An Institutional Perspective on the Number of Stent Retriever Pass and Rate of Recanalization in Mechanical Thrombectomy for Acute Ischemic Stroke: When to Stop?

Background and purpose: Mechanical thrombectomy is the standard treatment modality for flow restoration in acute ischemic stroke. In cases of persistent occlusion, the optimal number of retrieval attempts before considering procedure termination is currently undetermined and is a topic for research. Therefore in this study, we studied the impact of the number of stent retrieval maneuvers on the recanalization of vessels. Methods: In this retrospective single-center observational study we included 52 patients with large vessel occlusion who underwent stent retriever mechanical thrombectomy. Successful recanalization rate was defined as modified TICI (Thrombolysis in Cerebral Infarction) 2b or 3. Result: The overall successful recanalization rate was 44.24%. The recanalization rate per stent retrieval attempt was the highest in 1st attempt (28.84%) and no recanalization was observed with the 3rd, 5th, and 6th attempts (p<0.001). At most 6 retrieval attempts were used. Conclusions: After two retrieval attempts, 91% of the patients were successfully recanalized and other after the 5th attempt could not result in recanalization.

Mechanical Thrombectomy in Medium Vessels Occlusion (MeVOs): An Institutional Experience with M2 Divisions of Middle Cerebral Artery.

Background: Mechanical thrombectomy has been established as a safe, standard and effective treatment option for occlusions of the proximal segment of the middle cerebral artery (MCA), as demonstrated in numerous studies. However, performing thrombectomy in the M2 divisions of MCA presents inherent challenges. In this institutional experience, we aim to delineate the recanalisation rates achieved through mechanical thrombectomy in cases involving the M2 segment of the MCA. Methods: We conducted a retrospective analysis of patients who underwent thrombectomy due to M2 MCA occlusions in the period from January 2018 to December 2021. Various factors affecting recanalisation rates were assessed. Results: A total of 15 patients with M2 segment occlusions of the middle cerebral artery were included in the study, comprising 11 in the superior division and 4 in the inferior division. The successful recanalisation rate was 72.33%, with notably higher success observed in cases of inferior division occlusion. The primary outcome of our study was the mTICI recanalisation status, categorised as successful recanalisation (mTICI = 2b or mTICI = 3) and unsuccessful recanalisation (mTICI = 1 or mTICI = 2a) and mRS at 6 months. None of the predictors assessed reached statistical significance. Conclusions: Mechanical thrombectomy demonstrates favourable efficacy and recanalisation rates in cases of M2 MCA division occlusion. Notably, inferior division occlusions exhibit a higher likelihood of successful recanalisation.

Duplication of right vertebral artery in Klippel-Feil anomaly.

The duplicated origin of the vertebral artery (VA) is an uncommon anatomical variant, which is generally identified incidentally during angiography and can be misdiagnosed as dissection in the setting of posterior circulation stroke. Here, we describe a case of the right V1 VA duplication with embryological aspects in a patient with Klippel-Feil anomaly, which was diagnosed during preoperative evaluation. Surgeons must be aware to avoid vascular injury from a duplicated VA before head-neck and spinal surgery.

Imaging Feature of Leukoencephalopathy with Calcifications and Cysts (Labrune Syndrome).

Labrune syndrome is an uncommon central nervous system disorder characterized by leukoencephalopathy, cerebral calcifications, and cysts on brain imaging. The basic pathology is microangiopathy resulting from a mutation in the SNORD118 gene. Radiological imaging is the hallmark of the disease.

Emerging insights into cephalic neural crest disorders: A single center experience.

Objectives: Neural crest cells (NCCs) are transient structures in the fetal life in vertebrates, which develop at the junctional site of the non-neural and neural ectoderm, sharing a common developmental origin for diverse diseases. After Epithelio-mesenchymal (EMT) of the NCCs within the neural tube, delamination of NCCs occurs. After delamination, the transformation of these cells into various cell lineages produces melanocytes, bones, and cartilage of the skull, cells of the enteric and peripheral nervous system. After the conversion, these cells migrate into various locations of the entire body according to the cell lineage. Abnormalities in neural crest (NC) formation and migration result in various malformations and tumors, known as neurocristopathy. Material and Methods: Herein, this case series describes a single-center experience in cephalic NC disorders over the past 3 years, including 17 cases of varying composition (i.e., vascular, dysgenetic, mixed, and neoplastic forms) involving the brain and occasionally skin, eyes, and face of the patients. Results: In our study of 17 patients with cephalic NC disease, 6 (35.3%) patients had vascular form, 5 (29.4%) had dysgenetic form, 4 (23.5%) had mixed form, and 2 (11.7%) had neoplastic form. Brain involvement in the form of vascular or parenchyma or both vascular and parenchymal was seen in all of our patients (100%), skin in 6 (35.3%) patients, eye in 2 (11.7%), and face in 1 (5.9%) patient. Treatment was planned according to the various manifestations of the disease. Conclusion: Neural crest diseases (NCDs) are a rare and under-recognized group of disorders in the literature and may have been under-reported due to a lack of awareness regarding the same. More such reporting may increase the repertoire of these rare disorders such that clinicians can have a high degree of suspicion leading to early detection and timely counseling and also improve preventive strategies and help in developing new drugs for these disorders or prevent them.

RE-OPEN: Randomised trial of biosimilar TNK versus TPA during endovascular therapy for acute ischaemic stroke due to large vessel occlusions.

Rationale: Rapid and timely treatment with intravenous thrombolysis and endovascular treatment (EVT) in patients with acute ischaemic stroke (AIS) and large vessel occlusion (LVO) significantly improves patient outcomes. Bridging therapy is the current standard of care in these patients. However, an incompletely answered question is whether one thrombolytic agent is better than another during bridging therapy. Aim: The current study aims to understand if one thrombolytic agent is superior to the other during bridging therapy in the treatment of AIS and LVO. Sample size estimates: Using 80% power and an alpha error of 5 %, presuming a 10% drop out rate, a total of 372 patients will be recruited for the study. Methods and design: This study is a prospective, randomised, multicentre, open-label trial with blinded outcome analysis design. Study outcomes: The primary outcomes include proportion of patients who will be independent at 3 months (modified Rankin score (mRS) ≤2 as good outcome) and proportion of patients who achieve recanalisation modified thrombolysis in cerebral infarction grade 2b/3 at first angiography run at the end of EVT. Secondary outcomes include proportion of patients with early neurological improvement, rate of symptomatic intracerebral haemorrhage (ICH), rate of any ICH, rate of any systemic major or minor bleeding and duration of hospital stay. Safety outcomes include any intracranial bleeding or symptomatic ICH. Discussion: This trial is envisioned to confirm the theoretical advantages and increase the strength and quality of evidence for use of tenecteplase (TNK) in practice. Also, it will help to generate data on the efficacy and safety of biosimilar TNK. Trial registration number: CTRI/2022/01/039473.

Radiological Features and Management of Intracranial Aneurysms Associated With Moyamoya Disease: A Case Series of Single-Center Experience.

Background Moyamoya disease (MMD) can be a major cause of hemorrhagic stroke. Though extensive angiographic studies have been undertaken, the understanding of the association between aneurysms and MMD remains unanswered. In this study, we explore the association of the aneurysm with MMD and its management. We have also reviewed such associations described in the literature and how the present cases differ from those previously described. Materials and methods The clinical and radiologic data of moyamoya disease cases were accessed from medical and radiological records between January 2010 and July 2017. Two neuroradiologists independently analyzed the data and imaging details. Results Out of 103 patients with MMD, eight patients (7.77%) had associated intracranial aneurysms with eleven aneurysms. Out of the 11 aneurysms, five were the tip of the basilar artery aneurysms and were the most common location for aneurysm (45.5%), followed by lenticulostriate artery, PCA perforator, and distal ACA (DACA) in the P1 PCA, P2 PCA, and P3 PCA artery aneurysms. Out of eight patients, five (62.5%) had a hemorrhage on a non-contrast computed tomography (NCCT) scan of the brain, whereas three (37.5%) had an ischemic presentation. Out of 11 aneurysms, seven aneurysms, including three basilar tip aneurysms (unruptured) and one PCA perforator (ruptured), and three saccular PCA (P1, P2, and P3) (ruptured) were treated by endovascular coiling. Follow-up angiography showed stable aneurysmal occlusion except in one basilar tip, where recurrence was observed. Conclusions MMD-intracranial aneurysm is commonly observed in patients with intracranial hemorrhage and carries a higher risk of rupture. Therefore, identification of the aneurysm is essential for management. Endovascular treatment, either with coil or glue embolization, can be a safe and effective treatment method for such aneurysms with long-term good results.

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series.

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

Isolated ipsilateral abducens nerve palsy and contralateral homonymous hemianopsia associated with unruptured posterior cerebral artery aneurysm: A rare neurological finding.

Cranial nerve palsies can be presenting signs of intracranial aneurysms. There is a classic pairing between an aneurysmal vessel and adjacent nerves leading to cranial neuropathy. Isolated abducens nerve palsy can be a localizing sign of an unruptured vertebrobasilar circulation aneurysm. Aneurysms involving Anterior Inferior Cerebellar Artery (AICA) and Posterior Inferior Cerebellar Artery (PICA) have been reported to be associated with abducens nerve palsy. The symptoms in unruptured aneurysms are due to the mass effect on adjacent neurovascular structures. Most of the abducens nerve palsy resolves following microsurgical clipping. Here, we present a rare case of an unruptured Posterior Cerebral Artery (PCA) aneurysm presenting with abducens nerve palsy and diplopia associated with contralateral hemianopsia which markedly improved following endovascular coil embolization.

Multimodal imaging of the aging brain: Baseline findings of the LoCARPoN study.

We quantified and investigated multimodal brain MRI measures in the LoCARPoN Study due to lack of normative data among Indians. A total of 401 participants (aged 50-88 years) without stroke or dementia completed MRI investigation. We assessed 31 brain measures in total using four brain MRI modalities, including macrostructural (global & lobar volumes, white matter hyperintensities [WMHs]), microstructural (global and tract-specific white matter fractional anisotropy [WM-FA] and mean diffusivity [MD]) and perfusion measures (global and lobar cerebral blood flow [CBF]). The absolute brain volumes of males were significantly larger than those of females, but such differences were relatively small (<1.2% of intracranial volume). With increasing age, lower macrostructural brain volumes, lower WM-FA, greater WMHs, higher WM-MD were found (P = 0.00018, Bonferroni threshold). Perfusion measures did not show significant differences with increasing age. Hippocampal volume showed the greatest association with age, with a reduction of approximately 0.48%/year. This preliminary study augments and provides insight into multimodal brain measures during the nascent stages of aging among the Indian population (South Asian ethnicity). Our findings establish the groundwork for future hypothetical testing studies.

World Federation for Interventional Stroke Treatment (WIST) multispecialty training guidelines for endovascular stroke intervention.

Introduction: Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT. Aim: To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes. Material and methods: The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency - rather than time-based - guidelines for operator training, taking into consideration trainees' previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated. Results: The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. Conclusions: WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted.

World Federation for Interventional Stroke Treatment (WIST) Multispecialty Training Guidelines for Endovascular Stroke Intervention.

INTRODUCTION: Today, endovascular treatment (EVT) is the therapy of choice for strokes due to acute large vessel occlusion, irrespective of prior thrombolysis. This necessitates fast, coordinated multi-specialty collaboration. Currently, in most countries, the number of physicians and centres with expertise in EVT is limited. Thus, only a small proportion of eligible patients receive this potentially life-saving therapy, often after significant delays. Hence, there is an unmet need to train a sufficient number of physicians and centres in acute stroke intervention in order to allow widespread and timely access to EVT. AIM: To provide multi-specialty training guidelines for competency, accreditation and certification of centres and physicians in EVT for acute large vessel occlusion strokes. MATERIAL AND METHODS: The World Federation for Interventional Stroke Treatment (WIST) consists of experts in the field of endovascular stroke treatment. This interdisciplinary working group developed competency - rather than time-based - guidelines for operator training, taking into consideration trainees' previous skillsets and experience. Existing training concepts from mostly single specialty organizations were analysed and incorporated. RESULTS: The WIST establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in EVT. WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. CONCLUSIONS: WIST multispecialty guidelines outline competency and quality standards for physicians and centres to perform safe and effective EVT. The role of quality control and quality assurance is highlighted. SUMMARY: The World Federation for Interventional Stroke Treatment (WIST) establishes an individualized approach to acquiring clinical knowledge and procedural skills to meet the competency requirements for certification of interventionalists of various disciplines and stroke centres in endovascular treatment (EVT). WIST guidelines encourage acquisition of skills using innovative training methods such as structured supervised high-fidelity simulation and procedural performance on human perfused cadaveric models. WIST multispecialty guidelines outline competency and quality standards for physicians and centers to perform safe and effective EVT. The role of quality control and quality assurance is highlighted. SIMULTANEOUS PUBLICATION: The WIST 2023 Guidelines are published simultaneously in Europe (Adv Interv Cardiol 2023).

Cortico-limbic disruption, material-specificity, and deficits in cognitive-affective theory of mind.

The Theory of Mind deficit due to cognitive-affective disintegration is a poorly understood cognitive consequence of cortical and subcortical disruption in right temporal lobe epilepsy. Following Marr's trilevel approach, we used the material-specific processing model to understand the Theory of Mind deficit in drug-resistant epilepsy (N = 30). We examined pre- and post-surgery changes in first-order (somatic-affective, non-verbal component) and second-order Theory of Mind (cognitive-verbal component) in three groups formed using: (i) seizure side (right versus left), (ii) right temporal epilepsy (right temporal lobe epilepsy versus non-right temporal lobe epilepsy), and (iii) right temporal lobe epilepsy with amygdalohippocampectomy (right temporal lobe epilepsy versus left temporal lobe epilepsy amygdalohippocampectomy versus non-amygdalohippocampectomy). We observed a marked deficit in the first-order Theory of Mind in the right temporal lobe amygdalohippocampectomy group; we mapped this deficit to decline in the non-verbal component of Theory of Mind (somatic-affective component). Preliminary results support using a material-specific processing model to understand the Theory of Mind deficits in right temporal lobe epilepsy amygdalohippocampectomy. Malleability of verbal processing in presence of deterioration of non-verbal processing might have clinical relevance for post-surgery recovery in right temporal lobe epilepsy amygdalohippocampectomy. Documenting the material-specific nature of deficits (verbal versus non-verbal) in non-western, linguistically, and socioeconomically diverse country enables us to understand the problem of heterogeneity in post-surgery cognitive consequences in the right amygdalohippocampectomy.

Post-Vaccination/Post-COVID Immune-Mediated Demyelination of the Brain and Spinal Cord: A Novel Neuroimaging Finding.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which not only produces respiratory symptoms but is known to involve almost every system, and its neuroinvasive properties have been well demonstrated throughout the pandemic. Also, to combat the pandemic, there was rapid development and induction of various vaccination drives, following which many adverse events following immunization (AEFIs) have been reported, which include neurological complications as well. Method: We present a series of three cases, post vaccination, with and without a history of COVID illness that showed remarkably similar findings on magnetic resonance imaging (MRI). Result: A 38-year-old male presented with complaints of weakness of the bilateral lower limbs with sensory loss and bladder disturbance a day after receiving his first dose of ChadOx1 nCoV-19 (COVISHIELD) vaccine. A 50-year-old male with hypothyroidism characterized by autoimmune thyroiditis and impaired glucose tolerance experienced difficulty in walking 11.5 weeks after being administered with COVID vaccine (COVAXIN). A 38-year-old male presented with subacute onset progressive symmetric quadriparesis 2 months after their first dose of a COVID vaccine. The patient also had sensory ataxia, and his vibration sensation was impaired below C7. All three patients had typical pattern of involvement of the brain and spine on MRI with signal changes in bilateral corticospinal tracts, trigeminal tracts in the brain, and both lateral and posterior columns in the spine. Conclusion: This pattern of brain and spine involvement on MRI is a novel finding and is likely a result of post-vaccination/post-COVID immune-mediated demyelination.

Clinical and radiological spectrum of anti-myelin oligodendrocyte glycoprotein (MOG) antibody encephalitis: single-center observational study.

OBJECTIVE: The objective was to describe the clinical presentations, radiologic features, and outcomes of patients with autoimmune encephalitis associated with myelin oligodendrocyte glycoprotein antibody (MOG). BACKGROUND: During the past decade, the spectrum of the myelin oligodendrocyte glycoprotein antibody-associated diseases (MOGAD) has expanded. Recently, patients with MOG antibody encephalitis (MOG-E) who do not fulfill the criteria for ADEM have been reported. In this study, we aimed to describe the spectrum of MOG-E. METHODS: Sixty-four patients with MOGAD were screened for encephalitis-like presentation. We collected the clinical, radiological, laboratory, and outcome data of the patients who presented with encephalitis and compared it with the non-encephalitis group. RESULTS: We identified sixteen patients (nine males and seven females) with MOG-E. The median age of the encephalitis population was significantly lower than the non-encephalitis group (14.5 years (11.75-18) vs. 28 years (19.75-42), p = 0.0004). Twelve out of sixteen patients (75%) had fever at the time of encephalitis. Headache and seizure were present in 9/16 (56.2%) and 7/16 (43.75%) patients, respectively. FLAIR cortical hyperintensity was present in 10/16 (62.5%) patients. Supratentorial deep gray nuclei were involved in 10/16 (62.5%) patients. Three patients had tumefactive demyelination, and one patient had a leukodystrophy-like lesion. Twelve of 16 (75%) patients had a good clinical outcome. Patient with leukodystrophy pattern and other with generalized CNS atrophy showed a chronic progressive course. CONCLUSION: MOG-E can have heterogeneous radiological presentations. FLAIR cortical hyperintensity, tumefactive demyelination, and leukodystrophy-like presentations are novel radiological presentations associated with MOGAD. Though majority of MOG-E have a good clinical outcome, few patients can have chronic progressive disease even on immunosuppressive therapy.

Measurement of Neutrophil Gelatinase-Associated Lipocalin (Ngal) Following Neuroradiological Procedure/s in Patients with Aneurysmal Subarachnoid Hemorrhage: A Preliminary Study.

Background: Radiocontrast administration during interventional neuroradiology (INR) procedures for aneurysmal subarachnoid haemorrhage (aSAH) can add to renal insult. Serum creatinine (sCr) is a conventional marker of acute kidney injury (AKI). Serum neutrophil gelatinase-associated lipocalin (sNGAL) is a novel marker which is increasingly used to predict renal injury in susceptible patients. Objectives: The primary aim of this study was to evaluate correlation between serum neutrophil gelatinase-associated lipocalin (NGAL) and sCr in aSAH patients undergoing therapeutic or diagnostic INR procedures. The secondary aim was to find the incidence of contrast-induced AKI and hemodynamic complications during the study period. Material and Methods: All consenting aSAH patients (18-60 years, Modified Hunt and Hess grade 1-4) posted for INR procedures during the study time were included. Patients with history of chronic renal disease, recent contrast exposure, or renal insufficiency were excluded. Blood samples for sCr and sNGAL were obtained preprocedure and then at 1, 6, 24, and 48 h after contrast administration. Hourly urine output was noted. AKI was defined by KDIGO guidelines. Statistical Analysis Used: Repeated measurement analysis of variance, Posthoc Bonferroni test and Pearson correlation coefficient test. Results: Fifty patients, mean age 47.34 ± 9.31 years, were enrolled for the study. Majority (48; 96%) were Hunt and Hess (H and H) grade I-III. The mean volume of contrast administered was 123.2 ± 53.08 mL. The mean sNGAL and sCr values at pre-op, 1, 6, 24, and 48 h were 124.99 ± 64.58, 148.40 ± 77.90, 147.33 ± 76.00, 125.49 ± 64.44, and 116.38 ± 61.79 ng/mL and 0.629 ± 0.23, 0.624 ± 0.22, 0.612 ± 0.21, 0.632 ± 0.19, and 0.577 ± 0.22 mg/dL, respectively. There was a correlation in sCr and sNGAL value (P < 0.001) at all study time points. However, no specific pattern was seen. No patient developed any AKI or hemodynamic complications in first 48 h. Conclusions: There is a correlation between serum NGAL and sCr at individual time points. NGAL may represent a sensitive early biomarker of renal impairment after INR Procedures. There was no incidence of AKI after contrast administration in aSAH patients without predisposing renal risk factors.