom mapping was used to identify relationships between the surgical site location assessed on MRI and deficits in fluency, information content, comprehension, repetition, and naming.

Results Seventy-one percent of patients were classified as aphasic based on the Western Aphasia Battery 2–3 days postsurgery, with deficits observed in each of the language domains examined. Fluency deficits were associated with resection of the precentral gyrus and adjacent inferior frontal cortex. Reduced information content of spoken output was associated with resection of the ventral precentral gyrus and posterior inferior frontal gyrus (pars opercularis). Repetition deficits were associated with resection of the posterior superior temporal gyrus. Naming deficits were associated with resection of the ventral temporal cortex, with midtemporal and posterior temporal damage more predictive of naming deficits than anterior temporal damage. By 1 month postsurgery, nearly all language deficits were resolved, and no language measure except for naming differed significantly from its presurgical level.

Conclusions These findings show that transient aphasias are very common after left hemisphere resective surgery and that the precise nature of the aphasia depends on the specific location of the surgical site. The patient cohort in this study provides a unique window into the neural basis of language because resections are discrete, their locations are not limited by vascular distribution or patterns of neurodegeneration, and language can be studied prior to substantial reorganization.

The 6 thalamic regions: surgical approaches to thalamic cavernous malformations, operative results, and clinical outcomes

The 6 thalamic regions- surgical approaches to thalamic cavernous malformations, operative results, and clinical outcomes

J Neurosurg 123:676–685, 2015

The ideal surgical approach to thalamic cavernous malformations (CMs) varies according to their location within the thalamus. To standardize surgical approaches, the authors have divided the thalamus into 6 different regions and matched them with the corresponding surgical approach.

Methods The regions were defined as Region 1 (anteroinferior), Region 2 (medial), Region 3 (lateral), Region 4 (posterosuperior), Region 5 (lateral posteroinferior), and Region 6 (medial posteroinferior). The senior author’s surgical experience with 46 thalamic CMs was reviewed according to this classification. An orbitozygomatic approach was used for Region 1; anterior ipsilateral transcallosal for Region 2; anterior contralateral transcallosal for Region 3; posterior transcallosal for Region 4; parietooccipital transventricular for Region 5; and supracerebellar-infratentorial for Region 6.

Results Region 3 was the most common location (17 [37%]). There were 5 CMs in Region 1 (11%), 9 in Region 2 (20%), 17 in Region 3 (37%), 3 in Region 4 (6%), 4 in Region 5 (9%), and 8 in Region 6 (17%). Complete resection was achieved in all patients except for 2, who required a second-stage operation. The mean follow-up period was 1.7 years (range 6 months–9 years). At the last clinical follow-up, 40 patients (87%) had an excellent or good outcome (modified Rankin Scale [mRS] scores 0–2) and 6 (13%) had poor outcome (mRS scores 3–4). Relative to their preoperative condition, 42 patients (91%) were unchanged or improved, and 4 (9%) were worse.

Conclusions The authors have presented the largest series reported to date of surgically treated thalamic CMs, achieving excellent results using this methodology. In the authors’ experience, conceptually dividing the thalamus into 6 different regions aids in the selection of the ideal surgical approach for a specific region.

The Barrow Ruptured Aneurysm Trial: 6-year results

Aneurysm surgery

J Neurosurg 123:609–617, 2015

The authors report the 6-year results of the Barrow Ruptured Aneurysm Trial (BRAT). This ongoing randomized trial, with the final goal of a 10-year follow-up, compares the safety and efficacy of surgical clip occlusion and endovascular coil embolization in patients presenting with subarachnoid hemorrhage (SAH) from a ruptured aneurysm. The 1- and 3-year results of this trial have been previously reported.

Methods In total, 500 patients with an SAH met the entry criteria and were enrolled in the study. Of these patients, 471 were randomly assigned to the treatments: 238 to surgical clipping and 233 to endovascular coiling. Six patients who died before treatment and 57 patients with nonaneurysmal SAHs were excluded, leaving a total of 408 patients who underwent clipping (209 assigned) or coiling (199 assigned). Whether to treat patients within the assigned group or to cross over patients to the other group was at the discretion of the treating physician; 38% (75/199) of the patients assigned to coiling were crossed over to clipping and 1.9% (4/209) assigned to clipping were crossed over to coiling. The outcome data were collected by a dedicated nurse practitioner. The primary outcome analysis was based on the assigned treatment group; poor outcome was defined as a modified Rankin Scale (mRS) score > 2 and was independently adjudicated. Six years after randomization, 336 (82%) of 408 patients who had been treated were available for examination.

Results On the basis of an mRS score of > 2, and similar to the results at the 3-year follow-up, no significant difference in outcomes (p = 0.24) was detected between the 2 treatment groups. Complete aneurysm obliteration at 6 years was achieved in 96% (111/116) of the clipping group and in 48% (23/48) of the coiling group (p < 0.0001). In the period between the 3- and 6-year follow-ups, 3 additional patients assigned to coiling and none assigned to clipping received retreatment, for overall retreatment rates of 4.6% (13/280) for clipping and 16.4% (21/128) for coiling (p < 0.0001). When aneurysm location was considered, the 6-year results continued to match the previously reported results, with no difference in outcome for anterior circulation aneurysms at most time points. Of the anterior circulation aneurysms assigned to coiling treatment, 42% (70/168) were crossed over to clipping treatment. The outcomes for posterior circulation aneurysms continued to favor coiling. The randomization process was unexpectedly skewed, with 18 of 21 treated aneurysms of the posterior inferior cerebellar artery (PICA) being assigned to clipping, but even when PICA aneurysms were removed from the analysis, outcomes for the posterior circulation aneurysms still favored coiling.

Conclusions Although BRAT was statistically underpowered to detect small differences, these results suggest little difference in outcome between the 2 treatments for anterior circulation aneurysms. This was not the case for the posterior circulation aneurysms, where coil embolization appeared to provide a sustained advantage over clipping. Aneurysm obliteration rates in BRAT were significantly lower and retreatment rates significantly higher in the patients undergoing coiling than in those undergoing clipping. However, despite the fact that retreatment rates were higher after coiling, no recurrent hemorrhages were known to have occurred in patients undergoing coiling in BRAT who were followed up for 6 years. Sufficient questions remain about the relative benefits of the 2 treatment modalities to warrant further welldesigned randomized trials.

Occipital Nerve Stimulation for the Treatment of Patients With Medically Refractory Occipital Neuralgia

Occipital Nerve Stimulation for the Treatment of Patients With Medically Refractory Occipital Neuralgia

Neurosurgery 77:332–341, 2015

Occipital neuralgia (ON) is a disorder characterized by sharp, electrical, paroxysmal pain, originating from the occiput and extending along the posterior scalp, in the distribution of the greater, lesser, and/or third occipital nerve. Occipital nerve stimulation (ONS) constitutes a promising therapy for medically refractory ON because it is reversible with minimal side effects and has shown continued efficacy with long-term follow-up.

OBJECTIVE: To conduct a systematic literature review and provide treatment recommendations for the use of ONS for the treatment of patients with medically refractory ON.

METHODS: A systematic literature search was conducted using the PubMed database and the Cochrane Library to locate articles published between 1966 and April 2014 using MeSH headings and keywords relevant to ONS as a means to treat ON. A second literature search was conducted using the PubMed database and the Cochrane Library to locate articles published between 1966 and June 2014 using MeSH headings and keywords relevant to interventions that predict response to ONS in ON. The strength of evidence of each article that underwent full text review and the resulting strength of recommendation were graded according to the guidelines development methodology of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Joint Guidelines Committee.

RESULTS: Nine studies met the criteria for inclusion in this guideline. All articles provided Class III Level evidence.

CONCLUSION: Based on the data derived from this systematic literature review, the following Level III recommendation can be made: the use of ONS is a treatment option for patients with medically refractory ON.

Predictors of Outcome, Complications, and Recanalization of the Solitaire Device

Solitaire Device

Neurosurgery 77:355–361, 2015

The use of mechanical thrombectomy in the management of acute ischemic stroke is becoming increasingly popular.

OBJECTIVE: To identify notable factors that affect outcome, revascularization, and complications in patients with acute ischemic stroke treated with the Solitaire Flow Restoration Revascularization device.

METHODS: Eighty-nine patients treated with the Solitaire Flow Restoration Revascularization device (ev3/Covidien Vascular Therapies, Irvine, California) were retrospectively analyzed. Three endpoints were considered: revascularization (Thrombolysis In Cerebral Infarction), outcome (modified Rankin Scale score), and complications. Univariate analysis and multivariate logistic regression were conducted to determine significant predictors.

RESULTS: The mean time from onset of symptoms to the start of intervention was 6.7 hours. The average procedure length was 58 minutes. The mean NIH Stroke Scale (NIHSS) score was 16 on arrival and 8 at discharge. Of the patients, 6.7% had a symptomatic intracerebral hemorrhage, 16.8% had fatal outcomes within 3 months post-intervention, and 81.4% had a successful recanalization. Thrombus location in the M1 segment of the middle cerebral artery was associated with successful recanalization (thrombolysis in cerebral infarction 2b/3) (P = .003). Of the patients, 56.6% had a favorable outcome (modified Rankin Scale score at 3 months: 0-2). In patients younger than 80 years of age, 66.7% had favorable outcome. Increasing age (P = .01) and NIHSS score (P = .002) were significant predictors of a poor outcome. On multivariate analysis, NIHSS score on admission (P = .05) was a predictor of complications. On univariate analysis, increasing NIHSS score fromadmission to 24 hours after the procedure (P = .05) and then to discharge (P = .04) was a predictor of complications. Thrombus location in the posterior circulation (P = .04) and increasing NIHSS score (P = .04) predicted mortality.

CONCLUSION: The Solitaire device is safe and effective in achieving successful recanalization after acute ischemic stroke. Important factors to consider include age, NIHSS score, and location.

Two-level corpectomy versus three-level discectomy for cervical spondylotic myelopathy

Two-level corpectomy versus three-level discectomy for cervical spondylotic myelopathy

J Neurosurg Spine 23:280–289, 2015

In the treatment of cervical spondylotic myelopathy (CSM), anterior cervical corpectomy and fusion (ACCF) and anterior cervical discectomy and fusion (ACDF) are effective decompressive techniques. It remains to be determined whether ACCF and ACDF offer equivalent outcomes for multilevel CSM. In this study, the authors compared perioperative, radiographic, and clinical outcomes between 2-level ACCF and 3-level ACDF.

Methods Between 2006 and 2012, all patients at the authors’ hospital who underwent 2-level ACCF or 3-level ACDF performed by 1 of 2 surgeons were identified. Primary outcomes of interest were sagittal Cobb angle, adjacent-segment disease (ASD) requiring surgery, neck pain measured by visual analog scale (VAS), and Nurick score. Secondary outcomes of interest included estimated blood loss (EBL), length of stay, perioperative complications, and radiographic pseudarthrosis rate. Chi-square tests and 2-tailed Student t-tests were used to compare the 2 groups. A subgroup analysis of patients without posterior spinal fusion (PSF) was also performed.

Results Twenty patients underwent 2-level ACCF, and 35 patients underwent 3-level ACDF during a 6-year period. Preoperative Nurick scores were higher in the ACCF group (2.1 vs 1.1, p = 0.014), and more patients underwent PSF in the 2-level ACCF group compared with patients in the 3-level ACDF group (60.0% vs 17.1%, p = 0.001). Otherwise there were no significant differences in demographics, comorbidities, and baseline clinical parameters between the 2 groups. Two-level ACCF was associated with significantly higher EBL compared with 3-level ACDF for the anterior stage of surgery (382.2 ml vs 117.9 ml, p < 0.001). Two-level ACCF was also associated with a longer hospital stay compared with 3-level ACDF (7.2 days vs 4.9 days, p = 0.048), but a subgroup comparison of patients without PSF showed no significant difference in length of stay (3.1 days vs 4.4 days for 2-level ACCF vs 3-level ACDF, respectively; p = 0.267). Similarly, there was a trend toward more complications in the 2-level ACCF group (20.0%) than the 3-level ACDF group (5.7%; p = 0.102), but a subgroup analysis that excluded those who had second-stage PSF no longer showed the same trend (2-level ACCF, 0.0% vs 3-level ACDF, 3.4%; p = 0.594). There were no significant differences between the ACCF group and the ACDF group in terms of postoperative sagittal Cobb angle (7.2° vs 12.1°, p = 0.173), operative ASD (6.3% vs 3.6%, p = 0.682), and radiographic pseudarthrosis rate (6.3% vs 7.1%, p = 0.909). Both groups had similar improvement in mean VAS neck pain scores (3.4 vs 3.2 for ACCF vs ACDF, respectively; p = 0.860) and Nurick scores (0.8 vs 0.7, p = 0.925).

Conclusions Two-level ACCF was associated with greater EBL and longer hospital stays when patients underwent a second-stage PSF. However, the length of stay was similar when patients underwent anterior-only decompression with either 2-level ACCF or 3-level ACDF. Furthermore, perioperative complication rates were similar in the 2 groups when patients underwent anterior decompression without PSF. Both groups obtained similar postoperative cervical lordosis, operative ASD rates, radiographic pseudarthrosis rates, neurological improvement, and pain relief.

International differences in the management of intracranial aneurysms: implications for the education of the next generation of neurosurgeons

MCA aneurysm

Acta Neurochir 2015, 157,(9):1467-1475

The publication of the International Subarachnoid Aneurysm Trial rapidly changed the management of patients with subarachnoid hemorrhage. The present and perceived future trends of aneurysm management have significant implications for patients and how we educate future cerebrovascular specialists.

Objective

To determine present perceived competencies of final-year neurosurgical residents who have just finished their residencies and to relate those to what practitioners from a variety of continents expect of these persons. The goal is to provide a basis for further discussion regarding the design of further educational programs in neurosurgery.

Methods

A 55-item questionnaire with 33 questions related to competencies and expectations of competency from final-year residents who have just finished residency was completed by 229 neurosurgeons and neuro-radiologists (81 % response rate) of mixed seniority from 45 countries. We used bivariate and descriptive analyses to determine future trends and geographic differences in cerebral aneurysm management as well as the educational implications on the future.

Results

More North Americans than those from the rest of the world are of the opinion that graduating residents are presently competent to perform basic cerebrovascular procedures like evacuation of a hematoma and clipping a simple 7-mm middle cerebral artery aneurysm. Extremely few graduating neurosurgical residents anywhere are presently capable of performing endovascular techniques for even the most basic of aneurysms. Most of those surveyed also believe that endovascular and open surgical management of aneurysms should be a part of residency training for all residents (70.4 and 88.7 %, respectively).

Conclusions

Our findings have implications for the design of neurosurgical curricula for residents as well as for certification examinations and procedures. Specialty and educational organizations and those responsible for the education of future clinicians who will care for patients with cerebrovascular problems should adjust educational objectives and implement curricula and learning experiences that will ensure that cerebrovascular specialists are capable of providing the best care possible to the patient with an aneurysm, whether that be open surgery or endovascular management. These findings mean that organizations around the world will need to make these adjustments to the education of future specialists.

Intracranial meningioma surgery in the elderly (over 65 years): prognostic factors and outcome

Tuberculum Sellae Meningiomas

Acta Neurochir 157 (9): 1549-1557

Meningiomas are more prevalent in elderly individuals; however, the surgical outcome and prognostic factors in this age group are unclear. This retrospective study aimed to identify the prognostic factors of elderly patients with intracranial meningiomas who underwent surgical resection.

Methods

Eighty-six patients (aged ≥65) diagnosed with an intracranial meningioma were surgically treated at our department. The clinical, radiological, and follow-up data were retrospectively reviewed. Univariate and multivariate logistic analyses were performed to identify relationships between factors [age, sex, neurological condition, concomitant disease, American Society of Anesthesiology (ASA) classification, preoperative Karnofsky Performance Scale (KPS) score, tumor location and size, peritumoral edema, and Simpson resection grade] and outcome.

Results

One patient (1.2 %) died within 30 days of surgery. The morbidity rate was 37.2 %. Postoperative morbidities occurred more frequently in the patients with preoperative neurological deficits than in those without (p = 0.049). Univariate analysis identified significant relationships between a low KPS score (≤70) at discharge and preoperative neurological deficits, low preoperative KPS score (≤70), and critical tumor location (p < 0.001, p < 0.001, and p = 0.04, respectively). In the multivariate logistic analysis, only the preoperative KPS score remained significant for the KPS score at discharge (p = 0.005); there was no significant association with the most recent KPS score.

Conclusion

The outcome of intracranial meningioma resection in elderly individuals is favorable if the preoperative KPS score is >70 and no neurological deficits are present. Treatment decisions should be patient-specific, and additional factors should be considered when operations are performed in patients with a low preoperative KPS score or neurological deficits.