Vladimir Balik - Academia.edu (original) (raw)

Papers by Vladimir Balik

Research paper thumbnail of Rat Spinal Cord Injury Experimental Model

Folia veterinaria, Jun 1, 2016

Research paper thumbnail of Hypothermia as a potential remedy for canine and feline acute spinal cord injury: a review

Acta Veterinaria Brno

Severe spinal cord injury (SCI) resulting in permanent sensory-motor and autonomic dysfunction ca... more Severe spinal cord injury (SCI) resulting in permanent sensory-motor and autonomic dysfunction caudal to a damaged spinal cord (SC) segment is a catastrophic event in human as well as in veterinary medicine. The situation of paraplegic/tetraplegic people or animals is further impaired by serious complications and often displays an image of permanent suffering. Therapeutic hypothermia (TH) has shown neuroprotective capacity in numerous experimental and several clinical studies or case reports. Hence, the method draws increasing attention of neuroscientists as well as health care workers. While systemic TH is a too complex procedure for veterinary practice, local application of TH with a reduced risk of the whole body temperature fluctuations and minimal side effects can become one of the therapeutic tools considered in the treatment of acute traumatic SCIs in bigger animals, especially when surgical decompression of spinal medulla and vertebral column reconstruction is indicated. Sti...

Research paper thumbnail of A preliminary report on time dependent changes of some immunophenotypic characteristics of adult rat bone marrow derived stem/progenitor cells

Research paper thumbnail of Acquisition and Expansion of Adult Rat Bone Marrow Multipotent Mesenchymal Stromal Cells

Folia Veterinaria, 2017

This study was initiated in order to test a mini-invasive method of mesenchymal stem/progenitor c... more This study was initiated in order to test a mini-invasive method of mesenchymal stem/progenitor cells (MS/PCs) isolation from a rat bone marrow (BM), and subsequently their expansion, differentiation, and evaluation of their immunophenotypic characteristics; and later their preservation as donor cells in an optimal condition for potential autotransplantation. The study group comprised of 6 adult male Sprague-Dawley (S-D) rats, weighing 480—690 g. The rats were anaesthetised by isoflurane with room air in a Plexiglas box and maintained by inhalation of a mixture of isoflurane and O

Research paper thumbnail of Rat Spinal Cord Injury Experimental Model

Folia Veterinaria, 2016

Spinal cord injuries (SCI) with their tragic consequences belong to the most serious pathological... more Spinal cord injuries (SCI) with their tragic consequences belong to the most serious pathological conditions. That is why they have stimulated basic research workers, as well as health care practitioners, to search for an effective treatment for decades. Animal experimental models have been essential in these efforts. We have jointly decided to test and standardize one of the spinal cord injury compression models in rats. Twentythree adult female Wistar rats weighing 250-320 g were utilized. Employing general anaesthesia along with a mixture of sevoflurane with O2, 2 rats (sham controls) had their vertebral arch of either Th8 or Th9 vertebra removed (laminectomy). The other 21 experimental rats with similar laminectomies were divided into 3 subgroups (n = 7) which received compression impact forces of 30, 40 or 50 g (subgroups-1, -2, and -3, respectively) applied on their exposed spinal medulla for 15 minutes. All rats were observed for 28 days after the experimental procedure and t...

Research paper thumbnail of Redistribution of acute traumatic infratentorial subdural hematoma to the spinal subdural space

Soudni lekarstvi, 2019

Spinal subdural hematoma is a rare and potentionally life-threatening condition associated with t... more Spinal subdural hematoma is a rare and potentionally life-threatening condition associated with trauma and other pathological conditions. In this paper we report the autopsy findings of a 64 year old male who was repeatedly hospitalized with traumatic head injuries in the past. In this case spinal subdural hematoma was diagnosed post-mortem and later comfirmed by ante-mortem CT scan revaluation. Keywords: intracranial subdural hematoma - recurrent spinal subdural hematoma - diffuse axonal injury - autopsy findings.

Research paper thumbnail of A Histopathological Study of Ischemic and Compressive Paraplegia in Dogs

Folia Veterinaria, 2017

It is well known that neuronal death, clinically manifested as paresis or plegia, is the end resu... more It is well known that neuronal death, clinically manifested as paresis or plegia, is the end result of many pathological events affecting the central nervous system. However, several aspects of pathophysiological mechanisms involved in the development of tetra- or paraplegia caused by spinal cord traumatic or ischemic damage are only insufficiently understood and their histopathological manifestations remain poorly documented. That is why the authors decided to report on light-microscopic changes observed in 30 μm thick spinal cord sections cut from L3-S1 segments processed by the Nauta staining method in a group of 6 dogs with ischemic paraplegia induced by 30 min of a high thoracic aorta occlusion, and in a different group of 6 dogs with traumatic paraplegia induced by 5 min spinal cord compression with 200 g metallic rod. Both experimental groups (ischemic and compression) of spinal cord injuries (SCI) comprised the same number of mongrel dogs of both sexes, weighing 18-25 kg. In...

Research paper thumbnail of In Reply: Transcriptomic Profiling Revealed Lnc-GOLGA6A-1 as a Novel Prognostic Biomarker of Meningioma Recurrence

Research paper thumbnail of Autonomic Dysreflexia following Spinal Cord Injury

Asian Journal of Neurosurgery

Autonomic dysreflexia (AD) is a potentially life-threatening condition of the autonomic nervous s... more Autonomic dysreflexia (AD) is a potentially life-threatening condition of the autonomic nervous system following spinal cord injury at or above T6. One of the most common symptoms is a sudden increase in blood pressure induced by afferent sensory stimulation owing to unmodulated reflex sympathetic hyperactivity. Such episodes of high blood pressure might be associated with a high risk of cerebral or retinal hemorrhage, seizures, heart failure, or pulmonary edema. In-depth knowledge is, therefore, crucial for the proper management of the AD, especially for spine surgeons, who encounter these patients quite often in their clinical practice. Systematical review of the literature dealing with strategies to prevent and manage this challenging condition was done by two independent reviewers. Studies that failed to assess primary (prevention, treatment strategies and management) and secondary outcomes (clinical symptomatology, presentation) were excluded. A bibliographical search revealed ...

Research paper thumbnail of Surgical treatment of unruptured dissecting intracranial aneurysms of vertebral-posterior inferior cerebellar artery region

Journal of Neurosurgical Sciences, 2017

A lack of published surgical experience and higher symptomatic recurrence than previously recogni... more A lack of published surgical experience and higher symptomatic recurrence than previously recognized prompted the authors to present their experience with the surgical treatment of unruptured intracranial dissecting aneurysms (UIDAs). Hospital records, neuroimaging studies, operative reports, and follow-up records were retrospectively reviewed. Four patients with vertebral - posterior inferior cerebellar artery (VA-PICA) UIDAs surgically treated between September 2014 and September 2015 were included in the study along with a review of the literature. There were 3 men and 1 woman in the studied group, their age ranging from 42 to 66 years. Three presented with chronic headache, and in one the dissecting aneurysm was detected incidentally. All patients underwent surgical exploration of the lesion with proximal clipping of the parent artery through a far-lateral suboccipital craniotomy with or without partial condylar resection. In two patients (Cases 1 and 4) an occipital artery (OA)-PICA bypass was performed. Case 1 had a nasal cerebrospinal fluid (CSF) leak and loss of sweet taste postoperatively. The CSF leak was successfully treated conservatively and loss of sweet taste gradually improved. All patients reached a modified Rankin scale of 0-1 at discharge. The follow-up period ranged from 1 to 28 weeks with a mean of 17 weeks. No hemorrhagic or ischemic complications were observed during the follow-up period. The surgical treatment of VA-PICA UIDAs has acceptable risk regarding perioperative mortality and morbidity. The incidence of aneurysmal recurrence or the need for retreatment seems to be less than that associated with anticoagulation/antiplatelet therapy or endovascular treatment.

Research paper thumbnail of Comparison of Bypass and Non–Bypass Surgical Treatments for Internal Carotid Artery Blood Blister-Like Aneurysms: A Meta-Analysis of Efficacy, Safety, and Outcomes

World Neurosurgery, 2020

BACKGROUND An optimal surgical strategy for treating internal carotid artery (ICA) blood blister-... more BACKGROUND An optimal surgical strategy for treating internal carotid artery (ICA) blood blister-like aneurysm (BBA) remains unclear. While some prefer bypass surgery, others favour less-demanding surgical methods. The aim of this meta-analysis is to assess the efficacy, safety and outcomes of bypass and non-bypass surgical methods when intended as primary treatments for ICA BBA. METHODS Studies including data on outcomes of interest in surgically-treated patients with ICA BBA were sought in PubMed/MEDLINE, Evidence-Based Medicine (EBM) Reviews/Cochrane Central, ProQuest and Scopus databases, and were analyzed using random-effect modeling. RESULTS Seven observational studies involving 140 patients met the inclusion criteria. Patients treated with bypass surgery, compared to those treated with non-bypass techniques, had lower odds of: poor outcomes (OR: 0.75; 95% CI: 0.28-2.02; P = .57; I2 = 0%); postoperative vasospasm (OR: 1.73; 95% CI: 0.38-7.92; P = .48; I2 = 19%); intraoperative (OR: 3.37; 95% CI: 0.82-13.90; P = .09; I2 = 0%) and postoperative bleeding (OR: 1.91; 95% CI: 0.47-7.76; P = .36; I2 = 0%); and postoperative recurrence of BBA (OR: 2.16; 95% CI: 0.54-8.66; P < .28; I2 = 0%). No comparison, however, achieved statistical significance. CONCLUSIONS For surgeons who practice both bypass and non-bypass surgical strategies, the two methods seem comparable in terms of the outcomes of interest, though the bypass technique appears superior. However, comparisons with studies reporting bypass as the uniquely preferred technique indicates that specialization in and preference for the bypass procedure are associated with more favourable outcomes.

Research paper thumbnail of Recurrence of surgically treated parasagittal meningiomas: a meta-analysis of risk factors

Acta Neurochirurgica, 2020

Background As the predictive role of many risk factors for parasagittal meningioma (PM) recurrenc... more Background As the predictive role of many risk factors for parasagittal meningioma (PM) recurrence remains unclear, the objective of the meta-analysis was to make a comprehensive assessment of the predictive value of selected risk factors in these lesions. Methods Studies including data on selected risk factors, such as histology, tumor and sinus resection, sinus invasion, tumor localization, and immediate postoperative radiotherapy for PMs recurrence, were searched in the NCBI/NLM PubMed/ MEDLINE, EBM Reviews/Cochrane Central, ProQuest, and Scopus databases, and analyzed using random effects modeling. Results Thirteen observational studies involving 1243 patients met the criteria for inclusion in the meta-analysis. WHO grading of meningiomas was identified as the most powerful risk factor for recurrence. WHO grade II meningiomas (OR 11.61; 95% CI 4.43-30.43; P < .01; I 2 = 31%) or composite group of WHO grades II and III (OR 14.84; 95% CI 5.10-43.19; P < .01; I 2 = 48%) had a significantly higher risk of recurrence than benign lesions. Moreover, an advanced sinus involvement (types IV-VI according to the Sindou classification) (OR 3.49; 95% CI 1.30-9.33; P = .01; I 2 = 0%) and partial tumor resection (Simpson grades III-V) (OR 2.73; 95% CI 1.41-5.30; P = .03; I 2 = 52%) were associated with a significantly higher risk of recurrence than their counterparts. Conclusion Among the selected risk factors, high-grade WHO lesions, advanced sinus invasion, and partial tumor resection were associated with a higher risk of PM recurrence, with WHO grading system being the most powerful risk factor. Keywords Meta-analysis. Parasagittal meningioma. Recurrence. Risk factors This article is part of the Topical Collection on Tumor-Meningioma.

Research paper thumbnail of Identification of Meningioma Patients at High Risk of Tumor Recurrence Using MicroRNA Profiling

Neurosurgery, 2020

BACKGROUND Meningioma growth rates are highly variable, even within benign subgroups, with some r... more BACKGROUND Meningioma growth rates are highly variable, even within benign subgroups, with some remaining stable, whereas others grow rapidly. OBJECTIVE To identify molecular-genetic markers for more accurate prediction of meningioma recurrence and better-targeted therapy. METHODS Microarrays identified microRNA (miRNA) expression in primary and recurrent meningiomas of all World Health Organization (WHO) grades. Those found to be deregulated were further validated by quantitative real-time polymerase chain reaction in a cohort of 172 patients. Statistical analysis of the resulting dataset revealed predictors of meningioma recurrence. RESULTS Adjusted and nonadjusted models of time to relapse identified the most significant prognosticators to be miR-15a-5p, miR-146a-5p, and miR-331-3p. The final validation phase proved the crucial significance of miR-146a-5p and miR-331-3p, and clinical factors such as type of resection (total or partial) and WHO grade in some selected models. Follo...

Research paper thumbnail of 1927PIdentification of meningioma patients in high risk of tumor recurrence using microRNA profiling

Annals of Oncology, 2019

Background Meningioma growth rates are highly variable, even within benign subgroups, causing som... more Background Meningioma growth rates are highly variable, even within benign subgroups, causing some cases to remain stable while others grow rapidly despite radiotherapy. Biomarkers that differentiate meningiomas by aggression and enable prediction of their biological behavior would therefore be clinically beneficial. Methods Microarrays were used to identify microRNA (miRNA) expression in primary recurrent, non-recurrent and secondary meningiomas of all grades. miRNAs found to be deregulated in the microarray experiments were validated by quantitative real-time PCR using samples from a cohort of 191 patients (median age 56). Statistical analysis of the resulting dataset revealed miRNA predictors of meningioma recurrence. Results miRNAs exhibiting differential expression (independently of histological grade) in primary recurrent, non-recurrent and secondary meningiomas were identified. The most effective predictive model included miR-331-3p, extent of tumor resection and its localiza...

Research paper thumbnail of Safe and bloodless exposure of the third segment of the vertebral artery: a step-by-step overview based on over 50 personal cases

Neurosurgical Review, 2019

Craniovertebral junction surgery usually requires the exposure of the third segment of the verteb... more Craniovertebral junction surgery usually requires the exposure of the third segment of the vertebral artery (V3). However, the complexity of musculature, a relatively high incidence of anomalies in the course of the vertebral artery (VA), and the presence of a rich venous plexus in this region make the V3 exposure challenging with a high risk of serious complications while taking down the suboccipital muscles in a single layer. A muscle dissection in interfascial layers, however, overcomes the drawbacks inherent in a blind dissection of the V3 as each of the muscles represents substantial landmark aiding subsequent step of the procedure and thus helping identify underlying anatomical structure early and safely. Moreover, along with a bloodless VA dissection off its surrounding venous plexus, it permits a safe and comfortable V3 exposure during the surgically demanding procedures.

Research paper thumbnail of Histological Structure of the Major Dural Sinus Walls in the Posterior Cranial Fossa: A Factor that Might Matter in Dural Sinus Surgery

Research paper thumbnail of Abstract 2717: Identification of three distinct molecular subtypes in meningioma samples using microarrays for copy-number variants

Cancer Research, 2017

Background: Meningioma represents one of the most common intracranial tumors. They are generally ... more Background: Meningioma represents one of the most common intracranial tumors. They are generally thought to progress from low to high-grade lesions. However, the molecular mechanisms underlying their pathogenesis remain still uncertain. Identification of meningioma molecular subgroups may have significant potential to improve clinical management, through molecular disease risk stratification strategies and the identification of patients who could benefit from targeted molecular therapeutics. Methods and patients: Formalin-fixed paraffin embedded tumor samples were obtained from 45 meningioma patients and 5 healthy controls (dura mater). Comprehensive clinical-pathological data were mined. There were 15 males and 30 females; median age was 54 years, range 28 - 99 years. Total DNA was purified from FFPE samples after pathological verification using proteinase K treatment followed by QIAmp DNA FFPE Tissue Kit (Qiagen). Microarray analysis was performed using the OncoScan FFPE Assay Kit...

Research paper thumbnail of Comparison of computational fluid dynamics findings with intraoperative microscopy findings in unruptured intracranial aneurysms- An initial analysis

Asian journal of neurosurgery

The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Pre... more The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Prediction of risk based on the size of the aneurysm is not always accurate. There is no objective way of predicting rupture of aneurysm so far. Computational fluid dynamics (CFDs) was proposed as a tool to identify the rupture risk. To know the correlation of CFD findings with intraoperative microscopic findings and to know the relevance of CFD in the prediction of rupture risk and in the management of unruptured intracranial aneurysms. A prospective study involving nine cases over a period of 6 months as an initial analysis. Both males and females were included in the study. Preoperative analysis was performed using computed tomography angiogram, magnetic resonance imaging in all cases and digital substraction angiogram in some cases. Intraoperatively microscopic examination of the aneurysm wall was carried out and images recorded. The correlation was done between microscopic and CFD imag...

Research paper thumbnail of Bilateral position-related ulnar neuropathy at elbow in pediatric population and review of the literature

Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery, 2017

Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during s... more Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during surgical procedures are commonly found in adults. However, their extremely rare incidence in the pediatric population may cause absent awareness of the risk of nerve injury in anesthetized pediatric patients. Furthermore, young patients respond to conservative treatment of neuropathy less favorably than adults and their response also depends on the pathomechanism of the ulnar nerve injury. A surgeon's or anesthetist's failure to recognize all of these specifics in children may result in substantial morbidity of young patients leading to lawsuits. Fortunately, with an adequate knowledge of surgical anatomy and types of procedures and positions in which the ulnar nerve is particularly vulnerable, and familiarity with measures to minimize the potential for neuropathy, this serious complication can be prevented. The aims of this review are to highlight personal experience and current ...

Research paper thumbnail of Multifocal Supra and Infratentorial Medulloblastoma in an Adult: Histologic, Immunohistochemical, and Molecular Evaluation of a Rare Case and Review of the Literature

Applied Immunohistochemistry & Molecular Morphology, 2016

GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Alt... more GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Although previous studies have reported on mutation rates in cases of uveal melanoma, presently, no such report for the Japanese population exists. In this study, we examined the frequency of GNAQ and GNA11 somatic mutations in cases of uveal melanoma in Japan and their relationship with clinicopathologic features or Ki-67-positive cell rates (Ki-67 labeling index: Ki-67 LI) using immunofluorescence methods. The study involved 19 cases of uveal melanoma. We extracted the template DNA from formalin-fixed, paraffin-embedded specimens using a DNA extraction kit. We amplified the DNA sequences of GNAQ and GNA11 using polymerase chain reaction and analyzed mutations by direct sequencing. We evaluated Ki-67 LI using immunofluorescence methods. The frequencies of GNAQ and GNA11 somatic mutations were 26.3% (5/19) and 31.6% (6/19), respectively. The GNAQ and GNA11 mutations were mutually exclusive, as indicated in previous reports. The frequency of GNA11 mutations was significantly higher in epithelioid cells; however, no significant association between GNAQ mutations and cell type was evident, and there was no significant difference in Ki-67 LI between the mutationpositive and mutation-negative tumors. GNAQ and GNA11 mutations were identified in cases of uveal melanoma in Japan, although at lower frequencies than in white counterparts. The mutation frequency of GNA11 was significantly higher in epithelioid cells.

Research paper thumbnail of Rat Spinal Cord Injury Experimental Model

Folia veterinaria, Jun 1, 2016

Research paper thumbnail of Hypothermia as a potential remedy for canine and feline acute spinal cord injury: a review

Acta Veterinaria Brno

Severe spinal cord injury (SCI) resulting in permanent sensory-motor and autonomic dysfunction ca... more Severe spinal cord injury (SCI) resulting in permanent sensory-motor and autonomic dysfunction caudal to a damaged spinal cord (SC) segment is a catastrophic event in human as well as in veterinary medicine. The situation of paraplegic/tetraplegic people or animals is further impaired by serious complications and often displays an image of permanent suffering. Therapeutic hypothermia (TH) has shown neuroprotective capacity in numerous experimental and several clinical studies or case reports. Hence, the method draws increasing attention of neuroscientists as well as health care workers. While systemic TH is a too complex procedure for veterinary practice, local application of TH with a reduced risk of the whole body temperature fluctuations and minimal side effects can become one of the therapeutic tools considered in the treatment of acute traumatic SCIs in bigger animals, especially when surgical decompression of spinal medulla and vertebral column reconstruction is indicated. Sti...

Research paper thumbnail of A preliminary report on time dependent changes of some immunophenotypic characteristics of adult rat bone marrow derived stem/progenitor cells

Research paper thumbnail of Acquisition and Expansion of Adult Rat Bone Marrow Multipotent Mesenchymal Stromal Cells

Folia Veterinaria, 2017

This study was initiated in order to test a mini-invasive method of mesenchymal stem/progenitor c... more This study was initiated in order to test a mini-invasive method of mesenchymal stem/progenitor cells (MS/PCs) isolation from a rat bone marrow (BM), and subsequently their expansion, differentiation, and evaluation of their immunophenotypic characteristics; and later their preservation as donor cells in an optimal condition for potential autotransplantation. The study group comprised of 6 adult male Sprague-Dawley (S-D) rats, weighing 480—690 g. The rats were anaesthetised by isoflurane with room air in a Plexiglas box and maintained by inhalation of a mixture of isoflurane and O

Research paper thumbnail of Rat Spinal Cord Injury Experimental Model

Folia Veterinaria, 2016

Spinal cord injuries (SCI) with their tragic consequences belong to the most serious pathological... more Spinal cord injuries (SCI) with their tragic consequences belong to the most serious pathological conditions. That is why they have stimulated basic research workers, as well as health care practitioners, to search for an effective treatment for decades. Animal experimental models have been essential in these efforts. We have jointly decided to test and standardize one of the spinal cord injury compression models in rats. Twentythree adult female Wistar rats weighing 250-320 g were utilized. Employing general anaesthesia along with a mixture of sevoflurane with O2, 2 rats (sham controls) had their vertebral arch of either Th8 or Th9 vertebra removed (laminectomy). The other 21 experimental rats with similar laminectomies were divided into 3 subgroups (n = 7) which received compression impact forces of 30, 40 or 50 g (subgroups-1, -2, and -3, respectively) applied on their exposed spinal medulla for 15 minutes. All rats were observed for 28 days after the experimental procedure and t...

Research paper thumbnail of Redistribution of acute traumatic infratentorial subdural hematoma to the spinal subdural space

Soudni lekarstvi, 2019

Spinal subdural hematoma is a rare and potentionally life-threatening condition associated with t... more Spinal subdural hematoma is a rare and potentionally life-threatening condition associated with trauma and other pathological conditions. In this paper we report the autopsy findings of a 64 year old male who was repeatedly hospitalized with traumatic head injuries in the past. In this case spinal subdural hematoma was diagnosed post-mortem and later comfirmed by ante-mortem CT scan revaluation. Keywords: intracranial subdural hematoma - recurrent spinal subdural hematoma - diffuse axonal injury - autopsy findings.

Research paper thumbnail of A Histopathological Study of Ischemic and Compressive Paraplegia in Dogs

Folia Veterinaria, 2017

It is well known that neuronal death, clinically manifested as paresis or plegia, is the end resu... more It is well known that neuronal death, clinically manifested as paresis or plegia, is the end result of many pathological events affecting the central nervous system. However, several aspects of pathophysiological mechanisms involved in the development of tetra- or paraplegia caused by spinal cord traumatic or ischemic damage are only insufficiently understood and their histopathological manifestations remain poorly documented. That is why the authors decided to report on light-microscopic changes observed in 30 μm thick spinal cord sections cut from L3-S1 segments processed by the Nauta staining method in a group of 6 dogs with ischemic paraplegia induced by 30 min of a high thoracic aorta occlusion, and in a different group of 6 dogs with traumatic paraplegia induced by 5 min spinal cord compression with 200 g metallic rod. Both experimental groups (ischemic and compression) of spinal cord injuries (SCI) comprised the same number of mongrel dogs of both sexes, weighing 18-25 kg. In...

Research paper thumbnail of In Reply: Transcriptomic Profiling Revealed Lnc-GOLGA6A-1 as a Novel Prognostic Biomarker of Meningioma Recurrence

Research paper thumbnail of Autonomic Dysreflexia following Spinal Cord Injury

Asian Journal of Neurosurgery

Autonomic dysreflexia (AD) is a potentially life-threatening condition of the autonomic nervous s... more Autonomic dysreflexia (AD) is a potentially life-threatening condition of the autonomic nervous system following spinal cord injury at or above T6. One of the most common symptoms is a sudden increase in blood pressure induced by afferent sensory stimulation owing to unmodulated reflex sympathetic hyperactivity. Such episodes of high blood pressure might be associated with a high risk of cerebral or retinal hemorrhage, seizures, heart failure, or pulmonary edema. In-depth knowledge is, therefore, crucial for the proper management of the AD, especially for spine surgeons, who encounter these patients quite often in their clinical practice. Systematical review of the literature dealing with strategies to prevent and manage this challenging condition was done by two independent reviewers. Studies that failed to assess primary (prevention, treatment strategies and management) and secondary outcomes (clinical symptomatology, presentation) were excluded. A bibliographical search revealed ...

Research paper thumbnail of Surgical treatment of unruptured dissecting intracranial aneurysms of vertebral-posterior inferior cerebellar artery region

Journal of Neurosurgical Sciences, 2017

A lack of published surgical experience and higher symptomatic recurrence than previously recogni... more A lack of published surgical experience and higher symptomatic recurrence than previously recognized prompted the authors to present their experience with the surgical treatment of unruptured intracranial dissecting aneurysms (UIDAs). Hospital records, neuroimaging studies, operative reports, and follow-up records were retrospectively reviewed. Four patients with vertebral - posterior inferior cerebellar artery (VA-PICA) UIDAs surgically treated between September 2014 and September 2015 were included in the study along with a review of the literature. There were 3 men and 1 woman in the studied group, their age ranging from 42 to 66 years. Three presented with chronic headache, and in one the dissecting aneurysm was detected incidentally. All patients underwent surgical exploration of the lesion with proximal clipping of the parent artery through a far-lateral suboccipital craniotomy with or without partial condylar resection. In two patients (Cases 1 and 4) an occipital artery (OA)-PICA bypass was performed. Case 1 had a nasal cerebrospinal fluid (CSF) leak and loss of sweet taste postoperatively. The CSF leak was successfully treated conservatively and loss of sweet taste gradually improved. All patients reached a modified Rankin scale of 0-1 at discharge. The follow-up period ranged from 1 to 28 weeks with a mean of 17 weeks. No hemorrhagic or ischemic complications were observed during the follow-up period. The surgical treatment of VA-PICA UIDAs has acceptable risk regarding perioperative mortality and morbidity. The incidence of aneurysmal recurrence or the need for retreatment seems to be less than that associated with anticoagulation/antiplatelet therapy or endovascular treatment.

Research paper thumbnail of Comparison of Bypass and Non–Bypass Surgical Treatments for Internal Carotid Artery Blood Blister-Like Aneurysms: A Meta-Analysis of Efficacy, Safety, and Outcomes

World Neurosurgery, 2020

BACKGROUND An optimal surgical strategy for treating internal carotid artery (ICA) blood blister-... more BACKGROUND An optimal surgical strategy for treating internal carotid artery (ICA) blood blister-like aneurysm (BBA) remains unclear. While some prefer bypass surgery, others favour less-demanding surgical methods. The aim of this meta-analysis is to assess the efficacy, safety and outcomes of bypass and non-bypass surgical methods when intended as primary treatments for ICA BBA. METHODS Studies including data on outcomes of interest in surgically-treated patients with ICA BBA were sought in PubMed/MEDLINE, Evidence-Based Medicine (EBM) Reviews/Cochrane Central, ProQuest and Scopus databases, and were analyzed using random-effect modeling. RESULTS Seven observational studies involving 140 patients met the inclusion criteria. Patients treated with bypass surgery, compared to those treated with non-bypass techniques, had lower odds of: poor outcomes (OR: 0.75; 95% CI: 0.28-2.02; P = .57; I2 = 0%); postoperative vasospasm (OR: 1.73; 95% CI: 0.38-7.92; P = .48; I2 = 19%); intraoperative (OR: 3.37; 95% CI: 0.82-13.90; P = .09; I2 = 0%) and postoperative bleeding (OR: 1.91; 95% CI: 0.47-7.76; P = .36; I2 = 0%); and postoperative recurrence of BBA (OR: 2.16; 95% CI: 0.54-8.66; P < .28; I2 = 0%). No comparison, however, achieved statistical significance. CONCLUSIONS For surgeons who practice both bypass and non-bypass surgical strategies, the two methods seem comparable in terms of the outcomes of interest, though the bypass technique appears superior. However, comparisons with studies reporting bypass as the uniquely preferred technique indicates that specialization in and preference for the bypass procedure are associated with more favourable outcomes.

Research paper thumbnail of Recurrence of surgically treated parasagittal meningiomas: a meta-analysis of risk factors

Acta Neurochirurgica, 2020

Background As the predictive role of many risk factors for parasagittal meningioma (PM) recurrenc... more Background As the predictive role of many risk factors for parasagittal meningioma (PM) recurrence remains unclear, the objective of the meta-analysis was to make a comprehensive assessment of the predictive value of selected risk factors in these lesions. Methods Studies including data on selected risk factors, such as histology, tumor and sinus resection, sinus invasion, tumor localization, and immediate postoperative radiotherapy for PMs recurrence, were searched in the NCBI/NLM PubMed/ MEDLINE, EBM Reviews/Cochrane Central, ProQuest, and Scopus databases, and analyzed using random effects modeling. Results Thirteen observational studies involving 1243 patients met the criteria for inclusion in the meta-analysis. WHO grading of meningiomas was identified as the most powerful risk factor for recurrence. WHO grade II meningiomas (OR 11.61; 95% CI 4.43-30.43; P < .01; I 2 = 31%) or composite group of WHO grades II and III (OR 14.84; 95% CI 5.10-43.19; P < .01; I 2 = 48%) had a significantly higher risk of recurrence than benign lesions. Moreover, an advanced sinus involvement (types IV-VI according to the Sindou classification) (OR 3.49; 95% CI 1.30-9.33; P = .01; I 2 = 0%) and partial tumor resection (Simpson grades III-V) (OR 2.73; 95% CI 1.41-5.30; P = .03; I 2 = 52%) were associated with a significantly higher risk of recurrence than their counterparts. Conclusion Among the selected risk factors, high-grade WHO lesions, advanced sinus invasion, and partial tumor resection were associated with a higher risk of PM recurrence, with WHO grading system being the most powerful risk factor. Keywords Meta-analysis. Parasagittal meningioma. Recurrence. Risk factors This article is part of the Topical Collection on Tumor-Meningioma.

Research paper thumbnail of Identification of Meningioma Patients at High Risk of Tumor Recurrence Using MicroRNA Profiling

Neurosurgery, 2020

BACKGROUND Meningioma growth rates are highly variable, even within benign subgroups, with some r... more BACKGROUND Meningioma growth rates are highly variable, even within benign subgroups, with some remaining stable, whereas others grow rapidly. OBJECTIVE To identify molecular-genetic markers for more accurate prediction of meningioma recurrence and better-targeted therapy. METHODS Microarrays identified microRNA (miRNA) expression in primary and recurrent meningiomas of all World Health Organization (WHO) grades. Those found to be deregulated were further validated by quantitative real-time polymerase chain reaction in a cohort of 172 patients. Statistical analysis of the resulting dataset revealed predictors of meningioma recurrence. RESULTS Adjusted and nonadjusted models of time to relapse identified the most significant prognosticators to be miR-15a-5p, miR-146a-5p, and miR-331-3p. The final validation phase proved the crucial significance of miR-146a-5p and miR-331-3p, and clinical factors such as type of resection (total or partial) and WHO grade in some selected models. Follo...

Research paper thumbnail of 1927PIdentification of meningioma patients in high risk of tumor recurrence using microRNA profiling

Annals of Oncology, 2019

Background Meningioma growth rates are highly variable, even within benign subgroups, causing som... more Background Meningioma growth rates are highly variable, even within benign subgroups, causing some cases to remain stable while others grow rapidly despite radiotherapy. Biomarkers that differentiate meningiomas by aggression and enable prediction of their biological behavior would therefore be clinically beneficial. Methods Microarrays were used to identify microRNA (miRNA) expression in primary recurrent, non-recurrent and secondary meningiomas of all grades. miRNAs found to be deregulated in the microarray experiments were validated by quantitative real-time PCR using samples from a cohort of 191 patients (median age 56). Statistical analysis of the resulting dataset revealed miRNA predictors of meningioma recurrence. Results miRNAs exhibiting differential expression (independently of histological grade) in primary recurrent, non-recurrent and secondary meningiomas were identified. The most effective predictive model included miR-331-3p, extent of tumor resection and its localiza...

Research paper thumbnail of Safe and bloodless exposure of the third segment of the vertebral artery: a step-by-step overview based on over 50 personal cases

Neurosurgical Review, 2019

Craniovertebral junction surgery usually requires the exposure of the third segment of the verteb... more Craniovertebral junction surgery usually requires the exposure of the third segment of the vertebral artery (V3). However, the complexity of musculature, a relatively high incidence of anomalies in the course of the vertebral artery (VA), and the presence of a rich venous plexus in this region make the V3 exposure challenging with a high risk of serious complications while taking down the suboccipital muscles in a single layer. A muscle dissection in interfascial layers, however, overcomes the drawbacks inherent in a blind dissection of the V3 as each of the muscles represents substantial landmark aiding subsequent step of the procedure and thus helping identify underlying anatomical structure early and safely. Moreover, along with a bloodless VA dissection off its surrounding venous plexus, it permits a safe and comfortable V3 exposure during the surgically demanding procedures.

Research paper thumbnail of Histological Structure of the Major Dural Sinus Walls in the Posterior Cranial Fossa: A Factor that Might Matter in Dural Sinus Surgery

Research paper thumbnail of Abstract 2717: Identification of three distinct molecular subtypes in meningioma samples using microarrays for copy-number variants

Cancer Research, 2017

Background: Meningioma represents one of the most common intracranial tumors. They are generally ... more Background: Meningioma represents one of the most common intracranial tumors. They are generally thought to progress from low to high-grade lesions. However, the molecular mechanisms underlying their pathogenesis remain still uncertain. Identification of meningioma molecular subgroups may have significant potential to improve clinical management, through molecular disease risk stratification strategies and the identification of patients who could benefit from targeted molecular therapeutics. Methods and patients: Formalin-fixed paraffin embedded tumor samples were obtained from 45 meningioma patients and 5 healthy controls (dura mater). Comprehensive clinical-pathological data were mined. There were 15 males and 30 females; median age was 54 years, range 28 - 99 years. Total DNA was purified from FFPE samples after pathological verification using proteinase K treatment followed by QIAmp DNA FFPE Tissue Kit (Qiagen). Microarray analysis was performed using the OncoScan FFPE Assay Kit...

Research paper thumbnail of Comparison of computational fluid dynamics findings with intraoperative microscopy findings in unruptured intracranial aneurysms- An initial analysis

Asian journal of neurosurgery

The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Pre... more The increase in the detection of unruptured cerebral aneurysms has led to management dilemma. Prediction of risk based on the size of the aneurysm is not always accurate. There is no objective way of predicting rupture of aneurysm so far. Computational fluid dynamics (CFDs) was proposed as a tool to identify the rupture risk. To know the correlation of CFD findings with intraoperative microscopic findings and to know the relevance of CFD in the prediction of rupture risk and in the management of unruptured intracranial aneurysms. A prospective study involving nine cases over a period of 6 months as an initial analysis. Both males and females were included in the study. Preoperative analysis was performed using computed tomography angiogram, magnetic resonance imaging in all cases and digital substraction angiogram in some cases. Intraoperatively microscopic examination of the aneurysm wall was carried out and images recorded. The correlation was done between microscopic and CFD imag...

Research paper thumbnail of Bilateral position-related ulnar neuropathy at elbow in pediatric population and review of the literature

Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery, 2017

Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during s... more Perioperative ulnar neuropathies attributed to inappropriate arm positioning and padding during surgical procedures are commonly found in adults. However, their extremely rare incidence in the pediatric population may cause absent awareness of the risk of nerve injury in anesthetized pediatric patients. Furthermore, young patients respond to conservative treatment of neuropathy less favorably than adults and their response also depends on the pathomechanism of the ulnar nerve injury. A surgeon's or anesthetist's failure to recognize all of these specifics in children may result in substantial morbidity of young patients leading to lawsuits. Fortunately, with an adequate knowledge of surgical anatomy and types of procedures and positions in which the ulnar nerve is particularly vulnerable, and familiarity with measures to minimize the potential for neuropathy, this serious complication can be prevented. The aims of this review are to highlight personal experience and current ...

Research paper thumbnail of Multifocal Supra and Infratentorial Medulloblastoma in an Adult: Histologic, Immunohistochemical, and Molecular Evaluation of a Rare Case and Review of the Literature

Applied Immunohistochemistry & Molecular Morphology, 2016

GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Alt... more GNAQ and GNA11 mutations are thought to be important for the tumorigenesis of uveal melanoma. Although previous studies have reported on mutation rates in cases of uveal melanoma, presently, no such report for the Japanese population exists. In this study, we examined the frequency of GNAQ and GNA11 somatic mutations in cases of uveal melanoma in Japan and their relationship with clinicopathologic features or Ki-67-positive cell rates (Ki-67 labeling index: Ki-67 LI) using immunofluorescence methods. The study involved 19 cases of uveal melanoma. We extracted the template DNA from formalin-fixed, paraffin-embedded specimens using a DNA extraction kit. We amplified the DNA sequences of GNAQ and GNA11 using polymerase chain reaction and analyzed mutations by direct sequencing. We evaluated Ki-67 LI using immunofluorescence methods. The frequencies of GNAQ and GNA11 somatic mutations were 26.3% (5/19) and 31.6% (6/19), respectively. The GNAQ and GNA11 mutations were mutually exclusive, as indicated in previous reports. The frequency of GNA11 mutations was significantly higher in epithelioid cells; however, no significant association between GNAQ mutations and cell type was evident, and there was no significant difference in Ki-67 LI between the mutationpositive and mutation-negative tumors. GNAQ and GNA11 mutations were identified in cases of uveal melanoma in Japan, although at lower frequencies than in white counterparts. The mutation frequency of GNA11 was significantly higher in epithelioid cells.