Neurosurgical FOCUS (Neurosurg Focus)

Publications in this journal

• Article: Spontaneous intracerebral hemorrhage and the challenge of surgical decision making: a review.

  Michael L Kelly, Daniel P Sulmasy, Robert J Weil
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  ABSTRACT: Decision making for patients with spontaneous intracerebral hemorrhage (ICH) poses several challenges. Outcomes in this patient population are generally poor, prognostication is often uncertain, and treatment strategies offer limited benefits. Studies demonstrate variability in the type and intensity of treatment offered, which is attributed to clinical uncertainty and habits of training. Research has focused on new techniques and more stringent evidence-based selection criteria to improve outcomes and produce consensus around treatment strategies for patients with ICH. Such focus, however, offers little description of how ICH treatment decisions are made and how such decisions reflect patient preferences regarding medical care. A growing body of literature suggests that the process of decision making in ICH is laden with bias, value assumptions, and subjective impressions. Factors such as geography, cognitive biases, patient perceptions, and physician characteristics can all shape decision making and the selection of treatment. Such factors often serve as a barrier to providing patient-centered medical care. In this article, the authors review how surgical decision making for patients with ICH is shaped by these decisional factors and suggest future research pathways to study decision making in ICH. Such research efforts are important for establishing quality guidelines and pay-for-performance measures that reflect the preferences of individual patients and the contextual nature of medical decision making.
  Neurosurgical FOCUS 05/2013; 34(5):E1.
• Article: Emerging experimental therapies for intracerebral hemorrhage: targeting mechanisms of secondary brain injury.

  Praveen K Belur, Jason J Chang, Shuhan He, Benjamin A Emanuel, William J Mack
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  ABSTRACT: Intracerebral hemorrhage (ICH) is associated with a higher degree of morbidity and mortality than other stroke subtypes. Despite this burden, currently approved treatments have demonstrated limited efficacy. To date, therapeutic strategies have principally targeted hematoma expansion and resultant mass effect. However, secondary mechanisms of brain injury are believed to be critical effectors of cell death and neurological outcome following ICH. This article reviews the pathophysiology of secondary brain injury relevant to ICH, examines pertinent experimental models, and highlights emerging therapeutic strategies. Treatment paradigms discussed include thrombin inhibitors, deferoxamine, minocycline, statins, granulocyte-colony stimulating factors, and therapeutic hypothermia. Despite promising experimental and preliminary human data, further studies are warranted prior to effective clinical translation.
  Neurosurgical FOCUS 05/2013; 34(5):E9.
• Article: Rates and determinants of ventriculostomy-related infections during a hospital transition to use of antibiotic-coated external ventricular drains.

  Kelly Wright, Polly Young, Cristina Brickman, Teena Sam, Neeraj Badjatia, Marcus Pereira, E Sander Connolly, Michael T Yin
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  ABSTRACT: Object The authors evaluated the rates of ventriculostomy-related infections (VRIs) after antibiotic-coated extraventricular drains (ac-EVDs) were introduced as the standard of care. Methods A retrospective chart review was conducted of adult patients admitted to NewYork-Presbyterian Hospital neurological intensive care unit in whom an EVD was placed between February 2007 and November 2009, excluding individuals receiving EVDs due to an infection of a primary device. Three time periods were defined depending on type of EVD in use: Period 1, conventional EVDs; Period 2, either ac-EVDs or conventional EVDs; and Period 3, ac-EVDs. Definite/probable VRIs that occurred during the 3 periods were evaluated and established as determinants of VRIs by using a Cox proportional hazards model. Prolonged systemic antibiotics were given for the duration of EVD placement in each of the 3 periods per institutional policy. Results Data from 141 individuals were evaluated; mean patient age was 53.8 ± 17.2 years and 54% were female. There were 2 definite and 19 probable VRIs. The incidence of definite/probable VRI (per 1000 person-catheter days) decreased from Period 1 to 3 (24.5, 16.2, and 4.4 in Periods 1, 2, and 3, respectively; p < 0.0001). Patients with VRIs were more likely to be female than male (23.7% vs 3.1%, p < 0.003) and have had an EVD in place for a longer duration, although there was no significant difference among the 3 periods (7.9 ± 6.7 [Period 1], 8.1 ± 7.1 [Period 2], and 8.6 ± 5.8 [Period 3] mean days; p = 0.87, ANOVA). Analysis of effect modification in a stepwise model showed that period, age, and age and female interaction were significant predictors of VRIs. The period was the strongest predictor of VRI (p = 0.0075). After adjustment for age and age and sex interaction, the survival rate was 53% at the end of Period 2 and 91% at the end of Period 3. Conclusions Rates of VRIs have decreased with the addition of ac-EVDs to the routine use of prolonged systemic antibiotics at the authors' institution.
  Neurosurgical FOCUS 05/2013; 34(5):E12.
• Article: Hydrocephalus after arteriovenous malformation rupture.

  Bradley A Gross, Pui Man Rosalind Lai, Rose Du
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  ABSTRACT: Object The rates and risk factors for external ventricular drain (EVD) placement and long-term shunt dependence in patients with ruptured arteriovenous malformations (AVMs) have not been systematically studied. In this study the authors evaluated the rates of EVD placement and shunt dependence, and risk factors for them, in a cohort of patients with ruptured AVMs. Methods The records of 87 consecutive patients with ruptured AVMs were reviewed for patient demographics, hemorrhage pattern, AVM angioarchitectural features, and surgical treatment. Univariate and multivariate logistic regression analyses were performed to evaluate risk factors for EVD placement, permanent shunt dependence, and long-term outcome (as measured by the modified Rankin Scale). Results Thirty-eight patients (44%) required EVD placement, and 16 (18%) required a permanent shunt. Statistically significant risk factors for EVD placement in the univariate analysis included initial Glasgow Coma Scale (GCS) score (p = 0.002), the presence of intraventricular hemorrhage (IVH; p < 0.001), AVM-associated aneurysms (p = 0.002), and early surgery (p = 0.01). Multivariate analysis revealed only AVM-associated aneurysms as statistically significant (p = 0.006). Risk factors for shunt placement included initial GCS score (p = 0.003), IVH (p = 0.01), deep supratentorial location (p = 0.034), and associated aneurysms (p = 0.03). Multivariate analysis revealed initial GCS score as a statistically significant risk factor (p = 0.041) as well as a strong trend for associated aneurysms (p = 0.06). Patient age, sex, associated subarachnoid hemorrhage, AVM grade, AVM size, and deep venous drainage were not associated with EVD placement or long-term shunt dependence. Conclusions Hydrocephalus from AVM rupture was associated with initial GCS score, IVH, and AVM-associated aneurysms. Arteriovenous malformations with associated aneurysms thus not only have a greater risk of hemorrhage but also a greater risk of hemorrhage-associated morbidity as a result of hydrocephalus.
  Neurosurgical FOCUS 05/2013; 34(5):E11.
• Article: Decompressive hemicraniectomy for spontaneous intracerebral hemorrhage.

  Satoru Takeuchi, Kojiro Wada, Kimihiro Nagatani, Naoki Otani, Kentaro Mori
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  ABSTRACT: Intracerebral hemorrhage (ICH) is devastating, with high mortality rates, but its optimum management has not been fully established. Decompressive hemicraniectomy is a surgical procedure used to relieve the malignant elevation of intracranial pressure. The application of decompressive hemicraniectomy in patients with hemispheric ICH has been much less common, although several studies have shown the usefulness of this procedure for large hemispheric ICH. In this review, the present knowledge of the safety and efficacy of this procedure are evaluated. The authors conclude that decompressive hemicraniectomy with hematoma evacuation for large ICH might be a safe and effective procedure in patients with severely disturbed consciousness and large hematoma volume.
  Neurosurgical FOCUS 05/2013; 34(5):E5.
• Article: Modern intraoperative imaging modalities for the vascular neurosurgeon treating intracerebral hemorrhage.

  Oded Goren, Stephen J Monteith, Moshe Hadani, Mati Bakon, Sagi Harnof
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  ABSTRACT: This paper reviews the current intraoperative imaging tools that are available to assist neurosurgeons in the treatment of intracerebral hemorrhage (ICH). This review shares the authors' experience with each modality and discusses the advantages, potential limitations, and disadvantages of each. Surgery for ICH is directed at blood clot removal, reduction of intracranial pressure, and minimization of secondary damage associated with hematoma breakdown products. For effective occlusion and safe obliteration of vascular anomalies associated with ICH, vascular neurosurgeons today require a thorough understanding of the various intraoperative imaging modalities available for obtaining real-time information. Use of one or more of these modalities may improve the surgeon's confidence during the procedure, the patient's safety during surgery, and surgical outcome. The modern techniques discussed include 1) indocyanine green-based video angiography, which provides real-time information based on high-quality images showing the residual filling of vascular pathological entities and the patency of blood vessels of any size in the surgical field; and 2) intraoperative angiography, which remains the gold standard intraoperative diagnostic test in the surgical management of cerebral aneurysms and arteriovenous malformations. Hybrid procedures, providing multimodality image-guided surgeries and combining endovascular with microsurgical strategies within the same surgical session, have become feasible and safe. Microdoppler is a safe, noninvasive, and reliable technique for evaluation of hemodynamics of vessels in the surgical field, with the advantage of ease of use. Intraoperative MRI provides an effective navigation tool for cavernoma surgery, in addition to assessing the extent of resection during the procedure. Intraoperative CT scanning has the advantage of very high sensitivity to acute bleeding, thereby assisting in the confirmation of the extent of hematoma evacuation and the extent of vascular anomaly resection. Intraoperative ultrasound aids navigation and evacuation assessment during intracerebral hematoma evacuation surgeries. It supports the concept of minimally invasive surgery and has undergone extensive development in recent years, with the quality of ultrasound imaging having improved considerably. Image-guided therapy, combined with modern intraoperative imaging modalities, has changed the fundamentals of conventional vascular neurosurgery by presenting real-time visualization of both normal tissue and pathological entities. These imaging techniques are important adjuncts to the surgeon's standard surgical armamentarium. Familiarity with these imaging modalities may help the surgeon complete procedures with improved safety, efficiency, and clinical outcome.
  Neurosurgical FOCUS 05/2013; 34(5):E2.
• Article: Intracranial hemorrhage from dural arteriovenous fistulas: clinical features and outcome.

  David J Daniels, Ananth K Vellimana, Gregory J Zipfel, Giuseppe Lanzino
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  ABSTRACT: Object In this paper the authors' goal was to review the clinical features and outcome of patients with intracranial dural arteriovenous fistulas (DAVFs) who presented with hemorrhage. Methods A retrospective study of 28 patients with DAVFs who presented with intracranial hemorrhage to 2 separate institutions was performed. The information reviewed included clinical presentation, location and size of hemorrhage, angiographic features, treatment, and clinical and radiologically documented outcomes. Clinical and radiological follow-up were available in 27 of 28 patients (mean follow-up 17 months). Results The vast majority of patients were male (86%), and the most common presenting symptom was sudden-onset headache. All DAVFs had cortical venous drainage, and about one-third were associated with a venous varix. The most common location was tentorial (75%). Treatment ranged from endovascular (71%), surgical (43%), Gamma Knife surgery (4%), or a combination of modalities. The majority of fistulas (75%) were completely obliterated, and most patients experienced excellent clinical outcome (71%, modified Rankin Scale score of 0 or 1). There were no complications in this series. Conclusions Case series, including the current one, suggest that the vast majority of patients who present with intracranial hemorrhage from a DAVF are male. The most common location for DAVFs presenting with hemorrhage is tentorial. Excellent outcomes are achieved with individualized treatment, which includes various therapeutic strategies alone or in combination. Despite the hemorrhagic presentation, almost two-thirds of patients experience a full recovery with no or minimal residual symptoms.
  Neurosurgical FOCUS 05/2013; 34(5):E15.
• Article: Decompressive hemicraniectomy without clot evacuation in dominant-sided intracerebral hemorrhage with ICP crisis.

  Simon G Heuts, Samuel S Bruce, Brad E Zacharia, Zachary L Hickman, Christopher P Kellner, Eric S Sussman, Michael M McDowell, Rachel A Bruce, E Sander Connolly
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  ABSTRACT: Object Large intracerebral hemorrhage (ICH), compounded by perihematomal edema, can produce severe elevations of intracranial pressure (ICP). Decompressive hemicraniectomy (DHC) with or without clot evacuation has been considered a part of the armamentarium of treatment options for these patients. The authors sought to assess the preliminary utility of DHC without evacuation for ICH in patients with supratentorial, dominant-sided lesions. Methods From September 2009 to May 2012, patients with ICH who were admitted to the neurological ICU at Columbia University Medical Center were prospectively enrolled in that institution's ICH Outcomes Project (ICHOP). Five patients with spontaneous supratentorial dominant-sided ICH underwent DHC without clot evacuation for recalcitrant elevated ICP. Data pertaining to the patients' characteristics and outcomes of treatment were prospectively collected. Results The patients' median age was 43 years (range 30-55 years) and the ICH etiology was hypertension in 4 of 5 patients, and systemic lupus erythematosus vasculitis in 1 patient. On admission, the median Glasgow Coma Scale (GCS) score was 7 (range 5-9). The median ICH volume was 53 cm(3) (range 28-79 cm(3)), and the median midline shift was 7.6 mm (range 3.0-11.3 mm). One day after surgery, the median decrease in midline shift was 2.7 mm (range 1.5-4.6 mm), and the median change in GCS score was +1 (range -3 to +5). At discharge, all patients were still alive, and the median GCS score was 10 (range 9-11), the median modified Rankin Scale (mRS) score was 5 (range 5-5), and the median NIHSS (National Institutes of Health Stroke Scale) score was 22 (range 17-27). Six months after hemorrhage, 1 patient had died, 2 were functionally dependent (mRS Score 4-5), and 2 were functionally independent (mRS Score 0-3). Outcomes for the patients treated with DHC were good compared with 1) outcomes for all patients with spontaneous supratentorial ICH admitted during the same period (n = 144) and 2) outcomes for matched patients (dominant ICH, GCS Score 5-9, ICH volume 28-79 cm(3), age < 60 years) whose cases were managed nonoperatively (n = 5). Conclusions Decompressive hemicraniectomy without clot evacuation appears feasible in patients with large ICH and deserves further investigation, preferably in a randomized controlled setting.
  Neurosurgical FOCUS 05/2013; 34(5):E4.
• Article: Space-occupying cerebellar infarction: complications, treatment, and outcome.

  Hermann Neugebauer, Jens Witsch, Klaus Zweckberger, Eric Jüttler
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  ABSTRACT: Space-occupying brain edema is a frequent and one of the most dreaded complications in ischemic cerebellar stroke. Because the tight posterior fossa provides little compensating space, any space-occupying lesion can lead to life-threatening complications through brainstem compression or compression of the fourth ventricle and subsequent hydrocephalus, both of which may portend transtentorial/transforaminal herniation. Patients with large cerebellar infarcts should be treated and monitored very early on in an experienced stroke unit or (neuro)intensive care unit. The general treatment of ischemic cerebellar infarction does not differ from that of supratentorial ischemic strokes. Treatment strategies for space-occupying edema include pharmacological antiedema and intracranial pressure-lowering therapies, ventricular drainage by means of an extraventricular drain, and suboccipital decompressive surgery, with or without resection of necrotic tissue. Timely escalation of treatment is crucial and should be guided by clinical and neuroradiological rationales. Patients in a coma after hydrocephalus and/or local brainstem compression may also benefit from more aggressive surgical treatment, as long as the conditions are reversible. Contrary to the general belief that outcome in survivors of space-occupying cerebellar stroke is usually good, recent studies suggest that for many of these patients, the long-term outcome is not good. In particular, advanced age and additional brainstem infarction seem to be predictors for poor outcome. Further trials are necessary to investigate these findings systematically and provide better selection criteria to help guide decisions about surgical therapies, which should always be carried out in close cooperation among neurointensive care physicians, neurologists, and neurosurgeons.
  Neurosurgical FOCUS 05/2013; 34(5):E8.
• Article: Introduction: Intracerebral hemorrhage: a changing landscape.

  David W Newell
  Neurosurgical FOCUS 05/2013; 34(5):Introduction.
• Article: Transcranial MR-guided focused ultrasound sonothrombolysis in the treatment of intracerebral hemorrhage.

  Stephen J Monteith, Neal F Kassell, Oded Goren, Sagi Harnof
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  ABSTRACT: Intracerebral hemorrhage remains a significant cause of morbidity and mortality. Current surgical therapies aim to use a minimally invasive approach to remove as much of the clot as possible without causing undue disruption to surrounding neural structures. Transcranial MR-guided focused ultrasound (MRgFUS) surgery is an emerging technology that permits a highly concentrated focal point of ultrasound energy to be deposited to a target deep within the brain without an incision or craniotomy. With appropriate ultrasound parameters it has been shown that MRgFUS can effectively liquefy large-volume blood clots through the human calvaria. In this review the authors discuss the rationale for using MRgFUS to noninvasively liquefy intracerebral hemorrhage (ICH), thereby permitting minimally invasive aspiration of the liquefied clot via a small drainage tube. The mechanism of action of MRgFUS sonothrombolysis; current investigational work with in vitro, in vivo, and cadaveric models of ICH; and the potential clinical application of this disruptive technology for the treatment of ICH are discussed.
  Neurosurgical FOCUS 05/2013; 34(5):E14.
• Article: Editorial: Magnetic resonance-guided focused ultrasound.

  Felipe C Albuquerque
  Neurosurgical FOCUS 05/2013; 34(5):E13.
• Article: Alpha-7 nicotinic acetylcholine receptor agonists in intracerebral hemorrhage: an evaluation of the current evidence for a novel therapeutic agent.

  Eric S Sussman, Christopher P Kellner, Michael M McDowell, Samuel S Bruce, Simon G Heuts, Zong Zhuang, Rachel A Bruce, Jan Claassen, E Sander Connolly
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  ABSTRACT: Intracerebral hemorrhage (ICH) is the most deadly and least treatable subtype of stroke, and at the present time there are no evidence-based therapeutic interventions for patients with this disease. Secondary injury mechanisms are known to cause substantial rates of morbidity and mortality following ICH, and the inflammatory cascade is a major contributor to this post-ICH secondary injury. The alpha-7 nicotinic acetylcholine receptor (α7-nAChR) agonists have a well-established antiinflammatory effect and have been shown to attenuate perihematomal edema volume and to improve functional outcome in experimental ICH. The authors evaluate the current evidence for the use of an α7-nAChR agonist as a novel therapeutic agent in patients with ICH.
  Neurosurgical FOCUS 05/2013; 34(5):E10.
• Article: The role of anticoagulants, antiplatelet agents, and their reversal strategies in the management of intracerebral hemorrhage.

  Robert F James, Viktoras Palys, Jason R Lomboy, J Richard Lamm, Scott D Simon
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  ABSTRACT: New anticoagulant and antiplatelet medications have been approved and are prescribed with increased frequency. Intracranial hemorrhage is associated with the use of these medications. Therefore, neurosurgeons need to be aware of these new medications, how they are different from their predecessors, and the strategies for the urgent reversal of their effects. Utilization of intraluminal stents by endovascular neurosurgeons has resulted in the need to have a thorough understanding of antiplatelet agents. Increased use of dabigatran, rivaroxaban, and apixaban as oral anticoagulants for the treatment of atrial fibrillation and acute deep venous thrombosis has increased despite the lack of known antidotes to these medications.
  Neurosurgical FOCUS 05/2013; 34(5):E6.
• Article: Retrospective comparison of craniotomy and decompressive craniectomy for surgical evacuation of nontraumatic, supratentorial intracerebral hemorrhage.

  Seth B Hayes, Ronald J Benveniste, Jacques J Morcos, Mohammad A Aziz-Sultan, Mohamed Samy Elhammady
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  ABSTRACT: Surgical evacuation of nontraumatic, supratentorial intracerebral hemorrhage (SICH) is uncommonly performed, and outcomes are generally poor. On the basis of published experimental data and the authors' anecdotal observations, a retrospective chart review study was performed to test the hypothesis that large decompressive craniectomies (DCs), compared with craniotomies, would improve clinical outcomes after surgical evacuation of SICH. For patients with putaminal SICH, DC was associated with a statistically significant improvement in midline shift, compared with craniotomy. Decompressive craniectomies also resulted in a strong trend toward decreased likelihood of poor neurological outcome (modified Rankin Scale score > 3). For patients with lobar SICH, no associations were found between DC or craniotomy and clinical outcomes. For patients selected to undergo surgical evacuation of putaminal SICH, a DC in addition to surgical evacuation of the hematoma might improve outcome.
  Neurosurgical FOCUS 05/2013; 34(5):E3.
• Article: Dabigatran, intracranial hemorrhage, and the neurosurgeon.

  Ahmed J Awad, Brian P Walcott, Christopher J Stapleton, Vijay Yanamadala, Brian V Nahed, Jean-Valery Coumans
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  ABSTRACT: Dabigatran etexilate (Pradaxa) is a novel oral anticoagulant that has gained FDA approval for the prevention of ischemic stroke and systemic embolism in patients with nonvalvular atrial fibrillation. In randomized trials, the incidence of hemorrhagic events has been demonstrated to be lower in patients treated with dabigatran compared with the traditional anticoagulant warfarin. However, dabigatran does not have reliable laboratory tests to measure levels of anticoagulation and there is no pharmacological antidote. These drawbacks are challenging in the setting of intracerebral hemorrhage. In this article, the authors provide background information on dabigatran, review the existing anecdotal experiences with treating intracerebral hemorrhage related to dabigatran therapy, present a case study of intracranial hemorrhage in a patient being treated with dabigatran, and suggest clinical management strategies. The development of reversal agents is urgently needed given the growing number of patients treated with this medication.
  Neurosurgical FOCUS 05/2013; 34(5):E7.
• Article: The role of advanced neuroimaging in intracerebral hemorrhage.

  Michael M McDowell, Christopher P Kellner, Sunjay M Barton, Charles B Mikell, Eric S Sussman, Simon G Heuts, E Sander Connolly
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  ABSTRACT: In this report, the authors sought to summarize existing literature to provide an overview of the currently available techniques and to critically assess the evidence for or against their application in intracerebral hemorrhage (ICH) for management, prognostication, and research. Functional imaging in ICH represents a potential major step forward in the ability of physicians to assess patients suffering from this devastating illness due to the advantages over standing imaging modalities focused on general tissue structure alone, but its use is highly controversial due to the relative paucity of literature and the lack of consolidation of the predominantly small data sets that are currently in existence. Current data support that diffusion tensor imaging and tractography, diffusion-perfusion weighted MRI techniques, and functional MRI all possess major potential in the areas of highlighting motor deficits, motor recovery, and network reorganization. Novel clinical studies designed to objectively assess the value of each of these modalities on a wider scale in conjunction with other methods of investigation and management will allow for their rapid incorporation into standard practice.
  Neurosurgical FOCUS 04/2013; 34(4):E2.
• Article: Imaging preictal hemodynamic changes in neocortical epilepsy.

  Kunal S Patel, Mingrui Zhao, Hongtao Ma, Theodore H Schwartz
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  ABSTRACT: Object The ability to predict seizure occurrence is extremely important to trigger abortive therapies and to warn patients and their caregivers. Optical imaging of hemodynamic parameters such as blood flow, blood volume, and tissue and hemoglobin oxygenation has already been shown to successfully localize epileptic events with high spatial and temporal resolution. The ability to actually predict seizure occurrence using hemodynamic parameters is less well explored. Methods In this article, the authors critically review data from the literature on neocortical epilepsy and optical imaging, and they discuss the preictal hemodynamic changes and their application in neurosurgery. Results Recent optical mapping studies have demonstrated preictal hemodynamic changes in both human and animal neocortex. Conclusions Optical measurements of blood flow and oxygenation may become increasingly important for predicting and localizing epileptic events. The ability to successfully predict ictal onsets may be useful to trigger closed-loop abortive therapies.
  Neurosurgical FOCUS 04/2013; 34(4):E10.
• Article: Integration of functional neuronavigation and intraoperative MRI in surgery for drug-resistant extratemporal epilepsy close to eloquent brain areas.

  Björn Sommer, Peter Grummich, Roland Coras, Burkhard Sebastian Kasper, Ingmar Blumcke, Hajo Martinus Hamer, Hermann Stefan, Michael Buchfelder, Karl Roessler
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  ABSTRACT: Object The authors performed a retrospective study to assess the impact of functional neuronavigation and intraoperative MRI (iMRI) on surgery of extratemporal epileptogenic lesions on postsurgical morbidity and seizure control. Methods Twenty-five patients (14 females and 11 males) underwent extratemporal resections for drug-resistant epilepsy close to speech/motor brain areas or adjacent to white matter tracts. The mean age at surgery was 34 years (range 12-67 years). The preoperative mean disease duration was 13.2 years. To avoid awake craniotomy, cortical motor-sensory representation was mapped during preoperative evaluation in 14 patients and speech representation was mapped in 15 patients using functional MRI. In addition, visualization of the pyramidal tract was performed in 11 patients, of the arcuate fascicle in 7 patients, and of the visual tract in 6 patients using diffusion tensor imaging. The mean minimum distance of tailored resection between the eloquent brain areas was 5.6 mm. During surgery, blood oxygen level-dependent imaging and diffusion tensor imaging data were integrated into neuronavigation and displayed through the operating microscope. The postoperative mean follow-up was 44.2 months. Results In 20% of these patients, further intraoperative resection was performed because of intraoperatively documented residual lesions according to iMRI findings. At the end of resection, the final iMRI scans confirmed achievement of total resection of the putative epileptogenic lesion in all patients. Postoperatively, transient complications and permanent complications were observed in 20% and 12% of patients, respectively. Favorable postoperative seizure control (Engel Classes I and II) was achieved in 84% and seizure freedom in 72% of these consecutive surgical patients. Conclusions By using functional neuronavigation and iMRI for treatment of epileptogenic brain lesions, the authors achieved a maximum extent of resection despite the lesions' proximity to eloquent brain cortex and fiber tracts in all cases. The authors' results underline possible benefits of this technique leading to a favorable seizure outcome with acceptable neurological deficit rates in difficult-to-treat extratemporal epilepsy.
  Neurosurgical FOCUS 04/2013; 34(4):E4.