Embolization of a pseudoaneurysm of the innominate artery with a Woven EndoBridge (WEB) device.

The Woven EndoBridge (WEB) is an intra-aneurysmal flow disruptor designed for the treatment of broad-based arterial aneurysms with a high safety and effectiveness profile.1, 2 It does not require concomitant antiplatelet therapy compared to other devices such as flow diverters or intracranial stents. Innominate artery pseudoaneurysms are a rare consequence of blunt traumatic injury, infection, or atherosclerotic disease.3, 4 We describe the case of an innominate artery pseudoaneurysm successfully treated with a WEB SL device instead of stenting, therefore alleviating the need for dual antiplatelet therapy. The treatment was successful and uneventful and postprocedural computed tomography angiography confirmed the complete occlusion of the pseudoaneurysm.

Perimesencephalic subarachnoid hemorrhage as a rare delayed complication of radiation therapy in a patient with parotid basaloid squamous cell carcinoma.

In this case report, we address a rare entity of parotid cancer: basaloid squamous cell carcinoma, which was surgically unresectable and had thus far only been treated with radiation therapy. Following twenty years of continuous remission, our patient presented with an acute perimesencephalic subarachnoid hemorrhage. The cause of the acute perimesencephalic subarachnoid hemorrhage was a delayed complication of radiation therapy.

Clinical and radiographic response of a paravertebral hemangioma to radiotherapy.

Hemangiomas can arise anywhere in the body. While vertebral hemangiomas are common, atypical hemangiomas with paraspinal and epidural extension are rare. We present a case of a patient who presented with persistent cough and anorexia from a paravertebral hemangioma that invaded the adjacent vertebrae and neural foramen causing moderate spinal canal stenosis. She was treated with stereotactic body radiotherapy to prevent the development of symptomatic spinal cord compression. The hemangioma underwent significant shrinkage and her cough resolved. This case demonstrates impressive and sustained clinical and radiographic response of a paraspinal hemangioma to stereotactic body radiotherapy.

Stent retriever for Tandem Acute Revascularization Technique (START): a novel technique for the endovascular management of tandem occlusions.

Tandem occlusions, characterized by the simultaneous presence of an intracranial large vessel occlusion and extracranial carotid artery stenosis or occlusion,1 pose a unique endovascular challenge.2 3 Typically, the extracranial occlusion is a result of atherosclerotic plaque; however, dissections are also a possible cause. It is currently uncertain whether an intracranial first approach or an extracranial first approach should be employed.4 5 A new technique has been developed which allows for the simultaneous treatment of both the intracranial and the extracranial lesion.6 We describe a variation of this technique: the stent retriever for tandem acute revascularization technique (START), which consists of simultaneously treating the intracranial lesion with stent retriever and contact aspiration, and the extracranial lesion with balloon angioplasty. We present a technical video explaining all the steps of START.(video 1)neurintsurg;jnis-2023-021011v1/V1F1V1Video 1Description and example of the START.

Use of a Woven Endobridge device (WEB) for the treatment of an aneurysmal diverticulum of the transverse sinus causing pulsatile tinnitus.

Pulsatile tinnitus is a symptom with a potentially significant impact on the quality of life of patients.1 In some cases the pulsatile tinnitus is secondary to an arterial, arteriovenous, or a venous condition that can be treated endovascularly.2-5 One of the newly recognized entities that can cause pulsatile tinnitus is the presence of an ipsilateral aneurysmal diverticulum of the transverse sinus. The Woven EndoBridge (WEB) is an intra-aneurysmal flow disruptor for the treatment of broad-based arterial aneurysms with a high safety and effectiveness profile.3 The initial version of the WEB with a dual-layer structure evolved into a single-layer structure in two different versions (WEB SL, a barrel shape, and WEB SLS, a spherical shape).4 The WEB system does not require concomitant antiplatelet therapy, unlike other intraluminal devices such as flow diverters or intracranial stents. We describe a case of pulsatile tinnitus secondary to an aneurysmal diverticulum of the transverse sinus successfully treated with a WEB SL device instead of stent-assisted coiling, therefore alleviating the need for antiplatelets (video 1). The patient had an immediate clinical response with complete and persisting disappearance of her pulsatile tinnitus.neurintsurg;jnis-2023-020981v1/V1F1V1Video 1.

Distal to proximal snaring of a fractured microcatheter during dural AVF embolization.

Detachable-tip microcatheters are frequently used for endovascular embolization of arteriovenous shunts. Occasionally, the detachable tip can break during navigation resulting in the loss of the microcatheter tip in a vessel, which can lead to thrombo-embolic complications and also limit further navigation into the vessel to complete treatment. We present a case of dural AV-fistula embolization that was complicated by the accidental detachment and loss of the tip of a microcatheter during navigation to injection site. The proximal tip of the broken catheter was not visible and therefore we were unable to capture its proximal part with a Snare. Ultimately, we navigated a microcatheter distal to the broken segment and successfully snared the microcatheter fragment retrogradely. (Video 1).

Adverse Events Associated with Intra-Arterial Administration of Gadolinium-Based Contrast Agents: A Systematic Review and Meta-Analysis.

PURPOSE: To determine the risk of immediate hypersensitivity reactions (HRs), contrast-associated acute kidney injury (CA-AKI), nephrogenic systemic fibrosis (NSF), and gadolinium retention associated with use of intra-arterial gadolinium-based contrast agents (GBCAs). MATERIALS AND METHODS: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched from 1988 (GBCAs approved for clinical use) to March 2021 for studies reporting adverse events associated with intra-arterial administration of GBCAs. The number of adverse events and GBCA administrations were used to calculate incidence in individual studies, and results across studies were pooled using random-effects meta-analysis. RESULTS: There were 72 studies (patients = 1,221) that reported on HR, 59 studies (patients = 1,142) that reported on CA-AKI, and 6 studies (patients = 291) that reported on NSF. No studies reported gadolinium retention as an outcome. Based on 5 events and 1,451 GBCA administrations, the incidence of HR per 100 administrations was 0.95 (95% CI, 0.52-1.51). Based on 90 events and 1,318 GBCA administrations, the incidence of CA-AKI per 100 administrations was 5.94 (95% CI, 3.92-8.34). Based on 7 events and 361 GBCA administrations, the incidence of NSF per 100 Group I GBCA administrations was 4.72 (95% CI, 0.35-13.70). There were no unconfounded NSF events after Group II GBCA administration. CONCLUSIONS: HRs to intra-arterial administration of GBCAs are rare, with no serious reactions. Limited data demonstrate a higher-than-expected rate of CA-AKI; however, multiple confounding factors were noted. Thus, any causative link of CA-AKI to GBCA remains controversial. Also, severe physiologic reactions (including life-threatening arrhythmias) during coronary angiography have been reported.

Development of a Digital Platform: A Perspective to Advance Space Telepharmacy.

Goal: Lessons learned from decades of human spaceflight have helped advance the delivery of healthcare in rural and remote areas of the globe. Inclusion of the public in spaceflights is not yet accompanied by technology capable of monitoring their physical and mental health, managing clinical conditions, and rapidly identifying medical emergencies. Telepharmacy is a practice prioritizing pharmacotherapeutic guidance and monitoring to help improve patient quality of life, and can potentially expand the field of space medicine. We seek to advance pharmaceutical care through telepharmacy by developing a digital platform. Objective: This study focuses on the development of a digital platform for teleassistance and pharmaceutical teleconsulting services that builds on lessons learned in delivering space medicine. Methods: The platform contains evidence-based information on various drugs grouped by medical specialty, and also records and saves patient appointments. It has specific service protocols for service standardization, including artificial intelligence, to allow agility in services and escalation. All data is protected by privacy and professional ethics guidelines. Results: The telepharmacy platform is ready and currently undergoing testing for ground applications through validation studies in hospitals or medical clinics. Conclusions: Although developed for use on Earth, this telepharmacy platform provides a good example of how terrestrial healthcare knowledge and technology can be transferred to space missions.

Surgery and dose-escalated radiotherapy for a de novo intracranial squamous cell carcinoma of the cerebellopontine angle.

We report an extremely rare case of de novo intracranial squamous cell carcinoma of the cerebellopontine angle. The patient underwent craniotomy for debulking of the lesion to relieve mass effect on the brainstem and to establish a tissue diagnosis. Cancer staging revealed no other primary cancers and no evidence of metastatic disease. Postoperatively, he received image-guided intensity-modulated radiotherapy to the tumor bed followed by fractionated radiosurgery boost to the gross residual disease for a total average dose of 7000 cGy. He had a complete response to radiation and remains 42-months' disease-free post-treatment.

CSF Rhinorrhea: A Rare Clinical Presentation of Choroid Plexus Papilloma.

Choroid plexus papilloma (CPP) is a rare brain tumour occurring mostly in infants and children. Most CPPs are intraventricular and present with symptoms and signs of increased intracranial pressure (ICP). This case report describes a middle-aged female who presented with spontaneous cerebrospinal fluid (CSF) rhinorrhea from a tumour located in the cerebellopontine angle (CPA). She underwent craniotomy with subtotal tumour resection and remained progression and rhinorrhea-free for several years. Upon clinical progression, the patient was treated with Cyberknife stereotactic radiosurgery. The patient clinically improved and demonstrated a favourable radiologic response to radiosurgery.

Transition to virtual appointments for interventional neuroradiology due to the COVID-19 pandemic: a survey of satisfaction.

BACKGROUND: The COVID-19 pandemic has changed the way medicine is practiced, including the implementation of virtual care in many specialties. In the field of interventional neuroradiology (INR), virtual clinics are an uncommon practice with minimal literature to support its use. Our objective was to report prospective, single-centre data regarding patient and physician experience with virtual INR clinics for routine follow-up appointments. METHODS: We surveyed all patients that participated in a virtual INR clinic follow-up appointment at our hospital over a 3 month period. Information gathered included length of appointment delays (ie, wait times), length of appointment times, overall satisfaction, and perceived safety metrics. A survey was also sent out to all physicians who participated in virtual clinics with similar questions. RESULTS: 118/122 patients and 6/6 physicians completed the survey. Wait times before previous in-person appointments were perceived to be much longer than virtual appointments, whereas in-person appointment times were longer. 112/118 (94.9%) patients and 4/6 (67%) physicians reported general satisfaction with their virtual clinic experience. There were 8/118 patients who felt their conditions could not be safely assessed virtually, compared with 1/6 (17%) physicians. Lastly, 72.2% of patients reported that they would prefer virtual or telephone visits in the future for non-urgent follow-up, and 5/6 (83%) of physicians reported the same. CONCLUSION: Virtual INR clinics are more efficient and are preferred among patients and physicians for non-urgent follow-up appointments. Our study demonstrates the feasibility of a virtual platform for INR care, which could be sustainable for future practice.

Space motion sickness: A common neurovestibular dysfunction in microgravity.

This article presents a review of the current findings related to neurovestibular physiology, aetiology, and proposed theories on space motion sickness (SMS) during acute and sustained exposure to microgravity. The review discusses the available treatment options including medication and nonpharmacological countermeasure methods that help to prevent the development of SMS in weightlessness. Ground-based simulations using virtual reality, flight simulations, and Barany's chairs can be applied to study SMS and demonstrate its signs and symptoms to space crew members. Space motion sickness has been observed in approximately 70% of astronauts within the first 72 h in microgravity, having in general an instantaneous onset of signs and symptoms. Stomach discomfort, nausea, vomiting, pallor, cold sweating, salivation, tachypnoea, belching, fatigue, drowsiness, and stress hormone release have been documented. This can have detrimental effects on the well-being of astronauts in the initial phase of a space mission. Mental and physical performance may be affected, jeopardizing operational procedures and mission safety.

High sensitivity and specificity of 4D-CTA in the detection of cranial arteriovenous shunts.

PURPOSE: In a prospective cohort study, we evaluated the diagnostic accuracy of time-resolved CT angiography (4D-CTA) compared to digital subtraction angiography (DSA) for detecting cranial arteriovenous shunts. MATERIAL AND METHODS: Patients were enrolled if a DSA had been ordered querying either a dural arteriovenous fistula (dAVF) or a cerebral arteriovenous malformation (bAVM). After enrolment, both a DSA and a 4D-CTA were performed. Both studies were evaluated using a standardized form. If a dAVF or bAVM was found, its classification, angioarchitectural details, and treatment options were recorded. RESULTS: Ninety-eight patients were enrolled and 76 full datasets were acquired. DSA demonstrated a shunting lesion in 28 out of 76 cases (prevalence 37%). 4D-CTA demonstrated all but two of these lesions (sensitivity of 93%) and produced one false positive (specificity of 98%). These numbers yielded a positive predictive value (PPV) of 96% and a negative predictive value (NPV) of 96%. Significant doubt regarding the 4D-CTA diagnosis was reported in 6.6% of all cases and both false-negative 4D-CTA results were characterized by such doubt. CONCLUSIONS: 4D-CTA has very high sensitivity and specificity for the detection of intracranial arteriovenous shunts. Based on these results, 4D-CTA may replace DSA imaging as a first modality in the diagnostic workup in a large number of patients suspected of a cranial dAVF or bAVM, especially if there is no doubt regarding the 4D-CTA diagnosis. KEY POINTS: • 4D-CTA was shown to have a high diagnostic accuracy and is an appropriate, less invasive replacement for DSA as a diagnostic tool for cranial arteriovenous shunts in the majority of suspected cases. • Doubt regarding the 4D-CTA result should prompt additional DSA imaging, as it is associated with false negatives. • False-positive 4D-CTA results are rare, but do exist.

Ectopic Parathyroid Adenoma in Piriform Sinus: Case Report and Review of the Literature.

During routine blood work, a 53-year-old female patient was noted to have asymptomatic hypercalcemia and subsequently found to have hyperparathyroidism. Localization studies for a suspected parathyroid adenoma included 99mTc Sestamibi scintigraphy, Single Photon Emission Computed Tomography (SPECT)/computed tomography (CT) study, and ultrasound of the neck, which were initially read as negative for parathyroid adenoma. A contrast-enhanced CT scan of the neck was performed to locate the suspected parathyroid adenoma and demonstrated a soft tissue lesion within the right piriform sinus. Flexible fiber optic nasolaryngoscopy revealed a submucosal lesion in the right piriform sinus. Following these findings, the initial 99mTc Sestamibi scintigraphy and SPECT/CT were reviewed with confirmation of a focal area of increased activity superior to the right thyroid lobe, corresponding to a nodule in the right piriform sinus that demonstrated increased activity on SPECT/CT. The patient was brought to the operating room for surgical management where a laryngoscope and operating microscope were utilized. The encapsulated lesion was dissected and excised in total. The parathyroid hormone and ionized calcium levels normalized postoperatively. Pathology confirmed a parathyroid adenoma. Parathyroid adenomas are the most common cause of primary hyperparathyroidism. Sixteen percent of parathyroid adenomas can be situated in an ectopic location. Ectopic parathyroid adenomas in the piriform sinus are rare with only a few previously documented cases. We document a rare case of ectopic parathyroid adenoma in the piriform sinus overlooked on initial imaging studies. These lesions can be challenging to localize, however, an understanding of embryology, close scrutiny of possible ectopic locations, and the application of complementary imaging techniques may prove useful for surgeons and clinicians.

Vulnerable carotid plaque imaging and histopathology without a dedicated MRI receiver coil.

Stroke is associated with vulnerable carotid artery plaques showing specific histopathologic features, namely a lipid-rich necrotic core, intraplaque hemorrhage, ulceration, and thin fibrous cap. While ultrasound and computed tomography (CT) can identify carotid plaques and determine the extent of stenosis, magnetic resonance imaging (MRI) provides further information regarding plaque composition and morphology. In this feasibility study, three patients with symptomatic, moderately stenosed plaques were imaged with CT angiography (CTA) and MRI (3T and 1.5T) without a dedicated receiver coil. The patients subsequently underwent carotid endarterectomy with en-bloc excision of the plaque. The CT and MR images were analyzed independently by three neuroradiologists to identify vulnerable plaque features. The images were correlated with the histopathology to confirm the findings. All three patients had one or more vulnerable plaque features on histopathology. MRI allowed for better characterization of these features when compared to CTA. The pre- and post-contrast T1-weighted (T1W) images were most helpful for identifying the lipid-rich necrotic core and thin fibrous cap, while the time of flight-magnetic resonance angiography (TOF-MRA) and contrast-enhanced (CE)-MRA were excellent for detecting plaque hemorrhage and ulceration, respectively. The 3T images showed superior spatial and contrast resolution compared to the 1.5T images for all sequences. By providing direct correlation between imaging and histopathology, this study demonstrates that 3T MRI without a dedicated surface coil is an excellent tool for assessing plaque vulnerability. In smaller hospitals or those with limited resources, it is reasonable to consider conventional MRI for patient risk stratification. Further studies are needed to determine how MRI and plaque vulnerability can be incorporated into routine clinical practice.

Neuroimaging of ocular involvement in patients with sickle cell disease and review of the literature.

Endophthalmitis is a rare cause of ocular infection that can be associated with immunocompromising conditions and, more rarely, with sickle cell disease. In this case report and review of the literature, we present a case of a young male with sickle cell disease who presented with rapidly progressive ocular pain, edema, erythema, and decreased visual acuity. The key radiological findings to suggest endophthalmitis were demonstrated using computed tomography and magnetic resonance imaging.

Fatal Entrapment of the Basilar Artery in a Longitudinal Fracture of the Clivus Due to Head Injury: A Case Report and Review of the Literature.

Infarction of the posterior cerebral artery circulation arising from entrapment of the basilar artery in a fracture of the clivus has been reported in the medical literature, predominantly in the radiology and emergency medicine journals. Review of the medical literature on the topic revealed 14 published cases of entrapment of the basilar and/or vertebral artery within a longitudinal fracture of the clivus. These were all reported between 1964 and 2016 and postmortem examination had been conducted on seven cases. To date, no case of entrapment of the basilar and/or vertebral artery in a fracture of the clivus has been reported in the forensic pathology literature, and the published literature on the entity is reviewed.

Subarachnoid hemorrhage admissions retrospectively identified using a prediction model.

OBJECTIVE: To create an accurate prediction model using variables collected in widely available health administrative data records to identify hospitalizations for primary subarachnoid hemorrhage (SAH). METHODS: A previously established complete cohort of consecutive primary SAH patients was combined with a random sample of control hospitalizations. Chi-square recursive partitioning was used to derive and internally validate a model to predict the probability that a patient had primary SAH (due to aneurysm or arteriovenous malformation) using health administrative data. RESULTS: A total of 10,322 hospitalizations with 631 having primary SAH (6.1%) were included in the study (5,122 derivation, 5,200 validation). In the validation patients, our recursive partitioning algorithm had a sensitivity of 96.5% (95% confidence interval [CI] 93.9-98.0), a specificity of 99.8% (95% CI 99.6-99.9), and a positive likelihood ratio of 483 (95% CI 254-879). In this population, patients meeting criteria for the algorithm had a probability of 45% of truly having primary SAH. CONCLUSIONS: Routinely collected health administrative data can be used to accurately identify hospitalized patients with a high probability of having a primary SAH. This algorithm may allow, upon validation, an easy and accurate method to create validated cohorts of primary SAH from either ruptured aneurysm or arteriovenous malformation.