Predictors of outcome after endovascular treatment for tandem occlusions: a single center retrospective analysis.

BACKGROUND: The endovascular treatment procedure in tandem occlusions (TO) is complex compared to single occlusion (SO) and optimal management remains uncertain. The aim of this study was to identify clinical and procedural factors that may be associated to efficacy and safety in the management of TO and compare functional outcome in TO and SO stroke patients. METHODS: This is a retrospective single center study of medium (MeVO) and large vessel occlusion (LVO) of the anterior circulation. Clinical, imaging, and interventional data were analyzed to identify predictive factors for symptomatic intracranial hemorrhage (sICH) and functional outcome after endovascular treatment (EVT) in TO. Functional outcome in TO and SO patients was compared. RESULTS: Of 662 anterior circulation stroke patients with MeVO and LVO stroke, 90 (14%) had TO. Stenting was performed in 73 (81%) of TO patients. Stent thromboses occurred in 8 (11%) patients. Successful reperfusion with modified thrombolysis in cerebral infarction (mTICI) ≥ 2b was achieved in 82 (91%). SICH occurred in seven (8%). The strongest predictors for sICH were diabetes mellitus and number of stent retriever passes. Good functional clinical outcome (mRS ≤ 2) at 90-day follow up was similar in TO and SO patients (58% vs 59% respectively). General anesthesia (GA) was associated with good functional outcome whereas hemorrhage in the infarcted tissue, lower mTICI score and history of smoking were associated with poor outcome. CONCLUSIONS: The risk of sICH was increased in patients with diabetes mellitus and those with extra stent-retriever attempts. Functional clinical outcomes in patients with TO were comparable to patients with SO.

Endovascular versus surgical treatment of cranial dural arteriovenous fistulas: a single-center 8-year experience.

BACKGROUND: Cranial dural arteriovenous fistulas (dAVFs) are rare lesions managed mainly with endovascular treatment (EVT) and/or surgery. We hypothesize that there may be subtypes of dAVFs responding better to a specific treatment modality in terms of successful obliteration and cessation of symptoms and/or risks. METHODS: All dAVFs treated during 2011-2018 at our hospital were analyzed retrospectively. Presenting symptoms, radiological variables, treatment modality, complications, and residual symptoms were related to dAVF type using the original Djindjian classification. RESULTS: We treated 112 dAVFs in 107 patients (71, 66% males). They presented with hemorrhage (n = 23; 21%), non-hemorrhagic symptoms (n = 75; 70%), or were discovered incidentally (n = 9; 8%). There were 25 (22%) type I, 29 (26%) type II, 26 (23%) type III, and 32 (29%) type IV fistulas. EVT was the primary treatment modality in 72/112 (64%) dAVFs whereas 40/112 (36%) underwent primary surgery with angiographic obliteration rates of 60% and 90%, respectively. Using a secondary treatment modality in 23 dAVFs, we obtained a final obliteration rate of 93%, including all type III/IV and 26/27 (96%) type II dAVFs. Except for headache, residual symptoms were rare and minor. Permanent neurological complications consisted of five cranial nerve deficits. CONCLUSIONS: We recommend EVT as first treatment modality in types I, II, and in non-hemorrhagic type III/IV dAVFs. We recommend surgery as first treatment choice in acute hemorrhagic dAVFs and as secondary choice in type III/IV dAVFs not successfully occluded by EVT. Combining the two modalities provides obliteration in 9/10 dAVF cases at a low procedural risk.

Mechanical thrombectomy in acute ischaemic stroke. / Mekanisk trombektomi ved akutt hjerneinfarkt.

Mechanical thrombectomy is now the standard treatment for acute ischaemic stroke with occlusion of a carotid or intercranial artery. With occlusions of this type, thrombolytic treatment often has limited effect. The therapeutic outcome with the use of thrombectomy is time-dependent, and a personalised approach to indication is always necessary. To achieve the best possible results, the main prerequisites are good clinical procedures, an optimal patient pathway, high neuroradiological competence and coordinated, interdisciplinary teams.

Direct visual targeting versus preset coordinates for ANT-DBS in epilepsy.

OBJECTIVES: Deep brain stimulation (DBS) of the anterior thalamic nucleus (ANT) may be used against refractory focal epilepsy, but only two randomized double-blinded trials have been performed. The Oslo study was discontinued prematurely since reduction in seizure frequency was less than expected. The aim of the present study was to review the targeting used in the Oslo study and to identify the actual positions of the contacts used for stimulation. MATERIAL AND METHODS: BrainLab MRI data were available from 12 Oslo study patients. Based on MRI the coordinates of the center of the ANT were identified. The coordinates were considered as the visually identified preferred target and were compared with the target originally used for ANT electrode implantation and with the actual electrode positions estimated from post-operative CT scans. RESULTS: We found considerable differences between the visually identified preferred target, the originally planned target, and the actual electrode position. The total distance between the active electrode position and the visually identified preferred target was on average 3.3 mm on the right and 2.9 mm on the left side. CONCLUSION: Indirect targeting based on preset coordinates may contribute to explain the modest effect of ANT-DBS on seizure frequency seen in the Oslo study. Observed differences between the center of the ANT and the actual electrode position may at least in part be explained by variations in position and size of the ANT. Direct identification of the target using better MRI imaging protocols is recommended for future ANT-DBS surgery.

Clinical outcome after thrombectomy in patients with MeVO stroke: importance of clinical and technical factors.

BACKGROUND AND AIMS: Whereas high-level evidence has been proven for safety and efficacy of endovascular treatment (EVT) in large vessel occlusion (LVO) stroke, the evidence for EVT in medium vessel occlusion (MeVO) in both sexes and different age groupremains to be answered. The aim of this study was to evaluate the importance of clinical and technical parameters, focusing on sex, age and EVT procedural factors, on functional outcome in primary MeVO (pMeVO) strokes. METHODS: 144 patients with pMeVO in the MCA territory from the Oslo Acute Reperfusion Stroke Study (OSCAR) were included. Clinical and radiological data were collected including 90-day mRS follow-up. RESULTS: Successful reperfusion with modified thrombolysis in cerebral infarction (mTICI) ≥ 2b was achieved in 123 patients (84%). Good functional outcome (mRS ≤ 2) at 90-day follow-up was achieved in 84 patients (61.8%). Two or more passes with stent retriever was associated with increased risk of SAH, poor mTICI and poor functional outcome. In average, women had 62 min longer ictus to recanalization time compared to men. Age over 80 years was significantly associated with poor outcome and death. CONCLUSION: In pMeVO patients, TICI score and number of passes with stent retriever were the main technical factors predicting mRS ≤ 2. Good clinical outcome occurred almost twice as often in patients under 80 years of age compared to patients over 80 years. Women with MeVO strokes had significant longer time from ictus to recanalization; however, this did not affect the clinical outcome.

Intensity of pituitary adenoma on T2-weighted magnetic resonance imaging predicts the response to octreotide treatment in newly diagnosed acromegaly.

BACKGROUND: Primary, preoperative medical treatment is an option in selected patients with acromegaly, but a subset of patients respond poorly. Valid prediction of response to somatostatin analogues (SA) might thus alter treatment stratification. The aims of this study were to assess whether T2 signal intensity could determine long-term response to first-line SA treatment and to assess clinical and biochemical baseline characteristics, as well as histological subtype in relation to the magnetic resonance imaging (MRI) appearances. METHODS: In 45 newly diagnosed patients, T2-weighted signal intensity of the tumour was classified into hypo-, iso- or hyperintense. Biochemical and clinical baseline variables for the three groups were compared. In 25 patients primarily treated with long-acting SA for a median of 6 months [interquartile range (IQR):155-180 days], GH and IGF-1 reduction was assessed, and in 34 cases, immunohistochemical granulation pattern was evaluated. RESULTS: The results showed that 12 (27%) adenomas were hypointense, 15 (33%) isointense and 18 (40%) hyperintense. Median IGF-1 [ratio IGF-1/ULN; (upper limit of normal)] was 3·5 (2·3-4·9), 2·9 (2·6-3·8) and 1·9 (1·3-2·6), respectively (P = 0·006 for difference between groups). Median GH values (µg/l) of a 3- to 5-point profile were 17·5 (6·1-35), 9·3 (6·0-32·5) and 4·1 (1·5-8·3), (P = 0·025). Median IGF-1 reduction (% of baseline) after first-line SA treatment was 51 (49-70), 36 (19-74) and 13 (5-42) (P = 0·03); median reduction in GH (% of baseline) was 86 (72-94), 78 (62-85) and 46 (1-70) (P = 0·02). T2 hyperintensity was associated with sparse granulation pattern on immunohistochemistry. CONCLUSION: In patients with acromegaly, T2 signal intensity at diagnosis correlates with histological features and predicts biochemical outcome of first-line SA treatment.

Early surgical versus endovascular repair of ruptured blood-blister aneurysm of the internal carotid artery: a single-center 20-year experience.

OBJECTIVE: Early repair of ruptured blood-blister aneurysms (BBAs) of the internal carotid artery (ICA) remains challenging. Although both surgical and endovascular therapies have been established, their relative superiority remains debated. The authors assessed their single-center experience and compared early deconstructive versus reconstructive repair and early reconstructive surgical versus endovascular repair of ruptured BBAs of the ICA. METHODS: The study included patients who underwent repair of ruptured BBAs of the ICA within 1 week after the ictus during a 20-year period. Multiple variables were recorded, including clinical state, severity of subarachnoid hemorrhage (SAH), characteristics of the BBA, treatment details, complication profile, need for secondary treatment, and clinical outcome. RESULTS: In total, 27 patients underwent early surgical (n = 16) or endovascular (n = 11) repair of BBAs at a median of 24 hours (range 9-120 hours) after the ictus during the period from September 2000 to June 2021 (20.4 years). Primary deconstructive repair (n = 6) without bypass was accompanied by middle cerebral artery (MCA) territory infarction in 5 of 6 (83%) patients and a high mortality rate (4/6 [67%]). Among the 21 patients who underwent early reconstructive repair, surgery was performed in 11 patients (clipping in 6 and clip-wrapping in 5 patients) and endovascular repair in 10 patients (flow diversion in 7 and stent/stent-assisted coiling in 3 patients). No differences were found in complication profiles or clinical outcomes between the surgical and endovascular groups. The mortality rate was low (2/21 [9.5%]), with 1 fatality in each group. CONCLUSIONS: From the authors' experience, both surgical and endovascular approaches permitted reconstructive repair of ruptured BBAs of the ICA, with no modality proving superior. Reconstructive treatment is preferable to ICA sacrifice, and if sacrifice is chosen, it should be accompanied with bypass surgery or delayed to the phase when cerebral vasospasm has resumed. The rare occurrence of this disease calls for prospective multicenter studies to improve treatment and delineate which modality is preferable in individual cases.

Multiparametric analysis of magnetic resonance images for glioma grading and patient survival time prediction.

BACKGROUND: A systematic comparison of magnetic resonance imaging (MRI) options for glioma diagnosis is lacking. PURPOSE: To investigate multiple MR-derived image features with respect to diagnostic accuracy in tumor grading and survival prediction in glioma patients. MATERIAL AND METHODS: T1 pre- and post-contrast, T2 and dynamic susceptibility contrast scans of 74 glioma patients with histologically confirmed grade were acquired. For each patient, a set of statistical features was obtained from the parametric maps derived from the original images, in a region-of-interest encompassing the tumor volume. A forward stepwise selection procedure was used to find the best combinations of features for grade prediction with a cross-validated logistic model and survival time prediction with a cox proportional-hazards regression. RESULTS: Presence/absence of enhancement paired with kurtosis of the FM (first moment of the first-pass curve) was the feature combination that best predicted tumor grade (grade II vs. grade III-IV; median AUC = 0.96), with the main contribution being due to the first of the features. A lower predictive value (median AUC = 0.82) was obtained when grade IV tumors were excluded. Presence/absence of enhancement alone was the best predictor for survival time, and the regression was significant (P < 0.0001). CONCLUSION: Presence/absence of enhancement, reflecting transendothelial leakage, was the feature with highest predictive value for grade and survival time in glioma patients.

Glioma grading by using histogram analysis of blood volume heterogeneity from MR-derived cerebral blood volume maps.

PURPOSE: To retrospectively compare the diagnostic accuracy of an alternative method used to grade gliomas that is based on histogram analysis of normalized cerebral blood volume (CBV) values from the entire tumor volume (obtained with the histogram method) with that of the hot-spot method, with histologic analysis as the reference standard. MATERIALS AND METHODS: The medical ethics committee approved this study, and all patients provided informed consent. Fifty-three patients (24 female, 29 male; mean age, 48 years; age range, 14-76 years) with histologically confirmed gliomas were examined with dynamic contrast material-enhanced 1.5-T magnetic resonance (MR) imaging. CBV maps were created and normalized to unaffected white matter (normalized CBV maps). Four neuroradiologists independently measured the distribution of whole-tumor normalized CBVs and analyzed this distribution by classifying the values into area-normalized bins. Glioma grading was performed by assessing the normalized peak height of the histogram distributions. Logistic regression analysis and interobserver agreement were used to compare the proposed method with a hot-spot method in which only the maximum normalized CBV was used. RESULTS: For the histogram method, diagnostic accuracy was independent of the observer. Interobserver agreement was almost perfect for the histogram method (kappa = 0.923) and moderate for the hot-spot method (kappa = 0.559). For all observers, sensitivity was higher with the histogram method (90%) than with the hot-spot method (55%-76%). CONCLUSION: Glioma grading based on histogram analysis of normalized CBV heterogeneity is an alternative to the established hot-spot method, as it offers increased diagnostic accuracy and interobserver agreement.

Predictive modeling in glioma grading from MR perfusion images using support vector machines.

The advantages of predictive modeling in glioma grading from MR perfusion images have not yet been explored. The aim of the current study was to implement a predictive model based on support vector machines (SVM) for glioma grading using tumor blood volume histogram signatures derived from MR perfusion images and to assess the diagnostic accuracy of the model and the sensitivity to sample size. A total of 86 patients with histologically-confirmed gliomas were imaged using dynamic susceptibility contrast (DSC) MRI at 1.5T. Histogram signatures from 53 of the 86 patients were analyzed independently by four neuroradiologists and used as a basis for the predictive SVM model. The resulting SVM model was tested on the remaining 33 patients and analyzed by a fifth neuroradiologist. At optimal SVM parameters, the true positive rate (TPR) and true negative rate (TNR) of the SVM model on the 33 patients was 0.76 and 0.82, respectively. The interobserver agreement and the TPR increased significantly when the SVM model was based on an increasing sample size (P < 0.001). This result suggests that a predictive SVM model can aid in the diagnosis of glioma grade from MR perfusion images and that the model improves with increasing sample size.

Interpretation of Brain CT Scans in the Field by Critical Care Physicians in a Mobile Stroke Unit.

BACKGROUND AND PURPOSE: In acute stroke, thromboembolism or spontaneous hemorrhage abruptly reduces blood flow to a part of the brain. To limit necrosis, rapid radiological identification of the pathological mechanism must be conducted to allow the initiation of targeted treatment. The aim of the Norwegian Acute Stroke Prehospital Project is to determine if anesthesiologists, trained in prehospital critical care, may accurately assess cerebral computed tomography (CT) scans in a mobile stroke unit (MSU). METHODS: In this pilot study, 13 anesthesiologists assessed unselected acute stroke patients with a cerebral CT scan in an MSU. The scans were simultaneously available by teleradiology at the receiving hospital and the on-call radiologist. CT scan interpretation was focused on the radiological diagnosis of acute stroke and contraindications for thrombolysis. The aim of this study was to find inter-rater agreement between the pre- and in-hospital radiological assessments. A neuroradiologist evaluated all CT scans retrospectively. Statistical analysis of inter-rater agreement was analyzed with Cohen's kappa. RESULTS: Fifty-one cerebral CT scans from the MSU were included. Inter-rater agreement between prehospital anesthesiologists and the in-hospital on-call radiologists was excellent in finding radiological selection for thrombolysis (kappa .87). Prehospital CT scans were conducted in median 10 minutes (7 and 14 minutes) in the MSU, and median 39 minutes (31 and 48 minutes) before arrival at the receiving hospital. CONCLUSION: This pilot study shows that anesthesiologists trained in prehospital critical care may effectively assess cerebral CT scans in an MSU, and determine if there are radiological contraindications for thrombolysis.

Cerebral foreign body reaction after carotid aneurysm stenting.

Flow diverter stents are new important tools in the treatment of large, giant, or wide-necked aneurysms. Their delivery and positioning may be difficult due to vessel tortuosity. Common adverse events include intracranial hemorrhage and ischemic stroke, which usually occurs within the same day, or the next few days after the procedure. We present a case where we encountered an unusual intracerebral complication several months after endovascular treatment of a large left internal carotid artery aneurysm, and where brain biopsy revealed foreign body reaction to hydrophilic polymer fragments distally to the stent site. Although previously described, embolization of polymer material from intravascular equipment is rare. We could not identify any other biopsy verified case in the literature, with this particular presentation of intracerebral polymer embolization--a multifocal inflammation spread out through the white matter of one hemisphere without hemorrhage or ischemic changes.

Automatic glioma characterization from dynamic susceptibility contrast imaging: brain tumor segmentation using knowledge-based fuzzy clustering.

PURPOSE: To assess whether glioma volumes from knowledge-based fuzzy c-means (FCM) clustering of multiple MR image classes can provide similar diagnostic efficacy values as manually defined tumor volumes when characterizing gliomas from dynamic susceptibility contrast (DSC) imaging. MATERIALS AND METHODS: Fifty patients with newly diagnosed gliomas were imaged using DSC MR imaging at 1.5 Tesla. To compare our results with manual tumor definitions, glioma volumes were also defined independently by four neuroradiologists. Using a histogram analysis method, diagnostic efficacy values for glioma grade and expected patient survival were assessed. RESULTS: The areas under the receiver operator characteristics curves were similar when using manual and automated tumor volumes to grade gliomas (P = 0.576-0.970). When identifying a high-risk patient group (expected survival <2 years) and a low-risk patient group (expected survival >2 years), a higher log-rank value from Kaplan-Meier survival analysis was observed when using automatic tumor volumes (14.403; P < 0.001) compared with the manual volumes (10.650-12.761; P = 0.001-0.002). CONCLUSION: Our results suggest that knowledge-based FCM clustering of multiple MR image classes provides a completely automatic, user-independent approach to selecting the target region for presurgical glioma characterization.

Clinical and psychosocial follow-up study of children treated with extracorporeal membrane oxygenation.

BACKGROUND: Serious heart and pulmonary failure may be treated with extracorporeal membrane oxygenation (ECMO). The aim of this follow-up study was a multimodal assessment of outcome in children surviving ECMO at our hospital from 1991 to 2004. METHODS: Twenty-two children were, on average, 1.18 years old (SD = 1.92; range, 0.1 to 7.8) when ECMO was initiated. Average age at follow-up was 7.2 years (range, 1.8 to 13.9). Thirteen children were treated for cardiac and nine for pulmonary failure. Venoarterial ECMO was performed in 21 patients and venovenous ECMO in one patient. The protocol included a review of patients records, clinical, neurologic and neuropsychologic, and radiological examinations, electroencephalogram, and interviews with the parents. RESULTS: Moderate or severe impairment in at least two clinical assessments were found in 16 (72.7%) children. Five (22.7%) children had cerebral palsy and 15 (68.2%) had moderate or severe cognitive impairment. Eight (36%) children had pathological radiologic findings. Pathological electroencephalograms were found in 11 (50%) patients including four (18.2%) with epileptic activity. Children with radiologic findings had a slightly worse cognitive outcome. There was no association between the neurophysiologic findings and the neuropsychologic performance or the radiologic findings. Based on parental assessment, only four children had pathological scores. CONCLUSIONS: All children, except for two, came walking to the follow-up visit. All parents were positive to the ECMO treatment, and reported a good or slightly reduced quality of life for their child. Cerebral sequelae were frequently found in children treated with ECMO. The need for treatment and support should be assessed in order to optimize their physical and psychosocial functioning.

Cerebral outcome in adult patients treated with extracorporeal membrane oxygenation.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) carries a high risk of brain injury. The aim of this study was to determine the cerebral status in 28 adult survivors on average 5.0 (range, 0.5 to 12) years after ECMO treatment for severe cardiorespiratory failure. METHODS: All 28 patients were investigated at our institution. A comprehensive assessment protocol included a medical history, physical examination, neuropsychological assessment, electroencephalography, and neuroradiologic assessment. RESULTS: All patients were ambulant unaided, and 43% were without any clinical findings. Impaired neuropsychological performance was found in 41%, neuroradiologic findings in 52%, and a pathologic electroencephalogram in 41% of the patients. There was a significant correlation between the cognitive outcome and neuroradiologic findings. The incidence of neuroradiologic findings (cerebral infarction, microemboli or hemorrhage) was significantly higher in the venoarterial group compared with the venovenous group (75% versus 17%). There was no correlation between the type of ECMO and neuropsychological impairment. Electroencephalography findings did not correlate with neuropsychological performance, nor with the neuroradiologic findings. CONCLUSIONS: Late cerebral sequelae were frequently seen in patients treated on venoarterial ECMO. A significant correlation was found between cognitive impairment and neuroradiologic findings.

MR angiography in the follow-up of coiled cerebral aneurysms after treatment with Guglielmi detachable coils.

PURPOSE: Intra-arterial digital subtraction angiography (DSA) has been considered the gold standard examination in the follow-up of patients treated with Guglielmi detachable coils (GDCs). However, DSA is an invasive and expensive investigation and results in exposure to ionising radiation to both patient and operator. The aim of this study was to compare MR angiography (MRA) with DSA with regard to patency of the occlusion of aneurysms following GDC treatment. MATERIAL AND METHODS: We performed 75 MRA and DSA examinations on 51 patients treated with GDCs. The examinations were performed 3-36 months after embolisation and the interval between MRA and DSA was less than 1 week. Hard copies of both studies were interpreted retrospectively and independently for residual flow within the aneurysm, residual aneurysmal neck, and parent and branch vessel flow. RESULTS: Patency status of parent and branch vessel flow was correctly identified with MRA in all patients except 1. The sensitivity of MRA in revealing residual flow within the aneurysm was 97%. The specificity in ruling out residual flow within the aneurysm was 91%. CONCLUSION: MRA may replace DSA in the long-term follow-up of coiled cerebral aneurysms. The initial follow-up examination should, however, include both modalities.

Selective posterior cerebral artery amobarbital test: its role in presurgical memory assessment in temporal lobe epilepsy.

PURPOSE: To evaluate the efficacy and risk of complications of selective posterior cerebral artery (PCA) amobarbital anesthesia in memory assessment of patients with epilepsy under consideration for temporal lobe resection. METHODS: Thirty-two candidates for temporal lobectomy in whom conclusive memory assessment could not be obtained by the standard intracarotid amobarbital procedure were submitted to a selective PCA amobarbital test. A mean dose of 75 mg amobarbital was injected via microcatheter into the P2 segment of the PCA. Ten common objects were presented for naming and remembering while the anesthesia was judged efficient. After return to neurologic baseline, recall and recognition memory were assessed. RESULTS: In all of the 32 patients, angiography and PCA anesthesia were successfully accomplished without serious adverse events. All but one of the patients remained alert and cooperative for memory testing under the anesthesia, and 28 of these patients showed adequate memory capacity of the hemisphere contralateral to the side targeted for surgery. So far, 19 patients have proceeded to surgery, and no case of global amnesia or serious, material-specific memory impairment has resulted. Three patients failed the PCA test (fewer than 67% items correctly recognized) and were excluded from surgery, partly on the basis of the PCA test results, but also supported by an overall evaluation of all the diagnostic procedures used. CONCLUSIONS: The selective PCA amobarbital test appears justifiable when performed by interventional neuroradiologists and may significantly reduce the risk of erroneously excluding patients with epilepsy from temporal resection. Further corroboration of the safety of the procedure seems warranted.