This study explores default-mode network (DMN) abnormalities in patients with secondary progressive (SP) and primary progressive (PP) multiple sclerosis (MS) and whether such abnormalities correlate ...with cognitive impairment and damage to selected white matter (WM) fiber bundles, quantified using diffusion tensor (DT) MRI tractography.
Resting state (RS) functional MRI and DT MRI data were acquired from 33 patients with SPMS, 24 patients with PPMS, and 24 controls. Independent component analysis (ICA) was used to identify the DMN. SPM5 was used to assess within- and between-group activations.
Between-group differences in DMN activity were found in the left medial prefrontal cortex (mPFC), left precentral gyrus (PcG), and anterior cingulate cortex (ACC). Compared to controls, patients with SPMS had reduced activity in the mPFC (p = 0.01) and PcG (p = 0.02), while patients with PPMS had reduced activity in the PcG (p = 0.008) and the ACC (p = 0.002). Compared to patients with PPMS, patients with SPMS had increased ACC activity (p = 0.04). Reduction of RS activity in the ACC was more pronounced in cognitively impaired vs cognitively preserved patients with MS (p = 0.02). In patients with MS, DMN abnormalities correlated with the PASAT and word list test scores (r values ranging from 0.35 to 0.45) and DT MRI changes in the corpus callosum and the cingulum (r values ranging from 0.82 to 0.87).
These results suggest that a dysfunction of the anterior components of the default-mode network may be among the factors responsible for the accumulation of cognitive deficits in patients with progressive multiple sclerosis.
Objectives
At a European Society of Neuroradiology (ESNR) Annual Meeting 2015 workshop, commonalities in practice, current controversies and technical hurdles in glioma MRI were discussed. We aimed ...to formulate guidance on MRI of glioma and determine its feasibility, by seeking information on glioma imaging practices from the European Neuroradiology community.
Methods
Invitations to a structured survey were emailed to ESNR members (n=1,662) and associates (n=6,400), European national radiologists’ societies and distributed via social media.
Results
Responses were received from 220 institutions (59% academic). Conventional imaging protocols generally include T2w, T2-FLAIR, DWI, and pre- and post-contrast T1w. Perfusion MRI is used widely (85.5%), while spectroscopy seems reserved for specific indications. Reasons for omitting advanced imaging modalities include lack of facility/software, time constraints and no requests. Early postoperative MRI is routinely carried out by 74% within 24–72 h, but only 17% report a percent measure of resection. For follow-up, most sites (60%) issue qualitative reports, while 27% report an assessment according to the RANO criteria. A minority of sites use a reporting template (23%).
Conclusion
Clinical best practice recommendations for glioma imaging assessment are proposed and the current role of advanced MRI modalities in routine use is addressed.
Key Points
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We recommend the EORTC-NBTS protocol as the clinical standard glioma protocol.
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Perfusion MRI is recommended for diagnosis and follow-up of glioma.
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Use of advanced imaging could be promoted with increased education activities.
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Most response assessment is currently performed qualitatively.
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Reporting templates are not widely used, and could facilitate standardisation.
Cerebral plasticity is the ability of the central nervous system to reorganize itself in response to different injuries. The reshaping of functional areas is a crucial mechanism to compensate for ...damaged function. It is acknowledged that functional remodeling of cortical areas may occur also in glioma patients. Principal limits of previous investigations on cortical plasticity of motor and language functions included scarce reports of longitudinal evaluations and limited sample sizes. This systematic review is aimed at elucidating cortical brain plasticity for motor and language functions, in adult glioma patients, by means of preoperative and intraoperative mapping techniques. We systematically reviewed the literature for prospective studies, assessing cortical plasticity of motor and language functions in low-grade and high-grade gliomas. Eight longitudinal studies investigated cortical plasticity, evaluated by motor and language task-based functional MRI (fMRI), motor navigated transcranial magnetic stimulation (n-TMS), and intraoperative mapping with cortical direct electrocortical stimulation (DES) of language and motor function. Motor function reorganization appeared relatively limited and mostly characterized by intrahemispheric functional changes, including secondary motor cortices. On the other hand, a high level of functional reshaping was found for language function in DES studies. Occurrence of cortical functional reorganization of language function was described focusing on the intrahemispheric recruitment of perilesional areas. However, the association between these functional patterns and recovery of motor and language deficits still remains partially clear. A number of relevant methodological issues possibly affecting the finding generalization emerged, such as the complexity of plasticity outcome measures and the lack of large longitudinal studies. Future studies are required to further confirm these evidences on cortical plasticity in larger samples, combining both functional imaging and intraoperative mapping techniques in longitudinally evaluations.
The functional role of the uncinate fasciculus is still a matter of debate. We examined 44 patients submitted to awake surgery for removal of a left frontal or temporal glioma. In 18 patients, the ...removal included the uncinate fasciculus. We compared patients with or without removal on a series of neuropsychological tasks, performed at different time intervals: pre-surgery, in the first week after surgery and 3 months after surgery. Functional magnetic resonance and diffusion tensor imaging, fibre-tracking techniques were performed before surgery. At the last examination, patients with uncinate removal were significantly impaired in naming of famous faces and objects as compared with patients without removal. We further divided patients according to the site of the tumour (either frontal or temporal). At the follow-up, patients with a temporal glioma who underwent uncinate removal had the worst loss of performance in famous face naming. In addition, on the same task, the group with a frontal glioma that underwent resection of the frontal part of the uncinate performed significantly worse than the group with a frontal glioma but without uncinate removal. In conclusion, the resection of the uncinate fasciculus, in its frontal or temporal part, has long-lasting consequences for famous face naming. We suggest that this fibre tract is part of a circuitry involved in the retrieval of word form for proper names. Retrieval of conceptual knowledge was intact.
White matter (WM) tract damage was assessed in patients with the behavioral variant frontotemporal dementia (bvFTD) and the 3 primary progressive aphasia (PPA) variants and compared with the ...corresponding brain atrophy patterns. Thirteen bvFTD and 20 PPA patients were studied. Tract-based spatial statistics and voxel-based morphometry were used. Patients with bvFTD showed widespread diffusion tensor magnetic resonance imaging (DT MRI) abnormalities affecting most of the WM bilaterally. In PPA patients, WM damage was more focal and varied across the 3 syndromes: left frontotemporoparietal in nonfluent, left frontotemporal in semantic, and left frontoparietal in logopenic patients. In each syndrome, DT MRI changes extended beyond the topography of gray matter loss. Left uncinate damage was the best predictor of frontotemporal lobar degeneration diagnosis versus controls. DT MRI measures of the anterior corpus callosum and left superior longitudinal fasciculus differentiated bvFTD from nonfluent cases. The best predictors of semantic PPA compared with both bvFTD and nonfluent cases were diffusivity abnormalities of the left uncinate and inferior longitudinal fasciculus. This study provides insights into the similarities and differences of WM damage in bvFTD and PPA variants. DT MRI metrics hold promise to serve as early markers of WM integrity loss that only at a later stage may be detectable by volumetric measures.
In patients with ALS, conventional MR imaging is frequently noninformative, and its use has been restricted to excluding other conditions that can mimic ALS. Conversely, the extensive application of ...modern MR imaging-based techniques to the study of ALS has undoubtedly improved our understanding of disease pathophysiology and is likely to have a role in the identification of potential biomarkers of disease progression. This review summarizes how new MR imaging technology is changing dramatically our understanding of the factors associated with ALS evolution and highlights the reasons why it should be used more extensively in studies of disease progression, including clinical trials.
Bipolar disorder (BD) is associated with adverse childhood experiences (ACE), which worsen the lifetime course of illness, and with signs of widespread disruption of white matter (WM) integrity in ...adult life. ACE are associated with changes in WM microstructure in healthy humans.
We tested the effects of ACE on diffusion-tensor imaging (DTI) measures of WM integrity in 80 in-patients affected by a major depressive episode in the course of BD. We used whole-brain tract-based spatial statistics in the WM skeleton with threshold-free cluster enhancement of DTI measures of WM microstructure: axial, radial and mean diffusivity, and fractional anisotropy.
ACE hastened the onset of illness. We observed an inverse correlation between the severity of ACE and DTI measures of axial diffusivity in several WM fibre tracts contributing to the functional integrity of the brain and including the corona radiata, thalamic radiations, corpus callosum, cingulum bundle, superior longitudinal fasciculus, inferior fronto-occipital fasciculus and uncinate fasciculus.
Axial diffusivity reflects the integrity of axons and myelin sheaths, and correlates with functional connectivity and with higher-order abilities such as reasoning and experience of emotions. In patients with BD axial diffusivity is increased by lithium treatment. ACE might contribute to BD pathophysiology by hampering structural connectivity in critical cortico-limbic networks.
•Low muscle mass is associated with worse survival in primary central nervous system lymphoma.•Muscle mass biomarkers may be useful for prognostic stratification in primary central nervous system ...lymphoma.•There is a high correlation between different quantitative muscle mass biomarkers assessed with CT and MRI.
To investigate the role of quantitative muscle biomarkers assessed with skeletal muscle index at the third lumbar vertebra (L3-SMI) and temporal muscle thickness (TMT) in predicting progression-free and overall survival in patients with primary central nervous system lymphoma (PCNSL) undergoing first-line high-dose methotrexate-based chemotherapy.
L3-SMI and TMT were calculated on abdominal CT and brain high-resolution 3D-T1-weighted MR images, respectively, using predefined validated methods. Standardized sex-specific cut-off values were used to divide patients in different risk categories. Kaplan-Meier plots were calculated, and survival analysis was performed using log-rank tests, univariate, and multivariable Cox-regression models, calculating hazard ratios (HR) and 95% confidence intervals (CI), also adjusting for potential confounders (age, sex, and performance status).
Forty-three patients were included in this study. Median follow-up was 23 months (interquartile range 12–40); at median follow-up, rates of progression-free and overall survival for the cohort were 46% and 57%, respectively. Thirteen (30%) and 11 (26%) patients showed L3-SMI or TMT values below the predefined cut-offs. In Cox-regression multivariable analysis patients with low L3-SMI or TMT showed significantly worse progression-free (HR 4.40, 95% CI 1.66–11.61, p = 0.003; HR 4.40, 95% CI 1.68–11.49, p = 0.003, respectively) and overall survival (HR 3.16, 95% CI 1.09–9.11, p = 0.034; HR 4.93, 95% CI 1.78–13.65, p = 0.002, respectively) compared to patients with high L3-SMI or TMT.
Quantitative muscle mass evaluation assessed by both L3-SMI and TMT is a promising tool to identify PCNSL patients at high risk of negative outcome. Confirmatory studies on larger independent series are warranted.
Objectives
Since its introduction, MRI had a major impact on the early and more precise diagnosis of multiple sclerosis (MS), and the 2010 diagnostic criteria even allow a diagnosis to be made just ...after a single attack if stringent MRI criteria are met. Several other clinical and paraclinical markers have been reported to be associated with an increased risk of MS independently of MRI in patients with clinically isolated syndromes (CIS), but the incremental usefulness of adding them to the current criteria has not been evaluated. In this study, we determined whether multiple biomarkers improved the prediction of MS in patients with CIS in a real‐world clinical practice.
Materials and methods
This was a retrospective study involving patients with CIS admitted to our department between 2000 and 2013. We evaluated baseline clinical, MRI, neurophysiological, and cerebrospinal fluid (CSF) data.
Results
During follow‐up (median, 7.2 years), 127 of 243 participants (mean age, 31.6 years) developed MS. Cox proportional‐hazards models adjusted for established MRI criteria, age at onset, number of T1 lesions, and presence of CSF oligoclonal bands significantly predicted the risk of developing MS at 2 and 5 years. The use of multiple biomarkers led to 29% net reclassification improvement at 2 years (P<.001) and 30% at 5 years (P<.001).
Conclusions
The simultaneous addition of several biomarkers significantly improved the risk stratification for MS in patients with CIS beyond that of a model based only on established MRI criteria.
Objectives:
Involvement of selected central nervous system (CNS) regions has been associated with depression and fatigue in MS. We assessed whether specific regional patterns of lesion distribution ...and atrophy of the gray (GM) and white matter (WM) are associated with these symptoms in MS.
Methods:
Brain dual-echo and 3D T1-weighted images were acquired from 123 MS patients (69 depressed (D), 54 non-depressed (nD), 64 fatigued, 59 non-fatigued) and 90 controls. Lesion distribution, GM and WM atrophy were estimated using VBM and SPM8.
Results:
Gender, age, disease duration and conventional MRI characteristics did not differ between D-MS and nD-MS patients. Fatigued patients experienced higher EDSS and depression than non-fatigued ones. Lesion distribution and WM atrophy were not related to depression and fatigue. Atrophy of regions in the frontal, parietal and occipital lobes had a combined effect on depression and fatigue. Atrophy of the left middle frontal gyrus and right inferior frontal gyrus were selectively related to depression. No specific pattern of GM atrophy was found to be related to fatigue.
Conclusions:
Depression in MS is linked to atrophy of cortical regions located in the bilateral frontal lobes. A distributed pattern of GM atrophy contributes to the concomitant presence of depression and fatigue in these patients.
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