From Neurosurgical Planning to Histopathological Brain Tumor Characterization: Potentialities of Arcuate Fasciculus Along-Tract Diffusion Tensor Imaging Tractography Measures

Background: Tractography has been widely adopted to improve brain gliomas' surgical planning and guide their resection. This study aimed to evaluate state-of-the-art of arcuate fasciculus (AF) tractography for surgical planning and explore the role of along-tract analyses in vivo for characterizing tumor histopathology.

Methods: High angular resolution diffusion imaging (HARDI) images were acquired for nine patients with tumors located in or near language areas (age: 41 ± 14 years, mean ± standard deviation; five males) and 32 healthy volunteers (age: 39 ± 16 years; 16 males). Phonemic fluency task fMRI was acquired preoperatively for patients. AF tractography was performed using constrained spherical deconvolution diffusivity modeling and probabilistic fiber tracking. Along-tract analyses were performed, dividing the AF into 15 segments along the length of the tract defined using the Laplacian operator. For each AF segment, diffusion tensor imaging (DTI) measures were compared with those obtained in healthy controls (HCs). The hemispheric laterality index (LI) was calculated from language task fMRI activations in the frontal, parietal, and temporal lobe parcellations. Tumors were grouped into low/high grade (LG/HG).

Results: Four tumors were LG gliomas (one dysembryoplastic neuroepithelial tumor and three glioma grade II) and five HG gliomas (two grade III and three grade IV). For LG tumors, gross total removal was achieved in all but one case, for HG in two patients. Tractography identified the AF trajectory in all cases. Four along-tract DTI measures potentially discriminated LG and HG tumor patients (false discovery rate < 0.1): the number of abnormal MD and RD segments, median AD, and MD measures. Both a higher number of abnormal AF segments and a higher AD and MD measures were associated with HG tumor patients. Moreover, correlations (unadjusted p < 0.05) were found between the parietal lobe LI and the DTI measures, which discriminated between LG and HG tumor patients. In particular, a more rightward parietal lobe activation (LI < 0) correlated with a higher number of abnormal MD segments (R = −0.732) and RD segments (R = −0.724).

Conclusions: AF tractography allows to detect the course of the tract, favoring the safer-as-possible tumor resection. Our preliminary study shows that along-tract DTI metrics can provide useful information for differentiating LG and HG tumors during pre-surgical tumor characterization.

Single-sided NMR to estimate morphological parameters of the trabecular bone structure

PURPOSE

Single-sided ¹ H-NMR is proposed for the estimation of morphological parameters of trabecular bone, and potentially the detection of pathophysiological alterations of bone structure. In this study, a new methodology was used to estimate such parameters without using an external reference signal, and to study intratrabecular and intertrabecular porosities, with a view to eventually scanning patients.

METHODS

Animal trabecular bone samples were analyzed by a single-sided device. The Carr-Purcell-Meiboom-Gill sequence of ¹ H nuclei of fluids, including marrow, confined inside the bone, was analyzed by quasi-continuous T₂ distributions and separated into two ¹ H pools: short and long T₂ components. The NMR parameters were estimated using models of trabecular bone structure, and compared with the corresponding micro-CT.

RESULTS

Without any further assumptions, the internal reference parameter (short T₂ signal intensity fraction) enabled prediction of the micro-CT parameters BV/TV (volume of the trabeculae/total sample volume) and BS/TV (external surface of the trabeculae/total sample volume) with linear correlation coefficient >0.80. The assignment of the two pools to intratrabecular and intertrabecular components yielded an estimate of average intratrabecular porosity (33 ± 5)%. Using the proposed models, the NMR-estimated BV/TV and BS/TV were found to be linearly related to the corresponding micro-CT values with high correlation (>0.90 for BV/TV; >0.80 for BS/TV) and agreement coefficients.

CONCLUSION

Low-field, low-cost portable devices that rely on intrinsic magnetic field gradients and do not use ionizing radiation are viable tools for in vitro preclinical studies of pathophysiological structural alterations of trabecular bone.

Clinical and Demographic Characteristics of Upper Limb Dystonia

BACKGROUND

Knowledge of characteristics in upper limb dystonia remains limited, derived primarily from small, single-site studies.

OBJECTIVE

The objective of this study was to characterize demographic and clinical characteristics of upper limb dystonia from the Dystonia Coalition data set, a large, international, multicenter resource.

METHODS

We evaluated clinical and demographic characteristics of 367 participants with upper limb dystonia from onset, comparing across subcategories of focal (with and without dystonia spread) versus nonfocal onset.

RESULTS

Focal onset occurred in 80%; 67% remained focal without spread. Task specificity was most frequent in this subgroup, most often writer's cramp and affecting the dominant limb (83%). Focal onset with spread was more frequent in young onset (<21 years). Focal onset occurred equally in women and men; nonfocal onset affected women disproportionately.

CONCLUSIONS

Upper limb dystonia distribution, focality, and task specificity relate to onset age and likelihood of regional spread. Observations may inform clinical counseling and design, execution, and interpretation of future studies. © 2020 International Parkinson and Movement Disorder Society.

Oncology and Cardiac Rehabilitation: An Underrated Relationship

Cancer and cardiovascular diseases are globally the leading causes of mortality and morbidity. These conditions are closely related, beyond that of sharing many risk factors. The term bidirectional relationship indicates that cardiovascular diseases increase the likelihood of getting cancer and vice versa. The biological and biochemical pathways underlying this close relationship will be analyzed. In this new overlapping scenario, physical activity and exercise are proven protective behaviors against both cardiovascular diseases and cancer. Many observational studies link an increase in physical activity to a reduction in either the development or progression of cancer, as well as to a reduction in risk in cardiovascular diseases, a non-negligible cause of death for long-term cancer survivors. Exercise is an effective tool for improving cardio-respiratory fitness, quality of life, psychological wellbeing, reducing fatigue, anxiety and depression. Finally, it can counteract the toxic effects of cancer therapy. The protection obtained from physical activity and exercise will be discussed in the various stages of the cancer continuum, from diagnosis, to adjuvant therapy, and from the metastatic phase to long-term effects. Particular attention will be paid to the shelter against chemotherapy, radiotherapy, cardiovascular risk factors or new onset cardiovascular diseases. Cardio-Oncology Rehabilitation is an exercise-based multi-component intervention, starting from the model of Cardiac Rehabilitation, with few modifications, to improve care and the prognosis of a patient's cancer. The network of professionals dedicated to Cardiac Rehabilitation is a ready-to-use resource, for implementing Cardio-Oncology Rehabilitation.

Liquid Chromatographic Method for Nicarbazin in Broiler Feeds and Premixtures: Development, Validation, and Interlaboratory Study

A reversed-phase liquid chromatography method for nicarbazin in broiler feeds and premixtures was developed, validated, and interlaboratory studied. The extraction solvent was an acetonitrile–methanol (1 + 1) mixture. For feedingstuffs, water was also added. The 4,4′-dinitrocarbanilide moiety of nicarbazin was detected at a wavelength of 350 nm. Recovery was ≥ 87%. At 20 mg/kg, the repeatability was 0.7% and the within-laboratory reproducibility was 2.7%. The limit of determination was &lt;20 mg/kg. Other feed additives did not interfere in the assay that proved to be applicable to broiler feeds from different European Union countries. In an interlaboratory study, 4 positive broiler feeds, 1 blank pig feed, and 1 broiler premixture were analyzed by 19 laboratories using the method developed in this study. The relative standard deviation for repeatability (RSDr) of the feedingstuffs (20–240 mg/kg) varied between 2.6 and 10.2%. The HORRAT ranged between 0.70 and 1.22. Recoveries were 91–108%. Three laboratories detected small signals in the blind blank samples, ranging from 0.4 to 2 mg/kg. For the premixture, acceptable results for reproducibility could only be obtained after the sample weight and volume of extraction had been doubled. To avoid excessive dilution of the extracts, the range of the calibration curve had also been doubled. With this modified method, the RSDr was 5.7% and the HORRAT was 1.95 (10 laboratories).

L-Dopa Modulation of Brain Connectivity in Parkinson's Disease Patients: A Pilot EEG-fMRI Study

Studies of functional neurosurgery and electroencephalography in Parkinson's disease have demonstrated abnormally synchronous activity between basal ganglia and motor cortex. Functional neuroimaging studies investigated brain dysfunction during motor task or resting state and primarily have shown altered patterns of activation and connectivity for motor areas. L-dopa administration relatively normalized these functional alterations. The aim of this pilot study was to examine the effects of L-dopa administration on functional connectivity in early-stage PD, as revealed by simultaneous recording of functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) data. Six patients with diagnosis of probable PD underwent EEG-fMRI acquisitions (1.5 T MR scanner and 64-channel cap) before and immediately after the intake of L-dopa. Regions of interest in the primary motor and sensorimotor regions were used for resting state fMRI analysis. From the EEG data, weighted partial directed coherence was computed in the inverse space after the removal of gradient and cardioballistic artifacts. fMRI results showed that the intake of L-dopa increased functional connectivity within the sensorimotor network, and between motor areas and both attention and default mode networks. EEG connectivity among regions of the motor network did not change significantly, while regions of the default mode network showed a strong tendency to increase their outflow toward the rest of the brain. This pilot study provided a first insight into the potentiality of simultaneous EEG-fMRI acquisitions in PD patients, showing for both techniques the analogous direction of increased connectivity after L-dopa intake, mainly involving motor, dorsal attention and default mode networks.

Effects of Light Treatment on Sleep, Cognition, Mood, and Behavior in Alzheimer's Disease: A Systematic Review

BACKGROUND

Bright light treatment is a therapeutic intervention mainly used to treat sleep and circadian disturbances in Alzheimer's disease (AD) patients. Recently, a handful of studies also focused on the effect on cognition and behavior. Conflicting findings are reported in the literature, and no definite conclusions have been drawn about its specific therapeutic effect.

SUMMARY

The aim of this review is to provide a critical evaluation of available evidence in this field, highlighting the specific characteristics of effective bright light treatment. Eligible studies were required to assess at least one of the following outcome measures: sleep, cognition, mood, and/or behavior (e.g., depression, agitation). A total of 32 articles were included in this systematic review and identified as research intervention studies about light treatment in AD. The quality of the papers was evaluated based on the US Preventive Service Task Force guidelines. Key Messages: Overall, the current literature suggests that the effects of light treatment in AD patients are mixed and may be influenced by several factors, but with a general trend toward a positive effect. Bright light seems to be a promising intervention treatment without significant adverse effects; therefore, further well-designed randomized controlled trials are needed taking into account the highlighted recommendations.

Stridor-related gray matter alterations in multiple system atrophy: A pilot study

INTRODUCTION

The neuroanatomical substrate of stridor associated with Multiple System Atrophy (MSA) remains unclear. We evaluated stridor-related gray matter (GM) changes in MSA.

METHODS

36 MSA patients underwent standardized nocturnal video-polysomnography and brain MRI. Differences in GM density between MSA patients with and without stridor and a sample of 22 matched healthy controls were evaluated with Voxel Based Morphometry protocol supplemented by a specific tool (SUIT) for analysing infratentorial structures.

RESULTS

Stridor was confirmed in 14 patients (10 MSA-cerebellar variant; 10 M; mean ± SD age = 61.6 ± 8.9years; disease duration = 5.2 ± 2.9years) and absent in 22 (11 MSA-cerebellar variant; 18 M; age = 61.4 ± 9.9years; disease duration = 4.8 ± 3.4years). Compared to MSA without stridor, patients with stridor showed higher GM density in the cerebellum (p < 0.05, corrected for the MSA-cerebellar variant and uncorrected when considering both MSA-variants) and lower in the striatum (p < 0.05, uncorrected).

CONCLUSIONS

This preliminary study has demonstrated for the first time in MSA stridor-related GM changes in striatal and cerebellar regions. Abnormalities in these regions were previously reported in dystonic disorders affecting laryngeal muscles, suggesting the hypothesis that stridor pathophysiology is dystonia-related. These results need however to be confirmed in a larger sample of patients.

Along-tract analysis of the arcuate fasciculus using the Laplacian operator to evaluate different tractography methods

PURPOSE

We propose a new along-tract algorithm to compare different tractography algorithms in tract curvature mapping and along-tract analysis of the arcuate fasciculus (AF). In particular, we quantified along-tract diffusion parameters and AF spatial distribution evaluating hemispheric asymmetries in a group of healthy subjects.

METHODS

The AF was bilaterally reconstructed in a group of 29 healthy subjects using the probabilistic ball-and-sticks model, and both deterministic and probabilistic constrained spherical deconvolution. We chose cortical ROIs as tractography targets and the developed along-tract algorithm used the Laplacian operator to parameterize the volume of the tract, allowing along-tract analysis and tract curvature mapping independent of the tractography algorithm used.

RESULTS

The Laplacian parameterization successfully described the tract geometry underlying hemispheric asymmetries in the AF curvature. Using the probabilistic tractography methods, we found more tracts branching towards cortical terminations in the left hemisphere. This influenced the left AF curvature and its diffusion parameters, which were significantly different with respect to the right. In particular, we detected projections towards the middle temporal and inferior frontal gyri bilaterally, and towards the superior temporal and precentral gyri in the left hemisphere, with a significantly increased volume and connectivity.

CONCLUSIONS

The approach we propose is useful to evaluate brain asymmetries, assessing the volume, the diffusion properties and the quantitative spatial localization of the AF.

Cognitive Rehabilitation and Transcranial Direct Current Stimulation in a Patient with Posterior Cortical Atrophy: An fMRI Study

BACKGROUND Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that accounts for 5% of the atypical presentation of Alzheimer disease (AD). To date, only a few studies have explored the effect of non-pharmacological treatment in PCA patients and no studies have evaluated the efficacy of transcranial direct current stimulation (tDCS) in this disorder. CASE REPORT A 58-year-old PCA patient underwent a cognitive rehabilitation treatment followed by 2 cycles of tDCS stimulation. The effects of both treatments were monitored over time with a standardized task-based fMRI protocol and with a neuropsychological assessment. Improvements in cognitive abilities, increased fMRI activation in the dorsolateral prefrontal cortex, and deactivation of the default mode network during the Stroop test performance were detected after each session treatment. CONCLUSIONS This combined approach lead to both cognitive improvements and neurophysiological adaptive changes, however, further studies on a larger cohort are needed to confirm these preliminary results.

Cerebral Mitochondrial Microangiopathy Leads to Leukoencephalopathy in Mitochondrial Neurogastrointestinal Encephalopathy

BACKGROUND AND PURPOSE

Mitochondrial neurogastrointestinal encephalopathy is a rare disorder due to recessive mutations in the thymidine phosphorylase gene, encoding thymidine phosphorylase protein required for mitochondrial DNA replication. Clinical manifestations include gastrointestinal dysmotility and diffuse asymptomatic leukoencephalopathy. This study aimed to elucidate the mechanisms underlying brain leukoencephalopathy in patients with mitochondrial neurogastrointestinal encephalopathy by correlating multimodal neuroradiologic features to postmortem pathology.

MATERIALS AND METHODS

Seven patients underwent brain MR imaging, including single-voxel proton MR spectroscopy and diffusion imaging. Absolute concentrations of metabolites calculated by acquiring unsuppressed water spectra at multiple TEs, along with diffusion metrics based on the tensor model, were compared with those of healthy controls using unpaired t tests in multiple white matters regions. Brain postmortem histologic, immunohistochemical, and molecular analyses were performed in 1 patient.

RESULTS

All patients showed bilateral and nearly symmetric cerebral white matter hyperintensities on T2-weighted images, extending to the cerebellar white matter and brain stem in 4. White matter, N-acetylaspartate, creatine, and choline concentrations were significantly reduced compared with those in controls, with a prominent increase in the radial water diffusivity component. At postmortem examination, severe fibrosis of brain vessel smooth muscle was evident, along with mitochondrial DNA replication depletion in brain and vascular smooth-muscle and endothelial cells, without neuronal loss, myelin damage, or gliosis. Prominent periependymal cytochrome C oxidase deficiency was also observed.

CONCLUSIONS

Vascular functional and histologic alterations account for leukoencephalopathy in mitochondrial neurogastrointestinal encephalopathy. Thymidine toxicity and mitochondrial DNA replication depletion may induce microangiopathy and blood-brain-barrier dysfunction, leading to increased water content in the white matter. Periependymal cytochrome C oxidase deficiency could explain prominent periventricular impairment.

Brain functional connectivity in sleep-related hypermotor epilepsy

Objectives

To evaluate functional connectivity (FC) in patients with sleep-related hypermotor epilepsy (SHE) compared to healthy controls.

Methods

Resting state fMRI was performed in 13 patients with a clinical diagnosis of SHE (age = 38.3 ± 11.8 years, 6 M) and 13 matched healthy controls (age = 38.5 ± 10.8 years, 6 M).

Data were first analysed using probabilistic independent component analysis (ICA), then a graph theoretical approach was applied to assess topological and organizational properties at the whole brain level. We evaluated node degree (ND), betweenness centrality (BC), clustering coefficient (CC), local efficiency (LE) and global efficiency (GE). The differences between the two groups were evaluated non-parametrically.

Results

At the group level, we distinguished 16 RSNs (Resting State Networks). Patients showed a significantly higher FC in sensorimotor and thalamic regions (p < 0.05 corrected). Compared to controls, SHE patients showed no significant differences in network global efficiency, while ND and BC were higher in regions of the limbic system and lower in the occipital cortex, while CC and LE were higher in regions of basal ganglia and lower in limbic areas (p < 0.05 uncorrected).

Discussion and conclusions

The higher FC of the sensorimotor cortex and thalamus might be in agreement with the hypothesis of a peculiar excitability of the motor cortex during thalamic K-complexes. This sensorimotor-thalamic hyperconnection might be regarded as a consequence of an alteration of the arousal regulatory system in SHE. An altered topology has been found in structures like basal ganglia and limbic system, hypothesized to be involved in the pathophysiology of the disease as suggested by the dystonic-dyskinetic features and primitive behaviours observed during the seizures.

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Resting state functional connectivity was studied for the first time in SHE.

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SHE patients showed higher connectivity in thalamic and motor regions.

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Motor cortex might show a higher excitability in response to thalamic projections.

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Brain network topology was altered mainly in basal ganglia and limbic system.

Multi-class parkinsonian disorders classification with quantitative MR markers and graph-based features using support vector machines

BACKGROUND AND PURPOSE

In this study we attempt to automatically classify individual patients with different parkinsonian disorders, making use of pattern recognition techniques to distinguish among several forms of parkinsonisms (multi-class classification), based on a set of binary classifiers that discriminate each disorder from all others.

METHODS

We combine diffusion tensor imaging, proton spectroscopy and morphometric-volumetric data to obtain MR quantitative markers, which are provided to support vector machines with the aim of recognizing the different parkinsonian disorders. Feature selection is used to find the most important features for classification. We also exploit a graph-based technique on the set of quantitative markers to extract additional features from the dataset, and increase classification accuracy.

RESULTS

When graph-based features are not used, the MR markers that are most frequently automatically extracted by the feature selection procedure reflect alterations in brain regions that are also usually considered to discriminate parkinsonisms in routine clinical practice. Graph-derived features typically increase the diagnostic accuracy, and reduce the number of features required.

CONCLUSIONS

The results obtained in the work demonstrate that support vector machines applied to multimodal brain MR imaging and using graph-based features represent a novel and highly accurate approach to discriminate parkinsonisms, and a useful tool to assist the diagnosis.

Proton MR Spectroscopy in Patients With Sleep-Related Hypermotor Epilepsy (SHE): Evidence of Altered Cingulate Cortex Metabolism

Study Objectives

To identify structural and/or metabolic alterations in patients with sleep-related hypermotor epilepsy (SHE) using magnetic resonance imaging (MRI) and proton MR spectroscopy (1H-MRS).

Methods

Nineteen SHE patients (seven males; 34.7 ± 9.7 years, mean age ± standard deviation) and 17 matched healthy volunteers (seven males; 34.0 ± 8.9 years) were included in the study. In all patients, the diagnosis of SHE was confirmed by video-polysomnographic recording of seizures. Semiology, seizure frequency, and therapy were assessed for all patients. For each recruited participant, structural MRI and 1H-MRS sequences were acquired. 1H-MRS was performed on two regions of interest: the medial thalamus and the anterior cingulate gyrus.

Results

At examination, five patients were seizure free. In the remainder, seizure frequency ranged from yearly to multiple episodes per night. Brain MRI was normal in all patients but one. The ratio of N-acetyl-aspartate/Creatine (NAA/Cr) was significantly reduced in the anterior cingulate cortex in patients compared to controls (p < .05). Thalamic NAA/Cr showed no differences between patients and controls. Regression analysis showed that NAA/Cr in the anterior cingulate gyrus correlated with seizure frequency (p < .05), being lower in patients with higher seizure frequency.

Conclusions

Given the absence of structural MR changes, our 1H-MRS data point to a functional NAA reduction in the cingulate cortex of SHE patients, more severe in those patients with higher seizure frequency and thus supporting the involvement of the anterior mesial structures in the pathophysiology of SHE.

Metabolic Imaging in Prostate Cancer: Where We Are

In recent years, the development of diagnostic methods based on metabolic imaging has been aimed at improving diagnosis of prostate cancer (PCa) and perhaps at improving therapy. Molecular imaging methods can detect specific biological processes that are different when detected within cancer cells relative to those taking place in surrounding normal tissues. Many methods are sensitive to tissue metabolism; among them, positron emission tomography (PET) and magnetic resonance spectroscopic imaging (MRSI) are widely used in clinical practice and clinical research. There is a rich literature that establishes the role of these metabolic imaging techniques as valid tools for the diagnosis, staging, and monitoring of PCa. Until recently, European guidelines for PCa detection still considered both MRSI/MRI and PET/CT to be under evaluation, even though they had demonstrated their value in the staging of high risk PCa, and in the restaging of patients presenting elevated prostatic-specific antigen levels following radical treatment of PCa, respectively. Very recently, advanced methods for metabolic imaging have been proposed in the literature: multiparametric MRI (mpMRI), hyperpolarized MRSI, PET/CT with the use of new tracers and finally PET/MRI. Their detection capabilities are currently under evaluation, as is the feasibility of using such techniques in clinical studies.

Voxel-based morphometry to detect effect of APOE on brain gray matter changes in Parkinson's Disease

The goal of the study was to determine association between APOE Ɛ4 and gray matter changes in PD patients, with or without dementia. Twenty-five PD patients with the APOE Ɛ4 (13 with dementia), 24 without Ɛ4 (12 with dementia), and 26 controls were selected. We found no significant differences between PD patients and controls, or between PD patients with and without the APOE Ɛ4 allele, with regard to VBM analysis. Our results provide no evidence of an association of the APOE Ɛ4 and gray matter degenerative changes in patients with PD, either with or without dementia.

Voxel-based morphometry study on monozygotic twins discordant for Alzheimer's disease

OBJECTIVES

We set to investigate the possible role of genes and environment in developing Alzheimer's disease (AD) in monozygotic twin pairs discordant for AD.

METHODS

Three pairs of twins discordant for AD, who were enrolled in the Finnish Twin Cohort, were used in the study and compared with 13 controls. Gray matter changes were assessed with magnetic resonance images using voxel-based morphometry with statistical parametric mapping.

RESULTS

In the affected twins, the peaks of volume loss were located bilaterally in the temporal (including the hippocampus), the frontal, and the parietal lobes, while in the unaffected siblings, the peaks were located in the frontal gyri and in the parietal lobule. Thus, in the unaffected twins, the pattern of volume loss overlaps with the neocortical but not with the medial temporal areas.

DISCUSSION

These findings suggest that genetic factors more largely control neocortical regions, whereas environmental factors more strongly affect medial temporal regions.

Accuracy of MR markers for differentiating Progressive Supranuclear Palsy from Parkinson's disease

Background

Advanced brain MR techniques are useful tools for differentiating Progressive Supranuclear Palsy from Parkinson's disease, although time-consuming and unlikely to be used all together in routine clinical work. We aimed to compare the diagnostic accuracy of quantitative morphometric, volumetric and DTI metrics for differentiating Progressive Supranuclear Palsy-Richardson's Syndrome from Parkinson's disease.

Methods

23 Progressive Supranuclear Palsy-Richardson's Syndrome and 42 Parkinson's disease patients underwent a standardized 1.5T brain MR protocol comprising high-resolution T1W1 and DTI sequences. Brainstem and cerebellar peduncles morphometry, automated volumetric analysis of brain deep gray matter and DTI metric analyses of specific brain structures were carried out. We determined diagnostic accuracy, sensitivity and specificity of MR-markers with respect to the clinical diagnosis by using univariate receiver operating characteristics curve analyses. Age-adjusted multivariate receiver operating characteristics analyses were then conducted including only MR-markers with a sensitivity and specificity exceeding 80%.

Results

Morphometric markers (midbrain area, pons to midbrain area ratio and MR Parkinsonism Index), DTI parameters (infratentorial structures) and volumetric analysis (thalamus, putamen and pallidus nuclei) presented moderate to high diagnostic accuracy in discriminating Progressive Supranuclear Palsy-Richardson's Syndrome from Parkinson's disease, with midbrain area showing the highest diagnostic accuracy (99%) (mean ± standard deviation: 75.87 ± 16.95 mm²vs 132.45 ± 20.94 mm², respectively; p < 0.001).

Conclusion

Although several quantitative brain MR markers provided high diagnostic accuracy in differentiating Progressive Supranuclear Palsy-Richardson's Syndrome from Parkinson's disease, the morphometric assessment of midbrain area is the best single diagnostic marker and should be routinely included in the neuroradiological work-up of parkinsonian patients.

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We compared quantitative brain MR markers accuracy to differentiate advanced stages of PSP-RS from PD.

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Quantitative morphometric, DTI and volumetric data showed moderate-high accuracies.

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Midbrain area alone best discriminated advanced PSP-RS from PD (99%).

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Midbrain area evaluation should be added to brain MR protocols for parkinsonisms.

Relationship of white and gray matter abnormalities to clinical and genetic features in myotonic dystrophy type 1

BACKGROUND

Myotonic dystrophy type 1 (DM1) represents a multisystemic disorder in which diffuse brain white and gray matter alterations related to clinical and genetic features have been described. We aimed to evaluate in the brain of adult patients with DM1 (i) white and gray matter differences, including cortical-subcortical gray matter volume and cortical thickness and (ii) their correlation with clinical disability, global neuropsychological performance and triplet expansion.

METHODS

We included 24 adult genetically-confirmed DM1 patients (14 males; age: 38.5 ± 11.8 years) and 25 age- and sex-matched healthy controls (14 males; age: 38.5 ± 11.3 years) who underwent an identical brain MR protocol including high-resolution 3D T1-weighted, axial T2 FLAIR and DTI sequences. All patients underwent an extensive clinical and neuropsychological evaluation. Voxel-wise analyses of white matter, performed by using Tract Based Spatial Statistics, and of gray matter, with Voxel-based Morphometry and Cortical Thickness, were carried out in order to test for differences between patients with DM1 and healthy controls (p < 0.05, corrected). The correlation between MRI measures and clinical-genetic features was also assessed.

RESULTS

Patients with DM1 showed widespread abnormalities of all DTI parameters in the white matter, which were associated with reduced gray matter volume in all brain lobes and thinning in parieto-temporo-occipital cortices, albeit with less extensive cortical alterations when congenital cases were removed from the analyses. White matter alterations correlated with clinical disability, global cognitive performance and triplet expansions.

CONCLUSION

In patients with DM1, the combined smaller overall gray matter volume and white matter alterations seem to be the main morpho-structural substrates of CNS involvement in this condition. The correlation of white matter differences with both clinical and genetic findings lends support to this notion.