Author: cba

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Novel Device and Technique for Minimally Invasive Intracerebral Hematoma Evacuation in the Same Setting of a Ruptured Intracranial Aneurysm

Novel Device and Technique for Minimally Invasive Intracerebral Hematoma Evacuation in the Same Setting of a Ruptured Intracranial Aneurysm

Operative Neurosurgery 11:43–51, 2015

The presence of intracerebral hematoma from aneurysm rupture is an indication for craniotomy for clot evacuation and aneurysm clipping. Some centers have begun securing aneurysms with coil embolization followed by clot evacuation in the operating room. This approach requires transporting a patient from the angiography suite to the operating room, which can take valuable time and resources.

OBJECTIVE: To report our experience with 3 cases in which a novel technique for minimally invasive evacuation of intracerebral hematomas after endovascular treatment of ruptured intracranial aneurysms was used. The Penumbra Apollo system can be used in the angiography suite in conjunction with neuroendovascular techniques to simultaneously address a symptomatic hematoma associated with a ruptured aneurysm.

METHODS: Standard preoperative computed tomography angiography was performed on arrival to the emergency department. The patients underwent diagnostic cerebral angiography followed by balloon-assisted coil embolization and then remained in the neurointerventional suite for intracerebral hematoma evacuation with the Apollo system.

RESULTS: All patients tolerated coil embolization and hematoma evacuation well. The combined procedures lasted <3 hours in both cases. Two patients were eventually discharged to acute rehabilitation facilities less than a month after their initial insult, and 1 has been cleared to return to work. The other patient was transferred to hospice care.

CONCLUSION: The Apollo aspiration system appears to be a safe and effective minimally invasive option for intracerebral hematoma evacuation, particularly when coupled with endovascular embolization of ruptured intracranial aneurysms. Future work will address which patient population is most likely to benefit from this promising technique.

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A clinical prediction model to assess surgical outcome in patients with cervical spondylotic myelopathy

A clinical prediction model to assess surgical outcome in patients with cervical spondylotic myelopathy

The Spine Journal 15 (2015) 388–397

Clinical prediction rules are valuable tools in a surgical setting but should not be used to guide clinical practice until validated in other populations.

PURPOSE: The objective of this study was to validate a clinical prediction rule developed to determine surgical outcome in patients with cervical spondylotic myelopathy (CSM). The study will also identify key clinical predictors of outcome at a global level.

STUDY DESIGN/SETTING: This is a prospective multicenter cohort study.

PATIENT SAMPLE: Two-hundred seventy-eight and 479 surgical CSM patients enrolled in the AOSpine CSM—North American (CSM-NA) and CSM—International (CSM-I) studies, respectively.

OUTCOME MEASURES: The outcome measure was a Modified Japanese Orthopedic Association (mJOA) Scale.

METHODS: A clinical prediction model was built using data from 272 patients enrolled in the CSM-NA study. Bootstrapping was used for internal validation. The original model was externally validated using data on 471 patients participating in the CSM-I study. The predictive performance of the model was evaluated, including its discrimination, measured by area under the receiver operating curve (AUC), and calibration, assessed by calibration slope, observed: expected ratios, and Hosmer-Lemeshow goodness-of-fit test.

RESULTS: The modified original model consisted of six covariates: age (odds ratio [OR], 0.96), duration of symptoms (0.76), baseline severity score (1.21), psychiatric comorbidities (0.44), impairment of gait (2.48), and smoking status (0.50). The AUC for the original model was 0.77 (95% confidence interval [CI]: 0.71, 0.82) and across the bootstrap replicates was 0.77 (95% CI: 0.76, 0.77), reflecting good discrimination and internal validity. The model tested on the CSM-I dataset yielded an AUC of 0.74 (95% CI: 0.69, 0.79), a calibration slope of 0.75, and an insignificant Hosmer-Lemeshow test. The ORs generated for baseline mJOA (OR, 1.26), impairment of gait (2.67), age (0.97), and smoking (0.55) were very similar to the original values of 1.28, 2.39, and 0.97, respectively. Duration of symptoms (OR, 0.94) had a significantly different odds ratio than in the original model, but the direction of its relationship with outcome was the same. Psychiatric comorbidities was not a significant predictor at an international level, likely because of underreporting: only six patients outside of North American centers were diagnosed with depression or bipolar.

CONCLUSIONS: The parameter estimates generated from the original analysis were internally valid. The original model was also externally valid. The most significant global predictors of surgical outcome were baseline myelopathy severity, age, smoking status and impaired gait.

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Diffusion-weighted imaging–detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms

Diffusion-weighted imaging–detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms

J Neurosurg 122:627–636, 2015

It was initially considered safe for flow-diverting stents to cover the ostia of branching vessels during endovascular procedures for the treatment of intracranial aneurysms. As more recent evidence suggests, however, their use is not always free of ischemic concerns in terms of covered arterial ostia. The authors sought to determine the frequency of silent and clinically evident diffusion-weighted imaging (DWI)–detected abnormalities related to stent placement as a means of elucidating potential clinical risks.

Methods This is a prospective single-center study on a series of patients with intracranial aneurysms that were treated with flow-diverting stents. All patients systematically underwent an MRI protocol that included DWI before treatment, between 24 and 48 hours postprocedure, and 3 months postembolization. Effectiveness of anticoagulation treatment was assessed for all patients. Lesions seen on DWI were correlated to the parent artery and the side-branch territories and were statistically analyzed in relation to their time of occurrence and clinical presentation. The authors compared the DWI findings in these patients to findings obtained in patients treated with a stent-assisted coiling technique during the same time period.

Results Over the course of 18 consecutive months, 38 consecutive patients (7 males and 31 females) with 49 intracranial aneurysms were treated using flow-diverting stents. Overall, 81.6% of the DWI spots found remained clinically silent during the follow-up period. Five ischemic clinical complications (13.2%) occurred in the postprocedural period. No statistically significant correlation could be established between DWI spots or aneurysm location and clinical complications or follow-up modified Rankin Scale score at 3 months. The complication rate was 7.8% (n = 3) at the 3-month follow-up, and mortality was 0%. Compared with stent-assisted coiling, use of flow-diverting stents showed a statistically significant correlation with silent DWI findings postintervention.

Conclusions Lesions seen on DWI resulting from the procedure are far more common than anticipated, but the technique remains safe and effective, providing an interesting alternative for “difficult” aneurysms, regardless of location. Late-occurring DWI-detected lesions distal to side arterial branches imply a local pressure gradient drop, related to flow competition by collateral networks. Further research is needed to assess the extent and significance of these events.

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Trigeminal neuralgia due to neurovascular conflicts from venous origin: an anatomical-surgical study

Trigeminal neuralgia due to neurovascular conflicts from venous origin- an anatomical-surgical study-1

Acta Neurochir (2015) 157:455–466

Veins as the source of trigeminal neuralgias (TN) lead to controversies. Only a few studies have specifically dealt with venous implication in neurovascular conflicts (NVC). The aim of this study was the anatomical-surgical description of the compressive veins found during microvascular decompression (MVD).

Methods Patients retained were those in whom a vein was considered compressive, alone, or in association with an artery. The study defined the type of vein involved, its situation along, the location around the root, and management. For this study, denomination of veins in relation with the root was revisited.

Results Of the 326 consecutive patients who underwent MVD from 2005 to 2013, 124 (38.0 %) had a venous conflict, alone in 29 (8.9 %), or in association with an artery in 95 (29.1 %). The compressive veins belonged to one of the two venous systems described: the superficial or the deep superior petrosal venous system (sSPVS or dSPVS). A vein from sSPVS was found compressive in 81 cases (59.6 %), for the major part it was the pontine affluent of the superior petrosal vein (48 cases). The conflict was situated at TREZ in 28.4 %, midcisternal portion in 50.6 %, and porus in 8.6 %. The dSPVS was found compressive in 55 cases (40.4 %), almost always a transverse vein at porus (51 cases). Decompression was coagulation-division of the conflicting vein in 36.8 % and simple cleavage in the other.

Conclusions The study shows the frequent implication of veins in NVC as the source of TN. NVC are not only at TREZ but also at mid-cisternal portion and porus of Meckel cave.

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The endoscopic endonasal approach to the odontoid and its impact on early extubation and feeding

The endoscopic endonasal approach to the odontoid and its impact on early extubation and feeding-1

J Neurosurg 122:511–518, 2015

The gold-standard surgical approach to the odontoid is via the transoral route. This approach necessitates opening of the oropharynx and is associated with risks of infection, and swallowing and breathing complications. The endoscopic endonasal approach has the potential to reduce these complications as the oral cavity is avoided. There are fewer than 25 such cases reported to date. The authors present a consecutive, single-institution series of 9 patients who underwent the endonasal endoscopic approach to the odontoid.

Methods The charts of 9 patients who underwent endonasal endoscopic surgery to the odontoid between January 2005 and August 2013 were reviewed. The clinical presentation, radiographic findings, surgical management, complications, and outcome, particularly with respect to time to extubation and feeding, were analyzed. Radiographic measurements of the distance between the back of the odontoid and the front of the cervicomedullary junction (CMJ) were calculated, as well as the location of any residual bone fragments.

Results There were 7 adult and 2 pediatric patients in this series. The mean age of the adults was 54.8 years; the pediatric patients were 7 and 14 years. There were 5 females and 4 males. The mean follow-up was 42.9 months. Symptoms were resolved or improved in all but 1 patient, who had concurrent polyneuropathy. The distance between the odontoid and CMJ increased by 2.34 ± 0.43 mm (p = 0.03). A small, clinically insignificant fragment remained after surgery, always on the left side, in 57% of patients. Mean times to extubation and oral feeding were on postoperative Days 0.3 and 1, respectively. There was one posterior cervical wound infection; there were 2 cases of epistaxis requiring repacking of the nose and no instances of breathing or swallowing complications or velopharyngeal insufficiency.

Conclusions This series of 9 cases of endonasal endoscopic odontoidectomy highlights the advantages of the approach in permitting early extubation and early feeding and minimizing complications compared with transoral surgery. Special attention must be given to bone on the left side of the odontoid if the surgeon is standing on the right side.

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Surgical Management of Ruptured Middle Cerebral Artery Aneurysms With Large Intraparenchymal or Sylvian Fissure Hematomas

Ruptured MCA aneurysms

Neurosurgery 76:258–264, 2015

Craniotomy for hematoma evacuation and aneurysm clipping is the treatment modality of choice for ruptured middle cerebral artery (MCA) aneurysms with intracranial hematomas. Recent literature suggests that endovascular coil embolization followed by hematoma evacuation can be an acceptable alternative.

OBJECTIVE: To determine neurological outcomes in patients with ruptured MCA aneurysms and intraparenchymal or sylvian fissure hematomas.

METHODS: The records of 49 patients with ruptured MCA aneurysms with large intracranial hematomas treated with hematoma evacuation and aneurysm clipping between January 2000 and December 2013 were retrospectively reviewed.

RESULTS: Within this cohort, 35 patients (71.4%) were Hunt and Hess grade IV or V on presentation. The mean hematoma volume was 100.4 6 77.2 mL. Craniectomy was performed in 40 patients (81.6%). Angiographic vasospasm developed in 15 patients (30.6%). The in-hospital mortality rate was 28.6% (14 patients). At a mean of 25.3 6 34.0 months follow-up, a good outcome (modified Rankin Scale [mRS] score 0-3) was observed in 18 patients (36.7%). Significant factors associated with poor outcome or death (mRS scores of 4-6) included increasing age (P , .01), increasing Hunt and Hess grade (P = .03), increasing modified Fisher grade (P = .01), presence of intraventricular hemorrhage (P , .01), decreasing percentage of hematoma evacuation (P , .05), need for craniectomy (P ,. 01), need for external ventricular drainage (P = .04), and angiographic vasospasm (P = .02).

CONCLUSION: MCA aneurysm rupture with concomitant large intraparenchymal or sylvian fissure hematoma formation carries a grave prognosis. Simultaneous hematoma evacuation and aneurysm clipping with or without craniectomy can be an effective treatment modality.

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Comparison of indocyanine green fluorescent angiography to digital subtraction angiography in brain arteriovenous malformation surgery

ICG and AVM

Acta Neurochir (2015) 157:351–359

The potential utility of intraoperative microscope-integrated indocyanine green (ICG) fluorescence angiography in the surgery of brain arteriovenous malformations (AVMs) and evaluation of the completeness of resection is debatable. Postoperative catheter angiography is considered the gold standard. We evaluated the value of ICG and intraoperative catheter angiography in this setting.

Methods Between January 2009 and July 2013, 37 patients with brain AVMs underwent surgical resection of their vascular lesions. ICG videoangiography and an intraoperative catheter angiography were performed in 32 cases, and a routine postoperative angiogram was performed within 48 h to 2 weeks after surgery. The usefulness of ICG findings and the ability to confirm total resection and to identify residual nidus or persistent shunt were assessed and compared to intraoperative and postoperative digital subtraction angiography, respectively.

Results There were 7 grade 1, 11 grade 2, 11 grade 3 and 3 grade 4 Spetzler-Martin classification AVMs. ICG angiography helped to distinguish AVM vessels in 26 patients. In 31 patients, it demonstrated that there was no residual shunting. In one patient, a residual AVMwas identified and further resected. Intraoperative catheter angiography detected two additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. Further resection of the AVM was performed, and total resection was confirmed by a repeat intraoperative angiogram. Postoperative angiography in a patient with a grade 4 lesion revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intraoperative angiography. Overall ICG angiography missed three out of four residual AVMs after initial resection, while the intraoperative angiogram missed one.

Conclusion Although ICG angiography is a helpful adjunct in the surgery of some brain AVMs, it’s yield in detecting residual AVM nidus or shunt is low, especially for deepseated lesions and higher grade AVMs. ICG angiography should not be used as a sole and/or reliable technique. Highresolution postoperative angiography must be performed in brain AVM surgery and remains the best test to confidently confirm complete AVM resection.

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Classification of middle fossa floor dehiscence syndromes

Classification of middle fossa floor dehiscence syndromes

J Neurosurg 122:557–563, 2015

Middle fossa floor dehiscence (MFFD) can present as multiple syndromes depending on dehiscence location, tissue herniation, and dural integrity. The authors propose a classification system for MFFD with the potential to guide clinical decision making.

Methods A retrospective analysis of the electronic medical records (years 1995–2012) of patients who had undergone temporal craniotomy for the surgical repair of an MFFD syndrome at a single institution was undertaken. Reviewed data included demographic, operative, presentation, and outcome details. Middle fossa floor dehiscence was classified as follows: Class A, bony dehiscence without herniation of the brain and/or meninges; Class B, herniation of the brain and/or meninges through the middle fossa floor without CSF leakage; Class C, dehiscence with CSF leakage without meningitis; or Class D, dehiscence with meningitis.

Results Fifty-one patients, 22 males and 29 females, were included in the analysis. The mean age was 48.7 ± 15.5 years, mean body mass index was 32.65 ± 6.86 kg/m2, and mean symptom duration was 33 ± 42 months. Seven patients underwent repeat surgery for symptomatic recurrence; therefore, there were 58 surgical encounters. Repair included bony reconstruction with hydroxyapatite with or without resection of encephaloceles and/or repair of a dural defect. According to the MFFD classification system described, 15, 8, 27, and 8 cases were categorized as Class A, B, C, and D, respectively. The prevalence of hearing loss was 87%, 63%, and 70% in Classes A, B, and C, respectively. Vestibular symptoms were more prevalent in Class A. Seven patients reported persistent symptoms at the last follow-up. Transient complications were similar in each classification (13%–25%), and a single permanent complication related to anesthesia was observed. There were no mortalities or severe neurological morbidities in the series.

Conclusions Middle fossa floor dehiscence has a spectrum of clinical presentations. A classification system may help to clarify the diagnosis and guide therapy. Surgery, the mainstay of treatment, is safe and well tolerated.

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Brainstem Cavernous Malformations: Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Brainstem Cavernous Malformations- Surgical Results in 104 Patients and a Proposed Grading System to Predict Neurological Outcomes

Neurosurgery 76:265–278, 2015

Once considered inoperable lesions in inviolable territory, brainstem cavernous malformations (BSCM) are now surgically curable with acceptable operative morbidity. Recommending surgery is a difficult decision that would be facilitated by a grading system designed specifically for BSCMs that predicted surgical outcomes.

OBJECTIVE: Informed by our efforts to develop a supplementary grading system for arteriovenous malformations, we hypothesized that a similar system might predict long-term outcomes and guide clinical decision-making.

METHODS: A consecutive, single-surgeon series of 104 patients was used to assess preoperative clinical and imaging predictors of microsurgical outcomes. Univariable logistic regression identified predictors and a multivariable logistic regression model tested the association of the combined predictors with final modified Rankin Scale scores. A grading system assigned points for lesion size, location crossing the brainstem’s midpoint, presence of developmental venous anomaly, age, and time from last hemorrhage to surgery.

RESULTS: Average maximal diameter of BSCMs was 19.5 mm; 50% crossed the axial midpoint; 54.8% had developmental venous anomalies; mean age was 42.1 years; and median time from last hemorrhage to surgery was 60 days. One patient died (0.96%), and 15 patients (14.4%) experienced worsened cranial nerve or motor dysfunction, of which 10 increased their modified Rankin Scale scores (9.6%). BSCM grades ranged from 0 to 7 points and predicted outcomes with high accuracy (receiver operating characteristic = 0.86, 95% confidence interval: 0.78-0.94).

CONCLUSION: Rather than developing a grading system for all cerebral cavernous malformations that is weak with BSCMs, we propose a system for the patients who need it most. The BSCM grading system differentiates patients who might expect favorable surgical outcomes and offers guidance to neurosurgeons forced to select these patients.

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Management of C1–2 traumatic fractures using an intraoperative 3D imaging–based navigation system

Management of C1–2 traumatic fractures using an intraoperative 3D imaging–based navigation system

J Neurosurg Spine 22:128–133, 2015

Fractures of C-1 and C-2 are complex and surgical management may be difficult and challenging due to the anatomical relationship between the vertebrae and neurovascular structures. The aim of this study was to evaluate the role, reliability, and accuracy of cervical fixation using the O-arm intraoperative 3D image–based navigation system.

Methods The authors evaluated patients who underwent a navigation system–based surgery for stabilization of a fracture of C-1 and/or C-2 from August 2011 to August 2013. All of the fixation screws were intraoperatively checked and their position was graded.

Results The patient population comprised 17 patients whose median age was 47.6 years. The surgical procedures were as follows: anterior dens screw fixation in 2 cases, transarticular fixation of C-1 and C-2 in 1 case, fixation using the Harms technique in 12 cases, and occipitocervical fixation in 2 cases. A total of 67 screws were placed. The control intraoperative CT scan revealed 62 screws (92.6%) correctly placed, 4 (5.9%) with a minor cortical violation (< 2 mm), and only 1 screw (1.5%) that was judged to be incorrectly placed and that was immediately corrected. No vascular injury of the vertebral artery was observed either during exposition or during screw placement. No implant failure was observed.

Conclusions The use of a navigation system based on an intraoperative CT allows a real-time visualization of the vertebrae, reducing the risks of screw misplacement and consequent complications.

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Endoscopic Removal of Third Ventricular Colloid Cyst: Experience of 90 Cases

Endoscopic Removal of Third Ventricular Colloid Cyst- Experience of 90 Cases-1

Neurosurg Q 2015;25:46–50

Third ventricular colloid cysts are benign lesions originating in the roof of the anterior third ventricle. They constitute around 1% of all intracranial tumors. The optimal surgical management of colloid cysts continues to be a matter of debate.

Objective: This study was perfomed to assess the efficacy and safety of the endoscopic technique in treatment of 90 patients with colloid cysts.

Methods: During the period from June 2001 to October 2011, 90 patients with third ventricular colloid cyst were operated by the endoscopic single burr hole approach. The age ranged between 16 and 67 years (mean 40.3 years). Fifty-eight were females. The cyst size ranged between 8 and 35 mm. In computed tomography (CT) scan, the cyst was hyperdense in 74 cases and isodense in 16 cases. The standard Kocher burr hole was used in 63 and a more both anterior and lateral burr hole was used in 27 cases. Total cyst removal was achieved in 79 patients. Cyst content evacuation and capsule coagulation was done in 10 cases; whereas partial cyst excision was made in 1 case. All patients were followed by a CT scan at 1 and 6 months time from the surgery and then at 2-year interval. The follow-up period ranged from 6 to 120 months with a mean of 62 months.

Results: The operative time ranged between 60 and 175 minutes with a mean of 84 minutes. Ventriculostomy tube and prophylactic antiepileptics were not used for any of the cases. One patient needed ventricular shunting 5 months after the procedure. There was no reported mortality related to the endoscopic colloid cyst removal. The reported morbidities were hemiparesis in 2 cases, transient memory deficit in 7 patients, superficial wound infection in 5 patients, and CSF leakage from the wound in 3 cases. No recurrence was found in our series.

Conclusions: Being a burr hole technique, endoscopy offers a real safe and effective minimally invasive tool for treating third ventricular colloids. It offers superior illumination, greater magnification, and enhanced visualizations of the ventricular anatomy. There is no doubt that the mortality, morbidity, and operative costs are less with endoscopy when compared with other combating therapeutic modalities. In our opinion, if the endless argument considering the point of tumor recurrence is brought apart, endoscopy should be the first-line treatment for third ventricular colloid cysts.

Key Words: colloid cyst, third ventricle, endoscopic, surgical removal.

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Attrition rates in neurosurgery residency

surgeons

J Neurosurg 122:240–249, 2015

The objective of this study is to determine neurosurgery residency attrition rates by sex of matched applicant and by type and rank of medical school attended.

Methods The study follows a cohort of 1361 individuals who matched into a neurosurgery residency program through the SF Match Fellowship and Residency Matching Service from 1990 to 1999. The main outcome measure was achievement of board certification as documented in the American Board of Neurological Surgery Directory of Diplomats. A secondary outcome measure was documentation of practicing medicine as verified by the American Medical Association DoctorFinder and National Provider Identifier websites. Overall, 10.7% (n = 146) of these individuals were women. Twenty percent (n = 266) graduated from a top 10 medical school (24% of women [35/146] and 19% of men [232/1215], p = 0.19). Forty-five percent (n = 618) were graduates of a public medical school, 50% (n = 680) of a private medical school, and 5% (n = 63) of an international medical school. At the end of the study, 0.2% of subjects (n = 3) were deceased and 0.3% (n = 4) were lost to follow-up.

Results The total residency completion rate was 86.0% (n = 1171) overall, with 76.0% (n = 111/146) of women and 87.2% (n = 1059/1215) of men completing residency. Board certification was obtained by 79.4% (n = 1081) of all individuals matching into residency between 1990 and 1999. Overall, 63.0% (92/146) of women and 81.3% (989/1215) of men were board certified. Women were found to be significantly more at risk (p < 0.005) of not completing residency or becoming board certified than men. Public medical school alumni had significantly higher board certification rates than private and international alumni (82.2% for public [508/618]; 77.1% for private [524/680]; 77.8% for international [49/63]; p < 0.05). There was no significant difference in attrition for graduates of top 10–ranked institutions versus other institutions. There was no difference in number of years to achieve neurosurgical board certification for men versus women.

Conclusions Overall, neurosurgery training attrition rates are low. Women have had greater attrition than men during and after neurosurgery residency training. International and private medical school alumni had higher attrition than public medical school alumni.

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Brain surface reformatted imaging (BSRI) for intraoperative neuronavigation in brain tumor surgery

Brain surface reformatted imaging (BSRI) for intraoperative neuronavigation in brain tumor surgery

Acta Neurochir (2015) 157:265–274

For safe resection of lesions situated in or near eloquent brain regions, determination of their spatial and functional relationship is crucial. Since functional magnetic resonance imaging and intraoperative neurophysiological mapping are not available in all neurosurgical departments, we aimed to evaluate brain surface reformatted imaging (BSRI) as an additional display mode for neuronavigation.

Methods Eight patients suffering from perirolandic tumors were preoperatively studied withMRI and navigated transcranial magnetic stimulation (nTMS). Afterwards, the MRI was automatically transformed into BSR images in neuronavigation software (Brainlab, Brainlab AG, Feldkirchen, Germany). One experienced neuroradiologist, one experienced neurosurgeon, and two residents determined hand representation areas ipsilateral to each tumor on two-dimensional (2D) MR images and on BSR images. All results were compared to results from intraoperative direct cortical mapping of the hand motor cortex and to preoperative nTMS results.

Results Findings from nTMS and intraoperative direct cortical mapping of the hand motor cortex were congruent in all cases. Hand representation areas were correctly determined on BSR images in 81.3%and on 2D-MR images in 93.75%(p= 0.26). In a subgroup analysis, experienced observers showed more familiarity with BSRI than residents (96.9 vs. 84.4 % correct results, p=0.19), with an equal error rate for 2D-MRI. The time required to define hand representation areas was significantly shorter using BSRI than using standard MRI (mean 27.4 vs. 40.4 s, p=0.04).

Conclusions With BSRI, a new method for neuronavigation is now available, allowing fast and easy intraoperative localization of distinct brain regions.

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A treatment paradigm for high-grade brain arteriovenous malformations: volume-staged radiosurgical downgrading followed by microsurgical resection

A treatment paradigm for high-grade brain arteriovenous malformations- volume-staged radiosurgical downgrading followed by microsurgical resection

J Neurosurg 122:419–432, 2015

The surgical treatment of many large arteriovenous malformations (AVMs) is associated with substantial risks, and many are considered inoperable. Furthermore, AVMs larger than 3 cm in diameter are not usually treated with conventional single-session radiosurgery encompassing the entire AVM volume. Volume-staged stereotactic radiosurgery (VS-SRS) is an option for large AVMs, but it has mixed results. The authors report on a series of patients with highgrade AVMs who underwent multiple VS-SRS sessions with resultant downgrading of the AVMs, followed by resection.

Methods. A cohort of patients was retrieved from a single-institution AVM patient registry consisting of prospectively collected data. VS-SRS was performed as a planned intentional treatment. Surgery was considered as salvage therapy in select patients.

Results Sixteen AVMs underwent VS-SRS followed by surgery. Four AVMs presented with rupture. The mean patient age was 25.3 years (range 13–54 years). The average initial Spetzler-Martin grade before any treatment was 4, while the average supplemented Spetzler-Martin grade (Spetzler-Martin plus Lawton-Young) was 7.1. The average AVM size in maximum dimension was 5.9 cm (range 3.3–10 cm). All AVMs were supratentorial in location and all except one were in eloquent areas of the brain, with 7 involving primary motor cortex. The mean number of VS-SRS sessions was 2.7 (range 2–5 sessions). The mean interval between first VS-SRS session and resection was 5.7 years. There were 4 hemorrhages that occurred after VS-SRS. The average Spetzler-Martin grade was reduced to 2.5 (downgrade, -1.5) and the average supplemented Spetzler-Martin grade was reduced to 5.6 (downgrade, -1.5). The maximum AVM size was reduced to an average of 3.0 cm (downsize = -2.9 cm). The mean modified Rankin Scale (mRS) scores were 1.2, 2.3, and 2.2 before VS-SRS, before surgery, and at last follow-up, respectively (mean follow-up, 6.9 years). Fifteen AVMs were cured after surgery. Ten patients had good outcomes at last follow-up (7 with mRS Score 0 or 1, and 3 with mRS Score 2). There were 2 deaths (both mRS Score 1 before treatment) and 4 patients with mRS Score 3 outcome (from mRS Scores 0, 1, and 2 [n = 2]).

Conclusions Volume-staged SRS can downgrade AVMs, transforming high-grade AVMs (initially considered inoperable) into operable AVMs with acceptable surgical risks. This treatment paradigm offers an alternative to conservative observation for young patients with unruptured AVMs and long life expectancy, where the risk of hemorrhage is substantial. Difficult AVMs were cured in 15 patients. Surgical morbidity associated with downgraded AVMs is reduced to that of postradiosurgical/preoperative supplemented Spetzler-Martin grades, not their initial AVM grades.

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Linear array ultrasound in low-grade glioma surgery: histology-based assessment of accuracy in comparison to conventional intraoperative ultrasound and intraoperative MRI

Linear array ultrasound in low-grade glioma surgery

Acta Neurochir (2015) 157:195–206

In low-grade glioma (LGG) surgery, intraoperative differentiation between tumor and most likely tumor-free brain tissue can be challenging. Intraoperative ultrasound can facilitate tumor resection. The aim of this study is to evaluate the accuracy of linear array ultrasound in comparison to conventional intraoperative ultrasound (cioUS) and intraoperative high-field MRI (iMRI).

Methods We prospectively enrolled 13 patients harboring a LGG of WHO Grade II. After assumed near total removal, a resection control was performed using navigated cioUS, navigated lioUS, and iMRI. We harvested 30 navigated biopsies from the resection cavity and compared the histopathological findings with the respective imaging results. Spearman’s rho was calculated to test for significant correlations. Sensitivity and specificity as well as receiver operating characteristics (ROC) were calculated to assess test performance of each imaging modality.

Results Imaging results of lioUS correlated significantly (p<0.009) with iMRI. Both iMRI and lioUS correlated significantly with final histopathological diagnosis (p<0.006, p<0.014). cioUS did not correlate with other imaging findings or with final diagnosis. The highest sensitivity for residual tumor detection was found in iMRI (83 %), followed by lioUS (79 %). The sensitivity of cioUS was only 21 %. Specificity was highest in cioUS (100 %), whereas iMRI and lioUS both achieved 67 %. ROC curves showed fair results for iMRI and lioUS and a poor result for cioUS.

Conclusions Intraoperative resection control in LGGs using lioUS reaches a degree of accuracy close to iMRI. Test results of lioUS are superior to cioUS. cioUS often fails to discriminate solid tumors from “normal” brain tissue during resection control. Only in lesions <10 cc cioUS does show good accuracy.

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Volumetric CT analysis as a predictor of seizure outcome following temporal lobectomy

Volumetric brain analysis in neurosurgery- Part 3

J Neurosurg Pediatr 15:133–143, 2015

The incidence of temporal lobe epilepsy (TLE) due to mesial temporal sclerosis (MTS) can be high in developing countries. Current diagnosis of MTS relies on structural MRI, which is generally unavailable in developing world settings. Given widespread effects on temporal lobe structure beyond hippocampal atrophy in TLE, the authors propose that CT volumetric analysis can be used in patient selection to help predict outcomes following resection.

METHODS Ten pediatric patients received preoperative CT scans and temporal resections at the CURE Children’s Hospital of Uganda. Engel classification of seizure control was determined 12 months postoperatively. Temporal lobe volumes were measured from CT and from normative MR images using the Cavalieri method. Whole brain and fluid volumes were measured using particle filter segmentation. Linear discrimination analysis (LDA) was used to classify seizure outcome by temporal lobe volumes and normalized brain volume.

RESULTS Epilepsy patients showed normal to small brain volumes and small temporal lobes bilaterally. A multivariate measure of the volume of each temporal lobe separated patients who were seizure free (Engel Class IA) from those with incomplete seizure control (Engel Class IB/IIB) with LDA (p < 0.01). Temporal lobe volumes also separate normal subjects, patients with Engel Class IA outcomes, and patients with Class IB/IIB outcomes (p < 0.01). Additionally, the authors demonstrated that age-normalized whole brain volume, in combination with temporal lobe volumes, may further improve outcome prediction (p < 0.01).

CONCLUSIONS This study shows strong evidence that temporal lobe and brain volume can be predictive of seizure outcome following temporal lobe resection, and that volumetric CT analysis of the temporal lobe may be feasible in lieu of structural MRI when the latter is unavailable. Furthermore, since the authors’ methods are modality independent, these findings suggest that temporal lobe and normative brain volumes may further be useful in the selection of patients for temporal lobe resection when structural MRI is available.

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Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Effects of Hematoma Reduction by Stereotactic Aspiration for Patients With Spontaneous Intracerebral Hemorrhage

Neurosurg Q 2015;25:17–23

Spontaneous intracerebral hemorrhage (ICH) is a devastating medical condition associated with significant morbidity and mortality. Whether the hematoma should be surgically removed remains controversial. This study was a retrospective analysis of patients with spontaneous ICH who were treated with computed tomography (CT)-guided stereotactic aspiration. The aim of this study was to investigate whether hematoma volume reduction in deep-seated ICH utilizing this minimally invasive surgical procedure improves clinical outcome.

Methods: Ninety-nine patients who suffered spontaneous ICH provided informed consent and were included in the study. Patients were divided into an operated group that underwent CT-guided stereotactic aspiration, and a nonoperated group that received only medical treatment. CT-guided stereotactic aspiration was performed at least 8 hours after onset of ICH. Using the Leksell stereotactic frame for guidance, a 4-mm-diameter catheter was inserted into the body of the hematoma through a frontal burr hole. Glasgow Coma Scale, motor function, and length of hospital stay were used to assess differences in outcomes between the 2 groups. The correlation between clinical outcome and stereotactic aspiration was evaluated using multivariate regression analysis.

Results: Ninety-nine consecutive patients were entered into this study. Patients in the operated group (n=41) were treated with CT-guided stereotactic hematoma aspiration. The 3-month Glasgow Outcome Scale score in the nonoperated group (n=58) was significantly lower than that in the operated group (2.32±1.26 vs. 3.15±1.33, P<0.001). Patients in the operated group experienced greater motor function recovery than those in the nonoperated group. The average length of hospital stay of the operated group was significantly shorter than that of the nonoperated group (31.2±14.6 vs. 41.7±17.2 d, P=0.002).

Conclusions: Stereotactic aspiration may improve the functional outcome and shorten the hospital stay of patients who have suffered spontaneous ICH. This procedure is minimally invasive and shows promise as a safe and effective treatment method for these patients.

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Is atlantoaxial instability the cause of Chiari malformation? Outcome analysis of 65 patients treated by atlantoaxial fixation

Is atlantoaxial instability the cause of Chiari malformation?

J Neurosurg Spine 22:116–127, 2015

Understanding that atlantoaxial instability is the cause of Chiari malformation (CM), the author treated 65 patients using atlantoaxial stabilization. The results are analyzed.

Methods Cases of CM treated using atlantoaxial fixation during the period from January 2010 to November 2013 were reviewed and analyzed. Surgery was aimed at segmental arthrodesis.

Results The author treated 65 patients with CM in the defined study period. Fifty-five patients had associated syringomyelia. Forty-six patients had associated basilar invagination. Thirty-seven patients had both basilar invagination and syringomyelia. Three patients had been treated earlier using foramen magnum decompression and duraplasty. According to the extent of their functional capabilities, patients were divided into 5 clinical grades. On the basis of the type of facetal alignment and atlantoaxial instability, the patients were divided into 3 groups. Type I dislocation (17 patients) was anterior atlantoaxial instability wherein the facet of the atlas was dislocated anterior to the facet of the axis. Type II dislocation (31 patients) was posterior atlantoaxial instability wherein the facet of the atlas was dislocated posterior to the facet of the axis. Type III dislocation (17 patients) was the absence of demonstrable facetal malalignment and was labeled as “central” atlantoaxial dislocation. In 18 patients, dynamic images showed vertical, mobile and at-least partially reducible atlantoaxial dislocation. All patients were treated with atlantoaxial plate and screw fixation using techniques described in 1994 and 2004. Foramen magnum decompression or syrinx manipulation was not performed in any patient. Occipital bone and subaxial spinal elements were not included in the fixation construct. One patient died, and death occurred in the immediate postoperative phase and was related to a vertebral artery injury incurred during the operation. One patient had persistent symptoms. In the rest of the patients there was gratifying clinical improvement. More remarkably, in 7 patients, the symptoms of lower cranial nerve paresis improved. No patient worsened in their neurological function after surgery. Reductions in the size of the syrinx and regression of the CM were observed in 6 of 11 cases in which postoperative MRI was possible. During the follow-up period, there was no delayed worsening of neurological function or symptoms in any patient. Sixty-three patients improved after surgery, and the improvement was sustained during the average follow-up period of 18 months.

Conclusions On the basis of outcomes in this study, it appears that the pathogenesis of CM with or without associated basilar invagination and/or syringomyelia is primarily related to atlantoaxial instability. The data suggest that the surgical treatment in these cases should be directed toward atlantoaxial stabilization and segmental arthrodesis. Except in cases in which there is assimilation of the atlas, inclusion of the occipital bone is neither indicated nor provides optimum stability. Foramen magnum decompression is not necessary and may be counter-effective in the long run.

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Microvascular decompression under neuroendoscopic view in hemifacial spasm

Microvascular decompression under neuroendoscopic view in hemifacial spasm

Acta Neurochir (2015) 157:329–332

We report microvascular decompression (MVD) under neuroendoscopic view in hemifacial spasm (HFS) patients with rostral- and perforator-type compression of the root exit zone (REZ) of the facial nerve.

Using either a wireless iPad Mini as a monitor on the microscope or a high-resolution monitor, microscopic and endoscopic views enabled MVD for complete cure of HFS with rostral-type compression (the offender compressing the REZ on the opposite rostral side to the operative approach) or perforator-type compression (the offender tethered to the REZ by the perforator).

MVD under neuroendoscopic view may offer more accurate MVD and complete resolution of HFS.

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