CNS tumors with PLAGL1-fusion: beyond ZFTA and YAP1 in the genetic spectrum of supratentorial ependymomas

A novel methylation class, "neuroepithelial tumor, with PLAGL1 fusion" (NET-PLAGL1), has recently been described, based on epigenetic features, as a supratentorial pediatric brain tumor with recurrent histopathological features suggesting an ependymal differentiation. Because of the recent identification of this neoplastic entity, few histopathological, radiological and clinical data are available. Herein, we present a detailed series of nine cases of PLAGL1-fused supratentorial tumors, reclassified from a series of supratentorial ependymomas, non-ZFTA/non-YAP1 fusion-positive and subependymomas of the young. This study included extensive clinical, radiological, histopathological, ultrastructural, immunohistochemical, genetic and epigenetic (DNA methylation profiling) data for characterization. An important aim of this work was to evaluate the sensitivity and specificity of a novel fluorescent in situ hybridization (FISH) targeting the PLAGL1 gene. Using histopathology, immunohistochemistry and electron microscopy, we confirmed the ependymal differentiation of this new neoplastic entity. Indeed, the cases histopathologically presented as "mixed subependymomas-ependymomas" with well-circumscribed tumors exhibiting a diffuse immunoreactivity for GFAP, without expression of Olig2 or SOX10. Ultrastructurally, they also harbored features reminiscent of ependymal differentiation, such as cilia. Different gene partners were fused with PLAGL1: FOXO1, EWSR1 and for the first time MAML2. The PLAGL1 FISH presented a 100% sensitivity and specificity according to RNA sequencing and DNA methylation profiling results. This cohort of supratentorial PLAGL1-fused tumors highlights: 1/ the ependymal cell origin of this new neoplastic entity; 2/ benefit of looking for a PLAGL1 fusion in supratentorial cases of non-ZFTA/non-YAP1 ependymomas; and 3/ the usefulness of PLAGL1 FISH.

Is non-contrast MRI sufficient to detect meningioma residue after surgery?

BACKGROUND

Contrast-enhanced magnetic resonance imaging (MRI) is the imaging modality routinely used to follow up patients who have undergone surgical resection of brain meningiomas. There are growing concerns about the massive use of gadolinium-based contrast agents (GBCA). Our aim was to evaluate the performance of a new imaging protocol, performed without GBCA injection, in the detection of tumoral residue or local recurrence after surgery of parafalcine and convexity meningiomas.

MATERIALS AND METHODS

Only adult patients with a documented resected parafalcine or convexity meningioma were included. We performed a dedicated MRI protocol that included non-contrast and post-contrast sequences. The presence or absence of residue on the unenhanced sequences was independently recorded by three observers: first blindly, then in comparison with a baseline enhanced MRI examination.

RESULTS

A total of 51 patients were included. 37 of them featured a tumor residue on the reference enhanced sequence. Overall, an average of 32 of 37 (87%) residues were identified on the unenhanced sequences that were blindly reviewed; and more than 34 of 37 (93%) were identified with the help of the comparative baseline enhanced examination, with a high sensitivity. The missed cases were related to small residues.

CONCLUSION

Unenhanced MRI sequences are highly sensitive and specific in identifying a tumor residue or a local recurrence in the post operative follow up of brain meningiomas. Sensitivity is even higher with the help of a comparative baseline enhanced MRI examination, whatever the strength of magnetic field.

Is the OCT a predictive tool to assess visual impairment in optic chiasm compressing syndrome in pituitary macroadenoma? A prospective longitudinal study

Visual dysfunction is a prevalent symptom in patients with non-functioning pituitary macroadenoma (NFPM); the role of OCT in such patients has not been yet determined. This is a prospective longitudinal observational study over a period of 6 years, on 20 patients presenting a radiological compression of the optic chiasma without visual acuity (VA) and visual field (VF) disturbances. The primary endpoint was to evaluate the impact of NFPA on neuro-axonal loss by measuring RNFL thickness using OCT at inclusion (T0), 12 months (T1), 24 months (T2), and 36 months (T3), respectively. The secondary endpoint was to monitor the evolution of OCT over time and assess any relationship between the degree of OCT alteration and the degree of radiological and clinical optic chiasm compression syndrome. Among the 20 patients included, eight (40%) showed an altered RNFL-OCT at diagnosis, while the remaining 12 (60%) showed a normal pattern. During a mean ophthalmologic follow-up of 60 months, 4 patients (20%) presented an asymptomatic reduction of RNFL-OCT thickness although all 20 had a VA/VF stable. To our knowledge, this study represents the first attempt to longitudinally evaluate the natural history and evolution of RNFL-OCT in patients with radiologically asymptomatic chiasmatic compression syndrome. The results do not clearly demonstrate the role of the OCT as an early prognostic factor for visual dysfunction.

Cerebral perfusion using ASL in patients with COVID-19 and neurological manifestations: A retrospective multicenter observational study

BACKGROUND AND PURPOSE

Cerebral hypoperfusion has been reported in patients with COVID-19 and neurological manifestations in small cohorts. We aimed to systematically assess changes in cerebral perfusion in a cohort of 59 of these patients, with or without abnormalities on morphological MRI sequences.

METHODS

Patients with biologically-confirmed COVID-19 and neurological manifestations undergoing a brain MRI with technically adequate arterial spin labeling (ASL) perfusion were included in this retrospective multicenter study. ASL maps were jointly reviewed by two readers blinded to clinical data. They assessed abnormal perfusion in four regions of interest in each brain hemisphere: frontal lobe, parietal lobe, posterior temporal lobe, and temporal pole extended to the amygdalo-hippocampal complex.

RESULTS

Fifty-nine patients (44 men (75%), mean age 61.2 years) were included. Most patients had a severe COVID-19, 57 (97%) needed oxygen therapy and 43 (73%) were hospitalized in intensive care unit at the time of MRI. Morphological brain MRI was abnormal in 44 (75%) patients. ASL perfusion was abnormal in 53 (90%) patients, and particularly in all patients with normal morphological MRI. Hypoperfusion occurred in 48 (81%) patients, mostly in temporal poles (52 (44%)) and frontal lobes (40 (34%)). Hyperperfusion occurred in 9 (15%) patients and was closely associated with post-contrast FLAIR leptomeningeal enhancement (100% [66.4%-100%] of hyperperfusion with enhancement versus 28.6% [16.6%-43.2%] without, p = 0.002). Studied clinical parameters (especially sedation) and other morphological MRI anomalies had no significant impact on perfusion anomalies.

CONCLUSION

Brain ASL perfusion showed hypoperfusion in more than 80% of patients with severe COVID-19, with or without visible lesion on conventional MRI abnormalities.

Evolution of Neuroimaging Findings in Severe COVID-19 Patients with Initial Neurological Impairment: An Observational Study

BACKGROUND AND OBJECTIVES

Cerebral complications related to the COVID-19 were documented by brain MRIs during the acute phase. The purpose of the present study was to describe the evolution of these neuroimaging findings (MRI and FDG-PET/CT) and describe the neurocognitive outcomes of these patients.

METHODS

During the first wave of the COVID-19 outbreak between 1 March and 31 May 2020, 112 consecutive COVID-19 patients with neurologic manifestations underwent a brain MRI at Strasbourg University hospitals. After recovery, during follow-up, of these 112 patients, 31 (initially hospitalized in intensive care units) underwent additional imaging studies (at least one brain MRI).

RESULTS

Twenty-three men (74%) and eight women (26%) with a mean age of 61 years (range: 18-79) were included. Leptomeningeal enhancement, diffuse brain microhemorrhages, acute ischemic strokes, suspicion of cerebral vasculitis, and acute inflammatory demyelinating lesions were described on the initial brain MRIs. During follow-up, the evolution of the leptomeningeal enhancement was discordant, and the cerebral microhemorrhages were stable. We observed normalization of the vessel walls in all patients suspected of cerebral vasculitis. Four patients (13%) demonstrated new complications during follow-up (ischemic strokes, hypoglossal neuritis, marked increase in the white matter FLAIR hyperintensities with presumed vascular origin, and one suspected case of cerebral vasculitis). Concerning the grey matter volumetry, we observed a loss of volume of 3.2% during an average period of approximately five months. During follow-up, the more frequent FDG-PET/CT findings were hypometabolism in temporal and insular regions.

CONCLUSION

A minority of initially severe COVID-19 patients demonstrated new complications on their brain MRIs during follow-up after recovery.

Evaluation of neuroradiology emergency MRI interpretations: low discrepancy rates between on-call radiology residents' preliminary interpretations and neuroradiologists' final reports

OBJECTIVES

To evaluate the performance of on-call radiology residents in interpreting alone brain and spine MRI studies performed after hours, to describe their mistakes, and to identify influencing factors that increased the occurrence of errors.

METHODS

A total of 328 MRI examinations performed during a 13-month period (from December 1, 2019, to January 1, 2021) were prospectively included. Discrepancies between the preliminary interpretation of on-call radiology residents and the final reports of attending neuroradiologists were noted and classified according to a three-level score: level 1 (perfect interpretation or minor correction), level 2 (important correction without immediate change in patient management), or level 3 (major correction with immediate change in patient management). Categorical data were compared using Fisher's exact test.

RESULTS

The overall discrepancy rate (level-2 and level-3 errors) was 16%; the rate of major discrepancies (only level-3 errors) was 5.5%. The major-discrepancy rate of second-year residents, when compared with that of senior residents, was significantly higher (p = 0.02). Almost all of the level-3 errors concerned cerebrovascular pathology. The most common level-2 errors involved undescribed aneurysms. We found no significant difference in the major-discrepancy rate regarding time since the beginning of the shift.

CONCLUSIONS

The great majority of examinations were correctly interpreted. The rate of major discrepancies in our study was comparable to the data in the literature, and there was no adverse clinical outcome. The level of residency has an effect on the rate of serious errors in residents' reports.

KEY POINTS

• The rate of major discrepancies between preliminary MRI interpretations by on-call radiology residents and final reports by attending neuroradiologists is low, and comparable to discrepancy rates reported for head CT interpretations. • The youngest residents made significantly more serious errors when compared to senior residents. • There was no adverse clinical outcome in patient morbidity as a result of an initial misdiagnosis.

Brain MRI Findings in Severe COVID-19: A Retrospective Observational Study

Background Brain MRI parenchymal signal abnormalities have been associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Purpose To describe the neuroimaging findings (excluding ischemic infarcts) in patients with severe coronavirus disease 2019 (COVID-19) infection. Materials and Methods This was a retrospective study of patients evaluated from March 23, 2020, to April 27, 2020, at 16 hospitals. Inclusion criteria were (a) positive nasopharyngeal or lower respiratory tract reverse transcriptase polymerase chain reaction assays, (b) severe COVID-19 infection defined as a requirement for hospitalization and oxygen therapy, (c) neurologic manifestations, and (d) abnormal brain MRI findings. Exclusion criteria were patients with missing or noncontributory data regarding brain MRI or brain MRI showing ischemic infarcts, cerebral venous thrombosis, or chronic lesions unrelated to the current event. Categorical data were compared using the Fisher exact test. Quantitative data were compared using the Student t test or Wilcoxon test. P < .05 represented a significant difference. Results Thirty men (81%) and seven women (19%) met the inclusion criteria, with a mean age of 61 years ± 12 (standard deviation) (age range, 8-78 years). The most common neurologic manifestations were alteration of consciousness (27 of 37, 73%), abnormal wakefulness when sedation was stopped (15 of 37, 41%), confusion (12 of 37, 32%), and agitation (seven of 37, 19%). The most frequent MRI findings were signal abnormalities located in the medial temporal lobe in 16 of 37 patients (43%; 95% confidence interval [CI]: 27%, 59%), nonconfluent multifocal white matter hyperintense lesions seen with fluid-attenuated inversion recovery and diffusion-weighted sequences with variable enhancement, with associated hemorrhagic lesions in 11 of 37 patients (30%; 95% CI: 15%, 45%), and extensive and isolated white matter microhemorrhages in nine of 37 patients (24%; 95% CI: 10%, 38%). A majority of patients (20 of 37, 54%) had intracerebral hemorrhagic lesions with a more severe clinical presentation and a higher admission rate in intensive care units (20 of 20 patients [100%] vs 12 of 17 patients without hemorrhage [71%], P = .01) and development of the acute respiratory distress syndrome (20 of 20 patients [100%] vs 11 of 17 patients [65%], P = .005). Only one patient had SARS-CoV-2 RNA in the cerebrospinal fluid. Conclusion Patients with severe coronavirus disease 2019 and without ischemic infarcts had a wide range of neurologic manifestations that were associated with abnormal brain MRI scans. Eight distinctive neuroradiologic patterns were described. © RSNA, 2020.

How and why do French medical students choose the specialty of infectious and tropical diseases? A national cross-sectional study

BACKGROUND

Infectious and tropical diseases (ID) physicians are needed now more than ever to tackle existing and emerging global threats. However, in many countries, ID is not recognized as a qualifying specialty. The creation of ID residency in 2017 in France offers the opportunity to know how and why the specialty is chosen by medical students.

METHODS

We first analyzed the choice of specialty of all French medical students in 2017 and 2018 according to their rank at the national exam that ends medical studies. A web questionnaire was then sent in January 2019 to all ID residents in France (n = 100) to assess the factors influencing their choice of specialty and their career plan.

RESULTS

We analyzed the choice of 17,087 medical students. ID was the first-chosen specialty with a median national rank of 526/8539, followed by plastic surgery and ophthalmology. The questionnaire was completed by 90% of the French ID residents (n = 100). The most encouraging factors to choose ID were the multi-system approach of the specialty, the importance of diagnostic medicine and having done an internship in ID during medical school. The potential deterrents were the work-life balance, the workload and the salary.

CONCLUSIONS

The recent recognition of ID as a qualifying specialty in France can be considered a success insofar as the specialty is the most popular among all medical and surgical specialties. Individuals who choose ID are attracted by the intellectual stimulation of the specialty but express concerns about the working conditions and salaries.

Neurologic and neuroimaging findings in patients with COVID-19: A retrospective multicenter study

OBJECTIVE

To describe neuroimaging findings and to report the epidemiologic and clinical characteristics of patients with coronavirus disease 2019 (COVID-19) with neurologic manifestations.

METHODS

In this retrospective multicenter study (11 hospitals), we included 64 patients with confirmed COVID-19 with neurologic manifestations who underwent a brain MRI.

RESULTS

The cohort included 43 men (67%) and 21 women (33%); their median age was 66 (range 20-92) years. Thirty-six (56%) brain MRIs were considered abnormal, possibly related to severe acute respiratory syndrome coronavirus. Ischemic strokes (27%), leptomeningeal enhancement (17%), and encephalitis (13%) were the most frequent neuroimaging findings. Confusion (53%) was the most common neurologic manifestation, followed by impaired consciousness (39%), presence of clinical signs of corticospinal tract involvement (31%), agitation (31%), and headache (16%). The profile of patients experiencing ischemic stroke was different from that of other patients with abnormal brain imaging: the former less frequently had acute respiratory distress syndrome (p = 0.006) and more frequently had corticospinal tract signs (p = 0.02). Patients with encephalitis were younger (p = 0.007), whereas agitation was more frequent for patients with leptomeningeal enhancement (p = 0.009).

CONCLUSIONS

Patients with COVID-19 may develop a wide range of neurologic symptoms, which can be associated with severe and fatal complications such as ischemic stroke or encephalitis. In terms of meningoencephalitis involvement, even if a direct effect of the virus cannot be excluded, the pathophysiology seems to involve an immune or inflammatory process given the presence of signs of inflammation in both CSF and neuroimaging but the lack of virus in CSF.

CLINICALTRIALSGOV IDENTIFIER

NCT04368390.

CT patterns of acute type A aortic arch dissection: longer, higher, more anterior

OBJECTIVES

This study analysed CT patterns of the acute dissected aortic arch using original biometric features along with comparison with normal aortas.

METHODS

The diagnostic CT scans of 57 patients (42 males, age (mean ± SD: 64.5 ± 13.8 years) admitted with acute Stanford type A dissection involving the aortic arch were analysed by semi-automatic detection protocol of the true lumen of the dissection. We measured the distances from the apex to the ascending and descending aorta, the curvilinear length of the entire arch and of its segments (especially between the brachiocephalic artery trunk and the left subclavian artery), as well as the surface area, angle, height and shift of the arch. These measurements were compared with results previously obtained in a healthy cohort in an analysis adjusted for age, sex and weight. The surface area and rotation of the false lumen were also analysed.

RESULTS

Compared to normal aortic arches (N), dissected aortic arches (D) were longer (D: 155 ± 26  mm, N: 135 ± 25  mm, p = 0.002), higher (D: 51 ± 10  mm, N: 45 ± 9  mm, p = 0.04), and with a more anterior apex (shift: D: 1.19 ± 0.56, N: 1.40 ± 0.62, p = 0.007). False lumen occupied between 47-65% of the aorta, turned preferentially clockwise and its rotation decreased progressively along the arch.

CONCLUSIONS

The morphology of the dissected aortic arch differs from that of the normal arch. Thus, our compilation of aortic arch measurements may help improve existing endovascular devices and/or design of new endoprostheses. Advances in knowledge: In this article, we provide a comprehensive set of measurements of the dissected aortic arch, and show that dissected aortic arches are longer, higher, and with a more anterior apex than normal arches.

The apex of the aortic arch backshifts with aging

BACKGROUND

Only a few studies, involving small numbers of patients, have globally assessed the curvature of the thoracic aorta but without any details concerning the location of the supra-aortic trunks.

OBJECTIVES

Using CT to describe normal aortic-arch morphology and its changes with age and sex.

METHODS

344 CT scans were studied. We measured the distances from the apex to the ascending and descending aorta, the curvilinear length of the entire arch, that of the segment, including bifurcations of supra-aortic vessels, and the angle, height, and shift of the arch.

RESULTS

In men, the arch was significantly longer (146.2 vs 122.8 mm; p < 0.001), higher (49.3 vs 40.1 mm, p < 0.001), and wider transversely (83.6 vs 73.3 mm; p < 0.001) than in women. The average men's arch also had a more acute angle at the apex (79.7° vs 83.7° p < 0.001). Neither morphology nor age influenced the winding angle around the mediastinum. Aging was accompanied by deflection and extension of the aortic arch, which grew more anteroposteriorly (6.1 mm/10 years in men) than vertically (2.5 mm/10 years in men), while the apex moved towards the rear of the arch. The ascending aorta was the only curvilinear length unaffected by age, whereas the supra-aortic trunks parted from each other.

CONCLUSION

We believe that all these original observations could lead to a better assessment of normal aging of the aorta and guide technical choices during surgical or hybrid procedures.