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.

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.

Treatment of neuromyelitis optica with rituximab: a 2-year prospective multicenter study.

OBJECTIVE: Neuromyelitis optica (NMO) is a very severe autoimmune disorder of the central nervous system. It affects young subjects and has a poor prognosis both on a functional and vital level. Therefore, it is imperative to reduce the frequency of relapses. The purpose of this study was to evaluate the clinical and neuroradiological effectiveness of rituximab (RTX) on active forms of NMO. METHODS: We conducted a 2-year open prospective multicenter study that included 32 patients treated with RTX at a dose of 375 mg/m2/week for 1 month. When the number of circulating CD19+ B cells reached 1%, a maintenance therapy was started, consisting of two infusions of 1 g of RTX, administered at a 15-day interval. The primary objective was to reduce the annual relapse rate (ARR), in comparison to that observed in the 2 years before treatment onset. RESULTS: Rituximab administration reduced the ARR from 1.34 to 0.56 (p = 0.0005). The average Expanded Disability Status Scale (EDSS) score significantly improved by 1.1 point, from 5.9 (2-9) to 4.8 (0-9) after 2 years (p = 0.03). Anti-aquaporin-4 antibodies' level predicted treatment failure (p = 0.03). Frequency of Gad+ lesions in spinal cord decreased from 23.3 to 14.2%. RTX treatment did not prevent the death of three patients (treatment failure in two patients and acute myeloid leukemia in a patient previously treated with mitoxantrone). CONCLUSION: Rituximab is clinically effective in active forms of NMO, although few patients are resistant to the treatment.

Cervical spondylodiscitis caused by Blastoschizomyces capitatus.

A 37-year-old woman, during her second remission of acute myeloid leukemia, presented with severe neck pain and cervico-brachial neuralgia. Investigation revealed a C5-C6 spondylodiscitis. A CT-guided anterior biopsy decompressed the mass, immediately alleviated the symptoms, and isolated a rare yeast: Blastoschizomyces capitatus. To our knowledge, only three cases of spondylodiscitis with this yeast have been described. Six months of voriconazole and liposomal amphotericin B treatment produced a complete resolution on CT and MRI imaging. However, the ongoing severe yeast infection prevented the planned bone marrow allograft.

The role of surgery when endovascular treatment is considered the first choice therapy for ruptured intracranial aneurysms.

AIM: Nowadays endovascular therapy is more and more considered as first choice treatment for ruptured intracranial aneurysms. The aim of this study was to understand the impact that endovascular treatment (EVT), chosen as first therapeutic strategy, has had in the selection of ruptured intracranial aneurysms submitted to surgery at our Institution and what role neurosurgeons still play in this setting. METHODS: From 1998 to 2002, 272 consecutive patients were treated at the Hospital of Toulouse for ruptured intracranial aneurysms: 222 by embolization and 50 by surgery. The two groups were homogeneous for sex, age and aneurysms multiplicity. RESULTS: The patients of the surgical group had a worst clinical-radiological status at the treatment time than those treated by EVT. Clipping was performed for different reasons: 16% for failure of attempted EVT; 32% for intracranial hematoma requiring surgical evacuation; 30% for aneurysm morphology unsuitable for EVT and 22% for absence of the endovascular operator. Aneurysms of the middle cerebral artery (MCA) represented the main surgical group. The aneurysms judged unsuitable for EVT and addressed to surgery had often a complex morphology representing a challenge also for surgery. Mid-term outcome is significantly better for patients treated by EVT. CONCLUSION: The results show that microsurgery continues to have a role in the treatment of ruptured intracranial aneurysms even when EVT is the first choice. The precarious clinical conditions of the patients submitted to surgery and the frequent complexity of their aneurysms explain their worst outcome. This would advise training dedicated vascular Neurosurgeons to guaranty a high level treatment when EVT is not possible.

[Orbital tumors in children: CT and MR imaging features]. / Tumeurs orbitaires chez l'enfant: revue iconographique en TDM et IRM.

The purpose of the article is to review the CT and MR imaging features of orbital tumors in children. Tumors in children are usually different than those in adults. Clinical symptoms are usually non-specific. Clinical examination combined with US may be sufficient for diagnosis and follow-up of benign and superficial lesions. CT and/or MRI are needed for deep or malignant lesions. CT is valuable for osseous and/or calcified lesions. MR is advantageous because of its superior spatial resolution and non-ionizing nature. Malignant tumors correspond to about 20% of lesions and include primary tumors (retinoblastoma, rhabdomyosarcoma) and metastases. Benign pathology is more frequent (80%) with dermoid cyst corresponding to about 50% of orbital masses.

Pseudoaneurysm of internal carotid artery following mandibular reconstruction treated by covered stent.

SUMMARY: We describe the case of a 68-year-old woman who had a mandibular titanium plate reconstruction following surgery for a parotid carcinoma. Fifteen months later she presented bleeding episodes related to a pseudoaneurysm of the internal carotid artery located just above the bulb. This was probably related to the weakening of the arterial wall following friction with the mandibular plate and radiotherapy.We successfully obliterated this pseudoaneurysm using a covered stent. This rare diagnosis should be evoked in case of bleeding following a mandibular reconstruction. Stenting is an effective treatment strategy obviating the need for open surgery.