Sinonasal and ear manifestations of Erdheim-Chester disease.

To calculate the prevalence of sinonasal and ear involvement in an Erdheim-Chester disease (ECD) population, to describe the different ear, nose and throat (ENT) manifestations and to study the association between ENT involvement, other organ involvement, and BRAF mutations. We led a retrospective monocentric study in the national referral center for ECD. One hundred and sixty-two patients with ECD and ENT data were included between January 1, 1980 and December 31, 2020. Ear and nose clinical and radiological findings were noted. We described and studied the prevalence of ENT involvement in ECD population. The association between sinonasal and ear involvement, other organ involvement, and BRAF mutations was calculated. The prevalence of ENT manifestations is around 45%. No clinical rhinologic or otologic signs were specific to ECD. Sinus imaging was abnormal in 70% of cases. A bilateral maxillary sinus frame osteosclerosis was highly specific of ECD. Associations were found between the sinus MRI imaging type and BRAF status, central nervous system involvement, cerebellum involvement and xanthelasma. Sinonasal or ear involvement is frequent in ECD and has specific imaging features for sinuses. Trial registration: #2011-A00447-34.

Cochlear Implant Outcomes in Patients with Neurosarcoidosis.

INTRODUCTION: Audiovestibular symptoms are rare in sarcoidosis, but they may also be the first manifestation of the disease. Sudden or progressive bilateral hearing loss is usually associated with vestibular impairment. The mechanism of hearing loss remains unclear, but clinical presentation and magnetic resonance imaging suggest a retrocochlear site for the lesion in most patients. Several cases of hearing recovery after corticosteroid treatment have been reported. In patients with severe or profound hearing loss, the benefit of cochlear implantation is challenging to predict in the case of auditory neuropathy and is rarely described. We present a case series of cochlear implantation in patients with documented neurosarcoidosis. RESULTS: Seven cases of cochlear implantation in 4 patients with neurosarcoidosis are reported. All of the patients showed a great improvement very quickly in both quiet and noise. Speech performance remained stable over time with a follow-up ranging from 4 to 11 years, even in patients who had disease exacerbation. CONCLUSION: Cochlear implantation is possible in deaf patients with neurosarcoidosis. The excellent benefit obtained in our patients suggests a particular type of neuropathy, but endocochlear involvement cannot be entirely ruled out.

Retrospective Observational Study of Brain MRI Findings in Patients with Acute SARS-CoV-2 Infection and Neurologic Manifestations.

Background This study provides a detailed imaging assessment in a large series of patients infected with coronavirus disease 2019 (COVID-19) and presenting with neurologic manifestations. Purpose To review the MRI findings associated with acute neurologic manifestations in patients with COVID-19. Materials and Methods This was a cross-sectional study conducted between March 23 and May 7, 2020, at the Pitié-Salpêtrière Hospital, a reference center for COVID-19 in the Paris area. Adult patients were included if they had a diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with acute neurologic manifestations and referral for brain MRI. Patients with a prior history of neurologic disease were excluded. The characteristics and frequency of different MRI features were investigated. The findings were analyzed separately in patients in intensive care units (ICUs) and other departments (non-ICU). Results During the inclusion period, 1176 patients suspected of having COVID-19 were hospitalized. Of 308 patients with acute neurologic symptoms, 73 met the inclusion criteria and were included (23.7%): thirty-five patients were in the ICU (47.9%) and 38 were not (52.1%). The mean age was 58.5 years ± 15.6 [standard deviation], with a male predominance (65.8% vs 34.2%). Forty-three patients had abnormal MRI findings 2-4 weeks after symptom onset (58.9%), including 17 with acute ischemic infarct (23.3%), one with a deep venous thrombosis (1.4%), eight with multiple microhemorrhages (11.3%), 22 with perfusion abnormalities (47.7%), and three with restricted diffusion foci within the corpus callosum consistent with cytotoxic lesions of the corpus callosum (4.1%). Multifocal white matter-enhancing lesions were seen in four patients in the ICU (5%). Basal ganglia abnormalities were seen in four other patients (5%). Cerebrospinal fluid analyses were negative for SARS-CoV-2 in all patients tested (n = 39). Conclusion In addition to cerebrovascular lesions, perfusion abnormalities, cytotoxic lesions of the corpus callosum, and intensive care unit-related complications, we identified two patterns including white matter-enhancing lesions and basal ganglia abnormalities that could be related to severe acute respiratory syndrome coronavirus 2 infection. © RSNA, 2020 Online supplemental material is available for this article.

Phase II study of mTORC1 inhibition by everolimus in neurofibromatosis type 2 patients with growing vestibular schwannomas.

Neurofibromatosis type 2 (NF2) is a genetic disorder with bilateral vestibular schwannomas (VS) as the most frequent manifestation. Merlin, the NF2 tumor suppressor, was identified as a negative regulator of mammalian target of rapamycin complex 1. Pre-clinical data in mice showed that mTORC1 inhibition delayed growth of NF2-schwannomas. We conducted a prospective single-institution open-label phase II study to evaluate the effects of everolimus in ten NF2 patients with progressive VS. Drug activity was monitored every 3 months. Everolimus was administered orally for 12 months and, if the decrease in tumor volume was >20 % from baseline, treatment was continued for 12 additional months. Other patients stopped when completed 12 months of everolimus but were allowed to resume treatment when VS volume was >20 % during 1 year follow-up. Nine patients were evaluable. Safety was evaluated using CTCAE 3.0 criteria. After 12 months of everolimus, no reduction in volume ≥20 % was observed. Four patients had progressive disease, and five patients had stable disease with a median annual growth rate decreasing from 67 %/year before treatment to 0.5 %/year during treatment. In these patients, tumor growth resumed within 3-6 months after treatment discontinuation. Everolimus was then reintroduced and VS decreased by a median 6.8 % at 24 months. Time to tumor progression increased threefold from 4.2 months before treatment to > 12 months. Hearing was stable under treatment. The safety of everolimus was manageable. Although the primary endpoint was not reached, further studies are required to confirm the potential for stabilization of everolimus.

Anatomical features of skull base and oral cavity: a pilot study to determine the accessibility of the sella by transoral robotic-assisted surgery.

The role of transoral robotic surgery (TORS) in the skull base emerges and represents the natural progression toward miniinvasive resections in confined spaces. The accessibility of the sella via TORS has been recently described on fresh human cadavers. An anatomic study is mandatory to know if this approach would be feasible in the majority of patients regardless of their oral morphological features. From 30 skull base CT scans from patients who were asked to open their mouth as wide as they can, we measured specific dimensions of the oral cavity and the skull base, such as length of the palate, mouth opening and distance from the sella to the palate. All data were acquired on a sagittal midline plane and on a 25° rotation plane, which simulated the axis of the robotic instruments. Looking at the projection of the dental palatine line on the sella, we studied possible predictive factors of sellar accessibility and tried to bring objective data for surgical feasibility. We also proposed an angle α to study the working angle at the skull base. We observed that the maximal mouth opening was a good predictive factor of sellar accessibility by TORS (p < 0.05). The mouth aperture threshold value for a good sensitivity, over 80 %, was comparable to the mean value of mouth opening in our series, 38.9 and 39.4 mm respectively. Moreover, we showed a statistically significant increase of the working angle α at the skull base comparing the lateral access to the midline one (p < 0.05). This seemed to quantitatively demonstrate that the robotic arms placed at the labial commissure of the mouth can reach the sella. From these anatomical features and previous cadaveric dissections, we assume that TORS may be feasible on a majority of patients to remove pituitary adenomas.

Imaging Criteria to Predict Surgical Difficulties During Stapes Surgery.

BACKGROUND AND PURPOSE: Stapes surgery for otosclerosis can be challenging if access to the oval window niche is restricted. The aim of this study was to determine the accuracy of the computed tomographic (CT) scan in the evaluation of anatomical distances, and to analyze its reliability in predicting surgical technical difficulties. MATERIAL AND METHODS: A total of 96 patients (101 ears) were enrolled in a prospective study between 2012 and May 2015. During surgery, we evaluated the distance D1 between the stapes and the facial nerve, distance D2 between the promontory and the facial nerve after ablation of the superstructure, and the intraoperative discomfort of the surgeon. On preoperative CT scans, we measured the width and depth of the oval window niche, and the angle formed by two axes starting from the center-point of the footplate, the first tangential to the superior wall of the promontory, and the second tangential to the inferior wall of the fallopian canal. RESULTS: Intraoperative distances D1 and D2 were correlated with the width of the oval window and with the facial-promontory angle measured on imaging. CT scan measurements of the facial-promontory angle and width of the oval window were associated with the degree of discomfort of the surgeon. The cut-off threshold for intraoperative subjective discomfort was computed as 1.1 mm for the width of the oval window niche, with a sensibility of 71% and a specificity of 84%. CONCLUSION: Preoperative imaging analysis of the oval window width and the facialpromontory angle can predict operative difficulty in otosclerosis surgery.

Neuroimaging features in posterior reversible encephalopathy syndrome: A pictorial review.

Posterior reversible encephalopathy syndrome (PRES) is a radioclinical entity associating nonspecific neurological symptoms (headache, seizures, impairment of alertness, visual disturbances…) occurring in evocative clinical condition (hypertension, eclampsia, immunosuppressor agents, systemic lupus erythematosus…). In the acute stage, the typical imaging finding is a vasogenic edema predominant in the subcortical parietal-occipital white matter. The purpose of this pictorial review is to illustrate the different neuroimaging features of PRES and present key radiological elements to assert diagnosis. In this overview, we examine the following points: the distributions of vasogenic edema, hemorrhage, the varying patterns in diffusion and perfusion, the different types of enhancement encountered and the vascular modifications demonstrated by angiography. The cause of PRES is still unknown. Nevertheless, catheter angiography, MR angiography and MR perfusion features in PRES render further insight into its pathophysiology. Follow-up imaging shows evidence of radiologic improvement in the very large majority of cases in 1 or 2weeks, sometimes in up to 1month. Recurrent PRES attacks are uncommon. Atypical imaging presentation should not reject the diagnosis of PRES in a compatible clinical situation.

Transient reduction in venous susceptibility during posterior reversible encephalopathy syndrome.

We report a case of posterior reversible encephalopathy syndrome (PRES) in which followed-up MRI demonstrated a transient reduction in venous signal on initial SWAN images. The progressive normalization of venous signal on D10 and D40 imaging paralleled the progressive decrease of hyperperfusion on CBF images. Decreased venous susceptibility has never been reported in PRES; it relates most likely to a transient BOLD effect induced by brain hyperperfusion.

Fast and accurate semi-automated segmentation method of spinal cord MR images at 3T applied to the construction of a cervical spinal cord template.

OBJECTIVE: To design a fast and accurate semi-automated segmentation method for spinal cord 3T MR images and to construct a template of the cervical spinal cord. MATERIALS AND METHODS: A semi-automated double threshold-based method (DTbM) was proposed enabling both cross-sectional and volumetric measures from 3D T2-weighted turbo spin echo MR scans of the spinal cord at 3T. Eighty-two healthy subjects, 10 patients with amyotrophic lateral sclerosis, 10 with spinal muscular atrophy and 10 with spinal cord injuries were studied. DTbM was compared with active surface method (ASM), threshold-based method (TbM) and manual outlining (ground truth). Accuracy of segmentations was scored visually by a radiologist in cervical and thoracic cord regions. Accuracy was also quantified at the cervical and thoracic levels as well as at C2 vertebral level. To construct a cervical template from healthy subjects' images (n=59), a standardization pipeline was designed leading to well-centered straight spinal cord images and accurate probability tissue map. RESULTS: Visual scoring showed better performance for DTbM than for ASM. Mean Dice similarity coefficient (DSC) was 95.71% for DTbM and 90.78% for ASM at the cervical level and 94.27% for DTbM and 89.93% for ASM at the thoracic level. Finally, at C2 vertebral level, mean DSC was 97.98% for DTbM compared with 98.02% for TbM and 96.76% for ASM. DTbM showed similar accuracy compared with TbM, but with the advantage of limited manual interaction. CONCLUSION: A semi-automated segmentation method with limited manual intervention was introduced and validated on 3T images, enabling the construction of a cervical spinal cord template.

Evaluation of an albumin-binding gadolinium contrast agent in multiple sclerosis.

OBJECTIVE: The first goal of this study is to compare gadofosveset trisodium--a gadolinium agent that reversibly binds to albumin--to an extracellular contrast agent (Gd-DOTA) for the detection of multiple sclerosis lesions. The second goal is to determine the best postinjection time for the detection of contrast-enhanced lesions. METHODS: Nine patients underwent 2 MRI examinations, respectively, after Gd-DOTA (0.1 mmol/kg) and gadofosveset trisodium (0.03 mmol/kg) administration. Axial T1 spin-echo-weighted images were acquired at several time points after injection (4 minutes for Gd-DOTA, and 4, 8, 12, 16, 20 minutes, 1 hour, and 4 hours for gadofosveset trisodium). Images were analyzed by 4 neuroradiologists who marked the contrast-enhanced lesions and, for each marked lesion, chose the acquisition they preferred and segmented the lesion on their preferred acquisition. RESULTS: The 4-hour gadofosveset trisodium acquisition was ranked best for the 3 tasks: contrast-enhanced lesions were seen by more readers, they preferred this acquisition, and improvements of the signal enhancement (125%) and of the contrast-to-noise ratio (73%) vs Gd-DOTA at 4 minutes were observed (p < 0.05). CONCLUSION: Gadofosveset trisodium after 4 hours significantly improves the number of detected contrast-enhanced multiple sclerosis lesions as compared to Gd-DOTA after 4 minutes, even though the injected dose of gadolinium was two-thirds lower.