Outcomes of mechanical thrombectomy in acute stroke patients with atrial fibrillation detected after stroke versus known atrial fibrillation.

We aim to compare the outcomes in patients with atrial fibrillation detected after stroke (AFDAS) and their counterparts with known AF (KAF) presenting with large vessel occlusion (LVO) treated with mechanical thrombectomy (MT). This observational, prospective study included consecutive patients with acute LVO ischemic stroke of the anterior circulation with AFDAS, KAF and without AF. The primary study outcome was functional independence at 90 days after stroke. The secondary study outcomes were variation of the NIHSS score at 24 h, rate of successful reperfusion, death at 90 days and rate of immediate complications post-procedure. Overall, our cohort included 518 patients with acute ischemic stroke and LVO treated with MT, with 289 (56.8%) without a diagnosis of AF; 107 (21%) with AFDAS; 122 (22.2%) with KAF. There was no significant difference in terms of functional independence at 90 days after stroke between the three groups. Regarding the secondary study outcome, the rate of symptomatic intracranial haemorrhage (sICH) and/or parenchymal hematoma (PH) were significantly higher in the group of patients without AF (respectively, P = 0.030 and < 0.010). Logistic regression analysis showed that the subtypes of AF were not statistically significantly associated with functional independence at 90 days after stroke and with the likelihood of any ICH. Our results suggest that the subtypes of AF are not associated with clinical and safety outcomes of MT in patients with acute stroke and LVO. Further studies are needed to confirm our findings.

Challenges with segmenting intraoperative ultrasound for brain tumours.

Objective - Addressing the challenges that come with identifying and delineating brain tumours in intraoperative ultrasound. Our goal is to both qualitatively and quantitatively assess the interobserver variation, amongst experienced neuro-oncological intraoperative ultrasound users (neurosurgeons and neuroradiologists), in detecting and segmenting brain tumours on ultrasound. We then propose that, due to the inherent challenges of this task, annotation by localisation of the entire tumour mass with a bounding box could serve as an ancillary solution to segmentation for clinical training, encompassing margin uncertainty and the curation of large datasets. Methods - 30 ultrasound images of brain lesions in 30 patients were annotated by 4 annotators - 1 neuroradiologist and 3 neurosurgeons. The annotation variation of the 3 neurosurgeons was first measured, and then the annotations of each neurosurgeon were individually compared to the neuroradiologist's, which served as a reference standard as their segmentations were further refined by cross-reference to the preoperative magnetic resonance imaging (MRI). The following statistical metrics were used: Intersection Over Union (IoU), Sørensen-Dice Similarity Coefficient (DSC) and Hausdorff Distance (HD). These annotations were then converted into bounding boxes for the same evaluation. Results - There was a moderate level of interobserver variance between the neurosurgeons [ I o U : 0.789 , D S C : 0.876 , H D : 103.227 ] and a larger level of variance when compared against the MRI-informed reference standard annotations by the neuroradiologist, mean across annotators [ I o U : 0.723 , D S C : 0.813 , H D : 115.675 ] . After converting the segments to bounding boxes, all metrics improve, most significantly, the interquartile range drops by [ I o U : 37 % , D S C : 41 % , H D : 54 % ] . Conclusion - This study highlights the current challenges with detecting and defining tumour boundaries in neuro-oncological intraoperative brain ultrasound. We then show that bounding box annotation could serve as a useful complementary approach for both clinical and technical reasons.

2021 WHO classification of tumours of the central nervous system: a review for the neuroradiologist.

The fifth edition of the World Health Organization Classification of Tumours of the Central Nervous System (WHO CNS5) published in 2021 builds on the 2016 edition and incorporates output from the Consortium to Inform Molecular and Practical Approaches to CNS Tumour Taxonomy (cIMPACT-NOW). WHO CNS5 introduces fundamental changes to brain tumour classification through the introduction of new tumour families and types, especially in the paediatric population, and a revision of diagnostic criteria for some of the existing neoplasms. Neuroradiologists are central to brain tumour diagnostics, and it is therefore essential that they become familiar with the key updates. This review aims to summarise the most relevant updates for the neuroradiologist and, where available, discuss the known radiophenotypes of various new tumour types to allow for increased accuracy of language and diagnosis. Of particular importance, WHO CNS5 places greater emphasis on organising tumours by molecular type to reflect biology, as well as to allow for better planning of treatment. The principal updates in adult tumours concern the molecular definition of glioblastoma, restructuring of diffuse gliomas, and the introduction of several new tumour types. The updates to the paediatric classification are protean, ranging from the introduction of new types to establishing separate tumour families for paediatric-type gliomas. This review summarises the most significant revisions and captures the rationale and radiological implications for the major updates.

Intraoperative ultrasound in brain tumor surgery: A review and implementation guide.

Accurate and reliable intraoperative neuronavigation is crucial for achieving maximal safe resection of brain tumors. Intraoperative MRI (iMRI) has received significant attention as the next step in improving navigation. However, the immense cost and logistical challenge of iMRI precludes implementation in most centers worldwide. In comparison, intraoperative ultrasound (ioUS) is an affordable tool, easily incorporated into existing theatre infrastructure, and operative workflow. Historically, ultrasound has been perceived as difficult to learn and standardize, with poor, artifact-prone image quality. However, ioUS has dramatically evolved over the last decade, with vast improvements in image quality and well-integrated navigation tools. Advanced techniques, such as contrast-enhanced ultrasound (CEUS), have also matured and moved from the research field into actual clinical use. In this review, we provide a comprehensive and pragmatic guide to ioUS. A suggested protocol to facilitate learning ioUS and improve standardization is provided, and an outline of common artifacts and methods to minimize them given. The review also includes an update of advanced techniques and how they can be incorporated into clinical practice.

Cerebrospinal fluid cytology findings in a case of diffuse leptomeningeal glioneuronal tumour.

This case report describes the cytological features of a rare tumour: diffuse leptomeningeal glioneuronal tumour. This case highlights the value of cerebrospinal fluid analysis when this type of tumour is suspected, both for aiding the preliminary morphological diagnosis and for enabling potential molecular testing.

Epilepsy surgery in children: what the radiologist needs to know.

This review updates the radiologist on current epilepsy surgery practice in children, with a specific focus on the role of imaging in pre-surgical work-up, current and novel surgical techniques, expected post-surgical imaging appearances and important post-operative complications. A comprehensive review of the current and emerging international practices in paediatric epilepsy surgical planning and post-operative imaging is provided with details on case-based radiological findings. A detailed discussion of the pathophysiology and imaging features of different epileptogenic lesions will not be discussed as this is not the objective of this paper. Epilepsy surgery can be an effective method to control seizures in certain children with drug-resistant focal epilepsy. Early surgery in selected appropriate cases can lead to improved cognitive and developmental outcome. Advances in neurosurgical techniques, imaging and neuroanaesthesia have driven a parallel expansion in the array of epilepsy conditions which are potentially treatable with surgery. The range of surgical options is now wide, including minimally invasive ablative procedures for small lesions such as hypothalamic hamartomata, resections for focal lesions like hippocampal sclerosis and complex disconnective surgeries for multilobar conditions like Sturge Weber Syndrome and diffuse cortical malformations. An awareness of the surgical thinking when planning epilepsy surgery in children, and the practical knowledge of the operative steps involved will promote more accurate radiology reporting of the post-operative scan.

Venous pathologies in paediatric neuroradiology: from foetal to adolescent life.

The interpretation of cerebral venous pathologies in paediatric practice is challenging as there are several normal anatomical variants, and the pathologies are diverse, involving the venous system through direct and indirect mechanisms. This paper aims to provide a comprehensive review of these entities, as their awareness can avoid potential diagnostic pitfalls. We also propose a practical classification system of paediatric cerebral venous pathologies, which will enable more accurate reporting of the neuroimaging findings, as relevant to the underlying pathogenesis of these conditions. The proposed classification system comprises of the following main groups: arterio-venous shunting-related disorders, primary venous malformations and veno-occlusive disorders. A multimodal imaging approach has been included in the relevant subsections, with a brief overview of the modality-specific pitfalls that can also limit interpretation of the neuroimaging. The article also summarises the current literature and international practices in terms of management options and outcomes in specific disease entities.

Correction to: Venous pathologies in paediatric neuroradiology: from foetal to adolescent life.

The original version of this article unfortunately contained a referencing omission. Figure 11 is reused from the original publication of Figure 10 of Gunny and Lin [1].

The diagnostic role of diffusional kurtosis imaging in glioma grading and differentiation of gliomas from other intra-axial brain tumours: a systematic review with critical appraisal and meta-analysis.

PURPOSE: We aim to illustrate the diagnostic performance of diffusional kurtosis imaging (DKI) in the diagnosis of gliomas. METHODS: A review protocol was developed according to the (PRISMA-P) checklist, registered in the international prospective register of systematic reviews (PROSPERO) and published. A literature search in 4 databases was performed using the keywords 'glioma' and 'diffusional kurtosis'. After applying a robust inclusion/exclusion criteria, included articles were independently evaluated according to the QUADAS-2 tool and data extraction was done. Reported sensitivities and specificities were used to construct 2 × 2 tables and paired forest plots using the Review Manager (RevMan®) software. A random-effect model was pursued using the hierarchical summary receiver operator characteristics. RESULTS: A total of 216 hits were retrieved. Considering duplicates and inclusion criteria, 23 articles were eligible for full-text reading. Ultimately, 19 studies were eligible for final inclusion. The quality assessment revealed 9 studies with low risk of bias in the 4 domains. Using a bivariate random-effect model for data synthesis, summary ROC curve showed a pooled area under the curve (AUC) of 0.92 and estimated sensitivity of 0.87 (95% CI 0.78-0.92) in high-/low-grade gliomas' differentiation. A mean difference in mean kurtosis (MK) value between HGG and LGG of 0.22 (95% CI 0.25-0.19) was illustrated (p value = 0.0014) with moderate heterogeneity (I2 = 73.8%). CONCLUSION: DKI shows good diagnostic accuracy in the differentiation of high- and low-grade gliomas further supporting its potential role in clinical practice. Further exploration of DKI in differentiating IDH status and in characterising non-glioma CNS tumours is however needed.

Severe Disseminated Infection with Emerging Lineage of Methicillin-Sensitive Staphylococcus aureus.

We report a case of severe disseminated infection in an immunocompetent man caused by an emerging lineage of methicillin-sensitive Staphylococcus aureus clonal complex 398. Genes encoding classic virulence factors were absent. The patient made a slow recovery after multiple surgical interventions and a protracted course of intravenous flucloxacillin.

Marine antifouling performance of polymer coatings incorporating zwitterions.

Zwitterionic materials display antifouling promise, but their potential in marine anti-biofouling is still largely unexplored. This study evaluates the effectiveness of incorporating small quantities (0-20% on a molar basis) of zwitterions as sulfobetaine methacrylate (SBMA) or carboxybetaine methacrylate (CBMA) into lauryl methacrylate-based coatings whose relatively hydrophobic nature encourages adhesion of the diatom Navicula incerta, a common microfouling organism responsible for the formation of 'slime'. This approach allows potential enhancements in antifouling afforded by zwitterion incorporation to be easily quantified. The results suggest that the incorporation of CBMA does provide a relatively minor enhancement in fouling-release performance, in contrast to SBMA which does not display any enhancement. Studies with coatings incorporating mixtures of varying ratios of the cationic monomer [2-(methacryloyloxy)ethyl]trimethylammonium chloride and the anionic monomer (3-sulfopropyl)methacrylate, which offer a potentially lower cost approach to the incorporation of anionic and cationic charge, suggest these monomers impart little significant effect on biofouling.

Paired associative transspinal and transcortical stimulation produces plasticity in human cortical and spinal neuronal circuits.

Anatomical, physiological, and functional connectivity exists between the neurons of the primary motor cortex (M1) and spinal cord. Paired associative stimulation (PAS) produces enduring changes in M1, based on the Hebbian principle of associative plasticity. The present study aimed to establish neurophysiological changes in human cortical and spinal neuronal circuits by pairing noninvasive transspinal stimulation with transcortical stimulation via transcranial magnetic stimulation (TMS). We delivered paired transspinal and transcortical stimulation for 40 min at precise interstimulus intervals, with TMS being delivered after (transspinal-transcortical PAS) or before (transcortical-transspinal PAS) transspinal stimulation. Transspinal-transcortical PAS markedly decreased intracortical inhibition, increased intracortical facilitation and M1 excitability with concomitant decreases of motor threshold, and reduced the soleus Hoffmann's reflex (H-reflex) low frequency-mediated homosynaptic depression. Transcortical-transspinal PAS did not affect intracortical circuits, decreased M1 excitability, and reduced the soleus H-reflex-paired stimulation pulses' mediated postactivation depression. Both protocols affected the excitation threshold of group Ia afferents and motor axons. These findings clearly indicate that the pairing of transspinal with transcortical stimulation produces cortical and spinal excitability changes based on the timing interval and functional network interactions between the two associated inputs. This new PAS paradigm may constitute a significant neuromodulation method with physiological impact, because it can be used to alter concomitantly excitability of intracortical circuits, corticospinal neurons, and spinal inhibition in humans.

Transspinal constant-current long-lasting stimulation: a new method to induce cortical and corticospinal plasticity.

Functional neuroplasticity in response to stimulation and motor training is a well-established phenomenon. Transcutaneous stimulation of the spine is used mostly to alleviate pain, but it may also induce functional neuroplasticity, because the spinal cord serves as an integration center for descending and ascending neuronal signals. In this work, we examined whether long-lasting noninvasive cathodal (c-tsCCS) and anodal (a-tsCCS) transspinal constant-current stimulation over the thoracolumbar enlargement can induce cortical, corticospinal, and spinal neuroplasticity. Twelve healthy human subjects, blind to the stimulation protocol, were randomly assigned to 40 min of c-tsCCS or a-tsCCS. Before and after transspinal stimulation, we established the afferent-mediated motor evoked potential (MEP) facilitation and the subthreshold transcranial magnetic stimulation (TMS)-mediated flexor reflex facilitation. Recruitment input-output curves of MEPs and transspinal evoked potentials (TEPs) and postactivation depression of the soleus H reflex and TEPs was also established. We demonstrate that both c-tsCCS and a-tsCCS decrease the afferent-mediated MEP facilitation and alter the subthreshold TMS-mediated flexor reflex facilitation in a polarity-dependent manner. Both c-tsCCS and a-tsCCS increased the tibialis anterior MEPs recorded at 1.2 MEP resting threshold, intermediate, and maximal intensities and altered the recruitment input-output curve of TEPs in a muscle- and polarity-dependent manner. Soleus H-reflex postactivation depression was reduced after a-tsCCS and remained unaltered after c-tsCCS. No changes were found in the postactivation depression of TEPs after c-tsCCS or a-tsCCS. Our findings reveal that c-tsCCS and a-tsCCS have distinct effects on cortical and corticospinal excitability. This method can be utilized to induce targeted neuroplasticity in humans.

Safety and outcomes of different endovascular treatment techniques for anterior circulation ischaemic stroke in the elderly: data from the Imperial College Thrombectomy Registry.

BACKGROUND: Although previous studies investigated the main predictors of outcomes after endovascular thrombectomy (EVT) in patients aged 80 years and older, less is known about the impact of the procedural features on outcomes in elderly patients. The aim of this study was to investigate the influence of EVT technical procedures on the main 3-month outcomes in a population of patients aged 80 years and older. METHODS: This observational, prospective, single-centre study included consecutive patients with acute LVO ischaemic stroke of the anterior circulation. The study outcomes were functional independence at 3 months after EVT (defined as a mRS score of 0-2), successful reperfusion (mTICI ≥ 2b), incidence of haeamorrhagic transformation, and 90-day all cause of mortality. RESULTS: Our cohort included 497 patients with acute ischaemic stroke due to LVO treated with EVT. Among them, 105 (21.1%) patients were aged ≥ 80 years. In the elderly group, multivariable regression analysis showed that thromboaspiration technique vs stent-retriever was the single independent predictor of favourable post-procedural TICI score (OR = 7.65, 95%CI = 2.22-26.32, p = 0.001). CONCLUSIONS: Our study suggests that EVT for LVO stroke in the elderly could be safe. The use of thromboaspiration was associated with positive reperfusion outcome in this population. Further studies in larger series are warranted to confirm the present results and to evaluate the safety and efficacy of EVT in the elderly and oldest adults.

Unprecedented regiochemical control in the formation of aryl[1,2-a]imidazopyridines from alkynyliodonium salts: mechanistic insights.

Aryl(alkynyl)iodonium salts have been demonstrated to be valuable precursors to a diverse range of heteroaromatic ring systems including aryl[1,2-a]imidazopyridines. Successful application, using the recently described aryl(alkynyl)iodonium trifluoroacetate salts, is described, highlighting for the first time that the regioselectivity of this process is both counter-ion and concentration dependent. Studies with a carbon-13 labelled substrate established that the reactions of alkynyliodonium salts are highly complex and that multiple mechanistic processes appear to be underway simultaneously.

Imaging Spectrum of HTLV-1-Related Neurologic Disease: A Pooled Series and Review.

Purpose of Review: Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM) is a well-recognized neurologic complication of HTLV-1. Beyond HAM, several other neurologic manifestations are increasingly recognized, including acute myelopathy, encephalopathy, and myositis. The clinical and imaging features of these presentations are less well understood and potentially underdiagnosed. In this study, we summarize the imaging features of HTLV-1-related neurologic disease, providing both a pictorial review and pooled series of the less well-recognized presentations. Recent Findings: 35 cases of acute/subacute HAM and 12 cases of HTLV-1-related encephalopathy were found. In subacute HAM, cervical and upper thoracic longitudinally extensive tranverse myelitis was noted, while in HTLV-1-related encephalopathy, confluent lesions in the frontoparietal white matter and along the corticospinal tracts were the most prevalent finding. Summary: There are varied clinical and imaging presentations of HTLV-1-related neurologic disease. Recognition of these features aids early diagnosis where therapy may have the greatest benefit.

LGI1 Encephalitis and IgG4-Related Disease: Rare Conditions Collide.

OBJECTIVES: Leucine-rich glioma-inactivated 1 (LGI1) encephalitis and IgG4-related disease (IgG4RD) have traditionally been regarded as 2 distinct disease entities. METHODS: We detail the presentation, investigations, and management of a patient who showed typical signs and symptoms of LGI1 encephalitis and also found to possess pancreatic changes and a serum profile in keeping with IgG4RD. RESULTS: Serum and CSF analyses at presentation showed a significant hyponatraemia (117 mmol/L), elevated IgG4 concentration (1.73 g/L), and the presence of LGI1 antibodies. MRI revealed symmetrical diffuse T2-weighted hyperintensity and mild swelling throughout both medial temporal lobes. CT of the chest, abdomen and pelvis revealed an edematous, bulky pancreas with loss of lobulation, typical for IgG4RD. A glucocorticoid weaning regimen was commenced, facilitated by 2 rituximab infusions, with the patient showing an effective treatment response. HLA testing confirmed the presence of HLA DRB1 and HLA DQB1 risk alleles. DISCUSSION: This case suggests that there may be shared mechanisms between LGI1 encephalitis and IgG4RD, supported by common risk HLA associations and treatment strategies/responses. To our knowledge, this represents the first instance that LGI1 encephalitis and IgG4RD have been reported in the same patient and emphasizes the continued development of our understanding of the wide range of IgG4-mediated conditions.

Adult-onset leukodystrophies: a practical guide, recent treatment updates, and future directions.

Adult-onset leukodystrophies though individually rare are not uncommon. This group includes several disorders with isolated adult presentations, as well as several childhood leukodystrophies with attenuated phenotypes that present at a later age. Misdiagnoses often occur due to the clinical and radiological overlap with common acquired disorders such as infectious, immune, inflammatory, vascular, metabolic, and toxic etiologies. Increased prevalence of non-specific white matter changes in adult population poses challenges during diagnostic considerations. Clinico-radiological spectrum and molecular landscape of adult-onset leukodystrophies have not been completely elucidated at this time. Diagnostic approach is less well-standardized when compared to the childhood counterpart. Absence of family history and reduced penetrance in certain disorders frequently create a dilemma. Comprehensive evaluation and molecular confirmation when available helps in prognostication, early initiation of treatment in certain disorders, enrollment in clinical trials, and provides valuable information for the family for reproductive counseling. In this review article, we aimed to formulate an approach to adult-onset leukodystrophies that will be useful in routine practice, discuss common adult-onset leukodystrophies with usual and unusual presentations, neuroimaging findings, recent advances in treatment, acquired mimics, and provide an algorithm for comprehensive clinical, radiological, and genetic evaluation that will facilitate early diagnosis and consider active treatment options when available. A high index of suspicion, awareness of the clinico-radiological presentations, and comprehensive genetic evaluation are paramount because treatment options are available for several disorders when diagnosed early in the disease course.