Rescue version of a carotid micro-endarterectomy: an ACE-ICA anastomosis with proximal Ica and distal ACE hemoclip obliteration.

Aim of the study: To present our rescue approach of carotid artery occlusion as well as to discuss other possible techniques that can be applied in similar situations.Materials and methods: Two cases from our institution with acute complications during carotid micro-endarterectomy (CEA).Results: Two cases from our institution with acute postoperative complications during CEA that were successfully addressed are presented with imaging and detailed description of the surgical techniques used.Conclusion: CEA are common surgical procedures pursued to achieve revascularization of carotid arteries when occluded partially or fully by an atherosclerotic plaque. As with any surgical procedure, associated complications exist in small percentage of the cases. These can include blood flow limitation due to an insufficient artery wall after atherosclerotic plaque extraction as well as distal kinking of the internal carotid artery. A direct end-to-end ACE-ACI bypass with occlusion of the proximal ACI and distal ACE stump preserves distal flow to the ACI, however the original arteriotomy of ACC must be completely sutured up to the arterial stumps.

Magnetic resonance markers of bilateral neuronal metabolic dysfunction in patients with unilateral internal carotid artery occlusion.

OBJECTIVES: To evaluate cerebral hemodynamic, metabolic and anatomic changes occurring in patients with unilateral occlusion of the internal carotid artery (ICA). MATERIALS AND METHODS: Twenty-two patients with unilateral occlusion of ICA and twenty age and sex matched healthy subjects were included in the study. Single voxel proton magnetic resonance spectroscopy (1H-MRS) of the centrum semiovale, semi-automated hippocampal volumetry in T1-weighted scans and transcranial Doppler examination (TCD) with calculation of Breath Holding Index (BHI) were performed in both groups. Metabolic, anatomic, and hemodynamic features were compared between the two groups. RESULTS: The N-acetylaspartate (NAA)/choline (Cho) ratio was significantly lower in both hemispheres of enrolled patients compared to controls (p = 0.005 for the side with occlusion, p = 0.04 for the side without occlusion). The hippocampus volume was significantly reduced bilaterally in patients compared to healthy subjects (p = 0.049). A statistically significant difference in BHI values was observed between the side with occlusion and without occlusion (p = 0.037) of the patients, as well as between BHI values of the side with occlusion and healthy volunteers (p = 0.014). DISCUSSION: Patients with unilateral ICA occlusion have reduced NAA/Cho ratio in the white matter of both hemispheres and have bilateral atrophy of hippocampus. The alteration of hemodynamics alone cannot explain these changes.

What's known and what's new in adipose lesions of peripheral nerves?

BACKGROUND: Adipose lesions of nerve primarily include intra- and extraneural lipomas and lipomatosis of nerve (LN). This paper will summarize the advances that have been made in the past decade, particularly related to LN and nerve territory overgrowth that have improved our understanding of the natural history, genetic background, diagnosis, imaging features, and clinical management. METHODS AND MATERIALS: Articles about adipose lesions of nerve were reviewed from 2011, when the last comprehensive review on this topic was published. Papers reporting advances on natural history, genetic background, diagnosis, imaging features, and clinical management were screened using PubMed and Google Scholar databases and then analyzed. Case reports and small case series were included only if they reported model examples of discussed pathologies, as these types of articles were summarized in recent systematic reviews on intraneural lipomas and LN. All eligible papers were assessed by the authors, who are subject matter experts. RESULTS: The first screen revealed 404 articles. After careful evaluation, a total of 53 articles were analyzed which includes advances in diagnosis (especially imaging), classification of the lesions, the role of somatic mutations in PIK3CA in LN, and treatment approaches for all adipose lesions of the peripheral nerve. CONCLUSION: Many advances have been made in the understanding of adipose lesions of nerve in the past decade. These pathologic entities are more readily recognized as a spectrum of lesions that share common phenotypic features.

Combined treatment of a medulla oblongata hemangioblastoma via permanent cysto-cisternal drainage and (postponed) gamma knife radiosurgery: a case report and review of the literature.

BACKGROUND: Hemangioblastomas are histologically benign tumors with a variable degree of morbidity and mortality based on various factors, including their anatomical location. The following paper illustrates a unique approach of combined therapy of a brainstem hemangioblastoma (HB) not associated with von Hippel-Lindau disease (vHLd) located in the medulla oblongata. CASE DESCRIPTION: A 21-year-old preschool teacher presented with vertigo, followed by dysphagia, trouble coughing, tongue paresis and headache and vomiting. Magnetic resonance imaging (MRI) revealed a large cystic lesion with a small intramural nodule located in the left anterolateral medulla oblongata directly behind the vertebral artery. The diagnosis of hemangioblastoma was supported by digital subtraction angiography. CONCLUSION: Combined therapy consisted primarily of acute surgical fenestration and permanent drainage of the cystic portion of the tumor, due to symptomatic expansion. Follow-up stereotactic gamma knife radiosurgery was performed after 2 years for minor progression of the tumor nodule. To the best of our knowledge, this is the first time such approach has been described in the literature for this pathology.

Chemical angioplasty with spasmolytics for vasospasm after subarachnoid hemorrhage.

BACKGROUND: Clinically symptomatic vasospasm leading to delayed ischemic neurological deficits occurs in up to 30% of patients with subarachnoid hemorrhage (SAH). Vasospasm can result in a serious decline in clinical conditions of patients with SAH, yet the algorithm for vasospasm treatment and prevention remains unclear. Intra-arterial administration of vasodilators is one of the modalities used for vasospasm therapy. METHODS: Over the last 7 years, we have treated 27 female and 7 male patients with vasospasm using intra-arterial administration of either nimodipine or milrinone; all had suffered aneurysm rupture. Of these patients, 28 were treated surgically (clip), and 6 patients had their aneurysm coiled. Spasmolytics were applied from day 2 to day 18 after rupture. RESULTS: Of the 53 procedures, angiographic improvement was documented in 92% of cases with a mean flow velocity decrease of 65 cm/s. Brain metabolism changes were monitored after the procedure. The highest level of immediate clinical improvement was observed in conscious patients with a focal neurological deficit (aphasia, hemiparesis). Overall clinical outcomes (Glasgow outcome scale, GOS) were as follows: GOS 5 (12 patients), GOS 4 (5 patients), GOS 3 (5 patients), GOS 2 (6 patients), and GOS 1 (6 patients). CONCLUSIONS: Intra-arterial administration of spasmolytics is a safe and potent method of vasospasm treatment. It is most effective when applied to conscious patients with a focal deficit. For unconscious patients, its therapeutic benefits are inconclusive. Patients in severe clinical states would further require use of other diagnostic tools such as multimodal brain monitoring to complement vasospasm therapy.

Distant white-matter diffusion changes caused by tumor growth.

OBJECTIVES: Various reports have suggested that the involvement of normal-looking white matter with tumors is not limited to just signal abnormalities detectable on conventional imaging. Thus, the purpose of this study was to investigate the distant effects of glioblastomas and metastases on white matter using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Data for 21 patients harboring a glioblastoma (n=12) or a metastasis (n=9) located at a distance of smaller or equal to 10mm from a DTI-based reconstruction of the pyramidal tract were analyzed, using regions of interest (ROIs) placed along the pyramidal tracts in the cerebral peduncle distant (>15 mm) from the tumor. RESULTS: For the whole study population, fractional anisotropy (FA) was significantly lower on the side ipsilateral to the tumor (P<0.001), a difference that was also observed in the glioblastoma and metastasis subgroups. The trace value was significantly higher on the ipsilateral side in the whole population and metastasis subgroup, but not in the glioblastoma subgroup. The decrease in FA and the trace value increase were significant in a subgroup of patients with motor deficits, but not in those without such deficits. CONCLUSION: Hemispheric glioblastomas and metastases located close to the pyramidal tract induce diffusion changes in the tract that are observable at a distance of greater than 15 mm from the tumor border in the absence of T2 signal changes. These changes are different in glioblastomas and metastases, and mechanisms other than Wallerian degeneration may be contributing to the observed changes.

Quantitative MR imaging and spectroscopy of brain tumours: a step forward?

OBJECTIVES: A prospective quantitative MR study of brain tumours was performed to show the potential of combining different MR techniques to distinguish various disease processes in routine clinical practice. METHODS: Twenty-three patients with various intracranial tumours before treatment (diagnosis confirmed by a biopsy) and 59 healthy subjects were examined on a 3-T system by conventional MR imaging, 1H spectroscopic imaging, diffusion tensor imaging and T2 relaxometry. Metabolic concentrations and their ratios, T2 relaxation times and mean diffusivities were calculated and correlated on a pixel-by-pixel basis and compared to control data. RESULTS: Different tumour types and different localisations revealed specific patterns of correlations between metabolic concentrations and mean diffusivity or T2 relaxation times. The patterns distinguish given tissue states in the examined area: healthy tissue, tissue infiltrated by tumour, active tumour, oedema infiltrated by tumour, oedema, etc. This method is able to describe the complexity of a highly heterogeneous tissue in the tumour and its vicinity, and determines crucial parameters for tissue differentiation. CONCLUSIONS: A combination of different MR parameters on a pixel-by-pixel basis in individual patients enables better identification of the tumour type, direction of proliferation and assessment of the tumour extension. KEY POINTS : • Magnetic resonance offers many different methods of examining the brain. • A combination of quantitative MR parameters helps distinguish different brain lesions • Different tumour types revealed specific correlation patterns amongst different MR parameters • The correlation patterns reflect highly heterogeneous complex tissue within tumours.

Anatomy of the supraventricular portion of the pyramidal tract.

BACKGROUND: The anatomy and somatotopy of the pyramidal tract during its course in the internal capsule has recently been discussed by many publications. However, the reports on the anatomy of the clinically more important supraventricular portion of the tract are scarce. The objective of this study is to investigate the anatomy and somatotopy of the supraventricular portion of the pyramidal tract. METHODS: In 13 patients undergoing surgery with subcortical electric stimulation for tumors located in the supraventricular white matter close to the pyramidal tract (as depicted by diffusion tensor tracking [DTT]), the relationship between the position of the stimulation point and the motor response in the arm or leg was analyzed. Additionally, the somatotopic organization of the tract was studied using separate tracking of arm and leg fibers in 20 healthy hemispheres. Finally, the course of the tract was studied by dissecting 15 previously frozen human hemispheres. RESULTS: In most cases, subcortical stimulation during the resection of tumors located behind and in front of the pyramidal tract elicited leg and arm movement, respectively. This association of stimulation point position with motor response type was significant. A DTT study of the somatotopy demonstrated a varying degree of rotation of the leg and arm fibers from mediolateral to posteroanterior configuration. Anatomic dissections demonstrated a folding-fan like structure of the pyramidal tract with a similar rotation pattern. CONCLUSION: The pyramidal tract undergoes a large part of its rotation from mediolateral to posteroanterior configuration during its course in the supraventricular white matter, although interindividual differences exist.

Case report: Combined acute revascularization in early bilateral carotid stent occlusion.

Introduction: The introduction of a carotid stent involves the use of effective antiplatelet therapy to maintain stent patency. We present a case report of combined acute revascularization in a patient with occlusion in recently introduced stents of both carotid arteries. Methods: The patient (male, 73 years) was admitted for stroke recurrence upon discontinuation of antiplatelet therapy. According to the CTA, the closure of implanted stents of both carotid arteries was confirmed. Intravenous thrombolysis and mechanical thrombectomy were performed with complete recanalization of the left carotid stent. At 3 days apart, clinical deterioration was found with progressive stent restenosis. Percutaneous transluminal stent angioplasty, mechanical embolectomy and prolonged low-dose intravenous thrombolysis have been used repeatedly. Results: With the impossibility of maintaining the patency of carotid stents even on the maximum drug therapy and despite endovascular procedures, bilateral neurosurgical revascularization of the middle cerebral arteries using ECIC bypasses was successfully performed. Prolonged low-dose intravenous thrombolysis (20 mg recombinant plasminogen aktivator (rTPA)/10 h) has proven to be an acute bridging therapy until surgery. Conclusion: Early occlusion of the carotid stent is a significant complication of endovascular treatment of stenotic arteries. ECIC bypass revascularization of the middle cerebral artery can be a highly effective therapeutic procedure.

Next generation sequencing of glioblastoma circulating tumor cells: non-invasive solution for disease monitoring.

Treatment of aggressive glioblastoma multiforme (GBM) must be based on very precise histological and molecular diagnostic of GBM type. According to the WHO guidelines, only tissue biopsy is a relevant source of cellular material evaluated in the diagnostic process to specify the tumor features. Nevertheless, obtaining a GBM biopsy is complicated and relies mostly on resection surgery. Evaluating circulating free DNA and/or circulating tumor cells (CTCs) in the clinic, using a liquid biopsy could represent a non-invasive cancer care optimization. In the present study, the peripheral blood of patients undergoing GBM resection (n = 18) was collected and examined for CTCs. The feasibility of GBM molecular diagnostics from a simple non-invasive peripheral blood withdrawal was evaluated. The size-based enriched CTCs were analyzed using cytomorphology and their origin confirmed based on mutational analysis. In addition, shared DNA mutations in CTCs and in primary tumor tissue were searched. For the identification of CTCs, next generation sequencing (NGS) was used. The GeneReader™ sequencing platform enables targeted sequencing of a 12-gene panel and direct evaluation of detected gene variations using QIAGEN Clinical Insight Analyze (QCI-A) software with a special algorithm for liquid biopsy sequencing analysis. Herein, we present a standard operating procedure for CTC enrichment in GBM patients, CTC in vitro culture, CTC cytomorphological evaluation, and NGS analysis of CTCs using the QIAGEN Actionable Insights Tumor (ATP) Panel. CTCs were present in all tested patients (18/18). The NGS data generated for formalin-fixed paraffin-embedded (FFPE) primary tumor tissues and CTCs reached significantly high-quality parameters. The comparisons between different sample types (CTCs vs. primary tumors) and sampling area (different primary tumor regions) showed a significant level of concordance, indicating CTC testing could be used for patient monitoring and recurrence awareness. Notably, more mutations were detected when analyzing CTC samples compared with the paired primary tumors (n = 3). The results confirm the feasibility of using CTCs as a source of tumor DNA in a diagnostic process, especially when evaluating the molecular characteristics of GBMs. A major advantage of the presented NGS approach for detecting CTCs is the simultaneous identification of several markers relevant for GBM diagnostics, allowing molecular diagnostics on cytological specimens and potential administration of innovative targeted therapies.

Identification of the large descending tracts using diffusion tensor imaging in Chiari III malformation.

INTRODUCTION: The paper focuses on the use of diffusion tensor imaging (DTI) in the evaluation of one case of Chiari III malformation. CASE REPORT: In the case discussed, DTI was used to delineate the position of large descending tracts within the malformation and the reconstructed images were used to plan the surgical procedure. DISCUSSION: The clinical and imaging findings, the technical aspects of the DTI fiber tract reconstruction and the outcome are summarized.

The Iatrogenic Development of an Anterior Cerebral Artery Pseudoaneurysm during Lamina Terminalis Fenestration-Genesis, Diagnosis and Therapy: Lessons Learned.

Intracranial pseudoaneurysms (PSA) are scarcely presented in the literature. We describe the case of an intracranial PSA on the right anterior cerebral artery, which developed during the complicated surgical treatment of a ruptured right middle cerebral aneurysm. The pseudoaneurysm grew over time and was co-incidentally diagnosed 3 months after the original surgery. The PSA was successfully treated by coiling. In cases of vascular injuries during complicated brain surgery, the timely and careful radiological diagnosis of such a lesion is necessary to allow its fast and proper treatment and thus prevent the patient from potential risks.

Bypass Procedure Performed in the Field of a Decompressive Craniectomy in the Case of an MCA Dissecting Aneurysm: Case Report and Review of the Literature.

Treatment of complex aneurysms often requires additional surgical tools including the use of the extra-intracranial (EC-IC) bypass. The following report depicts the utilization of the EC-IC bypass in treating a dissecting aneurysm several hours after a salvage emergent evacuation of an acute subdural hematoma via decompressive craniectomy (DC). Preserving the superficial temporal artery during the DC provided a donor artery for the bypass surgery.

Validity of primary motor area localization with fMRI versus electric cortical stimulation: a comparative study.

BACKGROUND: Functional magnetic resonance imaging (fMRI) is a widely used method for research and visualization of the brain function. However, its clinical use is still limited. Our objective was to study fMRI reliability in localizing the primary hand motor cortex (M1) under pathological conditions caused by the proximity of a brain tumour. The results were then compared with standard technique of cortical function mapping-electric cortical stimulation (ECS). METHOD: We compared M1 areas localized with the fMRI and ECS in 18 patients with brain tumours in fronto-parietal regions. The 1.5 T blood oxygenation-level dependent (BOLD) fMRI was performed preoperatively using a motor task involving rhythmic touching of the thumb consecutively with other fingers on the same hand contralateral to the affected hemisphere. Each individual fMRI result was displayed at the P < 0.05 significance level corrected for family wise error (more conservative approach) or at the P < 0.001 level uncorrected (less conservative approach) and projected on the T1-weighted image used for neuronavigation. FINDINGS: In 12 patients (66.6%) we found full agreement between the fMRI and ECS. In 3 patients (16.6%) the overlap was only partial, with one ECS testing position on motor response found outside the BOLD signal cluster. In another 3 cases (16.6%) there was a discrepancy between the two methods. The fMRI sensitivity for localizing the ECS reactive M1 cortex was 71%. The fMRI/ECS consistency was within a 5-mm range in 77% of the testing positions used for ECS which complies with the inherent accuracy of the navigation system. CONCLUSIONS: Because the overlap between the two methods never exceeded 10-mm, we found that the fMRI method correctly guided the ECS to the M1 cortex in 83% of patients. Infiltrative growth of the tumour and collateral oedema were the reasons for the BOLD signal suppression in three patients. Our results support using ECS as a more reliable tool for M1 cortical mapping than fMRI.

Cerebrospinal Fluid Rhinorrhea due to Transethmoidal Encephalocele Following Occipital Meningioma Resection in an Adult: A Case Report.

Transethmoidal encephalocele is a rare condition in adult patients. It is usually diagnosed during childhood by cerebrospinal fluid (CSF) rhinorrhea, meningitis, a nasal mass, or seizures. We present a case of an adult woman with CSF rhinorrhea following resection of an occipital meningioma. The cribriform plate defect containing the encephalocele was diagnosed by computed tomography and magnetic resonance imaging. Transcranial surgery using a patch was performed successfully. We also discuss the possible pathophysiologic mechanisms of encephalocele and treatment options.

A selective carotid artery shunting for carotid endarterectomy: prospective MR DWI monitoring of embolization in a group of 754 patients.

BACKGROUND: Intraoperative use of the intraluminal shunt may reduce the risk of a stroke by reducing cerebral blood flow compromise, but it may also increase the risk of atherosclerotic arterial wall damage with subsequent stroke during carotid endarterectomy (CEA). There is still no evidence to support routine or selective shunting. MATERIAL AND METHODS: A total of 754 CEAs were performed in a prospective study from 2005 to 2011 at our department. All procedures were done under regional anesthesia with selective carotid artery shunting according to neurologic status after internal carotid artery clamping. Magnetic resonance (MR) evaluation of brain parenchyma using diffusion-weighed imaging (DWI) sequence was performed upon hospital admission and 24 hours after the surgical procedure. Acute new MR DWI lesions were evaluated according to the classification published by Szabo et al. A routine neurologic evaluation was recorded as well. RESULTS: The intraluminal shunt was used in 46 of 754 patients (6.1%). A new ischemic lesion was detected in 45 patients (6%). Most of these lesions were neurologically asymptomatic (80%). A new lesion on MR DWI in the subgroup of shunted patients was detected in 15 cases (32.6%) and in the subgroup of nonshunted patients in 30 cases (4.2%). Most of these lesions were due to embolization or hypoperfusion during shunt insertion. CONCLUSION: Use of the intraluminal shunt was the most important risk factor for the new MR DWI lesion in the entire group of CEAs. Results support the strategy of a selective use of intraluminal shunts.

The effect of a gadolinium-based contrast agent on diffusion tensor imaging.

OBJECTIVE: The aim of this study was to investigate in detail the effect of gadolinium contrast on diffusion tensor imaging scans. As the present literature offers conflicting results, we have included a large selection of indices in the analysis. MATERIALS AND METHODS: Sixteen patients harboring an intra-axial contrast enhancing brain tumor were included in this study. Two diffusion tensor imaging scans were performed-one natively, and the second following a gadolinium contrast agent application. Maps of the invariant indices fractional anisotropy (FA), linear, planar, and spherical indices, trace, eigenvalues λ(1), λ(2), λ(3) as well as of the components of the diffusion tensor matrix Dxx, Dyy, Dzz, Dxy, Dxz and Dyz were co-registered and compared statistically with matching ROI pairs in the contrast enhancing areas, peritumoral edema and the normal appearing white matter. RESULTS: We have observed a significant increase in the FA and disproportional decrease of the eigenvalues in the post-contrast scans. In accordance with these findings, the spherical index was decreased and the linear and planar indices were increased. There was a significant decrease of all diagonal components of the diffusion tensor matrix. These changes have been strongest in the contrast enhancing areas, but there were also significant changes in the peritumoral edema and the normal appearing white matter. CONCLUSION: Diffusion tensor imaging scans performed after gadolinium contrast agent administration may display artificially increased FA values due to disproportional changes of the measured eigenvalues. The distortion of the diffusion measurement is strongest in, but not limited to the contrasting areas.

The use of diffusion tensor images of the corticospinal tract in intrinsic brain tumor surgery: a comparison with direct subcortical stimulation.

BACKGROUND: Diffusion tensor imaging (DTI) is now widely used in neurosurgery to preoperatively delineate the course of the pyramidal tract. OBJECTIVE: To evaluate the accuracy of the method by comparison with subcortical electrical stimulation and to evaluate the influence of the distance of the pyramidal tract from the tumor on the resection extent and postoperative clinical deficits. METHODS: A diffusion tensor imaging depiction of the pyramidal tract was used in preoperative planning and intraoperative navigation in 72 cases. In 36 cases, subcortical electrical stimulation was used during the resection. The preoperative tumor-to-tract distance was compared with the stimulation result, the extent of resection, and the short-term postoperative course. RESULTS: A significant nonlinear relationship between the tract-to-tumor distance and the probability of a motor response to subcortical stimulation was observed. The largest preoperatively measured tumor-to-tract distance with a positive stimulation result was 8 mm. Moreover, we observed a trend toward transient postoperative motor deterioration in patients with tumors close to the pyramidal tract. Resection extent was not significantly affected by the tumor-to-tract distance. CONCLUSION: Despite methodological obstacles, reasonable accuracy of the diffusion tensor imaging reconstructions of the pyramidal tracts was confirmed by our study. The occurrence of transient postoperative motor deterioration is higher in patients with tumors located close to the pyramidal tract.