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Electrical source imaging is used in presurgical epilepsy evaluation and in cognitive neurosciences to localize neuronal sources of brain potentials recorded on EEG. This study evaluates the spatial accuracy of electrical source imaging for known sources, using electrical stimulation potentials recorded on simultaneous stereo-EEG and 37-electrode scalp EEG, and identifies factors determining the localization error. In 11 patients undergoing simultaneous stereo-EEG and 37-electrode scalp EEG recordings, sequential series of 99–110 biphasic pulses (2 ms pulse width) were applied by bipolar electrical stimulation on adjacent contacts of implanted stereo-EEG electrodes. The scalp EEG correlates of stimulation potentials were recorded with a sampling rate of 30 kHz. Electrical source imaging of averaged stimulation potentials was calculated utilizing a dipole source model of peak stimulation potentials based on individual four-compartment finite element method head models with various skull conductivities (range from 0.0413 to 0.001 S/m). Fitted dipoles with a goodness of fit of ≥80% were included in the analysis. The localization error was calculated using the Euclidean distance between the estimated dipoles and the centre point of adjacent stimulating contacts. A total of 3619 stimulation locations, respectively, dipole localizations, were included in the evaluation. Mean localization errors ranged from 10.3 to 26 mm, depending on source depth and selected skull conductivity. The mean localization error increased with an increase in source depth (r(3617) = [0.19], P = 0.000) and decreased with an increase in skull conductivity (r(3617) = [−0.26], P = 0.000). High skull conductivities (0.0413–0.0118 S/m) yielded significantly lower localization errors for all source depths. For superficial sources (40 mm, high skull conductivities of 0.0413 and 0.0206 S/m yielded significantly lower localization errors. In relation to stimulation locations, the majority of estimated dipoles moved outward-forward-downward to inward-forward-downward with a decrease in source depth and an increase in skull conductivity. Multivariate analysis revealed that an increase in source depth, number of skull holes and white matter volume, while a decrease in skull conductivity independently led to higher localization error. This evaluation of electrical source imaging accuracy using artificial patterns with a high signal-to-noise ratio supports its application in presurgical epilepsy evaluation and cognitive neurosciences. In our artificial potential model, optimizing the selected skull conductivity minimized the localization error. Future studies should examine if this accounts for true neural signals.

ObjectiveTo determine whether a fraction of patients with primary CNS lymphoma (PCNSL) had been cured by systemic and intraventricular methotrexate- and cytarabine-based chemotherapy (Bonn protocol) after a very long-term follow-up of nearly 20 years.MethodsSixty-five patients (median age 62 years, range 27–75; median Karnofsky performance score 70, range 20–90) had been treated with systemic and intraventricular polychemotherapy without whole brain radiotherapy from September 1995 until December 2001. All patients still alive in 2019 were contacted and interviewed on their current life situation.ResultsMedian follow-up for surviving patients was 19.6 years (17.5–23.3 years). Out of 65 patients, 11 (17%) were still alive. Six of those never experienced any relapse. For the whole study population, median overall survival (OS) was 4.4 years (95% confidence interval [CI] 2.9–5.9); for patients ≤60 years, 11.0 years (95% CI 4.8–17.0). The 10-year OS rate for the entire cohort was 29% and the estimated 20-year OS rate was 19%. Four late relapses were observed after 9.8, 10.3, 13.3, and 21.0 years.ConclusionAt a median follow-up of 19.6 years, 17% of patients were alive and free of tumor; however, even after response for decades, an inherent risk of relapse, either systemic or cerebral, characterizes the biology of PCNSL.Classification of evidenceThis work provides Class III evidence that PCNSL treatment with methotrexate-based polychemotherapy including intraventricular therapy is associated with long-term disease control in some patients.

Background To prospectively analyze factors associated with detecting epileptogenic lesions on MRI within the work-sharing process of neurologists, epileptologists, radiologists and neuroradiologists. Methods We assembled four sets of six MRI scans, each set representing five typical epileptogenic lesions (hippocampal sclerosis or limbic encephalitis; focal cortical dysplasias; periventricular nodular or other heterotopias; long-term epilepsy associated tumors; gliotic scar, hemosiderin or cavernoma), and non - lesional epilepsy. At professional conferences, we invited neurologists, epileptologists, radiologists, and neuroradiologists to read two out of four MRI sets, one of which was presented with a clinical focus hypothesis. Participants were randomly assigned to MRI sets. Effects of examiners’ specialty, duration of training and professional experience on detection rate of epileptogenic lesions were investigated. Results Fourty-eight neurologists, 22 epileptologists, 20 radiologists and 21 neuroradiologists read 1323 MRI scans. Overall, 613 of 1101 (55.7%) epileptogenic lesions were detected. Long-term epilepsy associated tumors (182/221, 82.4%) were found more frequently than gliotic scar, hemosiderin or cavernoma (157/220, 71.4%), hippocampal sclerosis or limbic encephalitis (141/220, 64.1%), nodular heterotopia (68/220, 30.9%) and focal cortical dysplasias (65/220, 29.5%, p p = 0.037). Neuroradiologists and epileptologists were more likely than radiologists and neurologists to be amongst the most successful readers. In multivariable analysis, type of epileptogenic lesion, specialty of MRI reader, and provision of focus hypothesis predicted correct identification of epileptogenic lesions. Conclusions Epileptogenic lesions are often not recognized on MRI even by expert readers. Their detection can be improved by providing a focus hypothesis. These results stress the need for training in the MRI characteristics of epilepsy - specific pathology, and, most importantly, interdisciplinary communication between neurologists/epileptologists and (neuro)radiologists to improve detection of epileptogenic lesions.

PurposeTo retrospectively evaluate the safety and efficacy of the endovascular treatment of wide-necked intracranial aneurysms assisted by a novel intra-/extra-aneurysm stent-like implant (pCONus).MethodsInitial and follow-up angiographic and clinical results are presented of 25 patients with 25 unruptured and ruptured wide-necked intracranial aneurysms treated by reconstruction of the aneurysm neck using the pCONus implant followed by coil occlusion of the fundus.ResultsSuccessful intra-/extra-aneurysm deployment of the pCONus with coil occlusion of the fundus was achieved in all but one case. Procedure-related ischemic complications were observed in three cases with permanent deterioration in one. Acceptable aneurysm occlusion was achieved in all cases. Follow-up angiography revealed sufficient occlusion in 81.0% of the aneurysms. Intimal hyperplasia in the stented segment of the parent artery or device migration has not been observed to date.ConclusionsThe pCONus device offers a promising treatment option for complex wide-necked bifurcation intracranial aneurysms. Acute or delayed dislocations of coils into the parent artery are successfully avoided.

BackgroundThe aim of this study was to assess reperfusion and clinical outcome of treatment with the self-expanding retrievable Separator 3D in revascularization of acute ischemic stroke. The three-dimensional (3D) device secures thrombus with direct aspiration and supports debulking of the clot.MethodsAt two centers, 129 consecutive stroke patients with National Institutes of Health Stroke Scale (NIHSS) scores ≥5 were treated with mechanical thrombectomy using the Separator 3D as a component of the Penumbra System within 8 h of symptom onset; modified Treatment in Cerebral Infarction (mTICI) revascularization scores, NIHSS score on admission and discharge, mortality rates, and modified Rankin Scale (mRS) outcomes at 90 days were evaluated.ResultsA total of 129 vessels in 129 patients were treated. Occlusions were located in the middle cerebral artery (MCA, 48%), internal carotid artery (ICA, 33%), cervical ICA–MCA (3%), and vertebrobasilar arteries (16%). Intravenous thrombolytic therapy with recombinant tissue plasminogen activator was given to 78% of patients. Median NIHSS was 15 prior to treatment. Reperfusion to mTICI 2b or 3 was successful in 96/129 (74%) target arterial lesions, with more than half of cases (51%) achieving mTICI 3. The mean time from arterial puncture to revascularization was 65 min. At 90 days, the symptomatic intracranial hemorrhage rate was 4%, all cause mortality was 32%, and 43/99 patients (43%) achieved functional independence with an mRS score of ≤2.ConclusionsThe results suggest that the Separator 3D enables safe and effective revascularization of occluded large arteries in acute stroke intervention, leading to a high rate of functional independence at 90 days.

IntroductionThe direct aspiration first pass technique (ADAPT) has been introduced as a rapid and safe endovascular treatment strategy in patients with ischemic stroke.ObjectiveTo determine the technical feasibility, safety, and functional outcome with ADAPT using the new large-bore 6F SOFIA Plus catheter.MethodsA retrospective analysis of prospectively collected data from six university hospitals was performed. The following parameters of all acute stroke procedures (June 2015– January 2016) using the SOFIA Plus catheter were analyzed: accessibility of the thrombus with the catheter, recanalization success (Thrombolysis in Cerebral Infarction ≥2b), time to recanalization, procedure-related complications. Furthermore, National Institutes of Health Stroke Scale (NIHSS) scores at presentation and discharge and the modified Rankin scale (mRS) score at 90 days were recorded.Results85 patients were treated using the SOFIA Plus catheter. The occlusion site was the anterior circulation in 94.1%. Median baseline NIHSS score was 18. In 64.7%, ADAPT alone was successful after a median procedure time of 21 min. With additional use of stent retrievers in the remaining cases, the recanalization rate was 96.5%. No catheter-related complications such as dissections were observed. Thrombus migration to a new vascular territory occurred in 4.7% and symptomatic hemorrhage in 4.7%. After 3 months, mRS 0–2 was achieved in 49.4%. Mortality rate was 20%.ConclusionsIn the majority of cases, thrombus aspiration using the SOFIA Plus catheter results in successful recanalization after a short procedure time. With additional use of stent retrievers, a high recanalization rate can be achieved (96.5%). The complication rate was in line with those of previous publications.

Reliable detection of leptomeningeal disease has the potential of facilitating the diagnosis of central nervous system (CNS) lymphoma and is important for therapeutic considerations. Currently, the standard diagnostic procedure for the detection of lymphoma in the cerebrospinal fluid is cytopathology. To improve the limited specificity and sensitivity of cytopathology, flow cytometry has been suggested as an alternative. Here, we evaluated multi-parameter flow cytometry in combination with conventional cytopathology in cerebrospinal fluid (CSF) samples from 30 patients with primary CNS lymphoma and seven patients with secondary CNS lymphoma. Overall, in 11 of 37 (29.7%) patients with CNS lymphoma, lymphoma cells were detected in CSF by flow cytometry, while cytopathology was less sensitive displaying unequivocally malignant CSF cells in only seven of all 37 (18.9%) patients. Six (16.2%) patients showed cytopathological results suspicious of lymphoma; however, in only one of these patients, the diagnosis of CSF lymphoma cells could be confirmed by flow cytometry. In primary CNS lymphomas (PCNSL), seven of 30 (23.3%) patients were positive for CSF lymphoma cells in flow cytometry, in contrast to four (13.3%) patients with PCNSL with definitely positive cytopathology. In summary, our results suggest that multi-parameter flow cytometry increases the sensitivity and specificity of leptomeningeal disease detection in CNS lymphomas. Both methods should be applied concurrently for complementary diagnostic assessment in patients with CNS lymphoma.

To assess the association between juxta-facet-joint cysts (JFC) occurrence at the lumbar spine and Facet Joint (FJ) orientation, -tropism and -arthritis.Study group, 36 consecutive patients with JFC and the same number of controls, with degenerative diseases without JFC were match paired for demographics and spine segment. Parameter assessment was by T2-weighted axial MRI scans. JFC diagnosis was confirmed histopathologically. Group comparison was by Student's t-test for continuous variables and X(2) for categorical variables.Nineteen female and 17 male patients, aged between 45 and 85 years (mean 67.19 ± 10.3 years) had a mean JFC size of 9.26 ± 4.8mm occurring most frequently in the segment L4-L5 (75% n=25) and on the left side (61%). Mean FJ orientation of the study group was significantly more coronal compared to controls (left side 42° vs 36°, p0.02*, 95% confidence interval: 0.9-11.5 and right side 43° vs 37°, p0.02*, 95% confidence interval: 0.6-10.6 respectively). However, individual intersegmental analysis for study group patients showed the JFC bearing side to be significantly more sagittally oriented 40° ± 11.2° compared to 45° ± 13.2° for the side without FJC (p0.03*, 95% confidence interval: 8.1-1.7). 50% of the study group showed FJ asymmetry compared to 30% in controls, with a trend for FJ tropism (p0.07). Severe (grade 3) FJ arthritis was significantly more predominant in the study group 23/33 (p0.001*) as compared to controls.Compared to a control group, JFC occurrence is associated with significant higher rates of arthritis and coronally orientated FJ. At intersegment comparison within the same patient cysts located in more sagittally orientated FJ and the asymmetric segments show a trend for FJ tropism.

Aim Several factors influence the outcome after acute ischemic stroke secondary to proximal occlusions of cerebral vessels. Among others, noneligibility for intravenous thrombolysis (IVT) and incomplete revascularization have been identified as predictors of unfavorable outcome. The aim of this study was to investigate whether concomitant IVT influences the revascularization efficacy in mechanical thrombectomy (MT). Methods This study conducted a retrospective analysis of all consecutive patients presenting with an anterior circulation stroke due to large-artery occlusion with imaging evidence who were treated with MT between July 2012 and December 2013 at 2 high-volume stroke centers. Imaging data were regraded and re-evaluated according to the modified Treatment in Cerebral Ischemia scale and its respective vessel occlusion site definitions. Clinical end points included National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale; imaging and procedural measures were technical end points. Results We identified 93 patients who presented with an occlusion of the middle cerebral artery (MCA): of these patients, 66 (71%) received IVT. We did not find statistically significant differences in the baseline NIHSS score, time from symptom onset to groin puncture, and age when comparing the IVT group with the non-IVT group. The rate of successful recanalizations (modified Treatment in Cerebral Ischemia score ≥ 2b) was significantly higher in patients with MCA occlusion and concomitant IVT ( P = .01). Stepwise logistic regression identified IVT and thrombus length as predictive factors for successful mechanical recanalization ( P = .004, P = .002). Conclusion IVT and thrombus length are predictive factors for a successful recanalization in MT for acute ischemic stroke with underlying MCA occlusion.

There is only limited data on the influence of the admission time (normal business hours versus nighttime and weekends) on procedural timings, revascularization efficacy, and outcome after mechanical thrombectomy. We investigated whether the admission time has an impact on the above-mentioned factors.Our neurointerventional database was screened for all mechanical thrombectomies in anterior circulation acute ischemic stroke between 07/13 and 06/14. Outcome measures were procedural timings and clinical and demographic data; we compared patients who were admitted at normal business hours (Monday to Friday 8:00-18:00) to those admitted at night or at the weekend.98 patients were identified. Of them, 52 (53%) were admitted during normal business hours, the remainder at night or at weekend. There was no statistically significant difference between the groups regarding the time from symptom-onset to admission, baseline National Institutes of Health Stroke Scale (NIHSS) or IVT-rate. There was a significant difference between groups for door-to-reperfusion timing, favoring patients admitted during normal business hours (146 versus 165 min, p = 0.02). Door-to-groin-puncture and groin-puncture-to-reperfusion time did not differ significantly. The rate of successful revascularizations (mTICI ≥ 2b) and the rate of favorable clinical outcome at discharge (mRS ≤ 2) did not differ between groups (77% versus 78% and 37% versus 35%, respectively).There was a statistically significant prolongation of door-to-reperfusion timings for patients admitted during nighttime and weekends; it went along neither with a lower rate of successful revascularizations nor with a lower rate of favorable outcome in our series.AFatrial fibrillationAISacute ischemic strokeCTAcomputed tomography angiographyDMdiabetes mellitusENTembolization to new territoryEVTendovascular therapyHLPhyperlipoproteinemiaHTNhypertensionIQRinter-quartile rangeIVTintravenous thrombolysismRSmodified Rankin ScaleMTmechanical thrombectomyNIHSSNational Institutes of Health Stroke Scalen.s.not significantsICHsymptomatic intracranial hemorrhage.

BACKGROUND AND PURPOSE: Several small case series reported a favorable clinical outcome for emergency stent placement in the extracranial internal carotid artery combined with mechanical thrombectomy in acute stroke. The rate of postinterventional symptomatic intracranial hemorrhages was reported to be as high as 20%. Therefore, we investigated the safety and efficacy of this technique in a large multicentric cohort. MATERIALS AND METHODS: The data bases of 4 German stroke centers were screened for all patients who received emergency stent placement of the extracranial internal carotid artery in combination with mechanical thrombectomy of the anterior circulation between 2007 and 2014. The primary outcome measure was the rate of symptomatic intracranial hemorrhage according to the European Cooperative Acute Stroke Study III criteria; secondary outcome measures included the angiographic revascularization results and clinical outcome. RESULTS: One hundred seventy patients with a median age of 64 years (range, 25–88 years) were treated. They presented after a median of 98 minutes (range, 52–160 minutes) with a median NIHSS score of 15 (range, 12–19). Symptomatic intracranial hemorrhages occurred in 15/170 (9%) patients; there was no statistically significant difference among groups pertaining to age, sex, intravenous rtPA, procedural timings, and the rate of successful recanalization. In 130/170 (77%) patients, a TICI score of ≥2b could be achieved. The in-hospital mortality rate was 19%, and 36% of patients had a favorable outcome at follow-up. CONCLUSIONS: Emergency stent placement in the extracranial internal carotid artery in combination with anterior circulation thrombectomy is effective and safe. It is not associated with a significantly higher risk of symptomatic intracranial hemorrhage compared with published series for mechanical thrombectomy alone.

Background and purpose The focus of this study was to determine ease of deployment, safety and effectiveness of the LVIS Jr device. Methods A retrospective analysis was performed of 32 cases comprising 34 aneurysms in which the LVIS Jr device was used for stent-assisted coil embolization of intracranial aneurysms from February to October 2012, including all clinical and angiographic data as well as mid-term follow-up (1–12 months of treatment). Results The median age of the patients was 54 years (range 21–76) and 19 (59%) were women. The aneurysms were ruptured in 12/34 cases (35.3%); 26 (76.4%) were located within the anterior circulation and the remaining 8 (23.5%) were located in the posterior circulation. Eleven of the 34 aneurysms (32.3%) were treated with a Y-stent configuration. Immediate total occlusion was observed in 16/34 (47%), near total occlusion (90–95%) in 5/34 (14.7%) and a ‘dog ear’ or subtotal occlusion in 12/34 (35.2%). A single aneurysm was treated without coil embolization. Complications occurred in 5/34 cases (15%), including two cases of in-stent thrombosis. Conclusions Implantation of the LVIS Jr device as a support device for stent-assisted coil embolization seems to be safe and effective. The LVIS Jr device can also be implanted in a Y-stent configuration, offering a novel technique with a potentially lower risk of thromboembolic complications compared with other devices.

Background Mechanical thrombectomy has been shown to be an effective and safe therapy for patients suffering an acute stroke. However, shortening the time span between onset of symptoms and recanalization has been partly achieved by a technical method known as aspiration thrombectomy. Our aim is to show the effectiveness of a new tool, the ACE 64, in order to further optimize neurological outcome and to minimize complications. Method Between the December 2014 and March 2015 we identified 55 Patients with acute ischemic stroke and occlusion of large cerebral vessels. These were treated with an aspiration thrombectomy using a new large bore aspiration catheter, the Penumbra ACE 64 on an intention to treat basis in multicentre setting (Utrecht, Netherlands; Murcia, Spain; St. Gallen, Switzerland; Bochum, Germany; Recklinghausen, Germany; Odense, Denmark; Homburg, Germany). Results Using the aspiration thrombectomy a Thrombolysis in Cerebral Infarction (TICI) Score of 2b or 3 was achieved in 53 of 55 cases (96,4%). In 17 cases, additional devices were used for the following reasons: Anchoring technique (9), distal vessel too small for ACE64 (5) and two cases were ACE64 could not pass preceding stenosis. In the aspiration thrombectomy only cases, a TICI score of 2b or 3 of 100% was achieved. The average time of groin puncture to revascularization was 32 min. Patients presented with a median National Institutes of Health Stroke Scale (NIHSS) score of 16 (4.0–26.0) and improved to a median NIHSS score of 4.5 (0.0–35.0) at discharge. There was each one case of major groin complication, vasospasm in preceding extracranial vessel, vessel dissection and of symptomatic intracerebral hemorrhage. Discussion Due to the design of this new large bore aspiration catheter, trackability and navigation through the carotid syphon up to M1 / M2 is excellent. This means that approaching the clot in the target vessel is fast and because of the large lumen, aspiration is effective. The complication rate is low. Most importantly, it is an extraordinarily fast method to achieving revascularization. In about 70% of patients, recanalization could be achieved by aspiration thrombectomy alone. As described with the method of aspiration thrombectomy before, there are various reasons for using additional devices. Inabout half of our cases, the stentretriever was used to maneuver the ACE64 to the thrombus. One other reason was the dislodgement of the thrombus to a distal part of the treated vessel or also called a distal embolization in the target downstream territory. In these cases, the aspiration catheter was too large to achieve a thrombectomy and a stent retriever was used. In conclusion, we are able to demonstrate the aspiration thrombectomy using the ACE64 to be an effective, easy to use, fast and safe method for treating acute stroke patients. Disclosures A. Kowoll: None. A. Moreno: None. J. Weber: None. C. Loehr: None. G. Gal: None. H. Korner: None. A. Berlis: None. W. Weber: None. T. Lo: None.

There is only very limited data about complications in mechanical thrombectomy for acute ischemic stroke. The purpose of this study was to evaluate the frequency and the clinical relevance of procedure-related complications in mechanical thrombectomy. We conducted a retrospective analysis of 176 consecutive acute ischemic stroke cases that were treated with mechanical thrombectomy. Primary outcome measures included the following: symptomatic intracranial hemorrhage (sICH), vessel dissection, emboli to new vascular territories, vasospasm, and stent dislocation/occlusion whenever appropriate. Secondary outcome measures included mTICI score, time from symptom onset to revascularization, and time from groin puncture to revascularization as well as the early clinical outcome at discharge. Complications occurred in 20/176 patients (11 %) comprising 23 adverse events at the following rates: sICH 8/176 (5 %), emboli to new vascular territories 4/176 (2 %); vessel dissection 3/176 (2 %); vasospasm of the access vessel 5/176 (3 %); stent dislocation in 1/42 (2 %); and stent occlusion in 2/42 (5 %). Two out of 20 (10 %) suffered from two or more procedure-related complications. There was a statistically significant correlation of complications with time from groin puncture to revascularization, unfavorable revascularization results, and unfavorable clinical outcome. Overall, the frequency of procedure-related complications lies within acceptable limits for an emergency procedure. The endovascular treatment does not seem to add significantly to the stroke patients’ risk of sICH but implies an innate risk of stroke in an initially uninvolved territory. Furthermore, a prolonged endovascular procedure beyond an hour is correlated with higher complication rates, which underlines the importance of a swift and complete revascularization.

Background: Chemotherapy for primary central nervous system lymphoma (PCNSL) is based on methotrexate (MTX), which interferes with both nucleic acid synthesis and methionine metabolism. We have reported previously that genetic variants with influence on methionine metabolism are associated with MTX side effects, that is, the occurrence of white matter lesions as a sign of MTX neurotoxicity. Here, we investigated whether such variants are associated with MTX efficacy in terms of overall survival in MTX-treated PCNSL patients. Methods: We analysed seven genetic variants influencing methionine metabolism in 68 PCNSL patients treated with systemic and facultative intraventricular MTX-based polychemotherapy (Bonn protocol). Results: Median age at diagnosis was 59 years (range: 28–77), 32 patients were female. Younger age (Wald=8.9; P=0.003) and the wild-type C (CC) allele of the genotype transcobalamin c (Tc2). 776C>G (Wald=6.7; P=0.010) were associated with longer overall survival in a multivariate COX regression analysis. Conclusion: This observation suggests that the missense variant Tc2. 776C>G influences both neurotoxicity and efficacy of MTX in the Bonn PCNSL protocol.

Reliable detection of leptomeningeal disease has the potential of facilitating the diagnosis of central nervous system (CNS) lymphoma and is important for therapeutic considerations. Currently, the standard diagnostic procedure for the detection of lymphoma in the cerebrospinal fluid is cytopathology. To improve the limited specificity and sensitivity of cytopathology, flow cytometry has been suggested as an alternative. Here, we evaluated multi-parameter flow cytometry in combination with conventional cytopathology in cerebrospinal fluid (CSF) samples from 30 patients with primary CNS lymphoma and seven patients with secondary CNS lymphoma. Overall, in 11 of 37 (29.7%) patients with CNS lymphoma, lymphoma cells were detected in CSF by flow cytometry, while cytopathology was less sensitive displaying unequivocally malignant CSF cells in only seven of all 37 (18.9%) patients. Six (16.2%) patients showed cytopathological results suspicious of lymphoma; however, in only one of these patients, the diagnosis of CSF lymphoma cells could be confirmed by flow cytometry. In primary CNS lymphomas (PCNSL), seven of 30 (23.3%) patients were positive for CSF lymphoma cells in flow cytometry, in contrast to four (13.3%) patients with PCNSL with definitely positive cytopathology. In summary, our results suggest that multi-parameter flow cytometry increases the sensitivity and specificity of leptomeningeal disease detection in CNS lymphomas. Both methods should be applied concurrently for complementary diagnostic assessment in patients with CNS lymphoma.

Intrathecal application of liposomal cytarabine (Ara-C) (DepoCyte(®)) has been associated with neurotoxicity when applied as part of a polychemotherapy regimen. Patients with primary central nervous system lymphoma treated with high-dose systemic methotrexate (MTX)- and Ara-C-based polychemotherapy including six cycles of liposomal Ara-C (50 mg intrathecally every 3 weeks) were prospectively monitored for neurotoxic side-effects. Between November 2005 and February 2009, 149 intrathecal applications of liposomal cytarabine (DepoCyte(®)) were carried out in 33 patients, 7 (21%) of whom developed an incomplete conus medullaris/cauda equina syndrome with incontinence for bladder (6) and bowel function (3) or lumbosacral polyradicular paresis (1), resolving only incompletely over a follow-up period of 9-30 months. In six of these seven patients, lumbosacral magnetic resonance imaging (MRI) was negative for leptomeningeal infiltration or arachnoiditis. Cerebrospinal fluid (CSF) analysis performed in six of these seven patients showed normal cell count in all and increased total protein in four of them. One patient among these seven suffered a seizure without other identifiable causes. Conus/cauda syndrome has to be considered as a serious potential neurotoxic side-effect in patients receiving liposomal Ara-C as part of a multimodal regimen including high-dose systemic MTX and Ara-C.

Aims Recent recommendations on the designation of target artery lesions in acute ischemic stroke include the anatomical differentiation between a proximal and a distal occlusion site of the M1 segment of the middle cerebral artery (MCA). The aim of this study was to evaluate whether these occlusion types differ in terms of a disability-free (modified Rankin Scale (mRS) 0 or 1) clinical outcome at 90 days. Methods A retrospective analysis was performed of all patients with MCA M1 occlusions who had a successful revascularization result after mechanical thrombectomy between October 2009 and September 2013 and for whom follow-up at 90 days was available. Imaging data were regraded and re-evaluated according to the modified Thrombolysis In Cerebral Infarction (mTICI) scale and the respective vessel occlusion site definitions. Outcome measures included National Institutes of Health Stroke Scale (NIHSS), mRS, Alberta Stroke Program Early CT Score (ASPECTS) scoring and procedural timings. Results 62 patients were successfully recanalized; follow-up at 90 days was available for 42/62 patients (68%). There were proximal MCA occlusions in 24/42 patients (57%) and distal occlusions in 18/42 (43%). Baseline NIHSS, ASPECTS, procedural timings and final mTICI scores did not differ significantly between proximal and distal M1 occlusions. There was a statistically significant difference between proximal and distal M1 occlusions regarding a disability-free early outcome (mRS 0 or 1) at discharge (p=0.03) and at 90 days (p=0.04). Conclusions Proximal occlusions of the M1 segment of the MCA incorporating the lenticulostriate perforators are associated with a poorer clinical outcome than distal M1 occlusions that spare these perforators. Involvement of these perforators might become an additional predictor of clinical outcome after mechanical thrombectomy in ischemic stroke.