Embolization techniques of spontaneous direct carotid-cavernous fistulae: a single-center experience.

PURPOSE: Spontaneous direct carotid-cavernous fistula (CCF) are usually caused by a ruptured carotid cavernous aneurysm. We studied treatment of spontaneous direct CCFs in a single-center cohort of a high-volume tertiary referral center, reporting anatomical details, technical approaches of treatment, and outcomes. METHODS: Adult patients with a spontaneous direct CCF treated between 2010-2022 with follow-up MRI and/or DSA imaging available were retrospectively analyzed. We studied age, sex, clinical presentation, angiographic findings, treatment techniques, outcomes, and complications. RESULTS: Out of 80 patients with CCFs, twelve patients were treated for a non-traumatic direct CCF (15%) in 13 sessions. Median age was 65 years. Two patients had an underlying connective tissue disorder. In 10 cases, the direct CCF was caused by a ruptured cavernous carotid aneurysm. The direct CCFs were treated by endovascular transarterial embolization (10 cases), transvenous embolization (1 case), or surgery (1 case). Selective closure of the shunt was possible in 10 patients. Two patients were treated with parent vessel occlusion (PVO; one endovascular; one surgical, with bypass). Complications occurred in 2 / 12 patients (17%), with permanent morbidity in two patients (17%): trigeminal neuralgia after PVO and new infarct after surgical PVO and bypass. Selective closure of CCF resulted in no morbidity. There was no mortality in our series. CONCLUSION: Spontaneous direct CCFs are caused by rupture of a cavernous carotid aneurysm in most cases. Selective closure of the shunt, usually feasible transarterially with coils, achieves good results. Reconstructive endovascular techniques are preferred to minimize treatment related neurological complications.

Assessment of Reversibility of Transverse Venous Sinus Stenosis in Patients With Papilledema.

BACKGROUND: Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema. METHODS: This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices. Inclusion criteria were the presence of papilledema, as quantified by optical coherence tomography, and bilateral TVSS, which is considered typical of IH on neuroimaging. During follow-up, included patients must have had confirmation of papilledema resolution as well as subsequent neuroimaging after conservative treatment or cerebrospinal fluid flow diversion. Patients with dural sinus vein thrombosis or intrinsic stenosis from sinus trabeculations or significant arachnoid granulations were excluded from the study. Either CT venography or MRI/MR venography was reviewed by a fellowship-trained neuroradiologist, and the degree of stenosis was scored through the combined conduit score (CCS), as described by Farb et al. The primary outcome was to assess TVSS changes after resolution or improvement of papilledema. RESULTS: From 435 patients, we identified a subset of 10 who satisfied all inclusion criteria. Our cohort comprised entirely women with a median age of 29.5 years and a median BMI of 32.5 kg/m2. Treatment consisted of acetazolamide in 7 patients, of which 1 had additional topiramate and 2 underwent cerebrospinal fluid flow diversion. Furthermore, 6 patients demonstrated significant weight loss during follow-up. For the primary outcome, 5 of 10 patients exhibited no appreciable TVSS change, and 5 patients demonstrated significant improvement in TVSS, of which 4 received conservative treatment only. Papilledema resolution or improvement was statistically significantly associated with increasing average CCS, TVSS diameter, and grade. CONCLUSIONS: We were able to demonstrate that TVSS can be both irreversible and reversible in patients with resolved papilledema. The finding of TVSS reversibility from conservative treatment alone is novel and has important implications to optimize patient care. Future studies should work to identify factors associated with irreversible TVSS for subsequent targeted intervention and prevention.

Visual and Pharmacotherapy Outcomes After Transverse Sinus Stenting for Idiopathic Intracranial Hypertension.

BACKGROUND: Transverse sinus stenting (TSS) is an increasingly common treatment for patients with idiopathic intracranial hypertension (IIH). However, detailed neuro-ophthalmic evidence on visual and pharmacotherapy outcomes after TSS is scarce and heterogeneous. This study aimed to describe the visual outcomes of patients undergoing TSS for IIH and to ascertain the proportion of patients who could be weaned off intracranial pressure (ICP)-lowering medication postoperatively. METHODS: A retrospective chart review of all patients with IIH from 2 tertiary academic neuro-ophthalmology practices who underwent TSS between 2016 and 2022 was performed. Indications for stenting included failure of pharmacotherapy, intolerance of pharmacotherapy, and acute vision loss from severe papilledema. Data on demographics, symptoms, visual function, pharmacotherapy, and TSS were collected. The paired Wilcoxon rank sum test was used to compare changes in visual acuity (VA) and visual field mean deviation (VFMD) between the baseline and most recent visits. RESULTS: Of the 435 patients with IIH, 15 (13 women) met inclusion criteria. After TSS, ICP-lowering pharmacotherapy was discontinued in 10 patients and decreased in 4; 1 patient was not on ICP-lowering medication before TSS. All patients experienced resolution or improvement of symptoms (10 resolution, 4 improved, 1 asymptomatic before TSS) and papilledema (11 resolution, 4 improved) after stenting. Papilledema resolution was confirmed with optical coherence tomography-measured peripapillary nerve fiber layer thickness (median decrease 147 µm, interquartile range 41.8-242.8 µm, P < 0.001). Change in VA between the baseline and most recent visit was not significant, but VFMD improved significantly after stenting (median increase 3.0, IQR 2.0-4.2, P < 0.001). No patient developed transverse sinus restenosis nor in-stent thrombosis postoperatively across a median venogram follow-up of 20.8 (11.3-49.8) weeks. In addition, no patient required subsequent surgical intervention for IIH. CONCLUSIONS: In this cohort of patients with IIH and fulminant presentation, medication resistance, or medication intolerance, TSS was an effective and safe treatment modality. Most patients were able to stop ICP-lowering medications while demonstrating striking improvement in symptomatology and visual function.

Periventricular nodular heterotopia associated with a "transmantle band sign" in patients with epilepsy.

OBJECTIVE: Previous studies using advanced magnetic resonance imaging (MRI) techniques have documented abnormal transmantle bands connecting ectopic nodules to overlying cortex in patients with periventricular nodular heterotopia (PNH). We describe a similar finding using conventional MRI techniques. METHODS: Patients were identified by means of a full-text search of radiological reports. All scanning was performed using conventional sequences at 3 Tesla (3T). Scans were reviewed by three neuroradiologists, and we characterized imaging features based on type of PNH and cortical irregularities associated with the transmantle band. RESULTS: A total 57 PNH patients were reviewed, of whom 41 demonstrated a "transmantle band" connecting the nodule to the overlying cortex. One or more periventricular heterotopic nodules was present in all 41 patients-this was bilateral in 29 of 41 (71%) and unilateral in the remaining 29%. In many cases there was more than one such band, and in some cases this band was nodular. In 19 of the cases, the cortex to which the band connected was abnormal, showing thinning in 4 cases, thickening in 5 cases, and polymicrogyria in another 10. SIGNIFICANCE: The transmantle band can be seen frequently in both unilateral and bilateral cases of PNH and can be visualized with conventional 3T MRI sequences. The band highlights the underlying neuronal migration issues at play in the pathogenesis of this disorder, but its underlying role in the complex, patient-specific epileptogenic networks in this cohort has yet to be determined and warrants further investigation.

The presence of pachymeningeal hyperintensity on non-contrast flair imaging in patients with spontaneous intracranial hypotension.

PURPOSE: Traditionally, in the work-up of patients for spontaneous intracranial hypotension, T1 post-contrast imaging is performed in order to assess for pachymeningeal enhancement. The aim of this study is to assess whether pachymeningeal hyperintensity can be identified on a non-contrast FLAIR sequence in these patients as a surrogate sign for pachymeningeal enhancement. METHODS: The patient cohort was identified from a prospectively maintained database of patients with a clinical diagnosis of intracranial hypotension. Patients who had both a post-contrast T1 sequence brain as well as non-contrast FLAR sequence of the brain were reviewed. Imaging was retrospectively reviewed by three independent neuroradiologists. Each study was assessed for the presence or absence of pachymeningeal hyperintensity on the FLAIR sequence. RESULTS: From January 2010 to July 2022, 177 patients were diagnosed with spontaneous intracranial hypotension. In total, 121 were excluded as post-contrast imaging was not performed during their work-up. Twenty-four were excluded as the FLAIR sequence was performed after administration of contrast. Six were excluded as there was no pachymeningeal thickening present on T1 post-contrast imaging, although there were other signs of intracranial hypotension. The study group therefore consisted of 26 patients. Pachymeningeal thickening was correctly identified on the non-contrast FLAIR sequence in all patients (100%). CONCLUSION: Where present, diffuse pachymeningeal hyperintensity can be accurately identified on a non-contrast FLAIR sequence in patients with spontaneous intracranial hypotension. This potentially obviates the need for gadolinium base contrast agents in the work-up of these patients.

Visual Recovery in 2 Cases of Central Retinal Artery Occlusion Treated With Prompt Intra-ophthalmic Artery Fibrinolysis.

BACKGROUND: Central retinal artery occlusion (CRAO) rapidly produces inner retinal ischemia and irreversible vision loss. Although many therapeutic interventions have been proposed, no interventions have proven effective in restoring vision in large randomized controlled trials and final visual outcome in most patients is very poor. METHODS: Retrospective case series. RESULTS: We describe 2 cases of CRAO occurring after uncomplicated cataract surgery under topical anesthesia and rapidly diagnosed. Both had very severe vision loss at presentation with dramatic improvement after intra-ophthalmic artery fibrinolysis administered 2.75 and 5.5 hours after symptom onset. CONCLUSIONS: Sudden monocular vision loss is an ophthalmologic emergency as CRAO must be ruled out and if diagnosed, rapid intervention should be performed. Devastating vision loss can be prevented if interventional neuroradiology is trained and available on a 24-hour basis for administration of local intra-arterial thrombolysis.

Idiopathic Intracranial Hypertension: Glymphedema of the Brain.

BACKGROUND: During the last decade, our understanding of cerebrospinal fluid (CSF) physiology has dramatically improved, thanks to the discoveries of both the glymphatic system and lymphatic vessels lining the dura mater in human brains. EVIDENCE ACQUISITION: We detail the recent basic science findings in the field of CSF physiology and connect them with our current understanding of the pathophysiology of idiopathic intracranial hypertension (IIH). RESULTS: Transverse sinus (TS) stenoses seem to play a major causative role in the symptoms of IIH, as a result of a decrease in the pressure gradient between the venous system and the subarachnoid space. However, the intracranial pressure can be highly variable among different patients, depending on the efficiency of the lymphatic system to resorb the CSF and on the severity of TS stenoses. It is likely that there is a subclinical form of IIH and that IIH without papilledema is probably under-diagnosed among patients with chronic migraines or isolated tinnitus. CONCLUSIONS: IIH can be summarized in the following pathological triad: restriction of the venous CSF outflow pathway-overflow of the lymphatic CSF outflow pathway-congestion of the glymphatic system. To better encompass all the stages of IIH, it is likely that the Dandy criteria need to be updated and that perhaps renaming IIH should be considered.

Endovascular Therapy of Acute Ischemic Stroke in Patients with Large-Vessel Occlusion Associated with Active Malignancy.

PURPOSE: There is limited data on the effectiveness of endovascular therapy (EVT) in stroke patients with active malignancy. In this study, we investigated the outcome of EVT for acute ischemic stroke for patients with active malignancy compared to those without malignancy. METHODS: We selected patients who underwent EVT for acute ischemic stroke between January 2015 and July 2019. Patients were divided into two groups, those with active malignancy (oncology group - OG) and those without (non-oncology group, NOG). RESULTS: 300 patients were included in this study. There were 19 EVT procedures (18 patients) in the OG and 285 procedures (282 patients) in the NOG. There was no difference in recanalization success rate (mTICI 2b & 3) between the groups: 94.7% versus 80.9% in OG and NOG respectively (p = 0.13). Success rate using the direct aspiration (ADAPT) technique of EVT was not different between compared groups (42.9% versus 67.7%; p = 0.18). However, when using smaller-caliber aspiration devices, ADAPT was less successful in OG (0.0% versus 64.7%, p < 0.05). There was no difference in recanalization success rate of EVT when using a stent-retriever or combined technique. Patients in the OG had a less favorable functional outcome than in the NOG group (mRS 0-2 at 90-days post event: 22.2% versus 48.2%, p < 0.05) CONCLUSION: The technical success rate of EVT in patients with active malignancy is similar to the general population of stroke patients. Interestingly, the success rate of EVT using the ADAPT technique was lower in the OG when using smaller caliber aspiration devices.

Acute Stroke Management During the COVID-19 Pandemic: Does Confinement Impact Eligibility for Endovascular Therapy?

During the coronavirus disease 2019 (COVID-19) pandemic, the World Health Organization recommended measures to mitigate the outbreak such as social distancing and confinement. Since these measures have been put in place, anecdotal reports describe a decrease in the number of endovascular therapy (EVT) treatments for acute ischemic stroke due to large vessel occlusion. The purpose of our study was to determine the effect on EVT for patients with acute ischemic stroke during the COVID-19 confinement. In this retrospective, observational study, data were collected from November 1, 2019, to April 15, 2020, at 17 stroke centers in countries where confinement measures have been in place since March 2020 for the COVID-19 pandemic (Switzerland, Italy, France, Spain, Portugal, Germany, Canada, and United States). This study included 1600 patients treated by EVT for acute ischemic stroke. Date of EVT and symptom onset-to-groin puncture time were collected. Mean number of EVTs performed per hospital per 2-week interval and mean stroke onset-to-groin puncture time were calculated before confinement measures and after confinement measures. Distributions (non-normal) between the 2 groups (before COVID-19 confinement versus after COVID-19 confinement) were compared using 2-sample Wilcoxon rank-sum test. The results show a significant decrease in mean number of EVTs performed per hospital per 2-week interval between before COVID-19 confinement (9.0 [95% CI, 7.8-10.1]) and after COVID-19 confinement (6.1 [95% CI, 4.5-7.7]), (P<0.001). In addition, there is a significant increase in mean stroke onset-to-groin puncture time (P<0.001), between before COVID-19 confinement (300.3 minutes [95% CI, 285.3-315.4]) and after COVID-19 confinement (354.5 minutes [95% CI, 316.2-392.7]). Our preliminary analysis indicates a 32% reduction in EVT procedures and an estimated 54-minute increase in symptom onset-to-groin puncture time after confinement measures for COVID-19 pandemic were put into place.

Cerebrofacial venous metameric syndrome-spectrum of imaging findings.

Cerebrofacial venous metameric syndrome (CVMS) is a complex craniofacial vascular malformation disorder in which patients have a constellation of venous vascular malformations affecting soft tissues, bone, dura, and neural structures including the eye and brain. It is hypothesized that a somatic mutation responsible for the venous abnormalities occurred prior to migration of the neural crest cells, and because of this, facial, osseous, and cerebral involvement typically follows a segmental or "metameric" distribution. The most commonly recognized form of CVMS is Sturge-Weber syndrome. However, a wide spectrum of CVMS phenotypical presentations exist with various metameric distributions of slow-flow vascular lesions including facial venous vascular malformations, developmental venous anomalies, venous angiomas, cavernous malformations (cavernomas), dural sinus malformations, and maybe even vascular tumors such as cavernous hemangiomas. Awareness of the various manifestations as described herewith is important for treatment and screening purposes.

Proposed achievable levels of dose and impact of dose-reduction systems for thrombectomy in acute ischemic stroke: an international, multicentric, retrospective study in 1096 patients.

BACKGROUND: International dose reference levels are lacking for mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusions. We studied whether radiation dose-reduction systems (RDS) could effectively reduce exposure and propose achievable levels. MATERIALS AND METHODS: We retrospectively included consecutive patients treated with thrombectomy on a biplane angiography system (BP) in five international, high-volume centers between January 2014 and May 2017. Institutional Review Board approvals were obtained. Technical, procedural, and clinical characteristics were assessed. Efficacy, safety, radiation dose, and contrast load were compared between angiography systems with and without RDS. Multivariate analyses were adjusted according to Bonferroni's correction. Proposed international achievable cutoff levels were set at the 75th percentile. RESULTS: Out of the 1096 thrombectomized patients, 520 (47%) were treated on a BP equipped with RDS. After multivariate analysis, RDS significantly reduced dose-area product (DAP) (91 vs 140 Gy cm2, relative effect 0.74 (CI 0.66; 0.83), 35% decrease, p < 0.001) and air kerma (0.46 vs 0.97 Gy, relative effect 0.63 (CI 0.56; 0.71), 53% decrease, p < 0.001) with 75th percentile levels of 148 Gy cm2 and 0.73 Gy, respectively. There was no difference in contrast load, rates of successful recanalization, complications, or clinical outcome. CONCLUSION: Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety. The respective thresholds of 148 Gy cm2 and 0.73 Gy represent achievable levels that may serve to optimize current and future radiation exposure in the setting of acute ischemic stroke treatment. As technology evolves, we expect these values to decrease. KEY POINTS: • Internationally validated achievable levels may help caregivers and health authorities better assess and reduce radiation exposure of both ischemic stroke patients and treating staff during thrombectomy procedures. • Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety in the setting of acute ischemic stroke due to large vessel occlusion.

Diagnostic accuracy of a clinical carotid plaque MR protocol using a neurovascular coil compared to a surface coil protocol.

BACKGROUND: Carotid plaque imaging with MRI is becoming more commonplace, but practical challenges exist in performing plaque imaging with surface coils. PURPOSE: To compare the diagnostic performance of a carotid plaque MRI protocol using a standard neurovascular coil (Neurovascular Coil Protocol) to a higher-resolution carotid plaque MRI using carotid surface coils (Surface Coil Protocol) in characterizing carotid plaque. STUDY TYPE: Prospective study comparing two MR techniques in plaque characterization. POPULATION: Thirty-eight consecutive carotid artery disease patients. FIELD STRENGTH/SEQUENCE: Patients underwent 3T MRI using 1) a Neurovascular Coil Protocol including the following sequences: 3D-FSE T1 pre/postcontrast and precontrast 3D IR-FSPGR, and 2) a Surface Coil Protocol using standard multicontrast MRI sequences. ASSESSMENT: Plaque characteristics analyzed by two independent neuroradiologists included intraplaque hemorrhage (IPH), lipid-rich necrotic-core (LRNC), and thin/ruptured fibrous cap (TRFC). STATISTICAL TESTS: Diagnostic performance of the Neurovascular Coil Protocol was compared to the Surface Coil Protocol reference standard using receiver-operating curves. RESULTS: For IPH, sensitivity, specificity, and area under the curve (AUC) of the Neurovascular Coil Protocol were 91.1% (95% confidence interval [CI] = 78.8-97.5%), 87.0% (95% CI = 66.4-97.2%), and 0.92, respectively. For LRNC without IPH sensitivity, specificity, and AUC were 73.3% (95% CI = 44.9-92.2%), 85.7% (95% CI = 67.3-96.0%), and 0.84, respectively. For TRFC, sensitivity, specificity, and AUC were 35.3% (95% CI = 14.2-61.7%), 97.6% (95% CI = 87.4-99.9%), and 0.66 respectively. Interobserver agreement for IPH, LRNC, and TRFC using the Neurovascular Coil Protocol were k = 0.87 (95% CI = 0.75-0.99), k = 0.54 (95% CI = 0.29-0.80), and k = 0.41 (95% CI = 0.08-0.74), respectively. DATA CONCLUSION: Our Neurovascular Coil Protocol has high sensitivity, specificity, and accuracy in identifying IPH and LRNC but is limited in assessment of TRFC. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1264-1272.

Longitudinally extensive transverse myelitis after Campylobacter jejuni enteritis.

Campylobacter jejuni infection is well-known to precipitate Guillain-Barré syndrome through an immune-mediated attack on the peripheral nervous system. Molecular mimicry between C. jejuni lipo-oligosaccharides on the surface of infectious agents and human gangliosides in the peripheral nerves induces cross-reactive immune responses. Although gangliosides also occur in the central nervous system (CNS), autoimmune CNS disorders rarely follow Cjejuni infections. However, longitudinally extensive transverse myelitis commonly has a parainfectious cause, triggered by a wide range of micro-organisms including viruses and bacteria. We report a patient who developed longitudinally extensive transverse myelitis after Cjejuni enteritis associated with antiganglioside antibodies.

Radiofrequency ablation for neuroendocrine liver metastases: a systematic review.

To determine the efficacy of radiofrequency (RF) ablation in neuroendocrine tumor (NET) liver metastases. A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight studies were included (N = 301). Twenty-six percent of RF ablation procedures were percutaneous (n = 156), with the remainder conducted at surgery. Forty-eight percent of patients had a concomitant liver resection. Fifty-four percent of patients presented with symptoms, with 92% reporting symptom improvement following RF ablation (alone or in combination with surgery). The median duration of symptom improvement was 14-27 months. However, recurrence was common (63%-87%). RF ablation can provide symptomatic relief in NET liver metastases alone or in combination with surgery.