Advanced multiparametric magnetic resonance imaging of multinodular and vacuolating neuronal tumor.

BACKGROUND AND PURPOSE: Multinodular and vacuolating neuronal tumor (MVNT) of the cerebrum is a rare brain lesion with suggestive imaging features. The aim of our study was to report the largest series of MVNTs so far and to evaluate the utility of advanced multiparametric magnetic resonance (MR) techniques. METHODS: This multicenter retrospective study was approved by our institutional research ethics board. From July 2014 to May 2019, two radiologists read in consensus the MR examinations of patients presenting with a lesion suggestive of an MVNT. They analyzed the lesions' MR characteristics on structural images and advanced multiparametric MR imaging. RESULTS: A total of 64 patients (29 women and 35 men, mean age 44.2 ± 15.1 years) from 25 centers were included. Lesions were all hyperintense on fluid-attenuated inversion recovery and T2-weighted imaging without post-contrast enhancement. The median relative apparent diffusion coefficient on diffusion-weighted imaging was 1.13 [interquartile range (IQR), 0.2]. Perfusion-weighted imaging showed no increase in perfusion, with a relative cerebral blood volume of 1.02 (IQR, 0.05) and a relative cerebral blood flow of 1.01 (IQR, 0.08). MR spectroscopy showed no abnormal peaks. Median follow-up was 2 (IQR, 1.2) years, without any changes in size. CONCLUSIONS: A comprehensive characterization protocol including advanced multiparametric magnetic resonance imaging sequences showed no imaging patterns suggestive of malignancy in MVNTs. It might be useful to better characterize MVNTs.

A quantitative and semi-automatic measurement of transverse sinus stenosis improves idiopathic intracranial hypertension diagnostic accuracy.

We propose a new reliable transverse sinus stenosis (TSS) index based on magnetic resonance venography (MRV) for the diagnosis of idiopathic intracranial hypertension (IIH). Our quantitative semi-automatic measurement analysis based on segmentation and cross-sectional TS diameter from 48 IIH patients and controls matched for age and sex, had a good inter-observer agreement (κ=0.729) compared to a visual examination (κ=0.467). A cut-off point≥2 discriminate IIH patients from controls, with a sensitivity and specificity of 100%.

[Basal ganglia calcification]. / Calcifications des noyaux gris centraux.

Calcifications of the basal ganglia are frequently seen on the cerebral CT scans and particularly in the globus pallidus. Their frequency increases physiologically with age after 50 years old. However, pathological processes can also be associated with calcium deposits in the gray nuclei, posterior fossa or white matter. Unilateral calcification is often related to an acquired origin whereas bilateral ones are mostly linked to an acquired or genetic origin that will be sought after eliminating a perturbation of phosphocalcic metabolism. In pathological contexts, these calcifications may be accompanied by neurological symptoms related to the underlying disease: Parkinson's syndrome, psychiatric and cognitive disorders, epilepsy or headache. The purpose of this article is to provide a diagnostic aid, in addition to clinical and biology, through the analysis of calcification topography and the study of different MRI sequences.

[Imaging of subarachnoid hemorrhage]. / Imagerie de l'hémorragie sous-arachnoïdienne.

Even if acute subarachnoid hemorrhage (SAH) accounts for only 5% of strokes, its diagnosis is very important because its clinical consequences can be tragic. Recent technological advances in medical imaging have improved diagnostic and therapeutic management of patients with SAH. Nonenhanced CT of the head is the initial imaging modality in suspected SAH for the detection of ruptured intracranial aneurysms. Digital subtraction angiography (DSA) remains the reference exam. Multidetector row CT angiography may potentially replace DSA in the emergency setting, as it provides image data that allows evaluating aneurysmal morphology, the neck size or the visualization of vessels in the vicinity of the aneurysm. For SAH unrelated to aneurysm rupture (15% of cases), MRI and MRA can be added to the diagnostic work-up in order to exclude other differential diagnoses such as venous thrombosis or angiitis. Finally, transcranial color-coded duplex sonography, CT, or MRI are used in clinical practice in order to detect aggravating factors of SAH like hydrocephalus or vasospasm.

Scaling Drug Clearance from Adults to the Young Children for Drugs Undergoing Hepatic Metabolism: A Simulation Study to Search for the Simplest Scaling Method.

Previous research showed that scaling drug clearance from adults to children based on body weight alone is not accurate for all hepatically cleared drugs in very young children. This study systematically assesses the accuracy of scaling methods that, in addition to body weight, also take age-based variables into account for drugs undergoing hepatic metabolism in children younger than five years, namely scaling with (1) a body weight-based function using an age-dependent exponent (ADE) and (2) a body weight-based function with fixed exponent of 0.75 (AS0.75) combined with isoenzyme maturation functions (MFPBPK) similar to those implemented in physiologically based pharmacokinetic (PBPK) models (AS0.75 + MFPBPK). A PBPK-based simulation workflow was used, including hypothetical drugs with a wide range of properties and metabolized by different isoenzymes. Adult clearance values were scaled to seven typical children between one day and four years. Prediction errors of ± 50% were considered reasonably accurate. Isoenzyme maturation was found to be an important driver of changes in hepatic metabolic clearance in children younger than five years, which prevents the systematic accuracy of ADE scaling. AS0.75 + MFPBPK, when accounting for maturation of isoenzymes and microsomal protein per gram of liver (MPPGL), can reasonably accurately scale hepatic metabolic clearance for all low and intermediate extraction ratio drugs except for drugs binding to alpha-1-acid glycoprotein in neonates. As differences in the impact of changes in system-specific parameters on drugs with different properties yield differences in clearance ontogeny, it is unlikely that for the remaining drugs, scaling methods that do not take drug properties into account will be systematically accurate.

Multinodular and Vacuolating Posterior Fossa Lesions of Unknown Significance.

Multinodular and vacuolating neuronal tumor of the cerebrum is a rare supratentorial brain tumor described for the first time in 2013. Here, we report 11 cases of infratentorial lesions showing similar striking imaging features consisting of a cluster of low T1-weighted imaging and high T2-FLAIR signal intensity nodules, which we referred to as multinodular and vacuolating posterior fossa lesions of unknown significance. No relationship was found between the location of the lesion and clinical symptoms. A T2-FLAIR hypointense central dot sign was present in images of 9/11 (82%) patients. Cortical involvement was present in 2/11 (18%) of patients. Only 1 nodule of 1 multinodular and vacuolating posterior fossa lesion of unknown significance showed enhancement on postcontrast T1WI. DWI, SWI, MRS, and PWI showed no malignant pattern. Lesions did not change in size or signal during a median follow-up of 3 years, suggesting that multinodular and vacuolating posterior fossa lesions of unknown significance are benign malformative lesions that do not require surgical intervention or removal.

Emotional facial palsy following striato-capsular infarction.

Emotional facial palsy (EFP) is a rare condition in which facial paresis is only apparent during reflex movements of the hemiface, such as smiling and laughter. We report the case of a 32-year-old man presenting with EFP as the main symptom of a small striatocapsular infarction. Our case strongly suggests that the anterior arm of the internal capsule is part of the corticonuclear tract that is involved in emotional facial motility.

Inaugural tumor-like multiple sclerosis: clinical presentation and medium-term outcome in 87 patients.

BACKGROUND: Tumefactive demyelinating lesions of the central nervous system can be the initial presentation in various pathological entities [multiple sclerosis (the most common), Balo's concentric sclerosis, Schilder's disease and acute disseminated encephalomyelitis] with overlapping clinical presentation. The aim of our study was to better characterize these patients. METHODS: Eighty-seven patients (62 women and 25 men) from different MS centers in France were studied retrospectively. Inclusion criteria were (1) a first clinical event (2) MRI showing one or more large demyelinating lesions (20 mm or more in diameter) with mass-like features. Patients with a previous demyelinating event (i.e. confirmed multiple sclerosis) were excluded. RESULTS: Mean age at onset was 26 years. The most common initial symptoms (67% of the patients) were hemiparesis or hemiplegia. Aphasia, headache and cognitive disturbances (i.e. atypical symptoms for demyelinating diseases) were observed in 15, 18 and 15% of patients, respectively. The mean largest diameter of the tumefactive lesions was 26.9 mm, with gadolinium enhancement in 66 patients (81%). Twenty-one patients (24%) had a single tumefactive lesion. During follow-up (median time 5.7 years) 4 patients died, 70 patients improved or remained stable and 12 worsened. 86% of patients received initial corticosteroid treatment, and 73% received disease-modifying therapy subsequently. EDSS at the end of the follow-up was 2.4 ± 2.6 (mean ± SD). CONCLUSION: This study provides further evidence that the clinical course of MS presenting with large focal tumor-like lesions does not differ from that of classical relapsing-remitting MS, once the noisy first relapsing occurred.

[Acute anterograde amnesia by infarction of the mamillothalamic tracts]. / Syndrome amnésique aigu par infarctus des faisceaux mamillothalamiques de Vicq d'Azir.

We report a case of persistent anterograde amnesia secondary to an anterior thalamic infarct. A 49-year-old right-handed man is referred for acute anterograde amnesia. Diffusion-weighted imaging performed at 24 hours shows an acute punctiform infarct of the left anterior thalamus, while T2-weighted imaging reveals a contralateral and symmetrical ischemic sequelae in the right anterior thalamus. The two lesions are isolated and remarkably centered with the mamillothalamic tract. We suggest the symptoms are caused by the addition of the two lesions interrupting the mamillothalamic tracts. This is the second clinico-pathological observation of a persistent amnestic syndrome secondary to a bilateral lesion of the mamillothalamic tract.

Intravenous Paracetamol Dosing Guidelines for Pain Management in (pre)term Neonates Using the Paediatric Study Decision Tree.

BACKGROUND: Intravenous paracetamol (acetaminophen) has not been licensed for analgesia in preterm neonates or infants < 2 years, respectively, in Europe and the United States. A variety of dosing regimens is therefore used off-label. Because evidence supports the use of the same target mean steady state paracetamol concentration (Cssmean, 9-11 mg/L) for pain relief in neonates compared to older children and adults, dosing regimens based on this Cssmean were evaluated in a two-step approach. METHODS: First, a systematic search was performed to provide pharmacokinetic (PK)-based dosing guidelines for pain in neonates (with subsequent searches on safety in these papers). Second, concentration-time profiles based on these dosing guidelines were generated to provide a dosing advice for paracetamol to treat neonatal pain. RESULTS: Of 2334 potentially relevant articles, 9 studies were included. For typical term neonates, dosages specified in packaging (labels) resulted in Cssmean below target (7.65 mg/L), while dosages from investigator-initiated studies resulted in either a Cssmean above (15.31), or around the target (11.78 and 10.21) for (pre)term neonates >32 weeks. Only one study suggested a dosing resulting in a tailored concentration (8.7) in preterm neonates <32 weeks. CONCLUSION: A loading dose 20 mg/kg, followed by 10 mg/kg/6h is recommended for 32-44 weeks' neonates, which is supported by short-term safety. For neonates < 32 weeks, a loading dose of 12 mg/kg and a maintenance dose of 6mg/kg/6h seems to lead to the target Cssmean, though additional clinical studies are needed to support its safety.

TIPIC Syndrome: Beyond the Myth of Carotidynia, a New Distinct Unclassified Entity.

BACKGROUND AND PURPOSE: The differential diagnosis of acute cervical pain includes nonvascular and vascular causes such as carotid dissection, carotid occlusion, or vasculitis. However, some patients present with unclassified vascular and perivascular changes on imaging previously reported as carotidynia. The aim of our study was to improve the description of this as yet unclassified clinico-radiologic entity. MATERIALS AND METHODS: From January 2009 through April 2016, 47 patients from 10 centers presenting with acute neck pain or tenderness and at least 1 cervical image showing unclassified carotid abnormalities were included. We conducted a systematic, retrospective study of their medical charts and diagnostic and follow-up imaging. Two neuroradiologists independently analyzed the blinded image datasets. RESULTS: The median patient age was 48 years. All patients presented with acute neck pain, and 8 presented with transient neurologic symptoms. Imaging showed an eccentric pericarotidian infiltration in all patients. An intimal soft plaque was noted in 16 patients, and a mild luminal narrowing was noted in 16 patients. Interreader reproducibility was excellent. All patients had complete pain resolution within a median of 13 days. At 3-month follow-up, imaging showed complete disappearance of vascular abnormalities in 8 patients, and a marked decrease in all others. CONCLUSIONS: Our study improved the description of an unclassified, clinico-radiologic entity, which could be described by the proposed acronym: TransIent Perivascular Inflammation of the Carotid artery (TIPIC) syndrome.

[Vertebrovertebral arteriovenous fistula diagnosis and treatment: report of 8 cases and review of the literature]. / Diagnostic et traitement des fistules vertébrovertébrales. Revue de la littérature: à propos de 8 observations.

Vertebrovertebral Arteriovenous Fistula (V.V.A.V.F.) is a relatively rare entity. It may be an incidental finding or be detected in patients presenting with pulsatile tinnitus, cervical bruit, or vertebro-basilar insufficiency. It can be spontaneous but it most frequently is post-traumatic in etiology. The authors report 8 patients, 4 women and 4 men aged between 20 to 77 years, with 4 post-traumatic V.V.A.V.F. and 4 spontaneous V.V.A.V.F. that were seen over a 15 year period. Imaging work-up included Doppler US (n=4), MRI 9n=3) and angiography (n=8). Seven of 8 patients were treated successfully using an endovascular technique (5 with balloon occlusion, 1 with coil embolization and 1 using a mechanical maneuver), without complication or recurrence, except in one case. We compare our results with published reports from the literature and review the underlying pathology and management strategies of V.V.A.V.F.

[Intracranial aneurysms presenting with ischemic stroke]. / Anévrysmes intracrâniens révélés par une ischémie cérébrale.

PURPOSE: To report four cases of patient with an acute ischemic event as a presenting symptom of a berry aneurysm. PATIENTS AND METHODS: One male and three female (aged range 38 to 65 years) patients were admitted for acute stroke. The neuroradiologic finding disclosed aneurysm thrombosis, inferior to twenty five millimetres in three cases. Lumbar puncture was done in one case and showed subarachnoid haemorrage. DISCUSSION: We will discuss the hypothesis leading to the mechanism of aneurysm thrombosis. Two theories will be presented: "hemodynamic" and "parietal" modifications. We will propose a management protocol for these patients with atypical presentation of intracranial aneurysms given the potential risk of rupture. CONCLUSION: The natural history of intracranial aneurysms is still not fully understood. Nevertheless, aneurym thrombosis may occur and lead to ischemic stroke.

[Natural history and management of mycotic intracranial aneurysm]. / Anévrysme mycotique cérébral: histoire naturelle et prise en charge thérapeutique.

INTRODUCTION: mycotic intracranial aneurysms are a rare complication of infectious endocarditis. We report four cases of patients with endocarditis, complicated by an acute stroke, revealing a mycotic intracranial aneurysm. PATIENTS AND METHODS: four men (aged range 24 to 63 year old) were admitted for endocarditis, complicated by ischemic stroke in two cases and hemorrhagic stroke in the two other cases, including one with subarachnoid hemorrhage. Neuroimaging disclosed a mycotic cerebral aneurysm in all four cases. DISCUSSION: we will discuss the natural history and the management of mycotic intracranial aneurysm based on a review of the literature and our experience. Three therapeutic options are possible: medical treatment, surgery and endovascular embolisation. CONCLUSION: management of mycotic intracranial aneurysms is still controversial, frequently requiring a multidisciplinary strategy with priority given to endovascular interventions.

[Hypertrophic olivary degeneration. MR imaging findings and temporal evolution]. / Degenerescence olivaire hypertrophique. Aspect IRM et évolution temporelle.

PURPOSE: to describe the magnetic resonance imaging features of hypertrophic olivary degeneration (HOD) subsequent to lesion in the "Guillain-Mollaret triangle". MATERIALS AND METHODS: 15 cases of HOD were diagnosed at MR imaging in 12 patients (4 women and 8 men) with posterior fossa lesion. The time interval from the beginning of the disease to the MR examination was 3 weeks to 8 (1/2) years. Evaluation of the changes in signal intensity over time of the lesions was available in 6 patients. RESULTS: Nine cases of HOD were unilateral and three were bilateral. HOD was associated to a lesion of the contralateral dentate nucleus in 8 cases, to a lesion of the ipsilateral central tegmental tract in 5 cases and to a lesion of the contralateral superior cerebellar peduncle in 2 cases. Hyperintensity and hypertrophy of the olive on proton density and T2-weighted images appeared as early as 3 weeks after the ictus. A curved central hyperintensity (CCH) could be observed 7 months after the initial presentation. Decrease in the signal intensity was observed after 3 (1/2) years and abnormal signal intensity could persist for up to 13 years. Palatal myoclonus at 5 months was associated with HOD in one case. CONCLUSION: HOD is considered a trans-synaptic degeneration subsequent to lesions in the Guillain-Mollaret triangle. Hyperintensity and hypertrophy of the olive are observed, sometimes with palatal myoclonus.

[MR-angiography of the head and neck vessels: technical considerations and clinical indications]. / ARM des vaisseaux cervico-encéphaliques: technique, principales applications cliniques.

Magnetic resonance angiography (MRA) is a very valuable tool in the routine evaluation of patients with stroke syndrome. It provides powerful noninvasive imaging of the cervical and intracranial vessels allowing the detection and the diagnosis of vascular anomalies. MRA usefully supplements, during the same examination, the analysis by MRI of the cerebral parenchyma. We will describe the indications of the various techniques (MRA with and without injection of contrast media) and show the value, artifacts and limitations of MRA in atherosclerotic stenosis or occlusive disease and in arterial dissections. This noninvasive vascular assessment will depend on the initial therapeutic orientation. Within the framework of the hemorrhagic stroke, we will discuss the role and the interest of dynamic MR angiography in the tracking and control of intracranial aneurysms and also the contribution of this newer sequences with gadolinium injection in the detection of cerebral vascular malformations.

[Endovascular carotid occlusion: a retrospective study of complications in 33 cases]. / L'occlusion carotidienne par voie endovasculaire: etude retrospective des complications á partir de 33 cas.

MATERIAL-METHODS: Thirty three patients (16 men, 17 women), mean age 45 years underwent an intravascular carotid balloon occlusion for intracavernous aneurysms, carotid-cavernous fistulas or cervical carotid injuries by Fogarty balloons (5 patients before 1982) or detachable balloons (28 patients). Transient balloon test occlusion consisted in a clinical examination, an angiographic study for 32 patients with an electroencephalogram for 16 patients. RESULTS: Early complications occurred for four patients by veineous rupture (1 patient) or ischemic injury (3 patients). Late complications occurred for two patients by ischemic injuries, one asymptomatic. DISCUSSION: These results are similar to the literature's results and the transient test occlusion consisting in clinical examination, angiographic study and EEG seems to be reliable compared to cerebral blood flow determination. CONCLUSION: Even if its indications have decreased because of technic improvements permitting carotid flow preservation, carotid endovascular balloon occlusion stays a reliable, cheap technic in carotid injuries' treatment.

[The evaluation of 3DFT time-of-flight MR-angiography versus angiography in the study of carotid atheromatous lesions with a review of the literature]. / Evaluation de l'angio-MR 3DFT temps-de-vol versus angiographie dans l'exploration de lésions athéromateuses carotidiennes avec revue de la littérature

In 37 patients suspected of having a stroke 71 carotid bifurcations were explored by MR-angiography and by digital angiography the reference technique. A 3D sequence was acquired with the time-of-flight technique, using a transmitter-receiver cranial coil, followed by a strictly receiver Helmoltz coil on a 1 Tesla magnet. Two examiners evaluated the carotid bifurcations and measured the degree of stenosis in terms of diameters, according to the north american symptomatic carotid endarterectomy trial (NASCET). Five classes were established: class 1: normal; class 2: 1 to 29%; class 3: 30 to 69%; class 4: 70 to 99% and class 5: thrombosis. The results obtained in the determination of classes were identical with both coils: the coefficient of correlation with straight angiography were 0.973 with the cranial coil and 0.966 with the Helmoltz coil. Five stenoses were overestimated and classified as Class 3 instead of Class 2. The five stenoses greater than 70% (Class 4) showed a signal-void area at their level, due to severe dephasing induced by turbulences. Finally, there was a false-negative image of occlusion: the high-intensity signal of the thrombus was mistaken for one of flow. The data of our study were in accordance with the excellent results obtained by several authors in the literature, which makes it possible for us to propose this type of examination as a novel mean of investigating bifurcations of carotid arteries. Provided a strict technique is applied, and in addition to carotid bifurcation the Willis' circle and the cerebral parenchyma are explored, MR-angiography can complete the results of Doppler-echo. Standard arteriography could then be reserved to surgical patients and to those with discordant results of MR-arteriography and Doppler echo systems.

[Symptomatic venous angioma. Report of a case]. / Angiome veineux symptomatique. A propos d'un cas.

We report a case of venous angioma revealed by seizure after a non hemorrhagic venous infarct. The initial neuroradiological work-up with CT scan, angiography and brain MRI evidenced the venous infarction with abnormal contrast uptake. The control MRI 3 months later showed clear involution of the venous infarct. Non-hemorrhagic venous infarction on venous angiomas are exceptional. Only 2 cases have been reported in the literature. Impaired venous drainage could be implicated.

[Capillary telangiectasis, angiographically occult vascular malformations. MRI symptomatology apropos of 7 cases]. / Les télangiectasies capillaires, malformations vasculaires angiographiquement occultes. Sémiologie IRM à propos de 7 observations.

OBJECTIVE: Describe the MRI findings in capillary telangiectasias. MATERIALS AND METHODS: Between 1996 and 1999, we observed 9 cases of capillary telangiectasia in 7 patients explored 5 times for posterior fossa symptoms. In two cases capillary telangiectasia was a fortuitous discovery. All patients were explored by MRI with T1 sequences with and without gadolinium injections, turbo spin echo T2 coupled in 5 cases with a double echo gradient echo T2 sequence (TR: 970 ms, TE: 15 and 35 ms). Two patients also underwent vertebral angiography. RESULTS: The telangiectasia gave a low intensity signal on T1 sequences in 2 of the 9 cases and a discretely high intensity signal on T2 sequences in all cases. After gadolinium injection, 9 telangiectasias showed homogeneous or speckled enhancement. The echo-gradient T2 images showed a very low intensity signal in 7 out of 7 cases on the second echo. At the first echo, 4 capillary telangiectasias were undetectable. The two vertebral angiographies were normal and the follow-up MRI in 5 patients showed lesion stability. CONCLUSION: Pontile lesions with no mass effect showing enhancement after gadolinium injection and with or without a discrete T2 high intensity signal but with a frank echo-gradient T2 signal strongly suggest capillary telangiectasia.