The importance of multimodal CT examination in stroke mimics diagnosis: design of prospective observational multicentre study.

Introduction: Non-contrast computed tomography (CT) and CT angiography are the gold standard in neuroimaging diagnostics in the case of suspected stroke. CT perfusion (CTP) may play an important role in the diagnosis of stroke mimics (SM), but currently, it is not a standard part of the stroke diagnostic procedure. The project is a multicentre prospective observational clinical research focused on refining the diagnostics of stroke and stroke mimics (SM) in hospital care. Aim: This study aimed to evaluate the degree of specificity and sensitivity of multimodal CT (NCCT, CTA, and CTP) in the diagnosis of SM versus stroke. Methodology: In this study, we will include 3,000 patients consecutively admitted to the comprehensive stroke centres with a diagnosis of suspected stroke. On the basis of clinical parameters and the results of multimodal CT and magnetic resonance imaging (MRI), the diagnosis of stroke and SM will be established. To clarify the significance of the use of the multimodal CT scan, the analysis will include a comparison of the blinded results for each imaging scan performed by radiologists and AI technology and a comparison of the initial and final diagnosis of the enrolled patients. Based on our results, we will compare the economic indicators and costs that would be saved by not providing inadequate treatment to patients with SM. Conclusion: The expected outcome is to present an optimised diagnostic procedure that results in a faster and more accurate diagnosis, thereby eliminating the risk of inadequate treatment in patients with SM. Clinical trial registration: clinicaltrials.gov, NCT06045455.

Emergent microsurgical intervention for acute stroke after mechanical thrombectomy failure: a prospective study.

BACKGROUND: Despite all the gains that have been achieved with endovascular mechanical thrombectomy revascularization and intravenous thrombolysis logistics since 2015, there is still a subgroup of patients with salvageable brain tissue for whom persistent emergent large vessel occlusion portends a catastrophic outcome. OBJECTIVE: To test the safety and efficacy of emergent microsurgical intervention in patients with acute ischemic stroke and symptomatic middle cerebral artery occlusion after failure of mechanical thrombectomy. METHODS: A prospective two-center cohort study was conducted. Patients with acute ischemic stroke and middle cerebral artery occlusion for whom recanalization failed at center 1 were randomly allocated to the microsurgical intervention group (MSIG) or control group 1 (CG1). All similar patients at center 2 were included in the control group 2 (CG2) with no surgical intervention. Microsurgical embolectomy and/or extracranial-intracranial bypass was performed in all MSIG patients at center 1. RESULTS: A total of 47 patients were enrolled in the study: 22 at center 1 (12 allocated to the MSIG and 10 to the CG1) and 25 patients at center 2 (CG2). MSIG group patients showed a better clinical outcome on day 90 after the stroke, where a modified Rankin Scale score of 0-2 was reached in 7 (58.3%) of 12 patients compared with 1/10 (10.0%) patients in the CG1 and 3/12 (12.0%) in the CG2. CONCLUSIONS: This study demonstrated the potential for existing microsurgical techniques to provide good outcomes in 58% of microsurgically treated patients as a third-tier option.

Ultrashort Door-to-Needle Time for Intravenous Thrombolysis Is Safer and Improves Outcome in the Czech Republic: Nationwide Study 2004 to 2019.

Background The benefit of intravenous thrombolysis is time dependent. It remains unclear, however, whether dramatic shortening of door-to-needle time (DNT) among different types of hospitals nationwide does not compromise safety and still improves outcome. Methods and Results Multifaceted intervention to shorten DNT was introduced at a national level, and prospectively collected data from a registry between 2004 and 2019 were analyzed. Generalized estimating equation was used to identify the association between DNT and outcomes independently from prespecified baseline variables. The primary outcome was modified Rankin score 0 to 1 at 3 months, and secondary outcomes were parenchymal hemorrhage/intracerebral hemorrhage (ICH), any ICH, and death. Of 31 316 patients treated with intravenous thrombolysis alone, 18 861 (60%) had available data: age 70±13 years, National Institutes of Health Stroke Scale at baseline (median, 8; interquartile range, 5-14), and 45% men. DNT groups 0 to 20 minutes, 21 to 40 minutes, 41 to 60 minutes, and >60 minutes had 3536 (19%), 5333 (28%), 4856 (26%), and 5136 (27%) patients. National median DNT dropped from 74 minutes in 2004 to 22 minutes in 2019. Shorter DNT had proportional benefit: it increased the odds of achieving modified Rankin score 0 to 1 and decreased the odds of parenchymal hemorrhage/ICH, any ICH, and mortality. Patients with DNT ≤20 minutes, 21 to 40 minutes, and 41 to 60 minutes as compared with DNT >60 minutes had adjusted odds ratios for modified Rankin score 0 to 1 of the following: 1.30 (95% CI, 1.12-1.51), 1.33 (95% CI, 1.15-1.54), and 1.15 (95% CI, 1.02-1.29), and for parenchymal hemorrhage/ICH: 0.57 (95% CI, 0.45-0.71), 0.76 (95% CI, 0.61-0.94), 0.83 (95% CI, 0.70-0.99), respectively. Conclusions Ultrashort initiation of thrombolysis is feasible, improves outcome, and makes treatments safer because of fewer intracerebral hemorrhages. Stroke management should be optimized to initiate thrombolysis as soon as possible optimally within 20 minutes from arrival to a hospital.

Intraoperative neurophysiological monitoring during urgent surgical extracranial internal carotid artery recanalization.

OBJECTIVE: The clinical outcome of surgical extracranial internal carotid artery (eICA) recanalization may be adversely affected by intraoperative ischemia. Median nerve somatosensory evoked potential (SEP) amplitude correlates well with cerebral blood flow. Our study presents the value of intraoperative SEP and selective shunting in the prevention of intraoperative ischemia development during urgent eICA recanalization. METHODS: Prospective recruitment of patients with acute unilateral eICA occlusion. All underwent surgical recanalization with intraoperative monitoring of scalp median SEPs. Preoperative clinical findings, cerebral collaterals, and 3 month functional outcome were evaluated. RESULTS: The cohort consisted of 33 patients. Intraoperative SEP amplitude decreased significantly in 6 (18.2%). An intraluminal shunt was inserted twice (6.1%), surgical complications occurred in 6 (18.2%), intracerebral hemorrhage was not found. Favorable outcome 3 months after surgery according to the modified Rankin scale (mRS 0-2) was achieved in 28 (84.8%), 3 patients died (9.1%). CONCLUSIONS: Intraoperative SEP during urgent eICA recanalization seems to be beneficial. Thanks to the effective measure based on the intraoperative SEP changes, the clinical outcome in four(12.1%) could be positively affected. SIGNIFICANCE: The results suggest that selective shunting based on intraoperative median SEPs may prevent intraoperative ischemia and may improve overall outcome of urgent eICA recanalization.

Between-Center Variation in Outcome After Endovascular Treatment of Acute Stroke: Analysis of Two Nationwide Registries.

BACKGROUND: Insight in differences in patient outcomes between endovascular thrombectomy (EVT) centers can help to improve stroke care. We assessed between-center variation in functional outcome of patients with acute ischemic stroke who were treated with EVT. We analyzed to what extent this variation may be explained by modifiable center characteristics. METHODS: We used nationwide registry data of patients with stroke treated with EVT in the Netherlands and in the Czech Republic. Primary outcome was modified Rankin Scale score at 90 days as an indicator of disability. We used multilevel ordinal logistic regression to quantify the between-center variation in outcomes and the impact of patient and center characteristics. Between-center variation was expressed as the relative difference in odds of a more favorable modified Rankin Scale score between a relatively better performing center (75th percentile) and a relatively worse performing center (25th percentile). RESULTS: We included a total of 4518 patients treated in 33 centers. Adjusted for patient characteristics, the odds of a more favorable outcome in a center at the 75th percentile of the outcome distribution were 1.46 times higher (95% CI, 1.31-1.70) than the odds in a center at the 25th percentile. Adjustment for center characteristics, including the median time between stroke onset and reperfusion per center, decreased this relative difference in odds to 1.30 (95% CI, 1.18-1.50, P=0.01). This translates into an absolute difference in likelihood of good functional outcome of 8% after adjustment for patient characteristics and to 5% after further adjustment for modifiable center characteristics. CONCLUSIONS: The considerable between-center variation in patient outcomes after EVT for acute ischemic stroke could be largely explained by center-specific characteristics, such as time to reperfusion. Improvement of these parameters may likely result in a decrease in center-specific differences, and an overall improvement in outcome of patients with acute ischemic stroke.

Stroke 20 20: Implementation goals for intravenous thrombolysis.

INTRODUCTION: Knowledge of the implementation gap would facilitate the use of intravenous thrombolysis in stroke, which is still low in many countries. The study was conducted to identify national implementation targets for the utilisation and logistics of intravenous thrombolysis. MATERIAL AND METHOD: Multicomponent interventions by stakeholders in health care to optimise prehospital and hospital management with the goal of fast and accessible intravenous thrombolysis for every candidate. Implementation results were documented from prospectively collected cases in all 45 stroke centres nationally. The thrombolytic rate was calculated from the total number of all ischemic strokes in the population of the Czech Republic since 2004. RESULTS: Thrombolytic rates of 1.3 (95%CI 1.1 to 1.4), 5.4 (95%CI 5.1 to 5.7), 13.6 (95%CI 13.1 to 14.0), 23.3 (95%CI 22.8 to 23.9), and 23.5% (95%CI 23.0 to 24.1%) were achieved in 2005, 2009, 2014, 2017, and 2018, respectively. National median door-to-needle times were 60-70 minutes before 2012 and then decreased progressively every year to 25 minutes (IQR 17 to 36) in 2018. In 2018, 33% of both university and non-university hospitals achieved median door-to-needle time ≤20 minutes. In 2018, door-to-needle times ≤20, ≤45, and ≤60 minutes were achieved in 39, 85, and 93% of patients. DISCUSSION: Thrombolysis can be provided to ≥ 20% of all ischemic strokes nationwide and it is realistic to achieve median door-to-needle time 20 minutes. CONCLUSION: Stroke 20-20 could serve as national implementation target for intravenous thrombolysis and country specific implementation policies should be applied to achieve such target.

Changes in Cognition and Hemodynamics 1 Year after Carotid Endarterectomy for Asymptomatic Stenosis.

OBJECTIVES: The impact of a change in hemodynamics on cognitive skills in patients with asymptomatic carotid stenosis (ACS) after carotid endarterectomy (CEA) remains unclear. The aim of this study was to evaluate the results of CEA for ACS at 1 year by assessing the changes in anterior, middle, and posterior cerebral artery blood flow in tandem with changes in cognitive efficiency. METHODS: Flow volume in cerebral arteries using quantitative magnetic resonance angiography was measured in a group of 14 males and 5 females before and at 1 year after CEA for ACS. Cognitive efficiency was assessed by Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The values of flow volume were processed using simple ratio (SR) and were used for covariance analyses with changes in cognitive skills after CEA. RESULTS: A significant improvement in cognitive efficiency indexes of immediate memory and visuospatial perception at 1 year after CEA for ACS was observed. Simultaneously, a significant deterioration of speech index was noted. During the analysis of association between flow and cognition, the highest correlation could be seen between the middle cerebral artery (MCA) flow and the visuospatial perception. A change in posterior cerebral artery (PCA) flow was associated with an increase in immediate memory index and anterior cerebral artery (ACA) flow change with the speech index. CONCLUSION: Convergence of data supporting the association between revascularization and cognitive improvement were added in a small, single-center cohort of ACS patients undergoing CEA. No significant differences in cognition were seen between preoperative findings and at 1 year after CEA. Visuospatial perception improvement was linked to flow change in MCA, immediate memory improvement to flow change in PCA, and speech index change to flow change in ACA. Methodical limitations of this small study preclude formulating larger generalizations. Hemodynamic factors in CEA should be assessed in a larger-scale study.

Median somatosensory evoked potential as a predictor of clinical outcome after urgent surgical extracranial internal carotid artery recanalization.

OBJECTIVE: Changes in the N20/P25 amplitude of somatosensory evoked potentials (SEP) of the median nerve have been found to correlate with those in cortical regional cerebral blood flow (rCBF). Our study presents the use of median nerve SEP amplitude in predicting the clinical outcome of urgent surgical internal carotid artery (ICA) recanalization. METHODS: A total of 27 patients suffering an acute ischemic stroke (AIS) with extracranial ICA occlusion within 24 h were prospectively recruited. The primary preoperative endpoints included the SEP amplitude absolute value (SEP-amp) and the SEP amplitude side-to-side ratio (SEP-ratio). Clinical outcome at 3 months postoperatively was assessed using the modified Rankin scale (mRS-3M). RESULTS: The positive predictive values (PPVs) for SEP-amp and SEP-ratio were 95.5% and 100%, respectively, with the negative predictive values (NPVs) being 60.0% and 100%, respectively. The SEP-ratio correlated fully with mRS-3M. CONCLUSION: The median SEP side-to-side N20/P25 amplitude ratio seems to be a very strong positive and negative predictor of the clinical outcome of urgent recanalization of an extracranial ICA occlusion. SIGNIFICANCE: The results suggest that cortical evoked activity may help in selection patient for surgical recanalization and predict clinical recovery after an acute ischemic stroke.

Blood Flow Volume Measurement in Cervical and Intracranial Arteries using Quantitative Magnetic Resonance Angiography and Duplex Sonography (Bocaccia) - A Prospective Observational Study.

PURPOSE: Cerebral blood flow volume is an important factor for the accurate diagnosis of neurovascular diseases and treatment indication. This study aims to assess correlations of blood flow volume measurements in cervical and intracranial arteries between duplex sonography and quantitative magnetic resonance angiography (qMRA). MATERIALS AND METHODS: Consecutive patients with suspicion of cerebral vascular pathology underwent qMRA and duplex sonography of cervical and intracranial arteries with measurement of blood flow volume in bilateral common (CCA), internal (ICA) and external carotid arteries, vertebral and basilar arteries, middle, anterior, posterior cerebral and posterior communicating arteries using 2 different ultrasound machines. Ten patients underwent all examinations twice. Correlations between blood flow volume measurements were evaluated using Spearman's correlation coefficient and inter-class correlation coefficient (ICC). RESULTS: In total, 21 subjects (15 males, mean age: 56.3 ± 6.2 years) were included in the study. Duplex sonography inter-investigator correlation was excellent (ICC = 0.972, p < 0.0001) as well as intra-investigator correlations of both qMRA and duplex sonography (ICC ˃ 0.990, p < 0.0001). Mostly high correlations were recorded between qMRA and duplex sonography in particular cervical arteries but only low to moderate correlations were obtained for intracranial arteries. The mean differences between blood flow volume measurements were 10.9 ±â€Š8.1 % in the CCA and its branches when using qMRA and 15.0 ±â€Š11.9 % when using duplex sonography, 13.5 ±â€Š11.8 %/35.4 ±â€Š34.2 % in the ICA siphon and its branches when using qMRA/duplex sonography, and 24.1 ±â€Š19.7 %/44.9 ± 44.0 % in both vertebral arteries and the basilar artery when using qMRA/duplex sonography. CONCLUSION: Duplex sonography as well as qMRA allow for highly reproducible measurement of blood flow volume in cervical and intracranial arteries in routine clinical practice.

Urgent Middle Cerebral Artery Embolectomy of Calcified Embolus After Intravenous Thrombolysis: 2-Dimensional Operative Video.

This video shows an urgent microsurgical embolectomy of the inferior division of the left middle cerebral artery in a patient treated by intravenous thrombolysis (IVT). Patient was eligible for endovascular mechanical thrombectomy1; however, the interventional radiologist was not comfortable performing the procedure given prior unsuccessful attempts to remove a calcified cerebral embolus.2 A 75-yr-old female presented with an acute ischemic stroke with isolated aphasia (NIHSS 9). Using the drip-and-ship concept, IVT (0.9 mg/kg rt-PA) was administered in a regional hospital. Fifty-five minutes after a complete recovery following IVT, multiple transient ischemic attacks of aphasia were observed. While the patient was a candidate for mechanical thrombectomy based on CT perfusion imaging, given the unsuccessful reports in the literature and the interventional radiologist's experience, the decision was made to offer microsurgical embolectomy of the calcified cerebral embolus.3 Informed consent for the procedure was obtained directly from the patient. Calcified, crumbly embolus was removed from a 5 mm longitudinal arteriotomy. The arteriotomy was sutured with interrupted 10-0 suture. Initial flow after the embolectomy was 6.5 mL/min. Upon inspection, a distal kink was found in the M2 and after repositioning, flow improved to 35 mL/min. Postoperative CT angiography documented complete recanalization. The clinical findings completely resolved (NIHSS 0) within 12 hr and remained unchanged at 3 mo and 1 yr. Informed consent was obtained from the patient for use of media for educational and publication purposes.

Mechanical Thrombectomy for Acute Ischemic Stroke in Czech Republic: Technical Results from the Year 2016.

BACKGROUND AND PURPOSE: Experienced multidisciplinary stroke team and well-organized hospital management are considered necessary to achieve good results after mechanical thrombectomy (MT) in acute ischemic stroke patients. We analyzed the technical results of MT performed in the Czech Republic in the year 2016 to provide relevant data for further quality improvement. MATERIAL AND METHODS: All centers performing MT in the CR were called for detailed technical and clinical data from year 2016, which were anonymously analyzed and relevant technical key time intervals were compared. Clinical outcomes were assessed according to the HERMES meta-analysis. RESULTS: In the 2016, 1053 MTs were performed in the CR. Of 15 dedicated centers, the data from 12 centers and from 886 (84%) patients (49.2% males, mean age 69.8 ± 12.3 years) were analyzed. The overall median of time from hospital arrival to groin puncture (GP) was 77 min with a range from 40 to 109 min among individual hospitals, from GP to first passage of stent retriever 20 (15-40) min and from GP to maximal reached recanalization 42 (33-80) min. The median of recanalization time was 240 (219-320) min. The recanalization (TICI 2b-3) was achieved in 81.7% of patients, 44.1% of patients had a good 3-month clinical outcome and 6.3% suffered from symptomatic intracerebral hemorrhage. Peri-procedural complications were recorded in 89 (10%) patients. CONCLUSION: Despite achieved good overall results, a great variability in some of the analyzed key time intervals among individual centers performing MT warrants further quality improvement.

Intravenous Thrombolysis in Patients with Acute Ischemic Stroke after a Reversal of Dabigatran Anticoagulation with Idarucizumab: A Real-World Clinical Experience.

BACKGROUND: Intravenous thrombolysis (IVT) is contraindicated in patients with acute ischemic stroke (AIS) using oral anticoagulants. A specific human monoclonal antibody was introduced to reverse immediately the anticoagulation effect of the direct inhibitor of thrombin, dabigatran. Until now, mostly individual cases presenting with successful IVT after a reversal of dabigatran anticoagulation in patients with AIS were published. Thus, we aimed to report real-world data from clinical practice. METHODS: Patients with AIS on dabigatran treated with IVT after antidote reversal were enrolled in the retrospective nationwide study. Neurological deficit was scored using the National Institutes of Health Stroke Scale (NIHSS) and 90-day clinical outcome using modified Rankin scale (mRS) with a score 0-2 for a good outcome. Intracerebral hemorrhage (ICH) was defined as a presence of any sign of bleeding on control imaging after IVT, and symptomatic intracerebral hemorrhage (SICH) was assessed according to the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) criteria. RESULTS: In total, 13 patients (7 men, mean age 70.0 ± 9.1 years) with a median NIHSS admission score of 7 points were analyzed. Of these patients, 61.5% used 2 × 150 mg of dabigatran daily. Antidote was administrated 427 ± 235 minutes after the last intake of dabigatran, with a mean activated prothrombin time of 38.1 ± 27.8 seconds and a mean thrombin time of 72.2 ± 56.1 seconds. Of the 13 patients, 2 had ICH and 1 had SICH, and no other bleeding complications were observed after IVT. Of the total number of patients, 76.9% had a good 3-month clinical outcome and 3 patients (23.1%) died. Recurrent ischemic stroke occurred in 2 patients (15.4%). CONCLUSION: The data presented in the study support the safety and efficacy of IVT after the reversal of the anticoagulation effect of dabigatran with antidote in a real-world clinical practice.

Cognitive impairment in cerebellar lesions: a logit model based on neuropsychological testing.

BACKGROUND: Damage to the cerebellum may lead to motor dysfunctions, but also to the neuropsychological deficits that comprise the Cerebellar Cognitive Affective Syndrome (CCAS). It can affect executive functions, attention, memory, visuospatial functions, language, and emotions. Our goal was to determine which neuropsychological tests could be effectively used to identify this syndrome during a short examination. METHODS: Twenty-five patients with an isolated cerebellar lesion and 25 matched healthy controls were examined using an extensive neuropsychological battery. RESULTS: Logistic regression models and sub-models were computed for individual tests, as well as for the full battery. The best results were produced by a model combining patient education level, the number of errors on the California Verbal Learning Test, and time on Prague Stroop Test (Dots). CONCLUSIONS: Based on the results, we suggest that a condensed battery of neuropsychological tests can be used to detect CCAS. The tests are easy to administer and could be helpful in both research and clinical settings.

Detection of carotid artery stenosis using histological specimens: a comparison of CT angiography, magnetic resonance angiography, digital subtraction angiography and Doppler ultrasonography.

BACKGROUND: Carotid endarterectomy (CEA) is accepted as a primary modality to treat carotid stenosis. The accuracy of measuring carotid stenosis is important for indication of the CEA procedure. Different diagnostic tools have been developed and used in the past 2 decades for the diagnosis of carotid stenosis. Only a few studies, however, have focused on the comparison of different diagnostic tools to histological findings of carotid plaque. METHOD: Patients with internal carotid artery (ICA) stenosis were investigated primarily by computed tomography angiography (CTA). Digital subtraction angiography (DSA), Doppler ultrasonography (DUS) and magnetic resonance angiography (MRA) were performed as well. Atherosclerotic plaque specimens were transversally cut into smaller segments and histologically processed. The slides were scanned and specimens showing maximal stenosis were determined; the minimal diameter and the diameter of the whole plaque were measured. High quality histological specimen and histological measurement was considered to be the prerequisite for inclusion into the analysis. The preoperative findings were compared with histological measurement. CTA and histological measurements were obtained from 152 patients. DSA measurements were available in 138 of these cases, MRA in 107 and DUS in 88. A comparison between preoperative and histological findings was performed. In addition, correlation coefficients were computed and tested. RESULTS: A significant correlation was found for each of the diagnostic procedures. The strongest correlation coefficient and the best allocation of stenosis into clinical significant groups (<50 %, 50-69 %, ≥70 %) was observed for CTA. Mean differences in the whole cohort between preoperative and histological measurements were as follows: CTA underestimated histological measurement by 2.4 % (based on European Carotid Surgery Trial [ECST] methodology) and 11.9 % (based on North American Symptomatic Carotid Endarterectomy Trial [NASCET] methodology). DSA underestimated the histological measurement by 7 % (ECST) and 12.2 % (NASCET). MRA overestimated the histological measurement by 2.6 % (ECST) and underestimated by 0.6 % (NASCET). DUS overestimated the stenosis by 1.8 %. CONCLUSIONS: CTA yields the best accuracy in detection of carotid stenosis, provided that all axial slices of the stenosis are checked and carefully analysed. DSA underestimates moderate and mild ICA stenosis, whereas DUS overestimates high-grade ICA stenosis. For MRA, a relatively low correlation coefficient was observed with histological findings. We conclude that CTA-ecst technique is the most reliable technique for carotid stenosis measurement.

Is intraoperative diffusion tensor imaging at 3.0T comparable to subcortical corticospinal tract mapping?

BACKGROUND: Primary brain tumors in motor eloquent areas are associated with high-risk surgical procedures because of potentially permanent and often disabling motor deficits. Intraoperative primary motor cortex mapping and corticospinal tract (CST) monitoring are well-developed and reliable techniques. Imaging of the CST by diffusion tensor tractography (DTT) is also feasible. OBJECTIVE: To evaluate the practical value of 3.0T intraoperative MRI (iMRI) with intraoperative DTT (iDTT) in surgery close to the CST, and to compare high-field iDTT with intraoperative neurophysiological CST mapping during glioma and metastasis resection in a routine setting. METHODS: Twenty-five patients (13 males, 12 females, median 47 years) were enrolled prospectively from June 2010 to June 2012. Patients were included if they had a solitary supratentorial intracerebral lesion compressing or infiltrating the CST according to preoperative MRI. Subcortical CST mapping was performed by monopolar (cathodal) stimulation (500 Hz, 400 µs, 5 pulses). CST DTT was made both at preoperative and intraoperative 3.0T MRI. Subcortical motor-evoked potential threshold current and probe-CST distance were recorded at 155 points before and at 103 points after iMRI. Current-distance correlations were performed both for pre-iMRI and for post-iMRI data. RESULTS: The correlation coefficient pre-iMRI was R = 0.470 (P < .001); post-iMRI, the correlation coefficient was R = 0.338 (P < .001). MRI radical resection was achieved in 17 patients (68%), subtotal in 5 (24%), and partial in 3 (12%). Postoperative paresis developed in 8 patients (32%); the paresis was permanent in 1 case (4%). CONCLUSION: The linear current-distance correlation was found both in pre-iMRI and in post-iMRI data. Intraoperative image distortion appeared in 36%. Neurophysiological subcortical mapping remains superior to DTT. Combining these 2 methods in selected cases can help increase the safety of tumor resection close to the CST.

Rolandic area meningioma resection controlled and guided by intraoperative cortical mapping.

BACKGROUND: The resection of convexity meningiomas should harbour a low rate of morbidity. Functional preservation should be the main goal of surgery and have higher priority over radicality. Involvement of the primary motor cortex (PMC) increases surgical risk. The goal of this study was to evaluate the effect of cortical mapping on surgical morbidity after rolandic area meningioma treatment. METHODS: From January 2005 to March 2011, 42 patients were operated on for rolandic meningioma involving or compressing the PMC. The cohort consisted of 25 (59.5%) convexity, 10 (23.8%) parasagittal and 7 (16.7%) falcine meningiomas. Four patients were treated for recurrent disease and 25 (59.5%). Intraoperative cortical mapping was used to identify location of PMC. The threshold stimulation current was set at every site of cortical monopolar anodal stimulation around the tumour and at the tumour-cortex junction repeatedly during the meningioma dissection. RESULTS: Radical resection (Simpson 1 and 2) was achieved in 30 patients (71.4%) and partial resection (Simpson 4) in 12 (28.6%). New permanent deficit occurred in three patients (7.1%). All patients had moderate preoperative deficit (muscle strength ≤ 3). WHO-I was in 28 cases (66.7%), WHO-II in 14 cases (33.3%). Average follow-up was 33.2 months. Five patients (11.9%) suffered from recurrence after an average of 23.8 months. CONCLUSIONS: Rolandic area meningiomas should be classified as a higher risk group. Intraoperative cortical mapping is in our experience useful in a situation when the cleavage plane at the PMC is lost. In such a scenario, resection outside the PMC is radical and only at the PMC is a thin remnant left without cortical damage, which helps to be safer with a better long-term prognosis.

Intraoperative MR imaging in a case of a cervical spinal cord lesion.

The aim of this article is to describe the feasibility of performing intraoperative MR imaging in patients with spinal cord lesions and the potential value of this technique. The authors report a case involving a 28-year-old man who presented with chronic cervical pain and pain along the ulnar side of the forearms during neck flexion. Findings on clinical examination were normal, but MR imaging revealed a multicystic cervical spinal cord lesion. Surgery was undertaken to open the cysts, evacuate old blood, and search for pathological tissue. Intraoperative MR imaging showed that the caudal cyst was not opened, and surgery was therefore continued. The caudal cyst was fenestrated and a suspected small cavernous malformation was removed. Electrophysiological monitoring was performed both before and after the intraoperative MR imaging. The use of intraoperative MR imaging changed the strategy of the procedure and helped the surgeon to safely enter all the cysts in the cervical cord.

Multifunctional surgical suite (MFSS) with 3.0 T iMRI: 17 months of experience.

The 3T ioMRI in Prague is composed of two independent suites: the operating theatre and the 3T MR suite, both of which can and do work independently. They are connected by a double door and a special transportation system. The whole operating table is moved on rails to and from the MR gantry. Anaesthesiological equipment is built from paramagnetic material, which is also moved to and from the MR suite. The integral parts of the multifunctional surgical suite (MFSS) are the neuronavigation system, electrophysiological monitoring, surgical microscope with availability of indocyanin green angiography and fluorescence-guided glioma resection technique and endoscopy equipment. The operating theatre is equipped in a normal fashion with the exception of a head holder that is paramagnetic. MR radiologist and MR assistants are alerted approximately 30 min before the requested intraoperative and out-patient service is interrupted to clean the MR suite. The ioMRI takes 15-20 min and immediately after the door closes the out patient activity is resumed. Intraoperative MR was performed in 332 surgeries in the first 17 months of operation. The most frequent indications were pituitary adenomas, followed by gliomas. Other indications were less frequent and included meningiomas, cavernomas, aneurysms, epilepsy surgery, intramedullary lesions, non-pituitary sellar lesions, metastases and various other surgeries. In 332 cases no technical or medical complication connected with ioMRI was encountered.

Magnetic resonance angiography, digital subtraction angiography and Doppler ultrasonography in detection of carotid artery stenosis: a comparison with findings from histological specimens.

BACKGROUND: Patients' life expectancy, clinical symptomatology and the extent of carotid stenosis are the most important factors when deciding whether to perform carotid endarterectomy (CEA) in patients with carotid stenosis. Therefore, the accuracy of measuring carotid stenosis is of utmost importance. METHODS: Patients with internal carotid artery (ICA) stenosis were investigated by digital subtraction angiography (DSA), Doppler ultrasonography (DUS) and magnetic resonance angiography (MRA). Atherosclerotic plaque specimens were transversally cut into smaller segments and histologically processed. The slides were scanned and specimens showing maximal stenosis were determined; the minimal diameter and the diameter of the whole plaque were measured. DSA, DUS and MRA measurements were obtained in 103 patients. A comparison between preoperative and histological findings was performed. In addition, correlation coefficients were computed and tested. RESULTS: Results show a significant correlation for each of the diagnostic procedures. Mean differences in the whole cohort between preoperative measurements and the histological measurements are as follows: angiographic measurement of carotid stenosis underestimated histological measurement by 14.5% and MRA by 0.7%, but DUS overestimated by 6.6%. The results in severe stenosis (> or =70%) are as follows: angiographic measurement underestimated the histological measurements by 2.3%, but MRA overestimated by 12.1% and DUS by 11.3%. The results in moderate stenosis (50-69%): angiographic measurement underestimated the histological measurements by 12.3%, but MRA overestimated by 0.2% and DUS by 7.2%. The results in mild stenosis (30-49%): angiographic measurement underestimated the histological measurements by 24.7% and MRA by 7.6%, but DUS overestimated by 3.3%. CONCLUSIONS: Our study confirms that DSA underestimates moderate and mild ICA stenosis. DUS slightly overestimated moderate ICA stenosis and highly overestimated high-grade ICA stenosis. MRA proved to be accurate in detecting moderate ICA stenosis, but slightly underestimated mild stenosis and overestimated high-grade stenosis. The surgeon should be aware of these discrepancies when deciding whether to perform CEA in patients with ICA stenosis.