Intra-aneurysmal contrast agent stasis during intraoperative digital subtraction angiography may predict long-term occlusion after clipping.

PURPOSE: The routine use of intraoperative digital subtraction angiography (iDSA) increases detection of intracranial aneurysm (IA) remnants after microsurgical clipping. Spontaneous thrombosis of IA remnants after clipping is considered a rare phenomenon. We analyse iDSA characteristics to find predictors for IA remnant thrombosis. METHODS: IA with intraoperative detection of a remnant after clipping were identified and divided into remnants experiencing spontaneous thrombosis, and remnants with long-term patency and/or remnant growth. Angiographic features of iDSA were analysed and compared between the two groups. RESULTS: Of 37 IAs with intraoperative remnant on 3D-iDSA, five sustained a spontaneous remnant thrombosis and remained occluded in long-term follow-up. In all five cases, iDSA revealed delayed inflow and consequent stasis of the contrast agent until the late venous phase. On the other hand, in all cases with persistent long-term IA remnants (n = 32) iDSA demonstrated timely arterial contrast inflow and wash-out without stasis of intra-aneurysmal contrast agent. CONCLUSIONS: Contrast stasis in IA remnants during iDSA appears to predict long-term IA occlusion, indicating that clip correction manoeuvres or even attempted endovascular treatment of the remnant IA may be avoided in these patients.

Interrater and intrarater agreement superior for three-dimensional digital subtraction angiography (3D-DSA) over 2D-DSA classification for detecting remnants after intracranial aneurysm clipping, a GRRAS Reliability and Agreement Study.

BACKGROUND: Growing evidence suggests that three-dimensional digital subtraction angiography (3D-DSA) is superior to 2D-DSA in detection of intracranial aneurysm (IA) remnants after clipping. With a simple, practical quantitative scale proposed to measure maximal remnant dimension on 3D-DSA, this study provides a rigorous interrater and intrarater reliability and agreement study comparing this newly established scale with a commonly used (Sindou) 2D-DSA scale. METHOD: Records of 43 patients with clipped IAs harboring various sized remnants who underwent 2D- and 3D-DSA between 2012 and 2018 were evaluated. Using the 2D and 3D scales, six raters scored these remnants and repeated the scoring task 8 weeks later. Interrater and intrarater agreement for both grading schemes were calculated using kappa (κ) statistics. RESULTS: Interrater agreement was highly significant, yielding κ-values at 95% CI (p = 0.000) of 0.225 for the first [0.185; 0.265] and 0.368 s [0.328; 0.408] time points for 2D-DSA and values of 0.700 for the first [0.654; 0.745] and 0.776 s [0.729; 0.822] time points for 3D-DSA. Intrarater agreement demonstrated κ-values between 0.139 and 0.512 for 2D-DSA and between 0.487 and 0.813 for 3D-DSA scores. CONCLUSION: Interrater and intrarater agreement was minimal or weak for 2D-DSA scores, but strong for 3D-DSA scores. We propose that baseline 3D-DSA characterization may prove more reliable when categorizing clipped IA remnants for purposes of risk stratification and lifelong follow-up.

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 ).

Extensive Convexity Flattening of a Synthetic Skull Implant the Overcome Major Scalp Deficiency After Multiple Craniotomies.

ABSTRACT: Multiple craniofacial surgeries and postoperative recalcitrant infections frequently can lead to secondary scalp tissue scarring and skin retraction. Although there are different methods of reducing and optimizing scalp skin tension, the authors describe a last resort treatment method of cranioplastic procedure, which despite of its unfavorable cosmetic outcome, relieves the skin tension through extensive flattening of the polyetheretherketone curvature. Thereby, a custom-made cranioplastic bone flap was extensively flattened in the curvature of the fronto-parietal area with consideration of the related brain hemisphere extension. The extent of bone curvature flatting reduced the skin tension significantly and allowed for plain and simple tension-free wound closure in a chronic smoker patient with poor skin quality and brain atrophy. Although brain extension was sufficient, the cosmetic outcome was unfavorable with regard to skull symmetry, but well accepted and satisfactory for the patient due to preoperative discussion outcome expectation from surgery. Thus, extensive polyetheretherketone curvature flattening is a straightforward and simple last resort treatment option for tension-free skin closure in high-risk patients with extensive skin scarring and retraction and previous reconstructive plastic skin relief procedures. However, this method is limited in patients with normal brain hemisphere extension.

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.

A Rare Case of a Good Neurological Outcome following Traumatic Foix-Chavany-Marie Syndrome.

Traumatic brain injury (TBI) can have profound acute and chronic effects, leading to permanent disabilities and diminished quality of life. Pseudobulbar palsy and its infrequent subtype, Foix-Chavany-Marie Syndrome (FCMS), represent rare complications of TBI, manifesting as deficits in craniofacial motor function and automatic-voluntary dissociation. We present a case of a 58-year-old male who developed FCMS following severe TBI from a cycling accident. Initial imaging revealed extensive brain injury with subsequent development of FCMS characterised by bilateral cranial nerve dysfunction, notably facio-pharyngo-glosso-masticatory diplegia with preserved automatic motor function. This case contributes to the limited literature on traumatic FCMS, highlighting its distinct clinical features and potential for favourable outcomes compared to nontraumatic cases. Early recognition and comprehensive management, including supportive therapy and addressing underlying conditions, are paramount for optimising patient outcomes.

Combined Microsurgical and Endovascular Intracranial Aneurysm Treatment: Interdisciplinary Experience Using a True Hybrid Approach and a Systematic Review of the Literature.

(1) Background: Most intracranial aneurysms (IAs) can be treated either with microsurgical clipping or endovascular techniques. In a few cases, simultaneous treatment utilizing both modalities in a hybrid operation room may be favorable. This study analyzes the indication and benefits of a true hybrid approach (tHA) that combines simultaneous endovascular and microsurgical procedures for treatment of IAs in one session. (2) Methods: All patients receiving a true hybrid procedure between 2010 and 2022 in our institution were included. Demographic characteristics, neurological symptoms, pre-interventional treatments, angiographic findings, and postoperative clinical and radiological outcomes were analyzed. Results are discussed in the light of a systematic literature review on reported true hybrid procedures for IA treatment. (3) Results: In total, 10 tHAs were performed. Of these, coiling and concomitant decompressive craniectomy or hematoma evacuation was performed on six occasions. In two patients, multiple IAs were treated with different modalities during the same procedure. In two patients, intraoperative conditions did not allow for complete IA clipping, and the remnant was coiled in the same session. The review of the literature revealed nine papers comprising 58 IAs treated with a tHA. (4) Conclusions: The need for a tHA for IA treatment is rare and limited to highly selective cases. In our experience, tHAs have been most valuable in an emergency setting concerning ruptured IAs. Furthermore, tHAs may also be considered in patients with multiple aneurysms in different vascular territories.

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.

From conservative to interventional management in unruptured intracranial aneurysms.

OBJECTIVE: Indication for treatment of unruptured intracranial aneurysms (UIAs) is based on several factors, such as patient age, previous medical history, and UIA location and size. For patients harboring UIAs initially managed noninvasively, the treatment strategy during follow-up (FU) can be changed to include surgical or endovascular intervention. This study aims to identify characteristic patterns and potential predictors of UIAs that require revision of the initial management strategy. METHODS: The authors identified intracranial aneurysm (IA) cases newly diagnosed between 2006 and 2022 and initially assigned conservative management. These cases were retrospectively reviewed for 1) patient and UIA characteristics at the time of diagnosis (patient age, comorbidities, previous medical history, potential risk factors, as well as UIA angioarchitecture, location, and size), and 2) any changes in treatment strategy (reason for change, time until intervention, modality of intervention). RESULTS: Among 1041 IA cases diagnosed in the study period, 144 were initially assigned conservative management. In 10 (6.9%) of these 144 cases, the treatment indication was modified to microsurgical clipping (n = 6) or endovascular embolization (n = 4) after a median FU of 26 months (IQR 8.5-64.5 months). In these 10 cases, the indication for intervention was attributable to IA growth (n = 7), a change in IA configuration (n = 2), or both (n = 1). Exploratory analyses of the effects of UIA size on diagnosis in terms of the hazard for a change of decision suggested an effect starting from 3 mm. No conservatively managed UIAs (n = 144) ruptured during the study period (median FU 24.5 months, IQR 7.75-55.75 months). CONCLUSIONS: The likelihood of a shift to invasive UIA treatment is relatively low if a conservative therapeutic strategy was initially established. However, for cases with changes to the treatment strategy, the change is most often attributable to UIA growth over time. UIAs measuring < 3 mm at initial diagnosis are less likely to be later treated interventionally than those > 3 mm at diagnosis. Therefore, conservatively managed patients with UIAs should be closely monitored with regular radiographic FUs, particularly if the UIA measured > 3 mm at the time of diagnosis.

Long-Term Hemorrhage and Reperfusion Rates of Coiled Aneurysms: A Single-Center Experience.

Background: The endovascular approach has emerged as standard therapy for many intracranial aneurysms (IAs) to prevent hemorrhage, yet its long-term durability varies considerably. The aim of this study was to evaluate the safety and effectiveness of an initially deliberate endovascular approach regarding IA hemorrhage rates over a long-term follow-up period. Methods: This retrospective single-center study included all consecutive patients with endovascularly treated IAs who presented between January 2008 and December 2020 with a follow-up of at least 12 months. The primary endpoint was the proportion of patients with long-term IA hemorrhage rates and reperfusion. The secondary endpoint was treatment-related morbidity and mortality. Independent risk factors for IA reperfusion over the long term were analyzed using multivariate logistic regression. Results: Endovascular treatment was the therapy of choice for 333 patients with IAs, among whom 188 (57%) experienced rupture upon presentation. Complete coiling (Raymond I) was noted in 162 (49%) of the patients, with primary supportive devices being used in 51 (15%) patients. After a median (±SD) follow-up time of 34 ± 41 months (range 12-265 months), IA reperfusion was noted in 158 (47%), necessitating retreatment in 105 (32%) of the patients. Over the long term, hemorrhage was noted in four (1%) patients. Multivariate analysis revealed aneurysmal multilobarity (HR 1.8, 95%CI 1.2-2.7; p = 0.004) and a patient age of ≥50 years (HR 1.7, 95% CI 1.1-2.5, p = 0.01) as independent predictors of reperfusion over time. Intervention-related morbidity was noted in 16 (4.8%) patients, namely, thrombosis formation and contrast extravasation in 8 (2.4%) patients each, while no intervention-induced mortality was observed. Conclusion: In the long term, the hemorrhage rate in patients with IA with an initially more conservative endovascular approach is low. Therefore, a deliberate endovascular treatment approach might be justified.

A Human-Scale Clinically Ready Electromagnetic Navigation System for Magnetically Responsive Biomaterials and Medical Devices.

Magnetic navigation systems are used to precisely manipulate magnetically responsive materials enabling the realization of new minimally invasive procedures using magnetic medical devices. Their widespread applicability has been constrained by high infrastructure demands and costs. The study reports on a portable electromagnetic navigation system, the Navion, which is capable of generating a large magnetic field over a large workspace. The system is easy to install in hospital operating rooms and transportable through health care facilities, aiding in the widespread adoption of magnetically responsive medical devices. First, the design and implementation approach for the system are introduced and its performance is characterized. Next, in vitro navigation of different microrobot structures is demonstrated using magnetic field gradients and rotating magnetic fields. Spherical permanent magnets, electroplated cylindrical microrobots, microparticle swarms, and magnetic composite bacteria-inspired helical structures are investigated. The navigation of magnetic catheters is also demonstrated in two challenging endovascular tasks: 1) an angiography procedure and 2) deep navigation within the circle of Willis. Catheter navigation is demonstrated in a porcine model in vivo to perform an angiography under magnetic guidance.

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.

Incidence and Outcome of Peri-interventional Vasospasm During Endovascular or Microsurgical Treatment of Unruptured Intracranial Aneurysms.

BACKGROUND: Peri-interventional vasospasm (PIVS) is associated with high risk of delayed cerebral vasospasm (DCVS), delayed cerebral ischemia, and poor outcome after aneurysmal subarachnoid hemorrhage. However, the incidence rate associated with treatment of unruptured intracranial aneurysm (UIA) remains unclear. OBJECTIVE: To define the incidence and clinical significance of PIVS in UIA repair based on intraoperative/peri-interventional digital subtraction angiography. METHODS: A consecutive series of 205 patients who underwent UIA treatment by means of microsurgical clipping (n = 109) or endovascular coil embolization (n = 96) was assessed for the occurrence of PIVS. In all cases, PIVS was detected, measured, and classified using intraoperative/peri-interventional digital subtraction angiography. Severity of PIVS, association of PIVS with the development of DCVS, and neurological outcome were analyzed. RESULTS: Intraoperative PIVS was present in n = 14/109 (13%) patients with microsurgical clipping. Of these, caliber irregularities were mild (n = 10), moderate (n = 3), and severe (n = 1). In endovascularly treated patients, 6/96 (6%) developed PIVS, which were either mild (n = 3) or moderate (n = 3). Management in all cases included immediate intensive blood pressure management and application of topical papaverine or intra-arterial nimodipine immediately on detection of PIVS. No patient developed DCVS or lasting neurological deficits attributable to PIVS. CONCLUSION: This series revealed a relatively high overall incidence of PIVS (10%). However, no association of PIVS with the development of DCVS or poor outcome was found. In contrast to ruptured intracranial aneurysms, PIVS in unruptured intracranial aneurysms-if immediately and adequately addressed-seems to be benign and without sequelae for patient's functional outcome.

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.

Risk of intracranial aneurysm recurrence after microsurgical clipping based on 3D digital subtraction angiography.

OBJECTIVE: Current knowledge of recurrence rates after intracranial aneurysm (IA) surgery relies on 2D digital subtraction angiography (DSA), which fails to detect more than 75% of small aneurysm remnants. Accordingly, the discrimination between recurrence and growth of a remnant remains challenging, and actual assessment of recurrence risk of clipped IAs could be inaccurate. The authors report, for the first time, 3D-DSA-based long-term durability and risk factor data of IA recurrence and remnant growth after microsurgical clipping. METHODS: Prospectively collected data for 305 patients, with a total of 329 clipped IAs that underwent baseline 3D-DSA, were evaluated. The incidence of recurrent IA was described by Kaplan-Meier curves. Risk factors for IA recurrence were analyzed by multivariable Cox proportional hazards and logistic regression models. RESULTS: The overall observed proportion of IA recurrence after clipping was 2.7% (9 of 329 IAs) at a mean follow-up of 46 months (0.7% per year). While completely obliterated IAs did not recur during follow-up, incompletely clipped aneurysms (76 of 329) demonstrated remnant growth in 11.8% (3.4% per year). Young age and large initial IA size significantly increased the risk of IA recurrence. CONCLUSIONS: The findings support those in previous studies that hypothesized that completely clipped IAs have an extremely low risk of recurrence. Conversely, the results highlight the significant risk posed by incompletely clipped IAs. Young patients with initial large IAs and incomplete obliteration have an especially high risk for IA recurrence and therefore should be monitored more closely.

Case Report: Cerebrospinal Fluid Dynamics in the Optic Nerve Subarachnoid Space and the Brain Applying Diffusion Weighted MRI in Patients With Idiopathic Intracranial Hypertension-A Pilot Study.

Purpose: The aim of this study was to examine the cerebrospinal fluid (CSF) flow rates in the subarachnoid space (SAS) of the optic nerve (ON) and the brain in patients with idiopathic intracranial hypertension (IIH) and papilledema (PE) compared to healthy controls by applying non-invasive diffusion-weighted MRI. Methods: A retrospective analysis of diffusion-weighted MR images of 5 patients with IIH (10 ONs), mean age: 31 ± 10 years (5 women), and 11 healthy controls (22 ONs, mean age: 60 ± 13 years, 5 women) was performed. The flow velocity flow-range ratio (FRR) between the intracranial cavity and the SAS of the ON was calculated in both groups and then compared. Results: The mean FRR was 0.55 ± 0.08 in patients with IIH and 0.63 ± 0.05 in healthy controls. The difference between patients with IIH and healthy controls was statistically significant (p < 0.05). Conclusions: The CSF flow velocity was decreased in patients with IIH with PE compared to healthy controls. The reduced CSF flow dynamics might be involved in the pathophysiology of PE in IIH and diffusion-weighted MRI can be a useful non-invasive tool to study the CSF flow dynamics within the SAS ON. Summary: Idiopathic intracranial hypertension is a neurological disease, where vision loss is the most feared complication of this disorder. The pathophysiology of IIH is not fully understood but is strongly linked to a reduced uptake of CSF into the central dural sinus veins. In this study, we examined the CSF flow rates in the SAS ON and the brain in patients with IIH and PE compared to healthy controls by applying non-invasive diffusion-weighted MRI. Knowing about the flow ratio of CSF may be of clinical relevance for the treatment decisions of IIH. If medical treatment fails, surgical options for lowering the ICP pressure need to be taken into consideration. As the primary goal of treatment is to prevent the loss of vision and visual field, it is important to know whether the communication of CSF between the intracranial CSF and the CSF in the perioptic space is intact. We showed that the CSF flow velocity was decreased in IIH patients with PE compared to healthy controls. The reduced CSF flow might be involved in the pathophysiology of PE in IIH, and diffusion-weighted MRI can be a useful non-invasive tool to study the CSF flow dynamics within the SAS ON.