Brain plasticity after rehabilitation in a severe case of artery of Percheron stroke assessed with multimodal MR imaging.

Artery of Percheron (AOP) stroke is a rare event. We describe an AOP stroke involving both thalami and the midbrain, resulting in a multifunctional clinical impairment. Intensive inpatient multidisciplinary rehabilitation favored the recovery of motor deficits, together with the improvement of cognitive dysfunctions. MRI assessment in the chronic post-stroke phase showed structural and functional reorganization in response to the extended thalamic tissue damage and absence of revascularization. Thalamo-cortical networks involving frontal and prefrontal regions, as well as parietal areas were disrupted, whereas increased functional thalamo-occipital connectivity was found. This report sheds light on brain reorganization following AOP stroke after rehabilitation..

MRI markers of functional connectivity and tissue microstructure in stroke-related motor rehabilitation: A systematic review.

BACKGROUND: Stroke-related disability is a major problem at individual and socio-economic levels. Neuromotor rehabilitation has a key role for its dual action on affected body segment and brain reorganization. Despite its known efficacy in clinical practice, the extent and type of effect at a brain level, mediated by neuroplasticity, are still under question. OBJECTIVE: To analyze studies applying MRI markers of functional and structural connectivity in patients affected with stroke undergoing motor rehabilitation, and to evaluate the effect of rehabilitation on brain reorganization. METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria were applied to select studies applying quantitative non-conventional MRI techniques on patients undergoing motor rehabilitation, both physical and virtual (virtual reality, mental imagery). Literature search was conducted using MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE from inception to 30th June 2020. RESULTS: Forty-one out of 6983 papers were included in the current review. Selected studies are heterogeneous in terms of patient characteristics as well as type, duration and frequency of rehabilitative approach. Neuromotor rehabilitation promotes neuroplasticity, favoring functional recovery of the ipsilesional hemisphere and activation of anatomically and functionally related brain areas in both hemispheres, to compensate for damaged tissue. CONCLUSIONS: The evidence derived from the analyzed studies supports the positive impact of rehabilitation on brain reorganization, despite the high data heterogeneity. Advanced MRI techniques provide reliable markers of structural and functional connectivity that may potentially aid in helping to implement the most appropriate rehabilitation intervention.

Movement cognition and narration of the emotions treatment versus standard speech therapy in the treatment of children with borderline intellectual functioning: a randomized controlled trial.

BACKGROUND: Borderline intellectual functioning (BIF) is defined as a "health meta-condition… characterized by various cognitive dysfunctions associated with an intellectual quotient (IQ) between 71 and 85 which determines a deficit in the individual's functioning both in the restriction of activities and in the limitation of social participation". It can be caused by many factors, including a disadvantaged background and prematurity. BIF affects 7-12% of primary school children that show academic difficulties due to poor executive functioning. In many children with BIF, language, movement and social abilities are also affected, making it difficult to take part in daily activities. Dropping out of school and psychological afflictions such as anxiety and depression are common in children with BIF. This study investigates whether an intensive rehabilitation program that involves all of the areas affected in children with BIF (Movement, Cognition and Narration of emotions, MCNT) is more effective than Standard Speech Therapy (SST). METHODS: This is a multicenter interventional single blind randomized controlled study. Children aged between 6 to 11 years who attend a mainstream primary school and have multiple learning difficulties, behavioral problems and an IQ ranging between 85 to 70 have been enrolled. Participants are randomly allocated to one of three groups. The first group receives individual treatment with SST for 45 min, twice a week for 9 months. The second group receives the experimental treatment MCNT for 3 h per day, 5 days/ week for 9 months and children work in small groups. The third group consists of children on a waiting list for the SST for nine months. DISCUSSION: BIF is a very frequent condition with no ad hoc treatment. Over the long term, there is a high risk to develop psychiatric disorders in adulthood. Due to its high social impact, we consider it very important to intervene during childhood so as to intercept the remarkable plasticity of the developing brain. TRIAL REGISTRATION: "Study Let them grow: A new intensive and multimodal Treatment for children with borderline intellectual functioning based on Movement, Cognition and Narration of emotions", retrospectively registered in ISRCTN Register with ISRCTN81710297 at 2017-01-09.

Mapping temporo-parietal and temporo-occipital cortico-cortical connections of the human middle longitudinal fascicle in subject-specific, probabilistic, and stereotaxic Talairach spaces.

Originally, the middle longitudinal fascicle (MdLF) was defined as a long association fiber tract connecting the superior temporal gyrus and temporal pole with the angular gyrus. More recently its description has been expanded to include all long postrolandic cortico-cortical association connections of the superior temporal gyrus and dorsal temporal pole with the parietal and occipital lobes. Despite its location and size, which makes MdLF one of the most prominent cerebral association fiber tracts, its discovery in humans is recent. Given the absence of a gold standard in humans for this fiber tract, its precise and complete connectivity remains to be determined with certainty. In this study using high angular resolution diffusion MRI (HARDI), we delineated for the first time, six major fiber connections of the human MdLF, four of which are temporo-parietal and two temporo-occipital, by examining morphology, topography, cortical connections, biophysical measures, volume and length in seventy brains. Considering the cortical affiliations of the different connections of MdLF we suggested that this fiber tract may be related to language, attention and integrative higher level visual and auditory processing associated functions. Furthermore, given the extensive connectivity provided to superior temporal gyrus and temporal pole with the parietal and occipital lobes, MdLF may be involved in several neurological and psychiatric conditions such as primary progressive aphasia and other aphasic syndromes, some forms of behavioral variant of frontotemporal dementia, atypical forms of Alzheimer's disease, corticobasal degeneration, schizophrenia as well as attention-deficit/hyperactivity Disorder and neglect disorders.

Technology-enhanced multi-domain at home continuum of care program with respect to usual care for people with cognitive impairment: the Ability-TelerehABILITation study protocol for a randomized controlled trial.

BACKGROUND: According to the World Alzheimer Report (Prince, The Global Impact of Dementia: an Analysis of Prevalence, Incidence, Cost and Trends, 2015), 46.8 million people worldwide are nowadays living with dementia. And this number is estimated to approximate 131.5 million by 2050, with an increasing burden on society and families. The lack of medical treatments able to stop or slow down the course of the disease has moved the focus of interest toward the nonpharmacological approach and psychosocial therapies for people with/at risk of dementia, as in the Mild Cognitive Impairment (MCI) condition. The purpose of the present study is to test an individualized home-based multidimensional program aimed at enhancing the continuum of care for MCI and outpatients with dementia in early stage using technology. METHODS: The proposed study is a single blind randomized controlled trial (RCT) involving 30 subjects with MCI and Alzheimer's disease (AD) randomly assigned to the intervention group (Ability group), who will receive the "Ability Program", or to the active control group (ACG), who will receive "Treatment As Usual" (TAU). The protocol provides for three steps of assessment: at the baseline (T_0), after treatment, (T_1) and at follow-up (T_2) with a multidimensional evaluation battery including cognitive functioning, behavioral, functional, and quality of life measures. The Ability Program lasts 6 weeks, comprises tablet-delivered cognitive (5 days/week) and physical activities (7 days/week) combined with a set of devices for the measurement and monitoring from remote of vital and physical health parameters. The TAU equally lasts 6 weeks and includes paper and pencil cognitive activities (5 days/week), with clinician's prescription to perform physical exercise every day and to monitor selected vital parameters. DISCUSSION: Results of this study will inform on the efficacy of a technology-enhanced home care service to preserve cognitive and motor levels of functioning in MCI and AD, in order to slow down their loss of autonomy in daily life. The expected outcome is to ensure the continuity of care from clinical practice to the patient's home, enabling also cost effectiveness and the empowerment of patient and caregiver in the care process, positively impacting on their quality of life. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT02746484 (registration date: 12/apr/2016 - retrospectively registered).

Assessment of Internal Jugular Vein Size in Healthy Subjects with Magnetic Resonance and Semiautomatic Processing.

Background and Objectives. The hypothesized link between extracranial venous abnormalities and some neurological disorders awoke interest in the investigation of the internal jugular veins (IJVs). However, different IJV cross-sectional area (CSA) values are currently reported in literature. In this study, we introduced a semiautomatic method to measure and normalize the CSA and the degree of circularity (Circ) of IJVs along their whole length. Methods. Thirty-six healthy subjects (31.22 ± 9.29 years) were recruited and the 2D time-of-flight magnetic resonance venography was acquired with a 1.5 T Siemens scanner. The IJV were segmented on an axial slice, the contours were propagated in 3D. Then, IJV CSA and Circ were computed between the first and the seventh cervical levels (C1-C7) and normalized among subjects. Inter- and intrarater repeatability were assessed. Results. IJV CSA and Circ were significantly different among cervical levels (p < 0.001). A trend for side difference was observed for CSA (larger right IJV, p = 0.06), but not for Circ (p = 0.5). Excellent inter- and intrarater repeatability was obtained for all the measures. Conclusion. This study proposed a reliable semiautomatic method able to measure the IJV area and shape along C1-C7, and suitable for defining the normality thresholds for future clinical studies.

Individual Thresholding of Voxel-based Functional Connectivity Maps. Estimation of Random Errors by Means of Surrogate Time Series.

INTRODUCTION: This article is part of the Focus Theme of Methods of Information in Medicine on "Biosignal Interpretation: Advanced Methods for Neural Signals and Images". BACKGROUND: Voxel-based functional connectivity analysis is a common method for resting state fMRI data. However, correlations between the seed and other brain voxels are corrupted by random estimate errors yielding false connections within the functional connectivity map (FCmap). These errors must be taken into account for a correct interpretation of single-subject results. OBJECTIVES: We estimated the statistical range of random errors and propose two methods for an individual setting of correlation threshold for FCmaps. METHODS: We assessed the amount of random errors by means of surrogate time series and described its distribution within the brain. On the basis of these results, the FCmaps of the posterior cingulate cortex (PCC) from 15 healthy subjects were thresholded with two innovative methods: the first one consisted in the computation of a unique (global) threshold value to be applied to all brain voxels, while the second method is to set a different (local) threshold of each voxel of the FCmap. RESULTS: The distribution of random errors within the brain was observed to be homogeneous and, after thresholding with both methods, the default mode network areas were well identifiable. The two methods yielded similar results, however the application of a global threshold to all brain voxels requires a reduced computational load. The inter-subject variability of the global threshold was observed to be very low and not correlated with age. Global threshold values are also almost independent from the number of surrogates used for their computation, so the analyses can be optimized using a reduced number of surrogate time series. CONCLUSIONS: We demonstrated the efficacy of FCmaps thresholding based on random error estimation. This method can be used for a reliable single-subject analysis and could also be applied in clinical setting, to compute individual measures of disease progression or quantitative response to pharmacological or rehabilitation treatments.

Altered and asymmetric default mode network activity in a "hypnotic virtuoso": an fMRI and EEG study.

Very highly hypnotizable subjects are rare, easily induced, and able to manifest the whole spectrum of hypnotic phenomena, including post-hypnotic amnesia. The aim of this study was to detect and localize by means of quantitative functional MRI and EEG changes in cortical activity during hypnosis induction and deep "pure hypnosis" in a hypnotic "virtuoso" subject. We focused on areas forming the default mode network (DMN), since previous studies found that very highly suggestible subjects in hypnosis showed decreased activity in anterior DMN. During undisturbed hypnosis, our "virtuoso" subject showed not only detectable changes in DMN, but also peculiar activations of non-DMN areas and hemispheric asymmetries of frontal lobe connectivity. Our findings confirm that hypnosis is associated with significant modulation of connectivity and activity which involve the DMN but are not limited to it, depending on the depth of the hypnotic state, the type of mental content and emotional involvement.

Voxel-wise analysis of diffusion tensor MRI improves the confidence of diagnosis of corticobasal degeneration non-invasively.

Corticobasal degeneration (CBD) presents with symptoms that often overlap with other neurological conditions. In many cases, diagnosis, prognosis and consequent clinical management remain uncertain. Structural and functional asymmetric brain changes represent the most consistent imaging findings that may assist in CBD diagnosis. Diffusion Tensor MRI (DT-MRI) is a quantitative technique that allows microscopic tissue abnormalities to be non-invasively assessed in vivo. A single case of clinically suspected CBD with symmetric diffuse brain atrophy on conventional-MRI scans was studied using DT-MRI by voxel-wise comparison with eight healthy subjects. The lateralized distribution of DT-MRI abnormalities was consistent with clinical features providing a substantial support to the diagnosis.

Brain tissue damage in dementia with Lewy bodies: an in vivo diffusion tensor MRI study.

The aim of the present study was to apply diffusion tensor MRI (DT-MRI), a quantitative MRI measure which reflects tissue organization, to dementia with Lewy bodies (DLB). DT-MRI scans were obtained from 15 patients with probable DLB and 10 sex- and age-matched healthy controls. Abnormalities were found in the corpus callosum, pericallosal areas and the frontal, parietal, occipital and, less prominently, temporal white matter of patients compared with controls. Abnormalities were also found in the caudate nucleus and the putamen. The average grey matter volume was lower in patients than in controls. These findings of concomitant grey matter atrophy and white matter abnormalities (as detected by DT-MRI) in regions with a high prevalence of long connecting fibre tracts might suggest the presence of neurodegeneration involving associative cortices. The modest involvement of the temporal lobe fits with the relative preservation of global neuropsychological measures and memory tasks in the early stage of DLB. The selective involvement of parietal, frontal and occipital lobes might explain some of the clinical and neuropsychological features of DLB, providing a possible distinctive marker for this disease. The abnormalities found in the subcortical grey matter may indicate that DLB and Parkinson's disease share a similar nigrostriatal involvement caused by common pathophysiological mechanisms.