Contained Rupture of a Posterior Communicating Artery Aneurysm in a Patient With a Third Nerve Palsy.

ABSTRACT: It is recommended that every patient with a new third nerve palsy undergo urgent neuroimaging (computed tomography angiography or magnetic resonance angiography) to exclude a posterior communicating artery aneurysm. Because of the novel coronavirus (COVID-19) pandemic, our institution noted a significant decline in the number of patients with aneurysmal subarachnoid hemorrhage presenting to the hospital. We report one such example of a patient who developed new-onset severe headache and vomiting and did not seek medical attention because of COVID-19. Two months later, she was noted to have ptosis during a routine follow-up and was found to have a complete, pupil-involving third nerve palsy. Computed tomography angiography was performed and revealed an irregular bilobed saccular aneurysm (7 × 9 × 5 mm) of the right posterior communicating (PComm) artery, but no acute hemorrhage was visible on CT. On MRI, immediately adjacent to the aneurysm, there was a small subacute hematoma in the right medial temporal lobe with surrounding vasogenic edema. This case had a fortunate and unique outcome as she had a contained hematoma adjacent to the ruptured PComm aneurysm and did not experience severe morbidity from the subarachnoid hemorrhage nor did she rebleed in the interval in which she did not seek care. This case highlights the importance of providing neuro-ophthalmic care even during a pandemic.

Intercellular propagated misfolding of wild-type Cu/Zn superoxide dismutase occurs via exosome-dependent and -independent mechanisms.

Amyotrophic lateral sclerosis (ALS) is predominantly sporadic, but associated with heritable genetic mutations in 5-10% of cases, including those in Cu/Zn superoxide dismutase (SOD1). We previously showed that misfolding of SOD1 can be transmitted to endogenous human wild-type SOD1 (HuWtSOD1) in an intracellular compartment. Using NSC-34 motor neuron-like cells, we now demonstrate that misfolded mutant and HuWtSOD1 can traverse between cells via two nonexclusive mechanisms: protein aggregates released from dying cells and taken up by macropinocytosis, and exosomes secreted from living cells. Furthermore, once HuWtSOD1 propagation has been established, misfolding of HuWtSOD1 can be efficiently and repeatedly propagated between HEK293 cell cultures via conditioned media over multiple passages, and to cultured mouse primary spinal cord cells transgenically expressing HuWtSOD1, but not to cells derived from nontransgenic littermates. Conditioned media transmission of HuWtSOD1 misfolding in HEK293 cells is blocked by HuWtSOD1 siRNA knockdown, consistent with human SOD1 being a substrate for conversion, and attenuated by ultracentrifugation or incubation with SOD1 misfolding-specific antibodies, indicating a relatively massive transmission particle which possesses antibody-accessible SOD1. Finally, misfolded and protease-sensitive HuWtSOD1 comprises up to 4% of total SOD1 in spinal cords of patients with sporadic ALS (SALS). Propagation of HuWtSOD1 misfolding, and its subsequent cell-to-cell transmission, is thus a candidate process for the molecular pathogenesis of SALS, which may provide novel treatment and biomarker targets for this devastating disease.

Practical uses of the BENCHMARK™ BMX®81 in the road less travelled: Guide catheter comparison for radial access in neurovascular intervention.

BACKGROUND: Radial arterial access has gained interest for neurovascular procedures in recent years. Although there are no randomized control trials for neurointervention procedures using radial access, there is growing literature demonstrating its feasibility and favorable outcomes. Equipment technical improvements, like the recently introduced BENCHMARK™ BMX®81 System, have made radial navigation safer, with improved maneuverability and support for a variety of procedures. We present a multicenter case series highlighting our institutional radial access experience comparing the BMX®81 with alternative catheters. METHODS: Multicenter retrospective cohort study of 80 patients who underwent neurovascular procedures through a radial approach. In half of the cases a BENCHMARK™ BMX®81 System was used. The comparison group consisted of the BENCHMARK™071 and 96, Neuron MAX®088 and BALLAST™ systems. Procedures included endovascular thrombectomy, carotid and brachiocephalic artery stenting, middle meningeal artery embolization, flow diverter stenting, vertebral artery sacrifice, aneurysm coiling, and WEB™ device deployment. RESULTS: In our series, the BMX®81 was successful in the navigation of the anatomy to the target location in 95% of cases. No radial access or BMX®81 related complications were identified. There was no significant difference in fluoroscopy time between the BMX81 and the comparison group. Four patients in the comparison group had catheter-related complications due to vasospasm. Eighty-six percent of BMX®81 cases had satisfactory outcomes and no technical difficulties. The remainder presented technical difficulties, but none of these were considered secondary to the puncture site or support structure. CONCLUSIONS: The BENCHMARK™ BMX®81 System is a recently developed guiding catheter which has design and size features supporting radial access for a variety of neurovascular interventions. Early multicenter experience highlights the ease of use and versatility of this new catheter as an alternative to transfemoral access as well as other catheters used for radial access.

Inverted stent deployment technique for stent assisted coiling of wide-necked posterior communicating artery aneurysm: Technical report.

BACKGROUND: Wide-necked aneurysms of the posterior communicating artery associated with a fetal posterior cerebral artery that arises from the neck or dome of the aneurysm is a clinical scenario that poses a challenge to endovascular methods. CASE DESCRIPTION: A patient presented with spontaneous subarachnoid hemorrhage and was found to have a 4 × 3 × 3 mm posterior communicating artery aneurysm. Of note the aneurysm projected superiorly and a fetal posterior communicating artery aneurysm arose from the neck of the aneurysm. After multidisciplinary discussion a treatment strategy of endovascular stent-assisted coiling was chosen. Given the unique morphology of the aneurysm a novel stent-inversion maneuver was used, in which the stent was deployed from the posterior communicating artery into the distal supra-clinoid internal carotid artery. The patient tolerated the procedure well and complete aneurysm occlusion was achieved. CONCLUSIONS: This case demonstrates a novel stent inversion technique that can be used for stent-assisted coiling of certain challenging aneurysms.

Calcium pyrophosphate dihydrate crystal deposition disease and retro-odontoid pseudotumor rupture managed via posterior occipital cervical instrumented fusion: illustrative case.

BACKGROUND: Craniocervical junction and subaxial cervical spinal manifestations of calcium pyrophosphate deposition disease are rarely encountered. The authors presented a severe case of retro-odontoid pseudotumor rupture causing rapid quadriparesis and an acute comatose state with subsequent radiographic and clinical improvement after posterior occipital cervical fusion. OBSERVATIONS: The authors surveyed the literature and outlined multiple described operative management strategies for compressive cervical and craniocervical junction calcium pyrophosphate deposition disease manifestations ranging from neck pain to paresthesia, weakness, myelopathy, quadriparesis, and cranial neuropathies. In this report, radiographic features of cervical and craniocervical junction calcium pyrophosphate deposition disease were explored. Several previously described surgical strategies were compiled, including patient characteristics and outcomes. LESSONS: With this case report, the authors presented for the first time an isolated posterior occipital cervical fusion for treatment of a compressive retro-odontoid pseudotumor with rupture into the brainstem. They demonstrated rapid clinical and radiographic resolution after stabilization of cranial cervical junction only 12 weeks postsurgery.

Digital Subtraction Myelography is Associated with Less Radiation Dose than CT-based Techniques.

PURPOSE: Both CT myelogram (CTM) and digital-subtraction myelogram (DSM) can be used to evaluate patients for possible cerebrospinal fluid (CSF) leaks. DSM is a relatively new technique. No data exists on the radiation dose associated with this procedure, and how it compares with CTM. MATERIALS AND METHODS: All patients who underwent DSM for spontaneous intracranial hypotension (SIH) refractory to blood patching from Dec 2016 - Sept 2019 were retrospectively assessed. DSM dose factors were then recorded (cumulative fluoroscopy time, total kerma area product (KAP, mGy.cm2), cumulative air kerma (mGy), as well as CTM dose factors (included CTDIvol (mGy) and dose-length product (DLP, mGy.cm). These indices were then used to calculate the effective dose for both procedures using standardized conversion factors. RESULTS: 61 DSMs were performed in 42 patients, 33 of which also underwent CTM. The median effective dose was 6.6 mSv per DSM study (range: 1.2 - 17.7). On a per-patient basis (i.e. those patients who underwent more than one DSM (as the initial one was negative), the median total effective dose was 13 mSv for their total DSM imaging (range: 2.6 -31.7). For the CTM, the median effective dose was 19.7 mSv (range: 3.2 - 82.4 mSv). CONCLUSION: The radiation dose with DSM appears to be significantly lower than that of CTM (p = 0.0005), when looking at CTM doses both from our institution and in the published literature.

Radial vs. Femoral Artery Access for Procedural Success in Diagnostic Cerebral Angiography : A Randomized Clinical Trial.

BACKGROUND AND PURPOSE: Radial artery access has become the standard of care in percutaneous coronary procedures due to demonstrated patient safety and comfort benefits; however, uptake of radial access for diagnostic cerebral angiography has been limited by practitioner concerns over the ability to achieve procedural success. We aimed to provide randomized clinical trial evidence for the non-inferiority of radial access to achieve procedural success. MATERIAL AND METHODS: Monocentric open label randomized controlled trial with a non-inferiority design and blinded primary outcome assessment. Adult patients referred in-hours for diagnostic cerebral angiography were eligible. Participants underwent permuted block randomization to radial or femoral artery access with an intention-to-treat analysis. The primary outcome was procedural success, defined as selective cannulation and/or diagnostic angiography of predetermined supra-aortic vessels of interest. The non-inferiority limit was 10.0%. Secondary outcomes included postprocedural complications, fluoroscopy and procedural times, radiation dose, contrast volume and rates of vertebral artery cannulation. RESULTS: A total of 80 participants were enrolled (female 42, male 38, mean age 47.0 years, radial access group n = 43, femoral n = 37). One patient in the radial group was excluded after enrollment due to insufficient sonographic radial artery internal diameter. Procedural success was achieved in 41 of 42 participants in the radial group (97.6%) and 36 of 37 in the femoral group (97.3%). The difference between groups was -0.3% (one-sided 95% confidence interval, CI 6.7%) and the null hypothesis was rejected. CONCLUSION: Radial artery access is non-inferior to femoral artery access for procedural success in cerebral angiography. A large multicenter trial is recommended as the next step.

Influence of Artificial Intelligence on Canadian Medical Students' Preference for Radiology Specialty: ANational Survey Study.

RATIONALE AND OBJECTIVES: Artificial intelligence (AI) has the potential to transform the clinical practice of radiology. This study investigated Canadian medical students' perceptions of the impact of AI on radiology, and their influence on the students' preference for radiology specialty. MATERIALS AND METHODS: In March 2018, an anonymous online survey was distributed to students at all 17 Canadian medical schools. RESULTS: Among 322 respondents, 70 students considered radiology as the top specialty choice, and 133 as among the top three choices. Only a minority (29.3%) of respondents agreed AI would replace radiologists in foreseeable future, but a majority (67.7%) agreed AI would reduce the demand for radiologists. Even among first-choice respondents, 48.6% agreed AI caused anxiety when considering the radiology specialty. Furthermore, one-sixth of respondents who would otherwise rank radiology as the first choice would not consider radiology because of the anxiety about AI. Prior significant exposure to radiology and high confidence in understanding of AI were shown to decrease the anxiety level. Interested students valued the opinions of local radiologists, radiology conferences, and journals. Students were most interested in "expert opinions on AI" and "discussing AI in preclinical radiology lectures" to understand the impact of AI. CONCLUSION: Anxiety related to "displacement" (not "replacement") of radiologists by AI discouraged many medical students from considering the radiology specialty. The radiology community should educate medical students about the potential impact of AI, to ensure radiology is perceived as a viable long-term career choice.