A computed tomography (CT)-based morphometric study of various skull base parameters and their anatomical relationships relevant to endoscopic endonasal skull base surgery.

Background: Endoscopic skull base surgery requires a thorough understanding of skull base anatomy. Orientation to regional anatomy to avoid complications like internal carotid artery injury can be assisted by knowledge of certain bony landmarks. These landmarks are themselves highly variable structures. This study focuses on the radiological morphometric characterization of these landmarks, which can be of great assistance to surgeons for better planning of endoscopic skull base approaches. Methods: Computed tomography scans of patients without skull base pathologies were analyzed retrospectively for the following parameters - Vidian canal (VC) length, VC and foramen rotundum (FR) distance from midline, the angle between the axis of VC and petrous internal carotid artery (pICA) and between VC and palatovaginal canal, the horizontal, vertical and direct distances between VC and FR and the patterns of sphenoid sinus (SS) pneumatization. Results: The VC-pICA angle was more obtuse and VC and FR were placed farther off the midline on the left as compared to the right side. Similarly, the distances between VC and FR were more on the left side. The VC length and distance of VC and FR from the midline were longer in males than in females. The VC-pICA angle was more obtuse in females. The post-sellar variant was the predominant pneumatization pattern seen (57.9%), and the incidence of lateral recess pneumatization was 15%. Conclusion: The results of our study can be utilized for a better understanding of the anatomy of the skull base. In skull base pathologies with distorted anatomical landmarks, a basic understanding of their interrelations can be used to have a better anatomical orientation. All these measures can help in avoiding complications and make extended endoscopic approaches safe.

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.

Reconstructive endovascular treatment of petrous ICA pseudoaneurysm in skull base osteomyelitis: a hidden catastrophe.

Skull base osteomyelitis can be more life-threatening in immunocompromised patients and patients with diabetes. Here, we present a case of a petrous internal carotid artery pseudoaneurysm resulting from skull base osteomyelitis in a diabetic male in his 50s. This case report highlights the need to be conscious of the various complications associated with skull base osteomyelitis, be proficient in detecting them and treat them as early as possible for better outcomes. After adequate control of the disease process with medical treatment, immediate management of the aneurysm with balloon angioplasty and stenting was done. Acknowledging the trivial nasal and ear bleed, radiological evaluation is necessary to rule out rare complications like pseudoaneurysms in a diagnosed case of skull base osteomyelitis. In the discussion, we have cited the various treatment methods and similar cases of pseudoaneurysm caused by osteomyelitis. Currently, the patient continues to live a disease and disability-free life.

Cortical malformation adjacent to a large pial arteriovenous fistula.

The coexistence of an arteriovenous fistula (AVF) and neuronal migration abnormalities is a rare phenomenon. The underlying pathophysiology responsible for these anomalies remains elusive. Neuronal architectural irregularities arise from complex neuronal formation, migration and organisation dysfunctions. Isolated cases of these associations are rarely described in the literature. Here, we present an unusual case involving the coexistence of a pial AVF and a pachygyria-polymicrogyria complex in an early childhood boy. We have provided a detailed description of the neuroimaging characteristics and the therapeutic embolisation in this case, along with follow-up. Additionally, we conduct a comprehensive review of potential hypotheses about the association, referencing prior case reports. The presence of an aberrant blood supply or deviant venous drainage from the developing cortex may contribute to a variety of neuronal migration anomalies.

Giant dissecting aneurysm of basilar artery in a child - treated by flow reversal: A case report.

Although intracranial aneurysms are rare in the paediatric population, the proportion of those involving posterior circulation is higher than that of adults (approximately 25% vs. 8%, respectively). Moreover, posterior circulation aneurysms in kids tend to be larger in size, many of them being giant dissecting types, and treatment of them is often challenging. Treatment of giant dissecting aneurysms, especially involving the Basilar artery is difficult due to strategic location and haemodynamic factors. Use of reconstructive techniques viz. flow-diverters and braided stents is difficult in children because of the lack of standard protocol for use of antiplatelet therapy and the need for prolonged use of the same. Continuous growth of parent vessel is also suggested as a pitfall for the use of a flow diverter/ braided stent which has a fixed caliber. Carefully planned endovascular parent or feeder branch artery occlusion (FAO) is a time-tested method to achieve flow reversal or favourable flow modifications in an arterial segment harbouring dissecting aneurysm. Here, in this case report, we describe a case of a ruptured distal giant basilar artery dissecting aneurysm in a 10-year-old boy treated with flow diversion by FAO. The dominant left vertebral artery was occluded, thereby diverting flow from the right vertebral artery towards the left posterior inferior cerebellar artery and decreasing flow through the aneurysm. On 1-year follow-up, the patient was asymptomatic and on check angiography, there was complete involution of the aneurysm with increased flow through bilateral posterior communicating arteries to distal posterior circulation which proved our hypothesis correct.

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.

COVID-19: Indian Society of Neuroradiology (ISNR) Consensus Statement and Recommendations for Safe Practice of Neuroimaging and Neurointerventions.

The ongoing COVID-19 pandemic has forced every radiology set-up to evolve and formulate guidelines for day-to-day functioning. The sub-speciality of neuroradiology, both diagnostic and neuro-intervention, forms a very important part of any radiology or 'neuro-care' set-up. The present document is a consensus statement of the Indian Society of Neuroradiology, prepared after reviewing the available data and working experience. It scientifically tries to answer many questions faced by neuroradiologists everyday in practice. It encompasses simple things such as which patients need to be imaged, what precautions are essential, the work-flows, cleaning of radiology equipment, how to carry out neuro-interventions in COVID-suspect patients, and what procedures/tests to avoid, or their alternatives, to minimise the spread of COVID infection both to the patients and health care personnel. As radiology set-ups can be large, every sub-speciality may have certain precautions which will not be covered in general guidelines, and this document tries to answer those for neuroradiologists. Carefully evolved Standards of Operating Procedure (SOPs) and guidelines are the need of the hour to guide in providing uninterrupted and adequate services to the needy without compromising the safety of the specialised work force and facilities involved.

Filar arteriovenous fistula associated with anomalous common posterior intercostal arterial trunk - A case report and review of literature.

An anomalous common trunk giving rise to bilateral intercostal arteries at multiple levels is exceedingly rare and its association with spinal filar AVF and low-lying cord has not been reported so far. Here, we report this uncommon anatomical variation in a 60-year-old male who presented with paraplegia and on imaging found to have low-lying spinal cord with filar AVF and venous congestive myelopathy and discuss its embryological basis and associated malformations. Although rare, interventional radiologists should be aware of this entity, as these trunks may be a major source of bleeding in patients with hemoptysis, and also may be involved in vital spinal cord supply.

Endovascular management of a ruptured aneurysm associated with distal PICA fenestration.

Fenestrations are rare but well-known arterial anatomic variations in which a segment of artery divides into two parallel channels that reunite distally. Although fenestrations as such are asymptomatic, they have gained clinical significance because of their association with aneurysms and other intracranial vascular pathologies. Here we present a 35-year-old woman with history of sudden severe occipital headache and vomiting. Imaging revealed a ruptured aneurysm in the distal posterior inferior cerebellar artery arising from one of the limbs of the fenestration. The aneurysm was successfully managed by coiling, and the patient made complete recovery without neurological sequelae.

Management of Arterial Pseudoaneurysms of the Neck in a Pediatric Population: An Endovascular Case Series and Review of Literature.

BACKGROUND: Arterial pseudoaneurysms of the neck are rarely reported in the pediatric population and no dedicated large series are available. Trauma and infection are the most common causes for these aneurysms, with congenital and collagen vascular disorders being the less common causes. These lesions can be life threatening, especially when they present with bleeding or airway compromise. METHODS: We searched our radiology information system for all cases of pediatric neck aneurysm presented between June 2015 and May 2018. These cases were analyzed for clinicoepidemiologic variables, clinical presentation, imaging findings, management, and follow-up. RESULTS: Six children were included in the study (male/female ratio, 5:1), with a mean age of 7.8 years (range, 2.5-15 years). Four presented acutely with either bleeding or rapidly enlarging neck swelling, whereas 2 presented with slowly increasing pulsatile swelling. One had a traumatic cause, 2 had infections, and 1 had infective cervical lymphadenitis complicated by iatrogenic injury whereas no definite causative mechanisms could be accounted for in 2 patients. Two of the children were managed by trapping of the aneurysm and 2 only by proximal parent vessel occlusion. The other 2 children were treated with stent graft deployment across the aneurysm neck to reconstruct the parent vessel. All the patients were doing well during the follow-up period (mean, 14.8 months). CONCLUSIONS: Endovascular means of treatment for pediatric neck aneurysms is relatively simple and safe. Although parent vessel sacrifice is the gold-standard management, vessel-preserving strategies can be tried in select cases with favorable anatomy.

Endovascular Management of a Rare Case of Pediatric Vertebral Artery Mycotic Aneurysm: A Case Report.

Pediatric posterior-circulation aneurysms are uncommon, difficult-to-treat lesions associated with significant morbidity and mortality. Infections and trauma are important risk factors in children. Here, we present a 10-year-old boy with a lower respiratory tract infection, rapidly progressive right-neck swelling, and weakness of the right upper limb. Imaging revealed a partially thrombosed right vertebral-artery pseudoaneurysm with multiple cavitory lung lesions. Subsequent laboratory work-up showed underlying primary immunodeficiency disorder (chronic granulomatous disease). The aneurysm was successfully managed by parent-artery occlusion. The child made a complete recovery without neurological sequelae.

Management of Pediatric Posterior Circulation Aneurysms-12-Year Single-Institution Experience.

BACKGROUND: Pediatric posterior circulation aneurysms are rare, complex, poorly understood lesions on which only limited literature is currently available. We report our 12-year experience of managing this condition to enhance knowledge of this rare entity. METHODS: Patients <18 years old with posterior circulation aneurysms managed at our institution from January 2005 to April 2017 were included. Demographic, clinical, radiologic and management details were retrieved from hospital records and characteristics of the aneurysms and treatment were analyzed. RESULTS: During this period, 20 pediatric patients (male-to-female ratio 15:6; mean age, 13.1 years) with posterior circulation aneurysms were treated. Most of the patients (75%) presented with subarachnoid hemorrhage. The most common location was the vertebrobasilar junction and vertebral artery (31.81%) followed by the basilar artery and the posterior cerebral artery (27.72% each). Dissecting (81.8%) and large (63.63%) aneurysms were the most common types noted. Of the15 patients with 22 aneurysms treated, 13 underwent endovascular management (parent vessel sacrifice in 8 aneurysms and parent vessel preservation in 5 aneurysms), 1 patient underwent surgery, and 1 patient received medical management for central nervous system tuberculosis. During follow-up, 1 patient had recurrence of aneurysm, and 1 patient died after discharge from the hospital. Overall good outcome was recorded in 90% of patients (Glasgow Outcome Scale score 4-5). CONCLUSIONS: Vertebrobasilar junction and vertebral artery was the most common location for posterior circulation aneurysms and most were dissecting aneurysms. Endovascular treatment was the mainstay of management. Overall good outcome was observed at long-term follow-up.

Vein of Galen aneurysmal malformation-clinical and angiographic spectrum with management perspective: an institutional experience.

BACKGROUND AND PURPOSE: Vein of Galen aneurysmal malformation (VGAM) is a rare developmental intracranial vascular malformation. We analyzed the clinical presentations, imaging findings, angioarchitecture, management options, and outcome in a demographically heterogeneous set of VGAM patients. METHODS: We retrospectively analyzed cases of VGAM from our departmental archive collected between 1988 and January 2015. Demographic, clinical, therapeutic, and follow-up details were obtained for each patient from the available records. RESULTS: We identified 36 patients with VGAM including 6 neonates, 18 infants, 7 children aged 2-10 years, and 5 adults. Macrocrania was the commonest presenting feature. Type of fistulae was mural in 14 and choroidal in 18 patients while 4 had a thrombosed sac at presentation. In 3 cases the dilated venous sac had connection with the deep venous system. Bilateral jugular atresia and stenosis were seen in 9 and 6 patients, respectively. Giant venous sac (>4 cm) was significantly correlated with mural type (p=0.0001). Dural arterial recruitment was seen in 4 patients including 3 adults. Among the 23 patients treated by endovascular means, 14 had a good outcome, 5 had a poor outcome, and 4 died. A significant correlation was noted between jugular atresia and poor outcome (p=0.003). CONCLUSIONS: We encountered a wide range of demographic, clinical, and angiographic features in VGAM. Mural type malformations were associated with giant venous sacs. Good outcome after embolization was seen in selected neonates and in most of the infants, children, and adults. Jugular atresia was significantly associated with poor outcome.

Spinal cord involvement and contrast enhancement in posterior reversible encephalopathy syndrome.

Although posterior reversible encephalopathy syndrome (PRES) is a widely encountered clinicoradiological entity, spinal cord involvement on MRI is very rarely reported. We found only eight cases that have been reported so far. Reports of post-contrast meningeal or parenchymal enhancement in PRES are even rarer. Herein we report a case of PRES with extensive spinal cord signal abnormality with contrast enhancement. Familiarity with this rare imaging finding of PRES, in the appropriate clinical setting, will avoid unnecessary investigations and inappropriate treatment.