Malignant middle cerebral artery stroke carries a very poor prognosis. Significant retrospective data support the hypothesis that decompressive hemicraniectomy decreases mortality rates due to this disease entity. Recently, 3 randomized controlled studies have been published and shed light on these issues and enhance the quality of evidence revolving around this procedure. In this review, the rationale, risks, benefits, and unanswered questions related to hemicraniectomy for acute ischemic stroke are reviewed with an emphasis on how 3 randomized trials have influenced knowledge on this life-saving yet controversial procedure. Further randomized studies are needed to clarify lingering questions regarding age indications and impact on quality of life.
Omar M. Arnaout, Salah G. Aoun, H. Hunt Batjer and Bernard R. Bendok
David G. Weinberg, Rudy J. Rahme, Salah G. Aoun, H. Hunt Batjer and Bernard R. Bendok
Moyamoya disease is an occlusive cerebrovascular disorder commonly resulting in neurocognitive impairment. The cognitive outcome parameters commonly affected are intelligence, memory, executive function, and quality of life. In this paper, the authors review the existing literature on cognitive and clinical outcomes in adult and pediatric moyamoya populations separately.
A systematic review of the cognitive and clinical outcome literature was performed using the PubMed/MEDLINE database. Outcomes data were contrasted between adult and pediatric populations.
Intelligence is the main cognitive outcome parameter affected in pediatric patients with moyamoya disease, whereas adults most commonly suffer from executive function impairment. Memory has not been studied sufficiently in pediatric patients, and its dysfunction in the adult population remains controversial. Quality of life has not been studied appropriately in either population. Surgical revascularization is the only beneficial treatment option, and a combination of direct and indirect bypass techniques has shown benefit, but the impact on the above-mentioned parameters has not been sufficiently elucidated.
Moyamoya disease affects the cognition and daily function in pediatric patients to a greater extent than in adult patients. Due to the rarity of the disease, there is a distinct lack of high-level evidence regarding cognitive and clinical outcomes.
David G. Weinberg, Omar M. Arnaout, Rudy J. Rahme, Salah G. Aoun, H. Hunt Batjer and Bernard R. Bendok
Moyamoya disease (MMD) is a rare cerebrovascular disorder involving stenosis of the major vessels of the circle of Willis and proximal portions of its principal branches. Despite concerted investigation, the pathophysiology of the disorder has not been fully elucidated. Currently, the major proteins believed to play an active role in the pathogenesis include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), transforming growth factor–β1 (TGFβ1), and granulocyte colony-stimulating factor (G-CSF). In terms of the genetics, recent literature suggests a low penetrance autosomal dominant or polygenic mode of transmission involving chromosomes 3, 6, 8, 12, and 17 for familial MMD. This review summarizes the current knowledge on the histopathology, pathophysiology and genetics of MMD.
A PubMed/Medline systematic study of the literature was performed, from which 45 articles regarding MMD pathophysiology were identified and analyzed.
Moyamoya disease is characterized by the intimal thickening and media attenuation of the proximal vessels of the circle of Willis as well as the development of an aberrant distal vascular network. The primary proteins that are currently implicated in the pathophysiology of MMD include VEGF, bFGF, HGF, TGFβ1, and G-CSF. Furthermore, the current literature on familial MMD has pointed to a low penetrance autosomal dominant or polygenic mode of transmittance at loci on chromosomes 3, 6, 8, 12, and 17.
Mark N. Pernik, Luke J. Dosselman, Salah G. Aoun, Adrienne D. Walker, Kristen Hall, Valery Peinado Reyes, David L. McDonagh and Carlos A. Bagley
The aim of this study was to determine if the use of tranexamic acid (TXA) in long-segment spinal fusion surgery can help reduce perioperative blood loss, transfusion requirements, and morbidity.
In this retrospective single-center study, the authors included 119 consecutive patients who underwent thoracolumbar fusion spanning at least 4 spinal levels from October 2016 to February 2019. Blood loss, transfusion requirements, perioperative morbidity, and adverse thrombotic events were compared between a cohort receiving intravenous TXA and a control group that did not.
There was no significant difference in any measure of intraoperative blood loss (1514.3 vs 1209.1 mL, p = 0.29) or transfusion requirement volume between the TXA and control groups despite a higher number of pelvic fusion procedures in the TXA group (85.9% vs 62.5%, p = 0.003). Postoperative transfusion volume was significantly lower in TXA patients (954 vs 572 mL, p = 0.01). There was no difference in the incidence of thrombotic complications between the groups.
TXA appears to provide a protective effect against blood loss in long-segment spine fusion surgery specifically when pelvic dissection and fixation is performed. TXA also seems to decrease postoperative transfusion requirements without increasing the risk of adverse thrombotic events.
Salah G. Aoun, Tarek Y. El Ahmadieh, Najib E. El Tecle, Marc R. Daou, Joseph G. Adel, Christine S. Park, H. Hunt Batjer and Bernard R. Bendok
Microsurgical skills remain an integral component of neurosurgical education. There is a need for an objective scale to assess microsurgical skills. The objective of this study was to assess the face and construct validity of a benchtraining microanastomosis module and an objective assessment scale, i.e., the Northwestern Objective Microanastomosis Assessment Tool (NOMAT).
Medical students, neurosurgical residents, and postdoctoral research fellows at Northwestern University were enrolled in the study. Trainees were divided into 3 groups based on microsurgical experience: 1) experienced, 2) exposed, and 3) novices. Each trainee completed two end-to-end microanastomoses using a 1-mm and a 3-mm synthetic vessel. Two cameras were installed to capture procedural footage. One neurosurgeon blindly graded the performance of trainees using both objective and subjective methods to assess construct validity. Two neurosurgeons reviewed the contents of the simulation module to assess face validity.
Twenty-one trainees participated in the study, including 6 experienced, 6 exposed, and 9 novices. The mean NOMAT score for experienced trainees on the 1-mm module was 47.3/70 compared with 26.0/70 and 25.8/70 for exposed and novice trainees, respectively (p = 0.02). Using subjective grading, experienced trainees performed significantly better on the 1-mm module (64.2/100) compared with exposed or novice trainees (23.3/100 and 25.0/100, respectively; p = 0.02). No statistical difference between groups was noted for the 3-mm module with both NOMAT and subjective grading. Experienced trainees took less time to perform both tasks compared with the others.
Face and construct validities of the microanastomosis module were established. The scale and the microanastomosis module could help assess the microsurgical skills of neurosurgical trainees and serve as a basis for the creation of a microsurgical curriculum.
Eva M. Wu, Tarek Y. El Ahmadieh, Cameron M. McDougall, Salah G. Aoun, Nikhil Mehta, Om James Neeley, Aaron Plitt, Vin Shen Ban, Rafael Sillero, Jonathan A. White, H. Hunt Batjer and Babu G. Welch
Endovascular embolization has been established as an adjuvant treatment strategy for brain arteriovenous malformations (AVMs). A growing body of literature has discussed curative embolization for select lesions. The transition of endovascular embolization from an adjunctive to a definitive treatment modality remains controversial. Here, the authors reviewed the literature to assess the lesional characteristics, technical factors, and angiographic and clinical outcomes of endovascular embolization of AVMs with intent to cure.
Electronic databases—Ovid MEDLINE, Ovid Embase, and PubMed—were searched for studies in which there was evidence of AVMs treated using endovascular embolization with intent to cure. The primary outcomes of interest were angiographic obliteration immediately postembolization and at follow-up. The secondary outcomes of interest were complication rates. Descriptive statistics were used to calculate rates and means.
Fifteen studies with 597 patients and 598 AVMs treated with intent-to-cure embolization were included in this analysis. Thirty-four percent of AVMs were Spetzler-Martin grade III. Complete obliteration immediately postembolization was reported in 58.3% of AVMs that had complete treatment and in 45.8% of AVMs in the entire patient cohort. The overall clinical complication rate was 24.1%. The most common complication was hemorrhage, occurring in 9.7% of patients. Procedure-related mortality was 1.5%.
While endovascular embolization with intent to cure can be an option for select AVMs, the reported complication rates appear to be increased compared with those in studies in which adjunctive embolization was the goal. Given the high complication rate related to a primary embolization approach, the risks and benefits of such a treatment strategy should be discussed among a multidisciplinary team. Curative embolization of AVMs should be considered an unanticipated benefit of such therapy rather than a goal.
Pasquale Gallina, Giancarlo Lastrucci, Saverio Caini and Beradino Porfirio
Salah G. Aoun, Valery Peinado Reyes, Tarek Y. El Ahmadieh, Matthew Davies, Ankur R. Patel, Vin Shen Ban, Aaron Plitt, Najib E. El Tecle, Jessica R. Moreno, Jack Raisanen and Carlos A. Bagley
Axial low-back pain is a disease of epidemic proportions that exerts a heavy global toll on the active workforce and results in more than half a trillion dollars in annual costs. Stem cell injections are being increasingly advertised as a restorative solution for various degenerative diseases and are becoming more affordable and attainable by the public. There have been multiple reports in the media of these injections being easily available abroad outside of clinical trials, but scientific evidence supporting them remains scarce. The authors present a case of a serious complication after a stem cell injection for back pain and provide a systematic review of the literature of the efficacy of this treatment as well as the associated risks and complications.
A systematic review of the literature was performed using the PubMed, Google Scholar, and Scopus online electronic databases to identify articles reporting stem cell injections for axial back pain in accordance with the PRISMA guidelines. The primary focus was on outcomes and complications. A case of glial hyperplasia of the roots of the cauda equina directly related to stem cell injections performed abroad is also reported.
The authors identified 14 publications (including a total of 147 patients) that met the search criteria. Three of the articles presented data for the same patient population with different durations of follow-up and were thus analyzed as a single study, reducing the total number of studies to 12. In these 12 studies, follow-up periods ranged from 6 months to 6 years, with 50% having a follow-up period of 1 year or less. Most studies reported favorable outcomes, although 36% used subjective measures. There was a tendency for pain relief to wane after 6 months to 2 years, with patients seeking a surgical solution. Only 1 study was a randomized controlled trial (RCT).
There are still insufficient data to support stem cell injections for back pain. Additional RCTs with long-term follow-up are necessary before statements can be made regarding the efficacy and safety.
Eva M. Wu, Tarek Y. El Ahmadieh, Benjamin Kafka, James P. Caruso, Om J. Neeley, Aaron R. Plitt, Salah G. Aoun, Daiwai Olson, Robert A. Ruchinskas, C. Munro Cullum, Babu G. Welch, H. Hunt Batjer and Jonathan A. White
Objective assessment tests are commonly used to predict the response to ventriculoperitoneal (VP) shunting in patients with normal pressure hydrocephalus (NPH). Whether subjective reports of improvement after a lumbar drain (LD) trial can predict response to VP shunting remains controversial. The goal in this study was to compare clinical characteristics, complication rates, and shunt outcomes of objective and subjective LD responders who underwent VP shunt placement.
This was a retrospective review of patients with NPH who underwent VP shunt placement after clinical improvement with the LD trial. Patients who responded after the LD trial were subclassified into objective LD responders and subjective LD responders. Clinical characteristics, complication rates, and shunt outcomes between the 2 groups were compared with chi-square test of independence and t-test.
A total of 116 patients received a VP shunt; 75 were objective LD responders and 41 were subjective LD responders. There was no statistically significant difference in patient characteristics between the 2 groups, except for a shorter length of stay after LD trial seen with subjective responders. The complication rates after LD trial and VP shunting were not significantly different between the 2 groups. Similarly, there was no significant difference in shunt response between objective and subjective LD responders. The mean duration of follow-up was 1.73 years.
Reports of subjective improvement after LD trial in patients with NPH can be a reliable predictor of shunt response. The currently used objective assessment scales may not be sensitive enough to detect subtle changes in symptomatology after LD trial.
Salah G. Aoun, Sonja E. Stutzman, Phuong-Uyen N. Vo, Tarek Y. El Ahmadieh, Mohamed Osman, Om Neeley, Aaron Plitt, James P. Caruso, Venkatesh Aiyagari, Folefac Atem, Babu G. Welch, Jonathan A. White, H. Hunt Batjer and Daiwai M. Olson
Cerebral vasospasm causing delayed cerebral ischemia (DCI) is a source of significant morbidity after subarachnoid hemorrhage (SAH). Transcranial Doppler is used at most institutions to detect sonographic vasospasm but has poor positive predictive value for DCI. Automated assessment of the pupillary light reflex has been increasingly used as a reliable way of assessing pupillary reactivity, and the Neurological Pupil Index (NPi) has been shown to decrease hours prior to the clinical manifestation of ischemic injury or herniation syndromes. The aim of this study was to investigate the role of automated pupillometry in the setting of SAH, as a potential adjunct to TCD.
Our analysis included patients that had been diagnosed with aneurysmal SAH and admitted to the neuro–intensive care unit of the University of Texas Southwestern Medical Center between November 2015 and June 2017. A dynamic infrared pupillometer was used for all pupillary measurements. An NPi value ranging from 3 to 5 was considered normal, and from 0 to 2.9 abnormal. Sonographic vasospasm was defined as middle cerebral artery velocities greater than 100 cm/sec with a Lindegaard ratio greater than 3 on either side on transcranial Doppler. Most patients had multiple NPi readings daily and we retained the lowest value for our analysis. We aimed to study the association between DCI and sonographic vasospasm, and DCI and NPi readings.
A total of 56 patients were included in the final analysis with 635 paired observations of daily TCD and NPi data. There was no statistically significant association between the NPi value and the presence of sonographic vasospasm. There was a significant association between DCI and sonographic vasospasm, χ2(1) = 6.4112, p = 0.0113, OR 1.6419 (95% CI 1.1163–2.4150), and between DCI and an abnormal decrease in NPi, χ2(1) = 38.4456, p < 0.001, OR 3.3930 (95% CI 2.2789–5.0517). Twelve patients experienced DCI, with 7 showing a decrease of their NPi to an abnormal range. This change occurred > 8 hours prior to the clinical decline 71.4% of the time. The NPi normalized in all patients after treatment of their vasospasm.
Isolated sonographic vasospasm does not seem to correlate with NPi changes, as the latter likely reflects an ischemic neurological injury. NPi changes are strongly associated with the advent of DCI and could be an early herald of clinical deterioration.