Hemodynamic response and clinical outcome following intravenous milrinone plus norepinephrine-based hyperdynamic hypertensive therapy in patients suffering secondary cerebral ischemia after aneurysmal subarachnoid hemorrhage.

PURPOSE: Intravenous and intra-arterial milrinone as a rescue measure for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) has been adopted by several groups, but so far, evidence for the clinical benefit is unclear and effect on brain perfusion is unknown. The aim of the actual analysis was to define cerebral hemodynamic effects and outcome of intravenous milrinone plus norepinephrine supplemented by intra-arterial nimodipine as a rescue strategy for DCI following aneurysmal SAH. METHODS: Of 176 patients with aneurysmal SAH treated at our neurosurgical department between April 2016 and March 2021, 98 suffered from DCI and were submitted to rescue therapy. For the current analysis, characteristics of these patients and clinical response to rescue therapy were correlated with hemodynamic parameters, as assessed by CT angiography (CTA) and perfusion CT. Time to peak (TTP) delay in the ischemic focus and the volume with a TTP delay of more than 4 s (T4 volume) were used as hemodynamic parameters. RESULTS: The median delay to neurological deterioration following SAH was 5 days. Perfusion CT at that time showed median T4 volumes of 40 cc and mean focal TTP delays of 2.5 ± 2.1 s in these patients. Following rescue therapy, median T4 volume decreased to 10 cc and mean focal TTP delay to 1.7 ± 1.9 s. Seventeen patients (17% of patients with DCI) underwent additional intra-arterial spasmolysis using nimodipine. Visible resolution of macroscopic vasospasm on CTA was observed in 43% patients with DCI and verified vasospasm on CTA, including those managed with additional intra-arterial spasmolysis. Initial WFNS grade, occurrence of secondary infarction, ischemic volumes and TTP delays at the time of decline, the time to clinical decline, and the necessity for additional intra-arterial spasmolysis were identified as the most important features determining neurological outcome at 6 months. CONCLUSION: The current analysis shows that cerebral perfusion in the setting of secondary cerebral ischemia following SAH is measurably improved by milrinone and norepinephrine-based hyperdynamic therapy. A long-term clinical benefit by the addition of milrinone appears likely. Separation of the direct effect of milrinone from the effect of induced hypertension is not possible based on the present dataset.

Carotid-cavernous sinus fistula following mechanical thrombectomy in acute ischaemic stroke: a rare complication.

Carotid-cavernous sinus fistulas (CCFs) are abnormal communications between the internal carotid artery (ICA) and the cavernous sinus (CS). Direct CCFs are associated with trauma or are iatrogenic complications of neuroendovascular procedures. Meanwhile, mechanical endovascular thrombectomy (MT) in acute ischaemic stroke (AIS) patients with large vessel occlusion (LVO) has been established as a common treatment approach. However, MT is not without its risks of complications, and only a few reports exist on CCF occurring after MT. Here, we present a case of a 63-year-old patient with iatrogenic high-flow CCF of the right horizontal cavernous ICA segment (C4) following repeated MT due to LVO of the middle cerebral artery, and the recent literature is reviewed.

Brain activation patterns in medicated versus medication-naïve adults with attention-deficit hyperactivity disorder during fMRI tasks of motor inhibition and cognitive switching.

BACKGROUND: Adult-attention-deficit-hyperactive-disorder (ADHD) is often unrecognized condition. FMRI examination along with neuropsychological testing might strengthen the diagnosis. We hypothesized that ADHD-adults with and without medication would show different fMRI pattern compared to healthy controls while testing tasks of motor inhibition and cognitive switching. METHODS: 45 subjects in three age-matched groups: (1) controls, (2) ADHD-adults under medication (ADHD+) and (3) medication-naïve adults with ADHD (ADHD-) underwent fMRI and neuropsychological testing. Group analysis and population-based statistics were performed. RESULTS: DTVP-A, intellectual ability as well as attention capability, visual-perceptual and visual-motor abilities showed no significant differences between the groups. However, fMRI revealed statistically significant differences between the ADHD+, ADHD- and control groups on tasks of motor inhibition and cognitive switching on adults in bilateral fronto-striatal brain regions, inferior fronto-frontal, fronto-cingulate and fronto-parietal networks as well as in the parietal lobe (p < 0.05). CONCLUSIONS: fMRI offers the potential to differentiate between the ADHD+, ADHD- and control groups. FMRI possibly opens a new window for monitoring the therapeutic effect of ADHD medication. TRIAL REGISTRATION: NCT02578342, registered at August 2015 to clinical trial registry ( https://ichgcp.net/clinical-trials-registry/NCT02578342 ).

Long-term apparent diffusion coefficient value changes in patients undergoing radiosurgical treatment of meningiomas.

PURPOSE: A noninvasive method to predict the progress or treatment response of meningiomas is desirable to improve the tumor management. Studies showed that apparent diffusion coefficient (ADC) pretreatment values can predict treatment response in brain tumors. The aim of this study was to analyze changes of intratumoral ADC values in patients with meningiomas undergoing conservative or radiosurgery. METHOD: MR images of 51 patients with diagnose of meningiomas were retrospectively reviewed. Twenty-five patients undergoing conservative or radiosurgery treatment, respectively, were included in the study. The follow-up data ranged between 1 and 10 years. Based on ROI analysis, the mean ADC values, ADC10%min, and ADC90%max were evaluated at different time points during follow-up. RESULTS: Baseline ADC values in between both groups were similar. The ADCmean values, ADC10%min, and ADC90%max within the different groups did not show any significant changes during the follow-up times in the untreated (ADCmean over 10 years period: 0.87 ± 0.05 × 10-3 mm2/s) and radiosurgically treated (ADCmean over 4 years period: 1.02 ± 0.12 × 10-3 mm2/s) group. However, statistically significant difference was observed when comparing the ADCmean and ADC90%max values of untreated with radiosurgically treated (p < 0.0001) meningiomas. Also, ADC10%min revealed statistically significant difference between the untreated and the radiosurgery group (p < 0.05). CONCLUSIONS: ADC values in conservatively managed meningiomas remain stable during the follow-up. However, meningiomas undergoing radiosurgery reveal significant change of the mean ADC values over time, suggesting that ADC may reflect a change in the biological behavior of the tumor. These observations might suggest the value of ADC changes as an indicator of treatment response.

Angioplasty Using Drug-Coated Balloons in Ostial Vertebral Artery Stenosis.

BACKGROUND: Ostial vertebral artery stenosis (OVAS) is a relevant cause of acute ischemic posterior circulation stroke. Percutaneous trans-luminal angioplasty (PTA) might offer a promising treatment modality, but restenosis rate is high. So far, little is known about recanalization using drug-coated balloons (DCB) in OVAS. We aimed to show feasibility and safety of DCB-PTA in OVAS. METHODS: Retrospective, monocenter case series of 12 patients with ostial vertebral artery stenosis (≥50%) treated with PTA using a drug-coated balloon. RESULTS: Median age was 69.5 years (IQR 57-78.5) with a female rate of 41%. Patients were treated either with a SeQuent Please NEO or Neuro Elutax SV DEB. Median preinterventional stenosis degree was 75% (IQR 70-85) with a median lesion length of 4.5 mm (IQR 4-7.5). Median postinterventional stenosis degree was 40% (IQR 27-50). All treated vessels remained patent. No major complications such as dissection, vessel perforation, hemorrhage, or ischemic events occurred. Moreover, we did not detect any restenosis during a median follow-up period of 6.1 months. The clinical outcome was excellent with median mRS scale of 0 (IQR 0-1). CONCLUSIONS: PTA using drug-coated balloons is feasible and safe in patients with ostial vertebral artery stenosis.

Flow dynamics of cerebrospinal fluid between the intracranial cavity and the subarachnoid space of the optic nerve measured with a diffusion magnetic resonance imaging sequence in patients with normal tension glaucoma.

IMPORTANCE: This study offers a new approach for the quantification of CSF dynamics. BACKGROUND: Non-invasive method to quantify the CSF dynamics in the subarachnoid space of the optic nerve is highly desirable. The aim of the study was to measure slow-flow CSF velocities in healthy controls and normal tension glaucoma patients between the intracranial cavity and the subarachnoid space of the optic nerve. DESIGN: Prospective observational study. PARTICIPANTS: Eleven age-matched healthy volunteers and 15 normal tension glaucoma patients. METHODS: Using phase contrast images, the phase shift in MRI diffusion images can be used to determine the flow velocity. Flow-range ratio between the intracranial cavity and the subarachnoid space of the optic nerve was calculated. MAIN OUTCOME MEASURE: Flow-range ratio between the intracranial cavity and the subarachnoid space of the optic nerve was calculated. RESULTS: First, phantom measurements were provided to validate the slow-flow velocity calculations. Second, flow-range ratio was validated for the healthy controls (0.63 ± 0.05), with the range being similar for the right and left optic nerve (P = 0.1). Statistically significant results were obtained (P < 0.05) when comparing the flow-range ratio in the optic nerve of healthy controls (n = 22 eyes, 0.63 ± 0.05) with the flow-range ratio in pathological optic nerves (n = 23, 0.55 ± 0.08) of normal tension glaucoma patients. MANOVA revealed no dependency between flow-range ratio and patient dependent variables. CONCLUSION AND RELEVANCE: Diffusion-weighted imaging provides a method to evaluate CSF flow within the subarachnoid space of the optic nerve in a non-invasive manner. Compared to healthy controls, patients with normal tension glaucoma measure a significantly lower flow-range ratio. This finding suggests a possible role of impaired CSF dynamics in the pathophysiology in normal tension glaucoma.

Emergent vs. elective stenting of carotid stenosis with intraluminal carotid thrombus.

BACKGROUND AND PURPOSE: Carotid stenosis (CS) with intraluminal carotid artery thrombus (ICAT) is rare but ominous finding. The optimal treatment modality is unclear. The aim of this study was to analyze the feasibility and outcome of acute endovascular intervention and delayed elective endovascular therapy after initial anticoagulation in these delicate cases. Moreover, both treatment points were compared and several parameters discussed to facilitate the determination of the optimal time modality in future cases. MATERIALS AND METHODS: A series of 11 consecutive cases with acute symptomatic CS with ICAT that received endovascular treatment was retrospectively analyzed. General patient data, pre and post-interventional symptoms and imaging were evaluated in an overall mean follow-up of 84 weeks. RESULTS: Urgent stenting and mechanical thrombectomy was performed in 6 patients. In the remaining 5 cases, elective endovascular treatment was planned after initial anticoagulation therapy with thrombus resolution. One case received secondary urgent treatment due to clinical deterioration. Overall outcome at three months follow-up was excellent (Modified Ranking Scale [mRS] 0-1) in 5 cases, good (mRS 2) in 4 and unfavorable in the remaining 2. Important differences between the two treatment arms were seen in 3 parameters (stenosis degree, thrombus length, and NIHSS score). CONCLUSIONS: This is one of the largest studies analysing endovascular treatment in patients with acute symptomatic CS and additional ICAT only. Both endovascular treatment strategies seem feasible. Parameters such as size of intraluminal thrombus and clinical symptoms should be included in the decision-making process regarding the optimal individual treatment time.

Diffusion tensor imaging for target volume definition in glioblastoma multiforme.

INTRODUCTION: Diffusion tensor imaging (DTI) is an MR-based technique that may better detect the peritumoural region than MRI. Our aim was to explore the feasibility of using DTI for target volume delineation in glioblastoma patients. MATERIALS AND METHODS: MR tensor tracts and maps of the isotropic (p) and anisotropic (q) components of water diffusion were coregistered with CT in 13 glioblastoma patients. An in-house image processing program was used to analyse water diffusion in each voxel of interest in the region of the tumour. Tumour infiltration was mapped according to validated criteria and contralateral normal brain was used as an internal control. A clinical target volume (CTV) was generated based on the T1-weighted image obtained using contrast agent (T1Gd), tractography and the infiltration map. This was compared to a conventional T2-weighted CTV (T2-w CTV). RESULTS: Definition of a diffusion-based CTV that included the adjacent white matter tracts proved highly feasible. A statistically significant difference was detected between the DTI-CTV and T2-w CTV volumes (p < 0.005, t = 3.480). As the DTI-CTVs were smaller than the T2-w CTVs (tumour plus peritumoural oedema), the pq maps were not simply detecting oedema. Compared to the clinical planning target volume (PTV), the DTI-PTV showed a trend towards volume reduction. These diffusion-based volumes were smaller than conventional volumes, yet still included sites of tumour recurrence. CONCLUSION: Extending the CTV along the abnormal tensor tracts in order to preserve coverage of the likely routes of dissemination, whilst sparing uninvolved brain, is a rational approach to individualising radiotherapy planning for glioblastoma patients.

Differentiation between calcification and hemorrhage in brain tumors using susceptibility-weighted imaging: a pilot study.

OBJECTIVE: Our aim was to develop a robust method to differentiate calcification from hemorrhage in gliomas. Histopathologic examination was performed to validate hemorrhage and calcification. CONCLUSION: Phase images from eleven patients with glioma yielded statistically significant phase-shift values for calcification and hemorrhage compared with normal brain, whereas CT showed substantial overlap of Hounsfield units. Phase image analysis correctly differentiated between intratumoral calcification and hemorrhage in 86% of cases.

Age related cerebrospinal fluid flow dynamics in the subarachnoid space of the optic nerve in patients with normal tension glaucoma, measured by diffusion weighted MRI.

BACKGROUND/OBJECTIVES: We aimed to measure cerebrospinal fluid (CSF) flow rates in the subarachnoid space (SAS) of the optic nerve (ON) by applying non-invasive diffusion-weighted MRI in patients with normal tension glaucoma (NTG) compared to age-matched controls. SUBJECTS/METHODS: In this prospective study, an analysis of diffusion-weighted images of 26 patients with NTG (49ONs) and age-matched volunteers (52ONs) was conducted. Subjects were classified into 4 groups: group I (50-59 y., n = 12 eyes), group II (60-69 y., n = 16 eyes), group III (70-79 y., n = 18 eyes) and group IV ( > 80 y., n = 6 eyes) for NTGs and healthy volunteers, respectively. The flow-range ratio (FRR) between the frontal lobe SAS and the SAS of the ON was calculated for each age category group and then compared between age-categories as well as between NTGs and controls. RESULTS: The mean FRR for age groups were (I) 0.54 ± 0.06 and 0.62 ± 0.03 (p < 0.05), (II) 0.56 ± 0.08 and 0.63 ± 0.03 (p < 0.05), (III) 0.54 ± 0.06 and 0.62 ± 0.02 (p < 0.001) as well as (IV) 0.61 ± 0.03 and 0.61 ± 0.04, for NTGs and controls, respectively. Using pooled data, the difference between the FRR in NTGs and controls was statistically significant (p < 0.0001). There were no statistically significant differences within the age categories of the control group. When comparing the FRR of NTGs by age categories, no statistically significant difference was found between the subgroups. CONCLUSIONS: FRR was significantly reduced in NTGs compared to age-matched controls without any significant differences within the age groups themselves. Given the physiological importance of CSF for the integrity of neurons, axons and glial cells, reduced CSF flow dynamics might be part of the underlying neurodegenerative process of NTG.

Large-scale in-silico analysis of CSF dynamics within the subarachnoid space of the optic nerve.

BACKGROUND: Impaired cerebrospinal fluid (CSF) dynamics is involved in the pathophysiology of neurodegenerative diseases of the central nervous system and the optic nerve (ON), including Alzheimer's and Parkinson's disease, as well as frontotemporal dementia. The smallness and intricate architecture of the optic nerve subarachnoid space (ONSAS) hamper accurate measurements of CSF dynamics in this space, and effects of geometrical changes due to pathophysiological processes remain unclear. The aim of this study is to investigate CSF dynamics and its response to structural alterations of the ONSAS, from first principles, with supercomputers. METHODS: Large-scale in-silico investigations were performed by means of computational fluid dynamics (CFD) analysis. High-order direct numerical simulations (DNS) have been carried out on ONSAS geometry at a resolution of 1.625 µm/pixel. Morphological changes on the ONSAS microstructure have been examined in relation to CSF pressure gradient (CSFPG) and wall strain rate, a quantitative proxy for mass transfer of solutes. RESULTS: A physiological flow speed of 0.5 mm/s is achieved by imposing a hydrostatic pressure gradient of 0.37-0.67 Pa/mm across the ONSAS structure. At constant volumetric rate, the relationship between pressure gradient and CSF-accessible volume is well captured by an exponential curve. The ONSAS microstructure exhibits superior mass transfer compared to other geometrical shapes considered. An ONSAS featuring no microstructure displays a threefold smaller surface area, and a 17-fold decrease in mass transfer rate. Moreover, ONSAS trabeculae seem key players in mass transfer. CONCLUSIONS: The present analysis suggests that a pressure drop of 0.1-0.2 mmHg over 4 cm is sufficient to steadily drive CSF through the entire subarachnoid space. Despite low hydraulic resistance, great heterogeneity in flow speeds puts certain areas of the ONSAS at risk of stagnation. Alterations of the ONSAS architecture aimed at mimicking pathological conditions highlight direct relationships between CSF volume and drainage capability. Compared to the morphological manipulations considered herein, the original ONSAS architecture seems optimized towards providing maximum mass transfer across a wide range of pressure gradients and volumetric rates, with emphasis on trabecular structures. This might shed light on pathophysiological processes leading to damage associated with insufficient CSF flow in patients with optic nerve compartment syndrome.

Age and Stroke Severity Matter Most for Clinical Outcome in Acute Arteriosclerotic Tandem Lesions.

Background: Tandem lesions (TLs) cause up to 15-30% of all acute ischemic strokes (AISs). Endovascular treatment (EVT) is regarded as the first-line treatment; however, uncertainties remain with respect to the treatment and predictive outcome parameters. Here, we aimed to identify the clinical and demographic factors associated with functional short- and long-term outcomes in AIS patients with arteriosclerotic TLs undergoing EVT. Methods: This was a retrospective, mono-centric cohort study of 116 consecutive AIS patients with arteriosclerotic TLs who were endovascularly treated at a stroke center, with analysis of the relevant demographic, procedural, and imaging data. Results: A total of 116 patients were included in this study, with a median age of 72 years (IQR 63-80), 31% of whom were female (n = 36). The median NIHSS on admission was 14 (IQR 7-19), with a median ASPECT score of 9 (IQR 8-10) and median NASCET score of 99% (IQR 88-100%). A total of 52% of the patients received intravenous thrombolysis. In 77% (n = 89) of the patients, an antegrade EVT approach was used, with a good recanalization (mTICI2b3) achieved in 83% of patients (n = 96). Symptomatic intracerebral hemorrhage occurred in 12.7% (n = 15) of patients. A favorable outcome (mRS0-2) and mortality at 3 months were obtained for 40% (n = 47) and 28% of patients (n = 32), respectively. Age and NIHSS on admission were strongly associated with outcome parameters. Diabetes mellitus and previous neurological disorders were independently associated with long-term mortality (median 11 months, IQR 0-42). Conclusions: Younger age, lower stroke severity, and good recanalization were found to be independently associated with a favorable outcome. In contrast, older age, higher stroke severity, previous neurological disorders, and diabetes were correlated with mortality. The endovascular treatment of acute arteriosclerotic tandem lesions is feasible and relatively safe.

Changes in the amygdala produced by viewing strabismic eyes.

PURPOSE: The aim of this study was to look for the response to strabismus images in the limbic network (amygdala, hippocampus, parahippocampus) of healthy volunteers and to compare it with their reaction to viewing normal eyes. DESIGN: Prospective, observational study. PARTICIPANTS: Thirty-one healthy volunteers underwent functional magnetic resonance imaging (fMRI). METHODS: Functional magnetic resonance imaging data and blood oxygen level-dependent signal changes were analyzed using the BrainVoyager QX software package (Brain Innovation, Maastricht, The Netherlands). MAIN OUTCOME MEASURES: Responses to viewing strabismus images were compared with those observed while viewing normal eye images. RESULTS: Strabismus images led to significant activation of the amygdala, hippocampus, parahippocampal, and fusiform gyri in 30 of 31 subjects compared with normal eye images, indicating a negative emotional response. CONCLUSIONS: These fMRI results confirm that strabismus influences organically not only the patient with nonparallel eyes but also observers. Treatment of strabismus therefore changes the interpersonal dynamic for patients with strabismus on a demonstrable organic basis. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Cortical hemosiderin is associated with seizures in patients with newly diagnosed malignant brain tumors.

Hemorrhage is common in brain tumors. Due to characteristic magnetic field changes induced by hemosiderin it can be detected using susceptibility weighted MRI (SWI). Its relevance to clinical syndromes is unclear. Here we investigated the patterns of intra-tumoral SWI positivity (SWI(pos)) as a surrogate for hemosiderin with regard to the prevalence of epilepsy. We report on 105 patients with newly diagnosed supra-tentorial gliomas and brain metastasis. The following parameters were recorded from pre-operative MRI: (1) SWI(pos) defined as dot-like or fine linear signal changes; (2) allocation of SWI(pos) to tumor compartments (contrast enhancement, central hypointensity, non-enhancing area outside contrast-enhancement); (3) allocation of SWI(pos) to include the cortex, or SWI(pos) in subcortical tumor parts only; (4) tumor size on T2 weighted and gadolinium-enhanced T1 images. 80 tumors (76 %) showed SWI(pos) (4/14 diffuse astrocytoma WHO II, 5/9 anaplastic astrocytoma WHO III, 41/46 glioblastoma WHO IV, 30/36 metastasis). The presence of SWI(pos) depended on tumor size but not on patient's age, medication with antiplatelet drugs or anticoagulation. Seizures occurred in 60 % of patients. Cortical SWI(pos) significantly correlated with seizures in brain metastasis (p = 0.044), and as a trend in glioblastoma (p = 0.062). Cortical SWI(pos) may confer a risk for seizures in patients with newly diagnosed brain metastasis and glioblastoma. Whether development of cortical SWI(pos) induced by treatment or by the natural course of tumors also leads to the new onset of seizures has to be addressed in longitudinal studies in larger patient cohorts.

Anisotropic phantom measurements for quality assured use of diffusion tensor imaging in clinical practice.

BACKGROUND: Diffusion-weighted magnetic resonance imaging (MRI) is being increasingly applied in clinical practice, for example in neuronavigation and in modern radiation treatment planning. Quality assurance (QA) is therefore important to avoid clinical errors. PURPOSE: To compare four analytical programs and a neuronavigation tool to evaluate our in-house diffusion-weighted imaging protocol in order to be able to implement diffusion tensor imaging (DTI) into clinical practice. MATERIAL AND METHODS: A phantom containing crossing fibers was used for the QA. Fiber tracking and fractional anisotropy (FA) analyses were performed, and the geometrical resolution was verified using the phantom. RESULTS: FA results were reproducible within each program and no significant differences between programs were observed. Also, no significant differences in FA values were found when comparing the results between the four software programs. Geometrical resolution of the anatomical data-set was satisfactory; however the crossing of the fibers was not accurately represented by three of the four programs. CONCLUSION: Phantom QA is necessary before using DTI for novel procedures to identify the uncertainties associated with DTI data. It is important to remember that the results are software-dependent and that representation of the tracts may vary between software products. We therefore recommend caution with regard to the application of fiber tracking results intraoperatively when dealing with abnormal fiber tract anatomy.

Case report: Experience with the Cube Navigation System in complex access routes during CT-guided lumbosacral infiltration therapy.

Purpose: Computed tomography (CT)-guided infiltrations are a mainstay in the treatment of lower back pain. Needle placement is usually performed using the free-hand method, where the translation from the planned needle angle to the actual needle insertion angle is estimated. However, the free-hand method is especially challenging in cases where a double-oblique access route (out-of-plane) rather than an in-plane route is necessary. In this case series, we report our experience with the patient-mounted Cube Navigation System to guide needle placement for complex access routes in lumbar pain therapy. Research design and methods: We retrospectively analyzed the cases of five patients in whom a double-oblique access route was necessary for CT-guided lumbar infiltration pain treatment. Each of those procedures was done using the Cube Navigation System to provide navigational guidance. The mean patient age was 69 ± 13 years (range 58-82 years; all females). Technical success, procedure time, and number of control scans were determined retrospectively. Results: Technical success (i.e., positioning and accuracy) was obtained in all cases. Mean procedure time was 15 ± 7 min (10-22 min); on average, 2 ± 1 CT control scans were performed. There were no complications or material failures reported in the present study. Conclusion: Double-oblique punctures with the Cube Navigation System in this initial case series of complex access routes at the lumbar spine were accurate and the procedure was time efficient. In the authors' view, the Cube Navigation System has the potential to improve needle guidance for complex access routes, especially considering the ease of use of the device.

Anatomical distribution and clinical significance of middle cerebral artery M2 segment vessel occlusions and its cortical branches in acute ischaemic stroke patients.

Background: Characterisation of anatomical distribution and the clinical impact of middle cerebral artery M2 (MCA-M2) segment occlusion and its subsequent cortical branches (CBs) in acute ischaemic stroke patients (AIS). Methods: Retrospective, monocentric study analysing radiological and clinical data of AIS patients with MCA-M2 segment occlusion with regard to the anatomic distribution of MCA-M2 occlusion and its subsequent CB. Results: A total of 203 patients (median age 77 (IQR 66-83) years, 112 women) were included. There was an equal distribution of right-sided versus left-sided MCA-M2 vessel occlusions (right: n=97; left: n=106), as well as with a median number of affected MCA-M2 CBs of 4 (IQR, 3-6) and a median National Institute of Health Stroke Scale score (NIHSS) on admission of 9 (3-15). For both hemispheres, CBs of the inferior trunks were significantly more affected than the superior trunks. Endovascular treatment (EVT, n=94) was associated with a significant better outcome compared with patients with medical management alone (p=0.027). Conclusion: In acute MCA-M2 segment occlusions, inferior trunks are significantly more affected compared with the superior trunks. The subsequent CBs of the paracentral region of both hemispheres are more commonly involved. In eloquent vascular territories, EVT was more often performed.

A Diagnostic Biomarker for Cervical Myelopathy Based on Dynamic Magnetic Resonance Imaging.

STUDY DESIGN: Multicenter prospective observational study. OBJECTIVE: Diffusion tensor imaging in flexion extension improves the diagnosis of degenerative cervical myelopathy (DCM). We aimed to provide an imaging biomarker for the detection of DCM. SUMMARY OF BACKGROUND DATA: DCM is the most common form of spinal cord dysfunction in adults; however, imaging surveillance for myelopathy remains poorly characterized. PATIENTS AND METHODS: Symptomatic DCM patients were examined in maximum neck flexion-extension and neutral positions in a 3T-magnetic resonance imaging scanner and allocated to 2 groups: (1) Patients with visible intramedullary hyperintensity (IHIS) on T2-weighted imaging (IHIS+, n = 10); and (2) Patients without IHIS (IHIS-, n = 11). Range of motion, space available for the spinal cord, apparent diffusion coefficient (ADC), axial diffusivity (AD), radial diffusivity, and fractional anisotropy were measured and compared between the neck positions and between the groups as well as between control (C2/3) and pathologic segments. RESULTS: Significant differences between the control level (C2/3) and pathologic segments were appreciated for the IHIS+ group at neutral neck position in AD; at flexion in ADC and AD; and at neck extension in ADC, AD, and fractional anisotropy values. For the IHIS- group, significant differences between the control level (C2/3) and pathologic segments were found only for ADC values in neck extension. When comparing diffusion parameters between groups, radial diffusivity was significantly different in all 3 neck positions. CONCLUSION: Significant increases in ADC values between the control and pathologic segments were found for both groups in neck extension only. This may serve as a diagnostic tool to identify early changes in the spinal cord related to myelopathy to indicate potentially reversible spinal cord injury and support the indication for surgery in select circumstances.

Large-scale morphometry of the subarachnoid space of the optic nerve.

BACKGROUND: The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater, the cerebrospinal fluid (CSF)-filled subarachnoid space (SAS) features a variety of trabeculae, septae and pillars. Like the arachnoid and the pia mater, these structures are covered with leptomeningeal or meningothelial cells (MECs) that form a barrier between CSF and the parenchyma of the optic nerve (ON). MECs contribute to the CSF proteome through extensive protein secretion. In vitro, they were shown to phagocytose potentially toxic proteins, such as α-synuclein and amyloid beta, as well as apoptotic cell bodies. They therefore may contribute to CSF homeostasis in the SAS as a functional exchange surface. Determining the total area of the SAS covered by these cells that are in direct contact with CSF is thus important for estimating their potential contribution to CSF homeostasis. METHODS: Using synchrotron radiation-based micro-computed tomography (SRµCT), two 0.75 mm-thick sections of a human optic nerve were acquired at a resolution of 0.325 µm/pixel, producing images of multiple terabytes capturing the geometrical details of the CSF space. Special-purpose supercomputing techniques were employed to obtain a pixel-accurate morphometric description of the trabeculae and estimate internal volume and surface area of the ON SAS. RESULTS: In the bulbar segment, the ON SAS microstructure is shown to amplify the MECs surface area up to 4.85-fold compared to an "empty" ON SAS, while just occupying 35% of the volume. In the intraorbital segment, the microstructure occupies 35% of the volume and amplifies the ON SAS area 3.24-fold. CONCLUSIONS: We provided for the first time an estimation of the interface area between CSF and MECs. This area is of importance for estimating a potential contribution of MECs on CSF homeostasis.

Striatal Iron Deposition in Recreational MDMA (Ecstasy) Users.

BACKGROUND: The common club drug MDMA (also known as ecstasy) enhances mood, sensory perception, energy, sociability, and euphoria. While MDMA has been shown to produce neurotoxicity in animal models, research on its potential neurotoxic effects in humans is inconclusive and has focused primarily on the serotonin system. METHODS: We investigated 34 regular, largely pure MDMA users for signs of premature neurodegenerative processes in the form of increased iron load in comparison to a group of 36 age-, sex-, and education-matched MDMA-naïve control subjects. We used quantitative susceptibility mapping, a novel tool able to detect even small tissue (nonheme) iron accumulations. Cortical and relevant subcortical gray matter structures were grouped into 8 regions of interest and analyzed. RESULTS: Significantly increased iron deposition in the striatum was evident in the MDMA user group. The effect survived correction for multiple comparisons and remained after controlling for relevant confounding factors, including age, smoking, and stimulant co-use. Although no significant linear relationship between measurements of the amounts of MDMA intake (hair analysis and self-reports) and quantitative susceptibility mapping values was observed, increased striatal iron deposition might nevertheless point to MDMA-induced neurotoxic processes. Additional factors (hyperthermia and simultaneous co-use of other substances) that possibly amplify neurotoxic effects of MDMA during the state of acute intoxication are discussed. CONCLUSIONS: The demonstrated increased striatal iron accumulation may indicate that regular MDMA users have an increased risk potential for neurodegenerative diseases with progressing age.