Consensus Guidelines of the French Society of Neuroradiology (SFNR) on the use of Gadolinium-Based Contrast agents (GBCAs) and related MRI protocols in Neuroradiology.

Gadolinium-based contrast agents (GBCAs) are used in up to 35% of magnetic resonance imaging (MRI) examinations and are associated with an excellent safety profile. Nevertheless, two main issues have arisen in the last two decades: the risk of nephrogenic systemic fibrosis and the risk of gadolinium deposition and retention. As a first step, this article reviews the different categories of GBCAs available in neuroradiology, their issues, and provides updates regarding the use of these agents in routine daily practice. Recent advances in MRI technology, as well as the development of new MRI sequences, have made GBCA injection avoidable in many indications, especially in patients with chronic diseases when iterative MRIs are required and when essential diagnostic information can be obtained without contrast enhancement. These recent advances also lead to changes in recommended MRI protocols. Thus, in a second step, this review focuses on consensus concerning brain MRI protocols in 10 common situations (acute ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, multiple sclerosis, chronic headache, intracranial infection, intra- and extra-axial brain tumors, vestibular schwannoma and pituitary adenoma). The latter allowing the standardization of practices in neuroradiology. Recommendations were also made concerning the use of GBCAs in neuroradiology, based on evidence in the literature and/or by consensus between the different coauthors.

New detailed description of the anterior part of the cribriform plate using anatomic specimens and computed tomography.

PURPOSE: Ethmoidal slit (ES) and cribroethmoidal foramen (CF) have been poorly studied, without any radiological description. They may ease cribriform plate's diseases. The objective was to describe the frequency, size, and computed tomography (CT) appearance of these foramina. METHODS: A two-part anatomoradiological study was performed: first on dry skulls using a surgical microscope and CT, second on patients CT scans. For each, foramina were searched for, described, and measured when possible. RESULTS: Thirteen dry macerated skulls were studied. The orbitomeatal plane was relevant for studying ES. With microscope, ES and CF were identified in, respectively, 92% and 100% of cases. Using CT, all ES and CF were visible, with a mean length and width of, respectively, 3.9 ± 1.7 mm and 0.9 ± 0.3 mm for ES and 1.6 ± 1 mm and 0.9 ± 0.3 mm for CF. CT scans from 153 patients were reviewed. ES and CF were identified in, respectively, 80% and 91% of cases, with a mean length and width of, respectively, 3.9 ± 0.8 mm and 0.8 ± 0.2 mm for ES. CONCLUSION: Large-sized ES was found frequently, and were clearly visible in patients CT scans. CF was markedly smaller, but seen in most patient scans. ES and CF could be areas of least resistance in the anterior part of the cribriform plate. CT might be helpful in understanding their pathological implications.

Solitaire FR as a first-line device in acute intracerebral occlusion: a single-centre retrospective analysis.

INTRODUCTION: Analysing the clinical and angiographical effectiveness of the Solitaire FR as a mechanical thrombectomy device in acute intracerebral occlusion. METHODS: Sixty-two patients were retrospectively included between January 2010 and March 2012. All of them underwent mechanical thrombectomy with the Solitaire FR device with or without intravenous thrombolysis. Twenty-five patients had an occlusion of the basilar artery, 1 had a posterior cerebral artery occlusion. There were 16 M1 middle cerebral artery occlusions, 9 carotid T occlusions and 11 tandem occlusions. Clinical status was evaluated using the National Institute of Health Stroke Scale (NIHSS) before and 24 hours after treatment and at discharge. The Modified Rankin Scale (mRS) was evaluated at 3 months. RESULTS: Mean age of patients was 64.8 years. Mean NIHSS score on admission was 19.8. Stand-alone thrombectomy was used in 47 patients (75.8%). Recanalization was successful (TICI score 2b or 3) in 23 of 26 (88.5%) patients with posterior circulation occlusion and in 23 of 36 (63.9%) patients with anterior circulation occlusion. NIHSS improved by more than 10 points for 15 of 59 patients with initial NIHSS over 10. MRS was 0-2 in 25 of 62 patients (40.3%). Overall, 23 patients out of 62 died (37%). No complications related to the Solitaire device occurred. CONCLUSION: These results confirm that the Solitaire FR device is safe and effective in stand-alone thrombectomy.

CT-scan imaging of iron marked chorda tympani nerve: anatomical study and educational perspectives.

The chorda tympani nerve (CTN) is the last collateral branch of the facial nerve in its third intraosseous portion just over the stylomastoid foramen. After a curved course against the medial aspect of the tympanum where it is likely to be injured in middle ear surgery, CTN reaches the lingual nerve in the infratemporal fossa. Knowledge of CTN topographic anatomy is not easily achieved by the students because of the deep location of this thin structure. The aim of this study was to assess the spatial relationships of the CTN in the infratemporal fossa. Therefore, ten nerves were dissected in five fresh cadavers. All the nerves were catheterized with a 3/0 wire. After a meticulous repositioning of surrounding structures, standard X-ray and CT scan examinations were performed with multiplanar acquisitions and three-dimensional surface rendering reconstructions. Ventral projection of the CTN corresponded to the middle of the maxillary sinus. Lateral landmark was the mandibular condyle. The CTN was present and unique in all the dissections. The average length of the nerve, as measured on CT scans, was 31.8 mm (29-34, standard deviation of 1.62); the anastomosis of the CTN to the lingual nerve was located at a mean 24.9 mm below the skull base (24-27, standard deviation of 0.99), approximately in the same horizontal plane as the lower part of the mandibular notch. The acute angle opened dorsally and cranially between CTN and LN measured mean 63.2° (60-65, standard deviation of 1.67). Three-dimensional volumetric reconstructions using surface rendering technique provided realistic educational support at the students' disposal.

Transient ischaemic attack mimics revealing focal subarachnoid haemorrhage.

We describe here 7 elderly patients with a transient neurological deficit due to a focal subarachnoid haemorrhage, identified from the Dijon Stroke Registry over 4 years. These 7 patients presented a clinical pattern marked by focal paraesthesia, with several stereotyped focal episodes (5 of the 7 cases), lasting less than 30 min (6 of the 7 cases), and associated with a cognitive decline (4 of the 7 cases). Headache was present in only 1 case. Neuroimaging revealed focal haemorrhage present in a cortical sulcus contralateral to the symptoms. No vascular lesions nor epileptic mechanisms nor ischemic lesions were observed. This syndrome could be explained by a spreading depression, and the focal subarachnoid haemorrhage could reflect possible cerebral amyloid angiopathy, suggested by the cognitive decline present in more than 50% of our series. Our observations suggest that focal subarachnoid haemorrhage may be diagnosed by MRI in the absence of acute headache and it may be revealed by transient focal and repetitive sensory perturbations. In medical practice, it is important to evoke this diagnosis in the elderly to avoid inappropriate treatment.

MT-DRAGON score for outcome prediction in acute ischemic stroke treated by mechanical thrombectomy within 8 hours.

OBJECTIVES: The MRI-DRAGON score includes clinical and MRI parameters and demonstrates a high specificity in predicting 3 month outcome in patients with acute ischemic stroke (AIS) treated with intravenous tissue plasminogen activator (IV tPA). The aim of this study was to adapt this score to mechanical thrombectomy (MT) in a large multicenter cohort. METHODS: Consecutive cases of AIS treated by MT between January 2015 and December 2017 from three stroke centers were reviewed (n=1077). We derived the MT-DRAGON score by keeping all variables of the MRI-DRAGON score (age, initial National Institutes of Health Stroke Scale score, glucose level, pre-stroke modified Rankin Scale (mRS) score, diffusion weighted imaging-Alberta Stroke Program Early CT score ≤5) and considering the following variables: time to groin puncture instead of onset to IV tPA time and occlusion site. Unfavorable 3 month outcome was defined as a mRS score >2. Score performance was evaluated by c statistics and an external validation was performed. RESULTS: Among 679 included patients (derivation and validation cohorts, n=431 and 248, respectively), an unfavorable outcome was similar between the derivation (51.5%) and validation (58.1%, P=0.7) cohorts, and was significantly associated with all MT-DRAGON parameters in the multivariable analysis. The c statistics for unfavorable outcome prediction was 0.83 (95%CI 0.79 to 0.88) in the derivation and 0.8 (95%CI 0.75 to 0.86) in the validation cohort. All patients (n=55) with an MT-DRAGONscore ≥11 had an unfavorable outcome and 60/63 (95%) patients with an MT-DRAGON score ≤2 points had a favorable outcome. CONCLUSION: The MT-DRAGON score is a simple tool, combining admission clinical and radiological parameters that can reliably predict 3 month outcome after MT.

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.

Spatial relationships between lingual nerve and mandibular ramus: original study method, clinical and educational applications.

Lingual nerve damage complicating oral surgery would sometimes require electrographic exploration. Nevertheless, direct recording of conduction in lingual nerve requires its puncture at the foramen ovale. This method is too dangerous to be practiced routinely in these diagnostic indications. The aim of our study was to assess spatial relationships between lingual nerve and mandibular ramus in the infratemporal fossa using an original technique. Therefore, ten lingual nerves were dissected on five fresh cadavers. All the nerves were catheterized with a 3/0 wire. After meticulous repositioning of the nerve and medial pterygoid muscle reinsertion, CT-scan examinations were performed with planar acquisitions and three-dimensional reconstructions. Localization of lingual nerve in the infratemporal fossa was assessed successively at the level of the sigmoid notch of the mandible, lingula and third molar. At the level of the lingula, lingual nerve was far from the maxillary vessels; mean distance between the nerve and the anterior border of the ramus was 19.6 mm. The posteriorly opened angle between the medial side of the ramus and the line joining the lingual nerve and the anterior border of the ramus measured 17 degrees . According to these findings, we suggest that the lingual nerve might be reached through the intra-oral puncture at the intermaxillary commissure; therefore, we modify the inferior alveolar nerve block technique to propose a safe and reproducible protocol likely to be performed routinely as electrographic exploration of the lingual nerve. What is more, this original study protocol provided interesting educational materials and could be developed for the conception of realistic 3D virtual anatomy supports.

A Rare and Treatable Cause of Medullar Claudication: Spinal Dural Arteriovenous Fistula.

Background: Spinal dural arteriovenous fistula is a rare and underdiagnosed disorder. Because of the nonspecific clinical presentation of the condition, patients are often referred to different specialists, resulting in delayed diagnosis. Case Report: A 76-year-old male presented with a 1-month history of gait trouble. His impairment was asymmetric, distally predominant, sensitive, and motor. Symptoms worsened with standing and walking. The patient also had sphincterial dysfunction. Classic spinal cord magnetic resonance imaging (MRI) showed an extended hypersignal indicating nonspecific myelopathy. Repeat spinal cord MRI that included a T2 spin echo sequence revealed abnormalities suggesting dural arteriovenous fistula. Medullar angiography confirmed the diagnosis, and endovascular treatment was successfully performed. Six months posttreatment, the patient reported resolution of his neurologic disabilities except for some residual paresthesia in his inferior limbs. Conclusion: Physicians should be aware of the specific abnormalities shown on spinal cord MRI that indicate dural arteriovenous fistula, as well as the criteria for performing medullar angiography, so that the condition can be diagnosed and treated in a timely manner. Early therapeutic treatment is the principal prognosis factor.

Real-World Thrombectomy Using the Sofia Catheter.

OBJECTIVE: To study the safety and performance of real-world thrombectomy using the SOFIA Catheter in our comprehensive stroke center. METHODS: We conducted a cohort study from a prospective clinical registry of consecutive stroke patients treated by mechanical thrombectomy between March 2016 and September 2017. Baseline clinical and imaging characteristics, recanalization rates, complications, and clinical outcomes were analyzed. RESULTS: Among the 140 patients included, 54 were treated using aspiration first, 64 were treated using aspiration and stent-retriever straightaway, and 22 were treated with SOFIA as a rescue device. Successful recanalization (Modified Thrombolysis In Cerebral Infarction score 2b/3) was achieved in 82.1% patients and good outcomes in 34.3%. Symptomatic intracranial hemorrhage occurred in 7.1% and mortality in 25%. CONCLUSIONS: In our single-center experience, thrombectomy using the SOFIA as an intermediate or aspiration catheter provided high recanalization rates under everyday conditions.

Subarachnoid Hemorrhage Revealing Moyamoya Syndrome in a Patient With May-Hegglin Anomaly.

INTRODUCTION: Moyamoya syndrome is a rare progressive cerebrovascular occlusive disease for which several associated conditions have been described. CASE REPORT: We report the case of a 76-year-old woman with a history of May-Hegglin anomaly who presented with an isolated unusual diffuse headache. Initial laboratory investigations showed only thrombocytopenia (platelet count 95000/µL). Unenhanced brain computed tomography scan revealed a small subarachnoid hemorrhage in the left frontal lobe. Computed tomography angiography showed occlusion of the terminal portion of the left internal carotid artery (ICA) and narrowing of the terminal portion of the right ICA with abnormal collateral vessels. Conventional angiography confirmed the tight stenosis of the extremity of the right ICA, and the occlusion of the left ICA, associated with an extensive collateral network consistent with moyamoya syndrome. No aneurysm was identified. CONCLUSIONS: The rarity of these 2 diseases makes a fortuitous association very unlikely. We thus concluded that this observation could be the first reported case of May-Hegglin anomaly as a cause of moyamoya syndrome.

Immune Reconstitution Inflammatory Syndrome Unmasking or Worsening AIDS-Related Progressive Multifocal Leukoencephalopathy: A Literature Review.

Incidence of progressive multifocal leukoencephalopathy (PML) in HIV-infected patients has declined in the combined antiretroviral therapy (cART) era although a growing number of acquired immunodeficiency syndrome (AIDS)-related PML-immune reconstitution inflammatory syndromes (PML-IRIS) have been published during the same period. Therapeutic management of PML-IRIS is not consensual and mainly relies on corticosteroids. Our main aim was, in addition to provide a thoughtful analysis of published PML-IRIS cases, to assess the benefit of corticosteroids in the management of PML-IRIS, focusing on confirmed cases. We performed a literature review of the 46 confirmed cases of PML-IRIS cases occurring in HIV-infected patients from 1998 to September 2016 (21 unmasking and 25 paradoxical PML-IRIS). AIDS-related PML-IRIS patients were mostly men (sex ratio 4/1) with a median age of 40.5 years (range 12-66). Median CD4 T cell count before cART and at PML-IRIS onset was 45/µl (0-301) and 101/µl (20-610), respectively. After cART initiation, PML-IRIS occurred within a median timescale of 38 days (18-120). Clinical signs were motor deficits (69%), speech disorders (36%), cognitive disorders (33%), cerebellar ataxia (28%), and visual disturbances (23%). Brain MRI revealed hyperintense areas on T2-weighted sequences and FLAIR images (76%) and suggestive contrast enhancement (87%). PCR for John Cunningham virus (JCV) in cerebrospinal fluid (CSF) was positive in only 84% of cases; however, when performed, brain biopsy confirmed diagnosis of PML in 90% of cases and demonstrated histological signs of IRIS in 95% of cases. Clinical worsening related to PML-IRIS and leading to death was observed in 28% of cases. Corticosteroids were prescribed in 63% of cases and maraviroc in one case. Statistical analysis failed to demonstrate significant benefit from steroid treatment, despite spectacular improvement in certain cases. Diagnosis of PML-IRIS should be considered in HIV-infected patients with worsening neurological symptoms after initiation or resumption of effective cART, independently of CD4 cell count prior to cART. If PCR for JCV is negative in CSF, brain biopsy should be discussed. Only large multicentric randomized trials could potentially demonstrate the possible efficacy of corticosteroids and/or CCR5 antagonists in the management of PML-IRIS.

Spontaneous resolution of perforator aneurysms of the posterior circulation.

The authors present the cases of 3 patients with ruptured perforator aneurysms of the posterior circulation. Patients were 39, 55, and 59 years old. None of the patients had relevant past medical or family history. All presented with World Federation of Neurosurgical Societies Grade I and Fisher Grade 2 or 3 subarachnoid hemorrhage. Initial angiography results were normal. A second cerebral angiogram in each case revealed a small (< 3 mm) aneurysm of perforator arteries of the posterior circulation. Patients were successfully managed conservatively. None of the patients developed symptomatic vasospasm, rebleeding, or hydrocephaly. Control angiograms at 3 months showed spontaneous resolution of the aneurysm in all cases. Rupture of perforator aneurysms of the posterior circulation is a rare condition and it may be underdiagnosed because of limitations of imaging techniques. Treatments can lead to complications in highly functional territories and should be considered wisely, especially due to the fact that the causes and natural history of such aneurysms are unknown and spontaneous healing remains a possibility.

[Stroke in children: a medical emergency]. / Accidents vasculaires cérébraux de l'enfant : une urgence médicale qui doit bénéficier des filières neurovasculaires régionales mises en place par le Plan National AVC.

Stroke in children is an important public health problem because, even if it is 10 folds less frequent than in adults, it may have severe consequences, related to the lack of dedicated stroke network in childhood. Therefore, it is important to know the initial clinical symptoms of stroke in children as well as the lack of aphasia opposed to the great frequency of epilepsy, and dystonia. The causes are different compared to the great frequency of cerebral hemorrhage from vascular malformations, cerebral infarct from genetic, cardiac or thrombophilic origin. Prognosis is more favourable compared to that of adults. The management of stroke in childhood must be included in the stroke network of adults, associating the paediatricians. Fibrinolysis is possible in children with a similar efficacy compared to that of adults.