Surgical Neurology - Articles in Press

Flow patterns and distributions of fluid velocity and wall shear stress in the human internal carotid and middle cerebral arteries - Corrected Proof

Shigekazu Takeuchi, Takeshi Karino — 2009-10-26

Abstract: Background: The aim of this study is to elucidate the relationship between the flow patterns and the preferred sites of the development of atherosclerotic lesions and cerebral aneurysms in the human ICA and MCA.Methods: Five isolated transparent arterial trees containing the ICA and MCA with a sufficient length of the carotid siphon were prepared from humans postmortem, and flow patterns and distributions of fluid velocity and wall shear stress in these vessels were studied in detail using flow visualization and high-speed cinemicrographic techniques.Results: In the carotid siphon that contained several acute bends, due to the impingement and deflection of the flow at the bends, a strong and complex helicoidal flow formed. As a result, the approaching velocity profile was flattened at the terminal bifurcation of the ICA, but it was sharpened at the first bifurcation of the MCA. Thus, at this latter bifurcation, fluid elements impinged on the vessel wall around the flow divider with much larger velocity than that at the preceding terminal bifurcation of the ICA. Throughout the entire arterial tree, atherosclerotic lesions were found almost exclusively in regions of low wall shear stress.Conclusions: The carotid siphon provided a flattened approaching velocity profile at the terminal bifurcation of the ICA, making the hemodynamic stresses (pressure, tension, and shear stress) exerted on the vessel wall much lower than that at the bifurcation of the MCA where the approaching velocity profile was sharpened. This may account for the relatively low incidence of aneurysm formation at this site.

Commentary - Corrected Proof

Kern H. Guppy — 2009-10-26

For several decades it has been shown that areas of formation of atherosclerotic lesion have been associated with areas of low shear stress. Elegant experiments have shown this in the carotid bifurcations and iliac arteries. This article uses 5 isolated arterial trees from humans postmortem with sufficient length of the carotid siphon and showing the ICA and MCA branches. The velocity profiles throughout the bifurcations are examined and nicely illustrated in the author's figures. Their conclusions are that areas of low shear stress support the development of atherosclerotic lesions almost exclusively along the inner wall of the curved segments and outer wall of one or both daughter vessels at major bifurcations. The article also points out that the incidence of aneurysm formation is related to the magnitude of the approaching velocity of blood at bifurcations and especially at sharp bends where these aneurysms can form. These conclusions are well accepted in mathematical models but are nicely illustrated in this article with flow visualization and high-speed cinemicrographic techniques.

Surgery for glioblastoma and influence of technology on outcomes between developed and developing parts of the world - Corrected Proof

Kishor A. Choudhari — 2009-10-23

For several decades, the role of surgery for patients with glioblastoma has been a major controversy in neurosurgery. The literature abounds with contrasting opinions from neuroscientists across the globe with arguments ranging from biopsy alone or no surgery, to those who would aim for nothing less than gross total resection. In spite of several noteworthy scientific and technological advances in an attempt to tackle the disease, glioblastoma remains incurable. Five-year survivals are almost unheard of, yet most of us optimistically continue to operate on these formidable lesions, often uncertain whether our surgical intervention is making any significant positive impact on patient's longevity and quality of life.

Evaluating the prognostic factors effective on the outcome of patients with glioblastoma multiformis: does maximal resection of the tumor lengthen the median survival? - Corrected Proof

Faramarz- Allahdini, Abbass Amirjamshidi, Mohammad Reza-Zarei, Morteza Abdollahi — 2009-10-22

Abstract: Background: The ETR that should be undertaken in patients with GBM remains controversial. This study aims to reiterate some independent predicting factors and to underscore the role and the ETR in increasing the survival of patients in the situation of developing countries, that is, without preoperative MRI or tractography. The authors submit additional information to be added to the list of CTRs in the management of malignant brain tumors.Methods: The authors prospectively analyzed a cohort of 35 consecutive patients with histologically proven GBM who underwent tumor resection in surgically amenable areas for the first time at Sina Hospital, Tehran, between 2003 and 2005. Demographic data, volumetric measurements, and other characteristics identified on preoperative and immediate postoperative MR imaging as well as intraoperative and postoperative clinical data were collectively analyzed by SPSS for Windows, version 11.5 (SPSS, Chicago, Ill).Results: Cox proportional hazards model multivariate analysis identified the following independent predictors of survival: Karnofsky performance scale ≥80 (P = .01), ETR (P = .01), tumor location in functionally silent prefrontal area (P = .002) vs tumor location in corpus callosum (P = .001), postoperative RT (P = .004), and postoperative chemotherapy (P = .001)Conclusion: Maximal resection of the tumor volume is an independent variable associated with longer survival times in patient with GBM. Gross total resection should be performed whenever possible, although not at the expense of increased morbidity.

Computed tomographic perfusion in assessing postoperative revascularization in moyamoya disease - Corrected Proof

Anil K. Nair, Doniel Drazin, Junichi Yamamoto, Alan S. Boulos — 2009-10-16

Abstract: Background: Our purpose in this study is to evaluate the use of computed tomographic perfusion (CTP) as an imaging modality to assess revascularization after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass in patients with moyamoya disease.Case description: We present a series of 5 patients (mean age, 35; range, 20-50) with moyamoya disease who underwent STA-MCA bypass for ischemic stroke or transient ischemic attack (TIA). Preoperatively, all patients were evaluated with CTP; all showed clinically significant hypoperfusion in the MCA territory. All surgeries were performed by the senior author (ASB) and there were no periprocedural complications. Postoperative CTPs were performed to assess improvement after the bypass. The postoperative CTP images clearly demonstrated patency of the bypass and restoration of flow, particularly in the MCA distribution. At follow-up (mean, 18 months), 3 patients continued to be asymptomatic, one patient's hemiparesis improved, and another patient's hemiparesis improved but remained aphasic (mean Glasgow Outcome Score, GOS = 4.5). All displayed a reduced risk of recurrent stroke; no MCA strokes were observed.Conclusion: This study demonstrates that CTP, a more convenient and less expensive imaging test than other available options, can provide an assessment of cerebral blood flow after cerebral bypass that appears to correlate with postoperative clinical and angiographic findings. In addition, in this small series of moyamoya patients, STA-MCA bypass appeared to prevent recurrent TIAs and strokes.

Commentary - Corrected Proof

Miki Fujimura, Teiji Tominaga — 2009-10-16

Nair et al reported a series of 5 patients with adult-onset moyamoya disease, who were postoperatively evaluated by computed tomography (CT) perfusion to assess revascularization after STA-MCA bypass. The postoperative CT perfusion demonstrated the improvement of cerebral hemodynamics as well as the patency of STA-MCA bypass in all 5 cases. Consistent with these findings, the postoperative course of all 5 patients was favorable, without recurrent stroke. The efficacy of postoperative cerebral blood flow (CBF) measurement for moyamoya disease has been reported using positron emission tomography and single photon emission computed tomography previously. The present series suggested that CT perfusion could be a useful tool for evaluating postoperative alteration of cerebral hemodynamics during the chronic stage after STA-MCA bypass for moyamoya disease. Alternatively, in light of the recent observations that postoperative CBF measurement is important to make an accurate diagnosis of cerebral hyperperfusion during the acute stage after STA-MCA bypass for moyamoya disease , it would be of great interest to evaluate the usefulness of CT perfusion during the acute stage after STA-MCA bypass for moyamoya disease in the future study.

Commentary - Corrected Proof

Daniel L. Barrow — 2009-10-16

The authors have presented their microneurosurgical experience in managing 51 consecutive patients with large or giant proximal carotid aneurysms managed for a 10-year period. These 51 patients had a number of complicating features of their aneurysms, increasing the complexity of surgical management. Complicating factors included presentation with subarachnoid hemorrhage in 73%, giant size in 53%, intraluminal thrombosis in 24%, and calcification of the aneurysm in 8%. Despite these confounding factors, the authors report very good results in their 6-month follow-up. Complications included death in 4%, visual loss, transient oculomotor palsy, stroke, and cerebrospinal fluid leakage. Overall, the results are quite impressive and are attributed to a number of surgical adjuncts used on a routine basis by the authors. Balloon test occlusion was performed in all patients, 14 of whom did not tolerate the temporary occlusion. Other surgical adjuncts include routine exposure of the cervical carotid artery for proximal exposure and complete removal of the anterior clinoid process with opening of the dural ring, if necessary. Once the aneurysm is exposed, the authors liberally used retrograde suction to collapse the aneurysm and monitored patients with intraoperative EEG and SSEP monitoring. Intraoperative imaging was enhanced by the use of the endoscope in selected cases, microvascular Doppler ultrasonography, and more recently, ICG videoangiography. In 14% of the patients the operation included an extracranial/intracranial bypass with trapping of the aneurysm.

Size of ruptured intracranial saccular aneurysms in patients in Izumo City, Japan - Corrected Proof

Tetsuji Inagawa — 2009-10-15

Abstract: Background: A community-based study was conducted to evaluate the factors related to the size of ruptured aneurysms and the effects of aneurysm size on clinical features.Methods: Data from 358 patients with subarachnoid hemorrhage (SAH) treated between 1980 and 1998 in Izumo, Japan, were reviewed. In 285 of these patients, the sizes of the ruptured aneurysms were determined.Results: Aneurysm diameter was less than 5 mm in 68 patients, at least 5 to less than 10 mm in 137 patients, and 10 mm or more in 80 patients. Aneurysm size tended to increase with patient age. Age (≥60 years of age) and cigarette smoking were independently associated with aneurysms of 5 mm or more in diameter. Multiple aneurysms were positively and anterior cerebral artery aneurysms were inversely related to aneurysms of 10 mm or more in diameter. The larger the aneurysm, the worse was the World Federation of Neurosurgical Societies grade. The risk of rebleeding was higher in patients with larger (≥10 mm) aneurysms than in those with smaller (<10 mm) aneurysms. The incidences of diffuse severe SAH on computed tomographic scans in patients with SAH alone, symptomatic vasospasm, and hydrocephalus were higher in patients with larger (≥5 mm) aneurysms than in those with smaller (<5 mm) aneurysms. The larger the aneurysm, the worse was either functional outcome or the 6-month and 2-year survival rates.Conclusion: Age, cigarette smoking, multiple aneurysms, and aneurysm site appear to be related to the size of ruptured aneurysms. Patients with larger aneurysms seem to have a worse clinical condition and more severe SAH, resulting in higher incidences of rebleeding, symptomatic vasospasm and hydrocephalus, and a worse outcome.

Commentary - Corrected Proof

Phillip Dickey — 2009-10-15

This is an important article regarding the characteristics of ruptured aneurysms in a single community in Japan. The data show that most ruptured aneurysms are less than 10 mm in diameter and that age, smoking, the presence of multiple aneurysms, and aneurysm site are all important factors in aneurysm rupture and outcome. Although the importance of these factors has been debated for years, this community-based study provides another data point for future study.

Early regrowth of juvenile cerebral arteriovenous malformations: report of 3 cases and immunohistochemical analysis - Corrected Proof

Yasushi Takagi, Ken-ichiro Kikuta, Kazuhiko Nozaki, Nobuo Hashimoto — 2009-10-15

Abstract: Background: Regrowth of cerebral AVMs after angiographically documented obliteration has been observed in children. In addition, AVMs in adults are reported to be at risk of regrowth despite an angiogram confirming complete removal. However, the mechanism by which regrowth occurs has not been clarified; neither is it clear when regrowth occurs after removal.Case Description: We report 3 cases showing regrowth of AVMs on postoperative angiogram performed 3 months after surgery. We also analyzed the protein levels of various factors that may influence AVM regrowth. Using immunohistochemistry, we analyzed the protein levels of the following factors: CD31 (PECAM), CD34, and CD105 (endoglin), which are endothelial or endothelial progenitor markers; VEGF, a growth factor that may influence AVM regrowth; and PCNA, a marker of proliferating cells. In addition, we analyzed the level of pERK.Conclusion: We report 3 cases of early regrowth of cerebral AVMs. In recurrent AVM samples obtained at second operations, increased levels of perivascular CD105 and pERK immunoreactivity were seen.

Lipoglioblastoma: a lipidized glioma radiologically and histologically mimicking adipose tissue - Corrected Proof

Michael W. Johnson, Doris Lin, Bassam N. Smir, Peter C. Burger — 2009-10-15

Abstract: Background: We report the case of a man with glioblastoma containing a component radiologically and histologically mimicking adipose tissue.Case Description: A 48-year-old man recently complaining of headaches and difficulty with speech presented with a cystic peripherally enhancing left temporoparietal mass with focal intrinsically (precontrast) bright nodules in fluid attenuated inversion recovery and T1-weighted images similar to adipose tissue. Histologically, the enhancing component was classic glioblastoma, whereas the bright nodules comprised tumor cells that in aggregate closely resembled adipose tissue.Conclusions: The case illustrates the extent to which lipidized central nervous system tumors of glial origin, or components thereof, can radiologically and histologically resemble adipose tissue. However, immunohistochemical staining and electron microscopy can eliminate diagnostic confusion.

Microsurgical management of large and giant paraclinoid aneurysms - Corrected Proof

2009-10-15

Abstract: Background: Because of the complex topographic anatomical relationship between vascular, dural and bone structures, paraclinoid aneurysms, especially those of larger size, remain a great challenge for vascular neurosurgeons. We present our microneurosurgical experience of 51 consecutive patients with large and giant paraclinoid aneurysms to scrutinize our personal strategies related to surgical treatment.Methods: Fifty-one patients with large or giant paraclinoid underwent micorneurosurgical aneurysm treatment. Operative strategies were planned according to preoperative state-of-the-art imaging studies, and a pterional-transsylvian approach was routinely used. Proximal control of the internal carotid artery (ICA) was achieved by exposure of the cervical portion of the vessel. Intraoperative electroencephalogram and somatosensory evoked potential monitoring, indocyanine green (ICG) videoangiography and/or microvascular Doppler ultrasonography (MDU) were regularly used. A postoperative digital subtraction angiography or computed tomography angiography was performed to verify the efficacy of treatment.Results: Forty-three large and giant paraclinoid aneurysm necks (84%) were directly clipped, seven unclippable aneurysms (14%) were trapped with extra-intracranial high-flow revascularization, and one aneurysm (2%) was treated with only ICA proximal Hunterian ligation. Two patients (4%) died in the early postoperative period. In 84% of the patients, the Glasgow Outcome Scale score was 4 or 5 at discharge. At the 6-month follow-up examination, the Rankin Outcome Scale score was 0-2 in 90% of patients.Conclusions: Temporary parent vessel occlusion, retrograde suction decompression, endoaneurysmectomy, parent vessel clip reconstruction, and bypass vascular anastomosis are essential techniques to treat complex paraclinoid aneurysms. The combined use of electrophysiological monitoring, MDU, intraoperative ICG videoangiography, and endoscopy can substantially improve microsurgical outcome.

Commentary - Corrected Proof

Thomas Kopitnik — 2009-10-15

The authors present a nice series of 51 patients treated for large or giant paraclinoid aneurysms. All 51 patients underwent some form of surgical treatment, including proximal ligation in 1, bypass and trapping in 7, and direct clipping in 43. The management algorithm presented by the authors offers a very rational treatment strategy. This study is biased toward surgical intervention, and the bias is recognized by the authors. I agree with surgical intervention by direct clipping as the optimal treatment in most cases of symptomatic giant proximal carotid artery aneurysms. In my experience, these aneurysms invariably have very broad-based necks that essentially require “vascular reconstruction” rather than technical aneurysm clip application. The size of (or lack of a definable) neck is the reason that endovascular obliteration of theses aneurysms is often extremely difficult and often necessitates use of stent/coil combinations. I have also found that often the sheer volume of giant paraclinoid aneurysms will mandate insertion of a great number of coils to fill the aneurysm, making endovascular treatment exceedingly expensive in many circumstances. I have also seen better symptom resolution with surgical clipping because of the ability to decompress the aneurysm after clipping, which does not occur with endovascular therapy and a large deposit of an intraaneurysmal mass of coils.

Heterotopic ossifications after vertebroplasty using calcium phosphate in osteoporotic vertebral compression fractures: Report of 2 cases - Corrected Proof

Dong Hwa Heo, Sung Min Cho, Yong Jun Cho, Jun Hyeung Cho, Seung Hun Sheen — 2009-10-15

Abstract: Background: Recently, calcium phosphate (CaP) cement, instead of polymethylmethacrylate, has been injected into the compressed vertebral body. Calcium phosphate may have the potential for ectopic or heterotopic ossification and, thus, injected CaP cement can induce unwanted heterotopic ossifications in the human body.Case Description: The authors describe 2 cases of heterotopic ossifications after vertebroplasty using CaP in osteoporotic vertebral compression fractures. We performed percutaneous vertebroplasty using CaP cement in a 69-year-old woman with L2 compression fracture and an 80-year-old man with L1 compression fracture. Follow-up radiologic studies for both cases showed that heterotopic ossifications had developed around the CaP augmented vertebral bodies and that the cemented vertebral bodies had recollapsed. Also, subsequent vertebral compression fractures had occurred.Conclusions: We suggest that heterotopic ossification may be complications of vertebroplasty with CaP. Therefore, we strongly recommended that the patients who undergo a vertebroplasty with CaP need strict observation.

Commentary - Corrected Proof

Nancy Epstein — 2009-10-15

The authors provide a succinct report of 2 cases in which CaP cement was substituted for PMMA when managing 2 patients with vertebral osteoporotic compression fractures. The first patient was a 69-year-old woman with an L2 compression fracture, and the second patient was an 80-year-old man with an L1 compression fracture. Nevertheless, post-procedure radiographic studies documented heterotopic ossification around the CaP vertebrae and evidence of repeated collapse at these levels. In addition, patients developed subsequent vertebral compression fractures at other levels. The authors concluded that patients undergoing vertebroplasty with CaP should be closely followed as they are at risk for developing heterotopic ossification (HO), which may facilitate further vertebral collapse at treated levels, while other untreated levels remain susceptible to subsequent vertebral compression fractures. Heterotopic ossification seen after vertebroplasty with CaP may (1) not afford sufficient “initial stiffness” for the compressed vertebral body, thus fostering further vertebral collapse, and (2) heterotopic ossification may alter the “normal biomechanics” of the spine, sufficient to result in collapse at the treated as well as untreated levels. I think the authors should be applauded for bringing these adverse reactions to CaP vertebroplasty to our attention.

Madurella mycetoma—a rare case with cranial extension - Corrected Proof

Shradha Maheshwari, Antonio Figueiredo, Swati Narurkar, Atul Goel — 2009-10-12

Abstract: Background: Madurella species of fungus causes chronic subcutaneous infection of lower extremities; the infection is commonly labeled as Madura foot. We report a case of Madurella infection involving the cranial cavity. Such an involvement by Madurella fungal infection is not recorded in the literature.Case description: A 31-year-old nonimmunocompromised male patient presented with complaints of left hemifacial pain for 1 year and diplopia on looking toward left side for a period of 2 weeks. On examination, he had ipsilateral sixth nerve paresis. Investigations revealed a large paranasal sinus lesion that extended in the cavernous sinus. The lesion was partially resected. Histologic examination revealed that the lesion was a fungus Madurella mycetomi.Conclusion: A rare cranial extension of Madurella fungal infection is reported.

Adenosine-induced cardiac arrest during intraoperative cerebral aneurysm rupture - Corrected Proof

2009-10-12

Abstract: Background: Rupture of an intracranial aneurysm during surgical clipping may have devastating consequences. Should this happen all methods ought to be considered to stop the bleeding. A short-term cardiac arrest induced by adenosine could be a feasible method to help the surgeon. We present our experiences in the administration of adenosine during an intraoperative aneurysm rupture.Methods: Medical records of patients who underwent surgical clipping of a cerebral arterial aneurysm were reviewed from 2 university hospitals' operative database in the years 2003 to 2008. Patients were included in this study if adenosine had been administered during intraoperative rupture of an aneurysm.Results: Altogether, 16 of 1014 patients were identified with the use of adenosine during an intraoperative rupture of an aneurysm. All of the patients had sinus rhythm and normotension before the rupture of the aneurysm. Twelve patients were administered a single dose of adenosine and 4 multiple boluses for induction of cardiac arrest; the median (range) total dose was 12 (6-18) mg and 27 (18-87) mg, respectively. The clipping of the aneurysm and the recovery of circulation were uneventful in all cases. In a subgroup analysis according to patient outcome as alive/dead, the pre- and postoperative neurologic condition correlated with the outcome, whereas adenosine did not have any effect on the patient outcome.Conclusion: In a case of a sudden aneurysm rupture, adenosine-induced circulatory arrest could be a safe option to facilitate clipping of an aneurysm. However, if adenosine is used, a very close collaboration between the surgeon and the anesthesiologist is required.

Commentary - Corrected Proof

Barbara Margaret Van de Wiele — 2009-10-12

The administration of adenosine by an anesthesiologist to assist surgical efforts at controlling bleeding in the setting of ruptured intracranial aneurysms is not yet common in the clinical practice of anesthesiologists, at least in the United States. The experience of 16 cases presented here is particularly valuable in the context of the paucity of information available on safety and efficacy, and the likelihood that additional information will be slowly forthcoming.

Spondylodiscitis due to Prevotella associated with ovarian mass—a rare case report and review of literature - Corrected Proof

Balaji Purushothaman, Palaniappan Lakshmanan, Simon Gatehouse, David Fender — 2009-10-12

Abstract: Background: Spondylodiscitis is commonly caused by aerobic bacteria. Of all the spinal infections, anaerobic organisms account for less than 3% and are usually seen in postoperative patients.Case Description: We report a rare case of spontaneous onset of spondylodiscitis caused by anaerobe Prevotella that led to the diagnosis of serous cystadenofibroma of the ovaries.Conclusion: The finding of Prevotella species in musculoskeletal infection should prompt investigation of the genitourinary system.

Risk factors for the formation and rupture of intracranial saccular aneurysms in Shimane, Japan - Corrected Proof

Tetsuji Inagawa — 2009-08-10

Abstract: Background: Prevention of aneurysmal SAH can be achieved by reducing risk factors, which include those for aneurysm formation and aneurysm rupture. However, neither of these 2 factors has been discussed separately so far. A case control study was undertaken in Shimane, Japan, to identify modifiable risk factors for the formation and rupture of aneurysms.Methods: This study included 858 patients with ruptured aneurysms, 285 patients with unruptured aneurysms without a history of SAH, and 798 control subjects. Hypertension, diabetes mellitus, heart disease, hypercholesterolemia, cigarette smoking, and alcohol consumption were assessed as risk factors by using conditional logistic regression.Results: After adjustment for other risk factors, hypertension was the most powerful risk factor for aneurysm formation, regardless of age and sex, followed by hypercholesterolemia, heart disease, and cigarette smoking, whereas diabetes mellitus and daily drinking were insignificant for aneurysm formation. Hypertension and daily drinking were not related to the risk of aneurysm rupture, regardless of age and sex, whereas cigarette smoking was associated with an increased risk of aneurysm rupture in patients 60 years or older and in men. In contrast, hypercholesterolemia was strongly associated with a decreased risk of rupture, regardless of age and sex, and in patients with small aneurysms (<5 mm). Diabetes mellitus and heart disease were also related to a decreased risk of rupture in patients 60 years or older and in women.Conclusion: Identification of risk factors for aneurysm formation and rupture separately seems to be pivotal for reducing the incidence of SAH.

Commentary - Corrected Proof

Thomas Kopitnik, Debra Steele — 2009-08-10

This is an outstanding case control study of the risk factors for aneurysm development and aneurysm rupture. This adds significant new information to the known medical literature regarding risk factors and odds ratios for cerebral aneurysms. The study is well planned and well executed, and the discussion is thoughtful regarding the findings and the limitations of the study. A few points that deserve re-emphasis are probably self-evident to most neurosurgeons. First, this study again demonstrates the dangerous nature of anterior communicating artery aneurysms, with a high percentage of aneurysms in this location presenting with subarachnoid hemorrhage. Secondly, this study seems to confirm what we have observed and perceived regarding aneurysm size, that once an aneurysm reaches a certain size (>10 mm in this study) the odds of rupture is less influenced by other associated risk factors other than size alone. And lastly, this study demonstrates a possible disconnection between the risk factors associated with aneurysm formation and the subsequent risk of aneurysm rupture. These findings should significantly impact the recommendations tendered to patients regarding treatment options and appropriate lifestyle alterations if observational treatment is chosen for an intracranial aneurysm.

Assessment of therapeutic response in patients with brain abscess using diffusion tensor imaging - Corrected Proof

2009-08-10

Abstract: Background: Accurate assessment of therapeutic response in patients with brain abscess (BA) is essential to direct appropriate therapy. This study was performed with an aim to see the treatment-induced changes in diffusion tensor imaging (DTI) indices (ie, fractional anisotropy [FA] and mean diffusivity [MD]) in follow-up patients with BA after treatment.Methods: Twenty patients with BA were prospectively studied in this study. Diffusion tensor imaging in first follow-up was done in all after 1 week and in 6 at 4 weeks of the initial study.Results: The mean FA and MD values in first, second, and third studies were 0.28 ± 0.03 and (0.81 ± 0.07) × 10−3 mm2/s, 0.18 ± 0.09 and (1.08 ± 0.09) × 10−3 mm2/s, and 0.13 ± 0.04 and (0.99 ± 0.13) × 10−3 mm2/s, respectively. The FA value was significantly (P < .01) decreased along with no significant change in MD value (P = .08) for 3 study periods. The mean volume (in milliliter) of the abscesses was 2.14 ± 1.04, 1.34 ± 0.45, and 0.77 ± 0.14 in first, second, and third studies, respectively.Conclusions: We conclude that the reduction in FA value reflects the down-regulation of the neuroinflammatory molecules in response to treatment in patient with BA and may be used to assess therapeutic response in these patients in future.

Commentary - Corrected Proof

Mahmood F. Mafee — 2009-08-10

Since the clinical application of DWI as early as 1986, its most common use has been to identify acute infarcted cerebral tissue, but many investigators have focused on the use of DWI in characterizing many other lesions, including abscesses. The mechanisms governing DWI are complex, and many efforts have been used to explain the DWI and DTI characteristics of varied pathologic conditions. It is known that abscesses (95%) are hyperintense on DWI and hypointense on ADC map, indicative of restriction. As abscesses respond to treatment, there will be an increase in ADC value, making an abscess cavity hyperintense on ADC map, which can be used to assess the therapeutic response. Gupta et al reported high fractional anisotropy (FA) in brain abscesses, reflecting the up-regulation of various cell molecules (CAMs). In this study, the authors report significant reductions in FA values observed in brain abscesses, reflecting the down-regulation of the inflammatory molecules in response to treatment for patients with brain abscesses. I concur with the authors that measurement of the ADC value along with an FA measurement are indicators of therapeutic response in the treatment of brain abscesses.

Role of intraoperative neurophysiologic monitoring in lumbosacral spine fusion and instrumentation: a retrospective study - Corrected Proof

Saeid Alemo, Amirali Sayadipour — 2009-08-10

Abstract: Background: This study was carried out to determine the efficacy of IONM in detecting iatrogenic neural injury during pedicle screw insertion, in comparison to the efficacy of computerized tomography (CT) and direct visual inspection of adjacent nerve roots.Methods: We reviewed the records of 86 patients, who had had 414 titanium pedicle screws inserted for posterior lumbar instrumentation. A standardized multimodality technique under total intravenous anesthesia was used. A relevant neurophysiologic change (surgical alert) was defined as a reduction in amplitude of at least 50% for somatosensory evoked potentials or at least 65% for transcranial electric motor evoked potentials (tcMEPs) compared with baseline. A stimulation threshold of 8 mA or less indicated that the screw was too close to the nerve root.Results: Immediate feedback via evoked electromyography (EMG) using stimulating pedicle probes in appropriate muscle groups was suggestive of pedicle cortical bone compromise in 28 screws (6.7%). Twenty-one screws were removed and redirected. Four false-positive evoked EMGs in 4 patients were detected by direct visual inspection of the nerve roots and the pedicles, and the surgeon elected not to reposition the screws. None of those patients had postoperative neurologic deficit, and the postoperative CT confirmed the integrity of pedicles. Three false-negative EMGs in 3 patients were detected postoperatively by new neurologic deficits and abnormal CT (3.48%).Conclusion: Intraoperative neurophysiologic monitoring is a valuable tool to add to the surgical skill and intraoperative fluoroscopy to protect neural tissue during pedicle screw instrumentation. However, postoperative CT is the ultimate test to determine the accuracy of positioning of the titanium screws. We propose a wake-up test in the operating room after extubation and urgent CT if the patient develops a new neurologic deficit to determine whether to reposition the screws in the same setting.

Commentary - Corrected Proof

Nancy Epstein — 2009-08-10

The authors point out the use of intraoperative monitoring when using pedicle screw instrumentation in the lumbar spine. They evaluated 86 patients who had 414 screws placed. With monitoring, in 28 cases, significant changes prompted screw replacement/redirection in 21. There were 4 false-positives (significant changes/no deficit) and 3 false-negatives (no changes but deficit present). Overall, their conclusion that intraoperative SEP and motor evoked potential monitoring, in conjunction with intraoperative fluoroscopy, were important adjuncts to performing instrumented lumbar procedures using pedicle screws. I would congratulate the authors on a job well done. Too frequently, the risks/complications of pedicle screw instrumentation are ignored although, as the authors point out, they may be malpositioned/misplaced in up to 15% of cases. Here is a candid and valid report affording honest documentation in a large series.

Rapid malignant transformation of low-grade astrocytomas: report of 2 cases and review of the literature - Corrected Proof

2009-08-10

Abstract: Background: Low-grade gliomas have been documented to undergo transformation into high-grade astrocytomas, and the time interval of this transformation has been reported to generally occur within 5 years in about 50% of patients harboring these low-grade lesions. Several studies have investigated the evolution of low-grade gliomas into malignant gliomas by CT and MRI characteristics, but many have not documented the timing of these transformation processes.Case Description: The authors discuss the cases of 2 patients with histopathologically confirmed grade II astrocytomas after craniotomies that underwent rapid evolution into malignant gliomas within 13 weeks. Interestingly, both low-grade astrocytomas were positive with immunostaining for the epidermal growth factor receptor, in which its amplification has been implicated as a molecular marker of malignant gliomas. In addition, the grade II astrocytomas were negative for p53 in both patients but were found to be positive upon transformation into malignant gliomas.Conclusions: To our knowledge, this is the first report of rapid malignant transformation of low-grade gliomas, which were proven by histology, within 13 weeks. There may be patients with a subtype of low-grade astrocytomas that may warrant molecular characterization to determine if aggressive adjuvant therapy would be of benefit.

Low-grade glioma: no longer to treat or not to treat, but why to treat - Corrected Proof

Lynn Stuart Ashby — 2009-08-10

At long last, the low-grade glioma debate is over, or should be, at least in the minds of most brain tumor clinicians, many of whom may have changed personal positions several times during the last two decades, including myself. The issues were concisely elucidated 20 years ago in a pair of “point and counterpoint” articles by Cairncross (1989, Archives of Neurology) and Shaw (1990, Archives of Neurology). Safety concerns about treatment for patients with low-grade gliomas have apparently not yet been sufficiently resolved to achieve consensus opinion and a rational standard of care, even today. Original objections focused on risk of surgery, toxicity of radiotherapy, and the view that the diagnosis of low-grade glioma might be considered a relatively benign process, not requiring early aggressive anticancer treatment. As of today, however, the roles of surgery and radiotherapy, less so of chemotherapy, have become clearer. Clinical neurosurgical series from University of California, San Francisco have firmly established the outcome benefits of gross total resection, when possible, for low-grade gliomas. In addition, the results of phase III randomized clinical trials from large consortia (EORTC [European Organization for Research and Treatment of Cancer] and RTOG [Radiation Therapy Oncology Group]) have been published and are remarkably consistent, favoring early treatment to significantly extend the progression-free interval. Perhaps even more important than the primary objectives of these studies (ie, benefit in overall and progression-free survival times due to treatment) have been the data collected characterizing patient- and tumor-related prognostic variables of these subject groups, suggesting stratification into low-risk, high-risk, and maybe even intermediate-risk groups. Risk of what? Risk of early progression and malignant transformation to high-grade glioma. Advanced age, size of tumor, extent of neurologic symptoms, and astrocytoma histology vs oligodendroglioma or mixed oligoastrocytoma have all proven to be reliably predictive of aggressive regrowth and likely contribute to the observation that of the patients who do not undergo postoperative radiotherapy, nearly half will recur in 5 years—many with malignant transformation to a higher-grade tumor. That said, the 2 patients presented in this article can be categorized into a high-risk group: both older than 40 years, both with significant neurologic symptoms, both with known subtotal resections, and both with histologic diagnoses of astrocytoma. The authors state that neither of these patients received any radiotherapy or chemotherapy after surgery, but the details are not explained. Was treatment simply delayed, then thwarted because of rapid relapse? Or was there a definitive clinical recommendation for these patients to be “observed” rather than treated postoperatively? Both of these cases are remarkable because of the extraordinarily rapid progression, supporting the suggestions that (1) glioblastoma was harbored in the residual unresected tumor (potential sampling error), or more likely, (2) that tumors that are EGFR positive, whether histologically low or high grade, should be considered aggressive. In the neurooncology clinical arena, rich because of the multidisciplinary participation of neurosurgeons, neurologists, neuroradiologists, pathologists, and oncologists, our radiation oncology colleagues have been the firm guardians of evidence-based treatment recommendations. At this point, in 2009, the evidence seems clear, and exemplified as well by these cases, that it is an error to “under”-treat our patients with low-grade glioma. In the future, molecular characterization will likely modify our treatment practice as our ability to assess risk becomes more refined and our therapeutic options become more targeted and customized.

Spinal cord injury in cervical spinal stenosis by minor trauma - Corrected Proof

Do-Sung Yoo, Sang-Bok Lee, Pil-Woo Huh, Seok-Gu Kang, Kyoung-Suok Cho — 2009-08-10

Abstract: Background: The size of the spinal canal is a factor that contributes to the neurologic deficits associated with cervical OPLL and CSM. We investigate the development of neurologic deterioration after minor trauma and the clinical results of decompressive surgery in cervical spinal stenosis retrospectively.Method: We treated 200 cases (98 cervical OPLLs and 102 CSMs) of cervical spinal stenosis for 8 years. There were 63 (33.5%) minor trauma cases to the cervical spine in 200 patients. Of these 63 patients, 18 developed myelopathy, 13 showed deterioration of preexisting myelopathy, and no neurologic change was observed in 32 patients. The neurologic status was assessed by the JOA score. The patients were divided into 2 groups according to the residual cervical spinal canal diameter: group I (<10 mm cervical spinal canal) and group II (≥10 mm cervical spinal canal).Results: Neurologic outcome depended on the diameter of the residual spinal canal; 22 of the 25 patients in group I developed neurologic deterioration, whereas that occurred in 8 of the 38 patients in group II (P < .05). After surgical decompression, 8 patients in group I and 30 patients in group II came out with an improved JOA score of more than 50% (P < .05).Conclusion: Even indirect minor trauma to the neck can cause irreversible changes in the spinal cord if there is marked stenosis of the cervical spinal canal. It may be beneficial to check lateral radiograph of the cervical spine as a screening tool for early detection of cervical spinal stenosis especially in Asian people older than 40 years.

Commentary - Corrected Proof

Nancy Epstein — 2009-08-10

This study is an important contribution to the literature, as it outlines the substantial risk of neurologic deterioration after even minor trauma in patients with cervical spinal stenosis and OPLL (98 patients) and in patients with CSM (102). Over an 8-year period, 63 (33.5%) patients sustained a minor traumatic event; of these, 18 developed new myelopathic deficits, 13 demonstrated an exacerbation of previously existing myelopathy, and 32 demonstrated no changes. When patients were further divided into 2 groups, those with the more severe stenosis (group I: <10 mm anteroposterior canal diameter) demonstrated greater degrees of neurologic deterioration (22 of 25 patients), whereas fewer with larger canals (≥1 mm) in group II exhibited neurologic worsening (8/38 cases). Furthermore, operative decompression more effectively provided neurologic improvement (better JOA scores) for 30 group II patients with larger baseline canal anteroposterior diameters, compared with a lesser 8 for group II patients with more severe stenosis. This article, of note, increases the reported frequency of such complications from the previously described 10% incidence of trauma-induced new deficits in such patients to the newer 33.5% figure. I commend the authors on an excellent study, which will be very useful to clinicians discussing the risks of nonsurgical vs surgical intervention for patients with differing degrees of cervical stenosis and OPLL or CSM.

N-acetylcysteine prevents vasospasm after subarachnoid hemorrhage - Corrected Proof

Onder Güney, Fatih Erdi, Hasan Esen, Aysel Kiyici, Yalcin Kocaogullar — 2009-08-10

Abstract: Background: This study investigated the ability of NAC to prevent cerebral vasospasm in a rabbit model of SAH.Methods: Twenty-one, male New Zealand white rabbits were randomly divided into 3 groups of 7 rabbits each: group 1 (control), group 2 (SAH only), group 3 (SAH + NAC treatment). NAC (150 mg/kg, single dose, IP) was administered just before SAH and continued until 72 hours after SAH in group 3.Animals were killed 72 hours after SAH. Tissue MDA levels, SOD, and GSH-Px activities were measured, and basilar artery cross-sectional areas, arterial wall thickness, and endothelial apoptosis in a cross section of basillary artery were determined in all groups.Results: Intraperitoneal administration of NAC was found to be markedly effective against developing a cerebral vasospasm following a SAH in rabbits. It could significantly reduce elevated lipid peroxidation and increase the level of tissue GSH-Px and SOD enzymatic activities. Also, NAC treatment was found to be effective in increasing the luminal area and reducing wall thickness of the basilar artery. The morphology of arteries in the NAC treatment group was well protected. NAC markedly reduced apoptotic index and protects the endothelial integrity.Conclusions: This study demonstrates, for the first time, that NAC treatment attenuates cerebral vasospasm in a rabbit SAH model. NAC treatment has significant neuroprotective effect and markedly prevents cerebral vasospasm after SAH. In conclusion, the NAC treatment might be beneficial in preventing cerebral vasospasm after SAH, thus showing potential for clinical implications.

Commentary - Corrected Proof

Ihsan Solaroglu, John H. Zhang — 2009-08-10

Guney et al investigated the effect of NAC on vasospasm, endothelial apoptosis and tissue lipid peroxidation following SAH in rabbits. They found that NAC when given 150 mg/kg per day prevents vasospasm and exerts neuroprotective effects. These data are provocative and provide impetus for further investigation. NAC has been shown to be a safe drug, as many patients have received it over the last decade mainly as a mucolytic agent and in the management of paracetamol overdose. It is therefore imperative to determine the mechanisms of neuroprotection of NAC following SAH. Although vasospasm has been the focus of the majority of research efforts during the past number of decades, the reversal of vasospasm does not appear to improve outcome alone. Based on these data, a recently described concept—early brain injury (EBI)—is being considered as a primary target for future research. It is clear that many pathways including apoptotis and oxidative stress lead to cell death and EBI following SAH. Its proven effect on apoptosis and oxidative stress, as shown by Guney et al, makes NAC a potential candidate for the treatment of EBI. Further studies can address this question adequately. Nonetheless, the effects of NAC described above may play a role in neuroprotection after SAH.

Coil-based endovascular treatment of single-hole cerebral arteriovenous fistulae: experiences in 11 patients - Corrected Proof

2009-08-10

Abstract: Background: An SHF is rare pial arteriovenous shunt with no nidal component, of which the feeder drains directly into a single venous channel. Casting with NBCA was described previously, but its control demands operator to accumulate a considerable learning curve. We are to present our experiences of coil-based endovascular treatment of SHF.Methods: Eleven patients harbored 12 SHFs (5 men, 6 women; mean age, 28.4 years; age range, 4-73 years), and they presented with hemorrhage, seizure, collapse, orbital mass, and as an incidental lesion. The location was frontal for 3, temporal for 5, parietal in 2, and occipital in 2 patients. The angioarchitectures, the methods of endovascular treatment, and outcomes were analyzed.Results: Fifteen feeders arose from 4 anterior, 8 middle, and 3 posterior cerebral arteries. The coil framework was constructed at the fistula before the penetration of a low concentrated NBCA. Nine fistulae were occluded completely, and 3 fistulae were occluded to near-completion with micro-AVM. There was no recanalization of SHF, either growth of a micro-AVM during follow-up period (mean, 48.3 months; range, 6-120 months). One patient with postprocedure hemorrhage developed hemiplegia, but 1 patient with seizure and the other 9 asymptomatic patients were uneventful.Conclusions: The coil-based endovascular treatment can achieve safe and stable occlusion of SHF, and the preventions against venous thrombosis and perfusion breakthrough should be essential.

Commentary - Corrected Proof

Erik F. Hauck, L. Nelson Hopkins — 2009-08-10

The authors present a small series of 11 patients with 12 single-hole arterial fistulae treated with coiling. Of 12 fistulae, 9 were completely obliterated and 3 had residual. One patient suffered a devastating hemorrhage after the procedure (9%). The authors used a combination of coiling and low-concentration n-butyl cyanoacrylate (NBCA) injections with good success. The coils were used to create a framework, which then made the glue injection safer, in the authors' opinion.

Clinical and radiologic outcome of laminar screw at C2 and C7 for posterior instrumentation—review of 25 cases and comparison of C2 and C7 intralaminar screw fixation - Corrected Proof

Jae Taek Hong, Jin Seok Yi, Jong Tae Kim, Chul Ji, Kyung Sik Ryu, Chun Kun Park — 2009-08-10

Abstract: Background: The aim of this study is 2-fold: to analyze a clinical case series in which we used laminar screws for cervical posterior instrumentation and to describe the difference between C2 and C7 laminar screws in terms of technique and anatomy.Methods: Data were obtained from 25 patients who underwent cervical posterior fixation with intralaminar screws at C2 or C7. C2 intralaminar screw instrumentation was used for 7 patients requiring occipitocervical fixation (basilar invagination [3 patients], C1 unstable bursting fracture [1 patient], C1-C2 instability with occipital assimilation [2 patients], and dystopic os odontoideum [1 patient]), 13 patients with C1-C2 instability, 1 patient with C2-C3 subluxation, and 4 patients undergoing C7 fixation due to pseudoarthrosis or cervical instability after trauma. A total of 34 laminar screws were placed including 1 thoracic laminar screw, and the patients were assessed both clinically and radiographically.Results: There were no instances where a screw violated the spinal canal nor any hardware fractures noted during the follow-up period. As for perioperative complications, there were 2 cases of postoperative wound infection, 1 case of dural laceration during dissection, and 2 cases of partial dorsal laminar breach. However, there was no neurologic compromise in any of the cases. The fusion success rate was 100%.Conclusion: These preliminary results support the use of intralaminar screws for posterior instrumentation at C2 and C7.

Commentary - Corrected Proof

Howard Morgan — 2009-08-10

This article by Hong et al describes a novel technique of C7 instrumentation rather than the more accepted C2 technique. In the past 4 years at the University of Texas Southwestern neurosurgery service, we have used C2 laminar screws in some dozen cases, and most have been placed bilaterally (crossed C2 screws). Of our cases, I know of only 1 pseudoarthrosis that occurred at the C2-C3 level, and in that case, we instrumented unilaterally. Understandably then, I found the C7 lamina screw technique of interest, and on several occasions since reading the original manuscript, I have considered placing a screw there instead of in the pedicle as we routinely do. To date, the anatomy has not been optimal, seemingly because of the downward slope of the C7 lamina moving laterally from the spinous process and/or because of the height and prominence of the C7 spinous process (vertebra prominens) obscuring visualization.

Stitch retractor—simple and easy technique to retract brain - Corrected Proof

Lokendra Singh, Nilesh Agrawal — 2009-08-07

Abstract: Background: Self-retaining brain retractors are commonly used during intracranial surgery, and they are indispensable during microneurosurgery. There is a common severe complication due to the use of self-held retractors, that is, formation of a hemorrhagic infarct area in the brain region exposed to traction. All the more, present retractor systems are fixed and rigid and obstruct surgeons during surgery. Sometimes these retractors create glare in the microscope that distracts the surgeon. We hereby propose a simple and easy method of retraction of brain especially the temporal lobe using the transsylvian approach and vermis using the transvermian approach.Methods: This is retrospective analysis of 47 patients in 4 years in which we have used our stitch retractor. We have analyzed their outcome, postoperative scan, and ease of performing surgery.Results: In 47 patients, there was only 1 postoperative contusion, and the longest period it was kept for is 6 hours. The other advantage was that it does not obstruct in any way while doing dissections and surgery. There was no glare while operating under a microscope.Conclusion: We hereby propose a simple and easy method of retraction of brain especially the temporal lobe using the transsylvian approach and vermis using the transvermian approach. It is minimally traumatic, reducing insult to the brain. It allows the surgeon to dissect without any obstruction and glare in the way. The biggest advantage of the present stitch retractor is that it is very cheap and simple to use.

A functional magnetic resonance imaging study of factors influencing motor function after surgery for gliomas in the rolandic region - Corrected Proof

2009-08-07

Abstract: Background: Pre- and postoperative fMRI was performed in patients with rolandic gliomas to evaluate factors influencing motor function after surgery.Methods: The study population consisted of 9 right-handed patients (mean age, 43.3 years; range, 25-67, 2 female/7 male) affected by high-grade gliomas growing within or adjacent to the rolandic cortex. Patients had a diverse onset and evolution of their disease. All patients underwent morphological imaging and fMRI on a 3-T scanner before and after surgery. Postprocessed imaging data were analyzed off-line using SPM.Results: Patterns of activation in real-time maps and SPM were similar when coregistered head motion artifacts did not exceed more than 50% voxel size of the echo-planar imaging sequence. Movements of the hand opposite the affected hemisphere showed activation of the cMI in all patients. Coactivation of the iMI occurred in 5 patients. The cMII was activated in 4 patients, all with excellent postoperative motor function. The iMII and SMA were activated in patients with a good functional outcome. When the unaffected hand was tested, this activation pattern was similar. Postoperative fMRIs were comparable with the preoperative scans.Conclusions: Postoperative evaluation is feasible and may add confirmatory information to preoperative findings in selected patients. Bilateral activation of primary and secondary motor areas may be the correlate for compensatory recruitment of additional functional areas and a predictor for better functional outcome.

Role of inflammation (leukocyte-endothelial cell interactions) in vasospasm after subarachnoid hemorrhage - Corrected Proof

Kaisorn L. Chaichana, Gustavo Pradilla, Judy Huang, Rafael J. Tamargo — 2009-08-07

Abstract: Background: Delayed vasospasm is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). This phenomenon was first described more than 50 years ago, but only recently has the role of inflammation in this condition become better understood.Methods: The literature was reviewed for studies on delayed vasospasm and inflammation.Results: There is increasing evidence that inflammation and, more specifically, leukocyte-endothelial cell interactions play a critical role in the pathogenesis of vasospasm after aSAH, as well as in other conditions including meningitis and traumatic brain injury. Although earlier clinical observations and indirect experimental evidence suggested an association between inflammation and chronic vasospasm, recently direct molecular evidence demonstrates the central role of leukocyte-endothelial cell interactions in the development of chronic vasospasm. This evidence shows in both clinical and experimental studies that cell adhesion molecules (CAMs) are up-regulated in the perivasospasm period. Moreover, the use of monoclonal antibodies against these CAMs, as well as drugs that decrease the expression of CAMs, decreases vasospasm in experimental studies. It also appears that certain individuals are genetically predisposed to a severe inflammatory response after aSAH based on their haptoglobin genotype, which in turn predisposes them to develop clinically symptomatic vasospasm.Conclusion: Based on this evidence, leukocyte-endothelial cell interactions appear to be the root cause of chronic vasospasm. This hypothesis predicts many surprising features of vasospasm and explains apparently unrelated phenomena observed in aSAH patients. Therapies aimed at preventing inflammation may prevent and/or reverse arterial narrowing in patients with aSAH and result in improved outcomes.

Microroll retractor for surgical resection of brainstem cavernoma - Corrected Proof

Tsutomu Ichinose, Hiroki Morisako, Takeo Goto, Toshihiro Takami, Kenji Ohata — 2009-08-07

Abstract: Background: Safe and complete surgical resection of brainstem cavernoma is difficult without injury surrounding normal structures because the lesions are deep and intra-axial. In this article, the authors describe the “microroll retractor” technique for brainstem cavernoma surgery.Methods: The microroll retractor is made of expanded polytetrafluoroethylene sheet. The sheet is cut in several sizes of square piece and transformed into a tubular shape. We insert this roll retractor via minimal brain incision and keep surgical corridor without usual spatulas during lesionectomy.Results: This technique was adopted for 7 patients with brainstem cavernomas. In all patients, we achieved total excision; improvement was recorded in 6 patients, and no change was recorded in 1 patient.Conclusions: The microroll retractor is extremely simple but provides enough surgical corridors for safe total resection of brainstem cavernomas.

Posterior-to-anterior circulation access using the Penumbra Stroke System for mechanical thrombectomy of a right middle cerebral artery thrombus - Corrected Proof

Ferdinand K. Hui, Sandra Narayanan, C. Michael Cawley — 2009-07-30

Abstract: Background: Mechanical thrombectomy devices rely on the ability of an operator to directly access a thrombus with the device. The authors demonstrate the first reported posterior-to-anterior circulation approach using the Penumbra Stroke System (Penumbra, Inc, Alameda, CA) for thrombectomy in acute stroke.Case Description: A 53-year–old man presented 5 hours and 15 minutes after onset of left homonymous hemianopia, left facial droop, left upper extremity plegia, and left lower extremity paresis (NIHSS = 15). Computed tomography of the head revealed hyperdense material in the right M1 to M2 segments without loss of gray-white differentiation in the right cerebral hemisphere. Cerebral angiography at 6 hours and 50 minutes revealed occlusion of the right ICA at its origin. Injection of the left vertebral artery demonstrated clot in the right M1 segment with no anterograde flow.An Excelsior 1018 (Boston Scientific, Natick, MA) microcatheter was used to access the right PCOM and subsequently the right ICA and right MCA. A joint decision was made with the stroke neurology service to bury the microcatheter within the right MCA clot and administer 13 mg of tPA.A triaxial system using the Penumbra 041 catheter, Excelsior SL-10 microcatheter, and Synchro2 (Boston Scientific) guidewire was used to traverse the left vertebral and basilar arteries, the right PCOM, and the right ICA to the thrombosed right M1 segment. Aspiration using the Penumbra 41 catheter and 41 Separator was performed, resulting in a TIMI-2 result with minimal residual superior right M2 thrombus.Conclusion: In patients with proximal vascular occlusion, mechanical thrombectomy with relatively stiff thrombectomy systems can be achieved through collateral pathways in the circle of Willis. Although the diameter mismatch between the Penumbra 41 catheter and a microguidewire may make sharp turns challenging, the use of an SL-10 microcatheter as a functional obturator may afford access.

Stereotactic radiosurgery as single-modality treatment of incidentally identified renal cell carcinoma brain metastases - Corrected Proof

2009-07-16

Abstract: Background: Initial staging evaluation of patients with RCC has led increasingly to the diagnosis of brain metastases in patients who are otherwise neurologically asymptomatic. We present our experience treating patients with incidentally identified brain metastases with initial SRS monotherapy and compare outcomes with those of patients treated at our institution with other strategies and with those reported in the literature.Methods: We conducted a retrospective outcomes analysis in patients with incidentally identified RCC brain metastasis treated with initial SRS monotherapy. Our radiation oncology and tumor databases were reviewed, identifying 80 patients treated between 1990 and 2006.Results: We found 19 patients with asymptomatic, incidentally identified brain metastasis (KPS, 90-100) treated with SRS monotherapy within 60 days of diagnosis. Stereotactic radiosurgery was performed at a mean of 17.8 days from diagnosis to an average of 3.1 lesions (range, 3-11; mean lesion volume, 1.72 cm3; mean total volume, 4.53 cm3). The mean prescription was 21.3 Gy delivered to the mean 59.97% isodose line. The mean survival for these patients was 21.5 months (median, 12.6 months) and was not statistically different from survival in similar patients treated with other therapeutic modalities. Local control was achieved in 95% of patients; distant CNS progression occurred in 79% of patients at a mean of 450 days.Conclusions: We demonstrate that patients with incidentally identified RCC brain metastases treated with initial SRS monotherapy achieved a survival rate comparable with that of patients managed with standard therapeutic modalities. Our findings suggest that SRS alone is an attractive therapeutic option for patients with incidentally identified brain metastases from RCC.

Carotid endarterectomy for stenoses of twisted carotid bifurcations - Corrected Proof

Hiroyuki Katano, Kazuo Yamada — 2009-07-16

Abstract: Background: The twisted carotid bifurcation is a variant in which the ICA courses medially to the ECA. Because descriptions in the literature have been limited, we here document clinical features and surgical experience of CEA for cases of twisted carotid bifurcation.Methods: Seventy-five out of a total of 106 consecutive cases with surgically treated carotid stenoses underwent CEA. The angle of twist was measured in the axial view of MDCT angiography as the medially deviated degree.Results: Seven cases (9.3%) demonstrated twisted carotid bifurcations. Six were found on the right side and one was on the left. The average angle of twist was 80.0° ± 17.6°, whereas that with a normally positioned bifurcation was −7.4° ± 7.7°. Six patients (85.7%) had diabetes mellitus and 5 patients (71.4%) had hypertension as a coexisting disease. Carotid endarterectomy was successfully performed with correction of the carotid position except in 1 case. Postoperative MDCT angiography revealed twisted position as in the preoperative state in 4, complete correction to the normal position in 2, and half-correction in 1.Conclusions: Twisted carotid bifurcations were preferentially found in right severely atherosclerotic carotids in patients with diabetes mellitus and/or hypertension. Carotid endarterectomy of twisted carotids can be safely accomplished, sometimes with correction of the carotid position. Multidetector computed tomography angiography was useful for perioperative evaluation. Variation should be considered by the neurosurgeon and neurologists concerned in the evaluation and treatment of carotid stenoses.

Commentary - Corrected Proof

Christopher M. Loftus — 2009-07-16

I like this article and think it is a most worthwhile contribution. Katano and Yamada are serious and highly regarded carotid surgeons in Nagoya; they have quantified and studied a phenomenon that I have noticed myself for years and have published in a more anecdotal way in my own contributions , as they kindly acknowledge.

Commentary - Corrected Proof

Robert Goodkin — 2009-07-16

“Stereotactic radiosurgery as single-modality treatment of incidentally identified renal cell carcinoma brain metastases” by Marko et al is a well-written and well-referenced article. Stereotactic radiosurgery has essentially replaced surgery and whole brain irradiation as the primary treatment paradigm except for selected cases. Surgery is the primary management consideration when the diagnosis is not certain and a diagnostic biopsy is indicated, when the tumor volume is exceptionally large, or when there is significant mass effect.

Arterial diameters on catheter and computed tomographic angiography - Corrected Proof

Sherise D. Ferguson, David S. Rosen, Diana Bardo, R. Loch Macdonald — 2009-07-16

Abstract: Background: The diagnosis of cerebral vasospasm is hampered by lack of an accurate, noninvasive test. Computed tomographic angiography (CTA) may be useful but the correlation between arterial diameters determined from catheter digital subtraction angiography (DSA) and CTA over a range of artery sizes would need to be determined to show this. The purpose of this study was to determine the correlation between artery diameters measured on DSA and multidetector CTA.Methods: Two hundred forty artery diameters were measured in DSA and CTA from 46 patients who underwent both studies within 12 hours of each other. Axial cross section, maximum intensity projection, and volume-rendered images were measured and compared by linear correlation. Two independent readers measured CTA diameters to determine interobserver variability by linear correlation. Values also were categorized and compared by χ2 and κ statistics. Analysis was repeated with unmeasurable arteries assigned a value of 0.Results: There were significant correlations between arterial diameters measured on DSA and those from CTA measured by any method (R2 ranging from 0.45 to 0.76, P < .0001), although there was a tendency for the slope of this relationship to be less than 1, indicating underestimation of diameter of large and overestimation of diameter of small arteries with CTA. Computed tomographic angiography diameters also correlated significantly between the 2 reviewers with higher values often when unmeasureable arteries were assigned a value of 0 (κ = 0.23-0.55, P < .0001).Conclusion: Arterial diameters measured on multidetector CTA correlate well with those determined from DSA and should permit use of CTA for quantitative study of cerebral vasospasm and other conditions requiring accurate measurement of arterial diameters. The limitation of CTA remains the inability to measure some arteries due to artifact.

Commentary - Corrected Proof

Nicholas W.C. Dorsch — 2009-07-16

The authors are to be congratulated on this detailed analysis comparing arterial diameters in DSA and CTA studies, which has helped greatly to validate CT angiography as a technique for assessing the presence and degree of vasospasm. This is particularly useful after SAH, where daily analysis is so often desirable but, as discussed, not possible with DSA alone.

Recovery of third nerve palsy after endovascular treatment of posterior communicating artery aneurysms - Corrected Proof

2009-07-16

Abstract: Background: High recovery rates after endovascular treatment of TNP-inducing PcomA aneurysms have been reported. However, only few and often small series were reported. The results of the 2 available comparative studies are controversial. Choosing clipping or coiling as treatment modality nowadays is still a matter of debate. We report the ophthalmologic outcome of 20 consecutive patients treated by coiling of TNP-inducing PcomA aneurysms.Methods: The third nerve function before and after endovascular treatment was assessed and studied retrospectively. Predictive recovery factors known from literature including treatment timing, the degree of preoperative nerve deficit, the association with SAH, coil type, cardiovascular risk factors, and age were analyzed. A review of the literature was performed.Results: Eight patients presented initially with complete nerve palsy (40%) and 12 with partial palsy (60%). Eleven patients had SAH. The mean aneurysm size was 7.14 mm; there were no partially thrombosed aneurysms. Of the 20 patients, 19 (95%) recovered. Recovery was complete in 7 patients (35%), partial in 12 patients (60%), and 1 patient remained unchanged (5%). The mean duration of follow-up was 24.7 months. One patient with complete TNP recovered completely after 5 months of coiling. One case of late complete nerve recovery was observed at 20 months. No cases of reoccurrences or worsening of the partial TNP were observed, including patients who developed recanalization of the aneurysmal sac.Clinical presentation with SAH and early management were statistically significant factors that positively influenced nerve recovery (P = .006549 and P = .015718, respectively). Initial partial TNP seems to influence recovery but did not reach significance (P = .079899).Conclusion: Coiling of PcomA aneurysms is associated with high rates of third nerve function recovery. Complete recovery can be expected even after long periods and in cases of initial complete nerve palsy. The early treatment and the association with SAH seem to promote the nerve recovery.

Commentary - Corrected Proof

Juha Hernesniemi, Martin Lehecka, Hanna Lehto, Rossana Romani, Mika Niemelä — 2009-07-16

In this series of 20 patients, recovery of the TNP was complete in only 7 (35%), partial in 12 (60%), and unchanged in 1 (5%). Of the 8 patients treated within 3 days of the onset of TNP, only 3 (37%) recovered completely.

Intradural cranial chordoma - Corrected Proof

2009-03-31

Abstract: Background: Intradural chordomas are rare and have been considered benign owing to the feasibility of complete resection and the display of lesser aggressive biologic behavior than typical chordomas.Case Description: We herein reported 2 cases of intradural cranial chordoma with aggressive biologic behavior. A tumor (anti–Ki-67 monoclonal antibody [MIB-1], 13.9%) in a 59-year-old woman was strongly adherent to the brainstem and involved the basilar artery and its branches. After subtotal removal, the remnant tumor was treated with stereotactic radiotherapy. A tumor (MIB-1, 6.2%) in a 75-year-old woman repeatedly recurred even after initial gross total removal. The recurrent chordomas were treated with γ-knife radiosurgery.Conclusion: The cases presented in this study indicate that intradural chordomas can also be aggressive such as typical chordomas. Long-term follow-ups with a large number of patients with this condition are essential for elucidating the prognosis of intradural chordomas.

Commentary - Corrected Proof

Johnny B. Delashaw — 2009-03-31

“Intradural cranial chordoma” by Ito et al is a well-written case presentation of a rare clinical entity. Although there have been previous reports of intracranial chordomas, they remain quite rare, and as a result, their natural history is not well-known. Furthermore, there is a distinct but related clinical entity—the ecchordosis physaliphora—which is a benign intradural entity that arises from notochordal rests that can be confused with a chordoma. It is important to recognize that despite their more benign prognosis, true intradural chordomas can behave aggressively and that this behavior may be correlated with an increased proliferation index.