Dural-based lesions: is it a meningioma?

PURPOSE: Meningiomas are the most common extra-axial intracranial neoplasms with typical radiological findings. In approximately 2% of cases, histopathological reports reveal different neoplasms or non-neoplastic lesions that can closely mimic meningiomas. We describe radiological features of meningioma mimics highlighting imaging red flags to consider a differential diagnosis. METHODS: A total of 348 lesions with radiological diagnosis of meningiomas which underwent to surgical treatment or biopsy between December of 2000 and September of 2014 were analyzed. We determined imaging features that are not a typical finding of meningiomas, suggesting other lesions. The following imaging characteristics were evaluated on CT and MRI: (a) bone erosion; (b) hyperintensity on T2WI; (c) hypointensity on T2WI; (d) bone destruction; (e) dural tail; (f) leptomeningeal involvement; (g) pattern of contrast enhancement; (h) dural displacement sign. RESULTS: We have a relatively high prevalence of meningioma mimics (7.2%). Dural-based lesions with homogeneous contrast enhancement (52%) are easily misdiagnosed as meningiomas. Most lesions mimic convexity (37.5%) or parafalcine (21.9%) meningiomas. We have determined five imaging red flags that can alert radiologists to consider meningioma mimics: (1) bone erosion (22.2%); (2) dural displacement sign (36%); (3) marked T2 hypointensity (32%); (4) marked T2 hyperintensity (12%); (5) absence of dural tail (48%). The most common mimic lesion in our series was hemangiopericytomas, followed by lymphomas and schwannomas. CONCLUSION: The prevalence of meningioma mimics is not negligible. It is important to have awareness on main radiological findings suggestive of differential diagnosis due to a wide range of differentials which lead to different prognosis and treatment strategies.

Clinical and genetic characterization of leukoencephalopathies in adults.

Leukodystrophies and genetic leukoencephalopathies are a rare group of disorders leading to progressive degeneration of cerebral white matter. They are associated with a spectrum of clinical phenotypes dominated by dementia, psychiatric changes, movement disorders and upper motor neuron signs. Mutations in at least 60 genes can lead to leukoencephalopathy with often overlapping clinical and radiological presentations. For these reasons, patients with genetic leukoencephalopathies often endure a long diagnostic odyssey before receiving a definitive diagnosis or may receive no diagnosis at all. In this study, we used focused and whole exome sequencing to evaluate a cohort of undiagnosed adult patients referred to a specialist leukoencephalopathy service. In total, 100 patients were evaluated using focused exome sequencing of 6100 genes. We detected pathogenic or likely pathogenic variants in 26 cases. The most frequently mutated genes were NOTCH3, EIF2B5, AARS2 and CSF1R. We then carried out whole exome sequencing on the remaining negative cases including four family trios, but could not identify any further potentially disease-causing mutations, confirming the equivalence of focused and whole exome sequencing in the diagnosis of genetic leukoencephalopathies. Here we provide an overview of the clinical and genetic features of these disorders in adults.

Dissecting neuropathic from poststroke pain: the white matter within.

ABSTRACT: Poststroke pain (PSP) is a heterogeneous term encompassing both central neuropathic (ie, central poststroke pain [CPSP]) and nonneuropathic poststroke pain (CNNP) syndromes. Central poststroke pain is classically related to damage in the lateral brainstem, posterior thalamus, and parietoinsular areas, whereas the role of white matter connecting these structures is frequently ignored. In addition, the relationship between stroke topography and CNNP is not completely understood. In this study, we address these issues comparing stroke location in a CPSP group of 35 patients with 2 control groups: 27 patients with CNNP and 27 patients with stroke without pain. Brain MRI images were analyzed by 2 complementary approaches: an exploratory analysis using voxel-wise lesion symptom mapping, to detect significant voxels damaged in CPSP across the whole brain, and a hypothesis-driven, region of interest-based analysis, to replicate previously reported sites involved in CPSP. Odds ratio maps were also calculated to demonstrate the risk for CPSP in each damaged voxel. Our exploratory analysis showed that, besides known thalamic and parietoinsular areas, significant voxels carrying a high risk for CPSP were located in the white matter encompassing thalamoinsular connections (one-tailed threshold Z > 3.96, corrected P value <0.05, odds ratio = 39.7). These results show that the interruption of thalamocortical white matter connections is an important component of CPSP, which is in contrast with findings from nonneuropathic PSP and from strokes without pain. These data can aid in the selection of patients at risk to develop CPSP who could be candidates to pre-emptive or therapeutic interventions.