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BackgroundTo analyse multimodal imaging alterations in the subclinical form of best vitelliform macular dystrophy (BVMD).MethodsThe study was designed as an observational, cross-sectional case series. Eleven eyes of 7 subclinical patients with BVMD and 12 age-matched and sex-matched controls were included. Multimodal imaging included fundus blue-light autofluorescence, near-infrared autofluorescence (NIR-AF), structural optical coherence tomography (OCT) and OCT angiography (OCTA). The quantitative analysis included the calculation of the following parameters: vessel density (VD), vessel tortuosity (VT), vessel dispersion (Vdisp), vessel rarefaction (VR), foveal avascular zone (FAZ) area, reflectivity of the outer retinal bands and choriocapillaris porosity (CCP).ResultsMean best-corrected visual acuity was 0.0±0.0 LogMAR in both groups. The round central hypoautofluorescent alteration on NIR-AF corresponded to a significant reflectivity attenuation of the outer retinal bands on structural OCT (0.55±0.18 vs 0.75±0.08; p0.05). The FAZ area turned out to be significantly restricted at the level of the deep capillary plexus in subclinical BVMD eyes (pConclusionsThe subclinical stage of BVMD is characterised by significant alterations of the outer retinal bands and the choriocapillaris. Quantitative multimodal imaging assessment suggests that subclinical BVMD is affected by the functional impairment of the outer retinal structures, leading to an alteration in melanin and growth factor production.

Purpose: To differentiate acute central serous chorioretinopathy (CSC) subtypes by multimodal imaging. Methods: The research was designed as a prospective, interventional study. Naive patients with acute CSC were followed for 24 months. Overall, 96 CSC patients (96 eyes) and 210 controls (210 eyes) were included. Multimodal imaging allowed the study to classify CSC into retinal pigment epithelium-related CSC (RPE-CSC) and choroidal-related CSC (choroidal-CSC) subtypes. The RPE-CSC type was characterized by normal choroidal thickness (CT) in association with disseminated RPE alterations. The choroidal-CSC type was distinguished by identifying a pachychoroid. All the patients underwent eplerenone or verteporfin photodynamic therapy (PDT). Patients developing macular neovascularization (MNV) underwent anti-VEGF injections. Quantitative measurements included central macular thickness (CMT), choroidal thickness (CT), Sattler layer thickness (SLT) and Haller layer thickness (HLT). Results: Considering the CSC patients as a whole, baseline BCVA was 0.18 ± 0.25 LogMAR, increasing to 0.13 ± 0.21 LogMAR after 24 months (P < 0.01), whereas baseline CMT improved from 337 ± 126 µm to 244 ± 84 µm after 24 months (P < 0.01). We found the following subdivision of CSC eyes: RPE-CSC type (45%) and choroidal-CSC type (55%). Overall, MNV were detected in 18 eyes (19%), 13 eyes (72%) in the RPE-CSC subgroup and five eyes (28%) in the choroidal-CSC subgroup. Forty eyes responded to eplerenone (57% of RPE-CSC and 47% of choroidal-CSC), whereas 38 eyes required PDT (43% of RPE-CSC and 53% of choroidal-CSC). Conclusions: Acute CSC includes two main clinical manifestations, displaying differing features concerning retinal and choroidal involvement. Translational relevance: This study identified two clinically different acute CSC subtypes on the basis of quantitative pachychoroid cutoff values.

The periaqueductal gray is a mesencephalic structure involved in modulation of responses to stressful stimuli. Structural connections between the periaqueductal gray and the cerebellum have been described in animals and in a few diffusion tensor imaging studies. Nevertheless, these periaqueductal gray–cerebellum connectivity patterns have yet to be fully investigated in humans. The objective of this study was to qualitatively and quantitatively characterize such pathways using high-resolution, multi-shell data of 100 healthy subjects from the open-access Human Connectome Project repository combined with constrained spherical deconvolution probabilistic tractography. Our analysis revealed robust connectivity density profiles between the periaqueductal gray and cerebellar nuclei, especially with the fastigial nucleus, followed by the interposed and dentate nuclei. High-connectivity densities have been observed between vermal (Vermis IX, Vermis VIIIa, Vermis VIIIb, Vermis VI, Vermis X) and hemispheric cerebellar regions (Lobule IX). Our in vivo study provides for the first time insights on the organization of periaqueductal gray–cerebellar pathways thus opening new perspectives on cognitive, visceral and motor responses to threatening stimuli in humans.

Introduction This study aimed to assess quantitative factors associated with treatment response and macular neovascularization (MNV) onset in central serous chorioretinopathy (CSC) through an artificial intelligence-based approach. Methods The study was designed as an interventional, prospective case series with a planned follow-up of 36 months. We included only eyes demonstrating the first episode of CSC. All the patients underwent eplerenone or photodynamic therapy (PDT) treatment. Eyes developing MNV underwent anti-VEGF injections. We developed an artificial intelligence-based model to assess predictive quantitative structural optical coherence tomography (OCT) factors related to treatment response and onset of MNV. Main outcome measures were best-correct visual acuity (BCVA), central macular thickness (CMT), retinal thickness (RT), retinal pigment epithelium (RPE) thickness, choroidal thickness, Sattler’s layer thickness (SLT), Haller’s layer thickness, retinal and choroidal hyperreflective foci (HF), and MNV. Results We included 96 naïve CSC eyes (96 patients). Baseline BCVA was 0.18 ± 0.25 logMAR, which increased to 0.16 ± 0.27 logMAR after 3 years (p > 0.05). Baseline CMT was 337 ± 126 µm, which improved to 229 ± 40 µm after 3 years (p

Graphical abstract Using an visuo-audio spatial task, a novel version of the Posner task, we support the idea that auditory and visual attentional systems are governed by modality-specific processes and provide novel evidence for audiovisual links in endogenous covert spatial attention., Highlights • Facilitation was observed for right-sided auditory stimuli in a new visuo-audio task. • Auditory space has dynamic nature, which adapts to changes in visual space. • Sound localization was enhanced by visual cues. • Crossmodal links in spatial attention were found between audition and vision. • These findings have theoretical and translational implications for future studies., Visuospatial attention is asymmetrically distributed with a leftward bias (i.e. pseudoneglect), while evidence for asymmetries in auditory spatial attention is still controversial. In the present study, we investigated putative asymmetries in the distribution of auditory spatial attention and the influence that visual information might have on its deployment. A modified version of the Posner task (i.e. the visuo-audio spatial task [VAST]) was used to investigate spatial processing of auditory targets when endogenous orientation of spatial attention was mediated by visual cues in healthy adults. A line bisection task (LBT) was also administered to assess the presence of a leftward bias in deployment of visuospatial attention. Overall, participants showed rightward and leftward biases in the VAST and the LBT, respectively. In the VAST, sound localization was enhanced by visual cues. Altogether, these findings support the existence of a facilitation effect for auditory targets originating from the right side of space and provide new evidence for crossmodal links in endogenous spatial attention between vision and audition.

Parkinson's disease (PD) is a complex neurological disorder characterized by motor and nonmotor symptoms. The onset of visual symptoms may occur many years before motor ones. Growing evidence shows a strong involvement of the visual system, including corneal changes, retinal layer thinning, and alterations of gray and white matter. These modifications can explain the wide range of visual symptoms, including visual acuity loss, eye movements and pupillary defects, electrophysiology alterations, and visual processing impairment. Moreover, visual symptoms and visual system involvement also can be detected in other forms of parkinsonism, such as Lewy body dementia and multiple system atrophy. However, the deep characterization of common features and differences between each parkinsonism, in terms of visual system changes, is still missing. The main aim of the present chapter is to describe the main alterations reported in the literature of the visual system in PD.

The current model of the basal ganglia system based on the ‘direct’, ‘indirect’ and ‘hyperdirect’ pathways provides striking predictions about basal ganglia function that have been used to develop deep brain stimulation approaches for Parkinson’s disease and dystonia. The aim of this review is to challenge this scheme in light of new tract tracing information that has recently become available from the human brain using MRI-based tractography, thus providing a novel perspective on the basal ganglia system. We also explore the implications of additional direct pathways running from cortex to basal ganglia and between basal ganglia and cerebellum in the pathophysiology of movement disorders.

According to the classical view, the cerebellum has long been confined to motor control physiology; however, it has now become evident that it exerts several non-somatic features other than the coordination of movement and is engaged also in the regulation of cognition and emotion. In a previous diffusion-weighted imaging-constrained spherical deconvolution (CSD) tractography study, we demonstrated the existence of a direct cerebellum-hippocampal pathway, thus reinforcing the hypothesis of the cerebellar role in non-motor domains. However, our understanding of limbic-cerebellar interconnectivity in humans is rather sparse, primarily due to the intrinsic limitation in the acquisition of in vivo tracing. Here, we provided tractographic evidences of connectivity patterns between the cerebellum and mammillary bodies by using whole-brain CSD tractography in 13 healthy subjects. We found both ipsilateral and contralateral connections between the mammillary bodies, cerebellar cortex, and dentate nucleus, in line with previous studies performed in rodents and primates. These pathways could improve our understanding of cerebellar role in several autonomic functions, visuospatial orientation, and memory and may shed new light on neurodegenerative diseases in which clinically relevant impairments in navigational skills or memory may become manifest at early stages.

The need to improve surgical efficacy in patients affected by high-grade gliomas has led to development of advanced pre-surgical MRI-based techniques such as tractography. This study investigates pre-surgical planning of optic radiations (ORs) in patients affected by occipito-temporo-parietal high-grade gliomas, by means of constrained spherical deconvolution (CSD) and diffusion tensor imaging (DTI) tractography. Twelve patients with occipito-temporo-parietal high-grade gliomas were recruited and analyzed using a 3 T MRI scanner. Diffusion-weighted imaging (DWI) was conducted with 64 gradient diffusion directions. OR alterations were assessed qualitatively and quantitatively to evaluate the effectiveness of CSD- and DTI-based pre-surgical planning. CSD-based tractography provided better qualitative evaluation of affected white matter tracts when compared to DTI; by thresholding tractographic probabilistic maps coming from all reconstructions, we detected, at the highest cutoff level, OR involvement in 75 % of patients (vs 41.67 % of patients with probabilistic DTI). Quantitative analysis of diffusion parameters revealed a statistically significant decrease in fractional anisotropy (FA) in the affected side following CSD-based reconstructions; on the contrary, DTI-based reconstructions did not show any significant quantitative alteration. Our results showed improvement in pre-surgical planning of high-grade gliomas involving ORs with use of CSD-based tractography. This technique provided more useful information regarding the white matter spatial relationship with brain neoplasm and its involvement in the glioma, when compared to DTI. Using CSD model for OR evaluation may optimize safe surgical resection margins, helping to reduce risk of post-operative visual deficits.

©2015 Arrigo A. This is an open access article distributed under the Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Volume 1 : Issue 1 Article Ref. #: 1000ROJ1e001 The Pre-Surgical Planning of Brain Neoplasms: From Diffusion Tensor Imaging to More Advanced Approaches

Purpose The aim of this work was to investigate the diagnostic value of the DIR sequence at 3T MR imaging operating in the evaluation of cortical development anomalies. Methods We studied 40 patients, with a previous diagnosis of cortical dysplasia, by FLAIR-3D, DIR, FSE T2 and MPR-GE T1 sequences at 3T MRI. Two independent observers evaluated, for each sequence and lesion, some semiological aspects (cortical thickness, cortical signal intensity, white-gray matter blurring, subcortical white matter intensity). We made also a quantitative evaluation of the cortical signal intensity in lesion site, drawing a ROI on each MRI sequences and comparing them to the correspondent normal contralateral cortical area. Results We identified 44 cortical development anomalies. Qualitative analyses showed a high level of agreement between the observers concerning DIR potentialities in detecting and characterizing the cortical development disorders. Particularly DIR sequence was able to demonstrate the blurring and the subcortical white matter anomalies. The quantitative analyses didn’t show a significant difference between DIR and traditional sequences in the evaluation of the cortical signal intensity. Conclusion 3T MRI-DIR sequence is a useful and better suitable sequence compared to the traditional sequences in the characterization of some semiological aspects of the cortical development disorders, particularly blurring and subcortical white matter hyperintensity.

Background Understanding the topographical organization of the cortico-basal ganglia circuitry is of pivotal importance because of the spreading of techniques such as DBS and, more recently, MR-guided focused ultrasound for the treatment of movement disorders. A growing body of evidence has described both direct cortico- and dento-pallidal connections, although the topographical organization in vivo of these pathways in the human brain has never been reported. Objective To investigate the topographical organization of cortico- and dento-pallidal pathways by means of diffusion MRI tractography and connectivity based parcellation. Methods High-quality data from 100 healthy subjects from the Human Connectome Project repository were utilized. Constrained spherical deconvolution-based tractography was used to reconstruct structural cortico- and dento-pallidal connectivity. Connectivity-based parcellation was performed with a hypothesis-driven approach at three different levels: functional regions (limbic, associative, sensorimotor, and other), lobes, and gyral subareas. Results External globus pallidus segregated into a ventral associative cluster, a dorsal sensorimotor cluster, and a caudal "other" cluster on the base of its cortical connectivity. Dento-pallidal connections clustered only in the internal globus pallidus, where also associative and sensorimotor clusters were identified. Lobar parcellation revealed the presence in the external globus pallidus of dissociable clusters for each cortical lobe (frontal, parietal, temporal, and occipital), whereas in internal globus pallidus only frontal and parietal clusters were found out. Conclusion We mapped the topographical organization of both internal and external globus pallidus according to cortical and cerebellar connections. These anatomical data could be useful in DBS, radiosurgery and MR-guided focused ultrasound targeting for treating motor and nonmotor symptoms in movement disorders. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

The claustrum is a thin grey matter structure which is involved in a wide brain network. Previous studies suggested a link between claustrum and Parkinson’s Disease (PD), showing how α-synuclein pathology may affect claustral neurons as well as how α-synuclein immunoreactivity may correlate with the onset of cognitive dysfunctions. Our aim is to investigate, via diffusion MRI, claustral structural network changes in drug naive PD patients, with the goal to understand whether such changes may contribute to cognitive decline in PD. 15 drug naive PD patients and 15 age-matched controls were enrolled; MR protocol was performed on a 3T scanner. Whole brain probabilistic tractography was obtained using Constrained Spherical Deconvolution (CSD) diffusion model. Connectivity matrices were estimated based on a robust anatomical parcellation of structural T1w images. In PD group, impaired subnetworks were correlated with psychological examinations. We found decreased claustral connectivity in PD patients compared to controls, especially with areas mainly involved in visuomotor and attentional systems. Moreover, we found a positive correlation between MoCA and density of pathways connecting ipsilaterally claustrum to left (r = 0.578, p = 0.021) and right (r = 0.640, p = 0.020) Pars Orbitalis. Our results support the hypothesis of claustral involvement in cognitive decline in drug naive PD patients.

We evaluated, by means of a non-invasive procedure based on MRI, the masticatory muscular microstructure in a 55-year-old-female patient affected by bruxism. The patient underwent MR examination before and after 1 month of splint therapy, when she mentioned the complete disappearance of all symptoms. By means of diffusion tensor imaging we observed changes at microstructural level of masticatory muscular complex. We conclude that diffusion tensor imaging may be a useful instrument both to perform panoramic reconstruction of the masticatory muscle complex and to investigate microstructural modifications related to the pain relief in bruxism.

Resistance to thyroid hormone (RTH) describes a rare syndrome in which serum levels of thyroid hormones are elevated but serum levels of thyroid stimulating hormone (TSH) are unsuppressed. The importance of thyroid hormones for the normal function of the adult brain is corroborated by the frequent association of thyroid dysfunctions with neurological and psychiatric symptoms. In this study we investigated whether adult thyroid hormone resistance affects cortical excitability and modulates inhibitory and excitatory intracortical circuitries by using transcranial magnetic stimulation. Cortical excitability was probed with transcranial magnetic stimulation in 4 patients with thyroid hormone resistance, 10 patients affected by overt hypothyroidism (OH) and 10 age-matched healthy controls. We tested motor thresholds, motor evoked potential recruitment curve, cortical silent period (CSP), short interval intracortical inhibition (SICI) and intracortical facilitation. In both OH and RTH patients, the inhibitory cortical circuits were affected compared with euthyroid controls, but in opposite ways. In OH patients, CSP was prolonged and SICI was decreased. On the contrary, in RTH patients CSP was shortened and SICI was increased. Thyroid hormones may influence cortical excitability and cortical inhibitory circuits.

In this study we described a case of lipofibromatous hamartoma involving the median nerve. We adopted diffusion tensor imaging and constrained spherical deconvolution-based tractography to reconstruct the affected median nerve. Moreover, we extracted diffusion-based parameters reflecting axonal integrity loss of median nerve fibres. Our data showed that constrained spherical deconvolution-based tractography outperformed the diffusion tensor imaging-based method, allowing the detection of the entire median nerve, including its branches, thus offering a robust method to investigate the involvement of the median nerve in pathological conditions. All clinical and technical implications are extensively described.

The amygdala plays a key role in gathering social cues to context-appropriate responses that require refined motor behavior, involving either direct or indirect connections with sensorimotor-related areas. Although, several studies investigated the structural and functional limbic connectivity of the amygdala both in animals and in humans, less is known about the limbic modulation on sensorimotor-related areas. However, recent evidences suggest the amygdala as a possible cornerstone in the limbic-motor interface. Herein, we used high-resolution diffusion data of the Massachusetts General Hospital-University of Southern California (MGH-USC) Adult Diffusion Dataset, constrained spherical deconvolution-based signal modeling and probabilistic tractography aimed at identifying and reconstructing the connectivity patterns linking the amygdala to the limbic- and sensorimotor-related areas. As regards the limbic network, our results showed that the amygdala has high probability to be connected with the fusiform gyrus and the lateral orbitofrontal cortex. On the other hand, our connectomic analysis revealed a close interplay between the amygdala and the inferior parietal lobule, followed by the postcentral gyrus, the precentral gyrus and the paracentral lobule. The findings of the present study are in line with previous literature and reinforce the idea of the existence of a limbic-motor interface, which is likely to be involved in the emotional modulation of complex functions such as spatial perception and movement computation. Considering that these pathways may play an important role, not on in physiological conditions, but also in pathological context, further studies should be fostered in order to confirm the existence of a limbic-motor interface and its precise functional meaning.

Objectives: There is increasing evidence of non-motor, sensory symptoms, mainly involving the spatial domain, in cervical dystonia (CD). These manifestations are likely driven by dysfunctional overactivity of the parietal cortex during the execution of a sensory task. Few studies also suggest the possibility that visuospatial attention might be specifically affected in patients with CD. Therefore, we asked whether non-motor manifestations in CD might also comprise impairment of higher level visuospatial processing. Methods: To this end, we investigated visuospatial attention in 23 CD patients and 12 matched healthy controls (for age, gender, education, and ocular dominance). The patients were identified according to the dystonia pattern type (laterocollis vs. torticollis). Overall, participants were right-handers, and the majority of them was right-eye dominant. Visuospatial attention was assessed using a line bisection task. Participants were asked to bisect horizontal lines, using their right or left hand. Results: Participants bisected more to the left of true center when using their left hand to perform the task than when using their right hand. However, overall, torticollis patients produced a significantly greater leftward deviation than controls. Conclusions: These data are consistent with preliminary findings suggesting the presence of biased spatial attention in patients with idiopathic cervical dystonia. The presence of an attentional bias in patients with torticollis seem to indicate that alterations of attentional circuits might be implicated in the pathophysiology of this type of CD. (JINS, 2018, 24, 23–32)

To describe corneal innervation and trigeminal alterations in drug-naive patients with Parkinson disease (PD).A case series study was conducted by recruiting 3 early drug-naive patients with PD, 2 men and 1 woman (age: 72, 68, and 66, respectively). Ophthalmologic assessment included Ocular Surface Disease Index questionnaire, visual acuity by the logarithm of the minimum angle of resolution score, pupillary light reflexes, extrinsic ocular movements, corneal sensitivity, and slit-lamp examination. Corneal innervation parameter changes were evaluated in vivo using the Confoscan 4 confocal microscope, and they were compared with a control data set. The Heidelberg Retina Tomograph 3 (HRT3) has been used to assess retinal alterations in our patients, if compared with normal range values provided by the HRT3. Moreover, 3T magnetic resonance imaging (MRI) analysis of water diffusion property changes of trigeminal nerves was performed. All data were analyzed and compared with 2 control data sets made by 14 age-matched controls.Patients with PD showed profound alterations of corneal innervation and of trigeminal diffusion MRI parameters, compared with controls. Strong differences (PD vs. controls) were found for deep nerve tortuosity (Kallinikos mean 19.94 vs. 2.13) and the number of beadings (mean 34.2 vs. 15.5). HRT3 retinal evaluation revealed less structural changes compared with the normal range. Diffusion MRI showed profound changes of white matter diffusion properties (PD vs. controls), with fractional anisotropy decrement (mean 0.3029 vs. 0.3329) and mean diffusivity increment (mean 0.00127 vs. 0.00106).Corneal innervation changes might occur earlier in patients with PD than in retinal ones. Confocal corneal innervation analysis might provide possible early biomarkers for a better PD evaluation and for its earlier diagnosis.

Background. Surround inhibition is a system that sharpens sensation by creating an inhibitory zone around the central core of activation. In the motor system, this mechanism probably contributes to the selection of voluntary movements, and it seems to be lost in dystonia. Objectives. To explore if sensory information is abnormally processed and integrated in focal hand dystonia (FHD) and if surround inhibition phenomena are operating during sensory-motor plasticity and somatosensory integration in normal humans and in patients with FHD. Methods. We looked at the MEP facilitation obtained after 5 Hz repetitive paired associative stimulation of median (PAS M), ulnar (PAS U), and median + ulnar nerve (PAS MU) stimulation in 8 normal subjects and 8 FHD. We evaluated the ratio MU/(M + U) ∗ 100 and the spatial and temporal somatosensory integration recording the somatosensory evoked potentials (SEPs) evoked by a dual nerve input. Results. FHD had two main abnormalities: first, the amount of facilitation was larger than normal subjects; second, the spatial specificity was lost. The MU/(M + U) ∗ 100 ratio was similar in healthy subjects and in FHD patients, and the somatosensory integration was normal in this subset of patients. Conclusions. The inhibitory integration of somatosensory inputs and the somatosensory inhibition are normal in patients with focal dystonia as well as lateral surrounding inhibition phenomena during sensory-motor plasticity in FHD.

Introduction: Eligibility for endovascular treatment (EVT) in patients with acute ischemic stroke (AIS) depends, amongst other factors, on CT- or MR-based scores. The aim of this study was to investigate the role of Alberta Stroke Program Early CT score based on diffusion weighted imaging (MR-ASPECT) in the assessment of brain damage pre-EVT, patient selection for EVT and outcome. Materials and methods: We included in this study patients with National Institute of Health stroke score (NIHSS) at admission ≥ 8, MR-ASPECT ≥ 5 and anterior AIS, who were treated with EVT in our hospital. All patients were clinically evaluated at admission, post-EVT, discharge and at 3-month follow-up. We used MR-ASPECT to establish infarct core extension at admission. We evaluated ASPECT score at admission (CT-ASPECT-IN), 24 h after EVT and at discharge, NIHSS, modified Ranking Scale (mRS), Thrombolysis in Cerebral Infarction scale (TICI), onset-to-intervention-delay (OTID) and Collateral Circulation Score (CCS). Results: 68 patients (mean age 78 ± 11.9 years) were included in this study. 54.4 and 64.7% of patients had strong clinical improvement after 24 h from EVT and at discharge, respectively. NIHSS evaluated 24 h after EVT correlated with CCS, TICI and OTID. We observed a favourable outcome (mRS 0–2) in 52.9% of patients at 3-month follow-up. MR-ASPECT score correlated with post-EVT outcome better than CT-ASPECT-IN scores. Conclusion: MR-ASPECT score based on diffusion weighted imaging is useful for the selection of patients with AIS that can have a favourable outcome from EVT. A prompt EVT has huge impact on patient outcome.

The present study is aimed at further exploring structural and functional correlates of fatigue in Relapsing- Remitting Multiple Sclerosis (RRMS) patients by using a combined approach by means of transcranial magnetic stimulation (TMS) and a Diffusion Tensor Imaging (DTI). The physiopathology of fatigue in MS is still poorly understood, although a variety of pathogenic mechanisms has been proposed. Our working hypothesis is that diffuse microstructural white matter damage may subtend the cortico-subcortical functional disconnection described in patients with MS and fatigue. We enrolled 30 RRMS patients (mean age 39±13; age range 24-63 years) with mild neurological impairment Expanded Disability Status Scale

Although the olfactory sense has always been considered with less interest than the visual, auditive or somatic senses, it does plays a major role in our ordinary life, with important implication in dangerous situations or in social and emotional behaviors. Traditional Diffusion Tensor signal model and related tractography have been used in the past years to reconstruct the cranial nerves, including the olfactory nerve (ON). However, no supplementary information with regard to the pathways of the olfactory network have been provided. Here, by using the more advanced Constrained Spherical Deconvolution (CSD) diffusion model, we show for the first time in vivo and non-invasively that, in healthy humans, the olfactory system has a widely distributed anatomical network to several cortical regions as well as to many subcortical structures. Although the present study focuses on an healthy sample size, a similar approach could be applied in the near future to gain important insights with regard to the early involvement of olfaction in several neurodegenerative disorders.

Objective: Investigation of spatial and temporal cognitive processing in Idiopathic Cervical Dystonia (CD) by means of specific tasks based on perception in time and space domains of visual and auditory stimuli. Background: Previous psychophysiological studies have investigated temporal and spatial characteristics of neural processing of sensory stimuli (mainly somatosensorial and visual), whereas the definition of such processing at higher cognitive level has not been sufficiently addressed. The impairment of time and space processing is likely driven by basal ganglia dysfunction. However, other cortical and subcortical areas, including cerebellum, may also be involved. Methods: We tested twenty-one subjects with Cervical Dystonia and twenty-two age-matched healthy controls with four recognition tasks exploring visuo-spatial, audio-spatial, visuo-temporal and audio-temporal processing. Dystonic subjects were subdivided in three groups according to the head movement pattern type (lateral: Laterocolis, rotation: Torticollis) as well as the presence of tremor (Tremor). Results: We found significant alteration of spatial processing in Laterocollis subgroup compared to controls, whereas impairment of temporal processing was observed in Torticollis subgroup compared to controls. Conclusions: Our results suggest that Dystonia is associated with a dysfunction of temporal and spatial processing for visual and auditory stimuli that could underlie the well-known abnormalities in sequence learning. Moreover, we suggest that different movement pattern type might lead to different dysfunctions at cognitive level within dystonic population.

The limbic system has a central role for the integration of several cognitive and visceral functions through an extended network of connections involving the hippocampus and the amygdala. A number of studies performed in humans have been dedicated to the investigation of supratentorial limbic pathways by means of non-invasive MRI approaches, such as DTI. However, detection of possible limbic connections involving the brainstem and the spinal cord is still missing. Subtentorial limbic pathways have been previously studied in animals by means of invasive approaches, including viral tracing. The detection of limbic connections with the brainstem and the spinal cord has raised several new hypotheses regarding the interaction between the central nervous system and the periphery of the body. We investigated subtentorial limbic connections in twenty-one healthy humans by means of probabilistic constrained spherical deconvolution tractography. Our connectivity analysis showed, for both the hippocampus and the amygdala, a high probability of connections with the midbrain, pons, and bulb. Moreover, hippocampal and amygdalar pathways reaching the cervical spinal cord were also detected. Quantitative evaluation of diffusion parameters was also performed. Findings of the present study are in agreement with the literature and provide the first report of possible limbic connections between the brainstem and the spinal cord in human brain. Since these pathways might also have important implications both in physiological and pathological contexts, further studies should be conducted in order to confirm our data as well as to define functional features of these brain connections.

Purpose To assess intracranial visual system changes of newly diagnosed Parkinson disease in drug-naive patients. Materials and Methods Twenty patients with newly diagnosed Parkinson disease and 20 age-matched control subjects were recruited. Magnetic resonance (MR) imaging (T1-weighted and diffusion-weighted imaging) was performed with a 3-T MR imager. White matter changes were assessed by exploring a white matter diffusion profile by means of diffusion-tensor imaging-based parameters and constrained spherical deconvolution-based connectivity analysis and by means of white matter voxel-based morphometry (VBM). Alterations in occipital gray matter were investigated by means of gray matter VBM. Morphologic analysis of the optic chiasm was based on manual measurement of regions of interest. Statistical testing included analysis of variance, t tests, and permutation tests. Results In the patients with Parkinson disease, significant alterations were found in optic radiation connectivity distribution, with decreased lateral geniculate nucleus V2 density (F, -8.28; P < .05), a significant increase in optic radiation mean diffusivity (F, 7.5; P = .014), and a significant reduction in white matter concentration. VBM analysis also showed a significant reduction in visual cortical volumes (P < .05). Moreover, the chiasmatic area and volume were significantly reduced (P < .05). Conclusion The findings show that visual system alterations can be detected in early stages of Parkinson disease and that the entire intracranial visual system can be involved. © RSNA, 2017 Online supplemental material is available for this article.

Surround inhibition is a system that sharpens sensation by creating an inhibitory zone around the central core of activation. In the motor system, this mechanism probably contributes to the selection of voluntary movements and seems to be lost in dystonia. To explore if sensory information is abnormally processed and integrated in focal dystonia and if surround inhibition phenomena are operating during sensory-motor plasticity and sensory-motor integration in normal humans and in patients with focal hand dystonia. We looked at motor evoked potential (MEP) facilitation, in the APB and ADM muscles, obtained after 5 Hz repetitive paired associative stimulation, stimulating median (PAS M), ulnar (PAS U) and median + ulnar nerve (PAS MU) in 8 normal subjects and 8 dystonic patients. We evaluated the ratio MU/(M + U) × 100. Moreover, we tested the spatial and temporal somatosensory integration recording SEPs evoked by a dual nerve input. Our data confirmed that in dystonic patients the amount of facilitation was larger than normal subjects and the spatial specificity was lost. The MU/(M + U) × 100 ratio was similar in healthy subjects and in dystonic patients and the somatosensory integration was normal in this subset of patients. These data suggest that lateral surround inhibition phenomena during sensory-motor plasticity are normal in focal hand dystonia.

To study optic radiations connectivity by means of advanced magnetic resonance imaging (MRI) approaches, noninvasively, in vivo, in healthy human brains.Sixteen healthy subjects (nine males, age range, 25-40 years) were included in this study. Morphologic and diffusion data were acquired by means of a 3T MRI scanner. Using an advanced tractographic technique, based on probabilistic constrained spherical deconvolution algorithm, postprocessing analyses were performed. Statistical analysis was carried out using the 2-tailed Wilcoxon rank sum test. Outcome measure was the percentage distribution of optic radiations streamlines in different cortical visual areas (V1-V5). The latter were detected by means of Juelich probabilistic histologic atlas.Average connectivity analyses revealed that the optic radiations are mainly distributed in V1 (47.46% ± 5.5) and V2 (32.45% ± 3.98); furthermore, direct connections with V3 (7.81 ± 3.06), V4 (4.22% ± 1.82), and V5 (8.06% ± 2.65) were also detected.In the present study, the connectivity profile of optic radiations, obtained by means of algorithms not affected by the limitations of other tractographic techniques, such as diffusion tensor imaging, was shown in healthy human brains. Interestingly, direct connections with V4 were detected for the first time in humans; moreover, further support on the possible existence of V5 connections was provided. Our findings showed new connections between lateral geniculate nuclei and cortical visual areas, giving a further possible comprehension of the phenomena leading to the visual signals elaboration.

The aim of this study was to validate a novel classification for the diagnosis of PNESs. Fifty-five PNES video-EEG recordings were retrospectively analyzed by four epileptologists and one psychiatrist in a blind manner and classified into four distinct groups: Hypermotor (H), Akinetic (A), Focal Motor (FM), and with Subjective Symptoms (SS). Eleven signs and symptoms, which are frequently found in PNESs, were chosen for statistical validation of our classification. An artificial neural network (ANN) analyzed PNES video recordings based on the signs and symptoms mentioned above. By comparing results produced by the ANN with classifications given by examiners, we were able to understand whether such classification was objective and generalizable. Through accordance metrics based on signs and symptoms (range: 0-100%), we found that most of the seizures belonging to class A showed a high degree of accordance (mean ± SD = 73% ± 5%); a similar pattern was found for class SS (80% slightly lower accordance was reported for class H (58% ± 18%)), with a minimum of 30% in some cases. Low agreement arose from the FM group. Seizures were univocally assigned to a given class in 83.6% of seizures. The ANN classified PNESs in the same way as visual examination in 86.7%. Agreement between ANN classification and visual classification reached 83.3% (SD = 17.8%) accordance for class H, 100% (SD = 22%) for class A, 83.3% (SD = 21.2%) for class SS, and 50% (SD = 19.52%) for class FM. This is the first study in which the validity of a new PNES classification was established and reached in two different ways. Video-EEG evaluation needs to be performed by an experienced clinician, but later on, it may be fed into ANN analysis, whose feedback will provide guidance for differential diagnosis. Our analysis, supported by the ML approach, showed that this model of classification could be objectively performed by video-EEG examination.

Complex claustral connection network was widely demonstrated both in humans and animals. Moreover, several studies have suggested that claustral connections directly involve also the contralateral hemisphere. Detection of contralateral cortico-claustral and inter-claustral connections was reported mainly in animals and only partially in humans. The main purpose of this study was to provide more robust tractography-driven support of the existence of inter-hemispheric claustral connections in humans, by means of a dedicated optimized tractographic protocol. Fifteen healthy subjects were examined by means of an advanced magnetic resonance imaging-based probabilistic constrained spherical deconvolution tractographic protocol. Moreover, quantitative diffusion parameters were extracted by each reconstructed pathway. In this study, further imaging-based support on the possible existence in humans of contralateral cortico-claustral and inter-claustral connections was provided. These connections were found to involve almost all the superior portion of each claustrum, showing a topographical organization. Moreover, the detection of inter-claustral connections passing through the anterior commissure was reported, for the first time, in humans. The possible existence of inter-claustral and cortico-claustral contralateral pathways might provide the morphological basis for the complex functional phenomena observed in previous studies. Furthermore, these connections might have several important clinical implications, since they might explain how the inter-hemispheric coordination governed by the claustrum, as well as the functional recovery subsequent to damages involving one claustrum, takes place.

Background A noninvasive method to predict the grade of a meningioma would be desirable since it would anticipate information about tumour nature, recurrence and improve tumour management and outcomes. The aim of the present study was to assess the ability of perfusion computed tomography (PCT) technique in predicting the meningioma grade before surgery. Data from PCT, such as cerebral blood volume (CBV) and permeability surface (PS), were correlated with immunohistolopathological information. Methods Twenty-three patients with a diagnosis of intracranial meningioma underwent PCT for pre-surgical evaluation of CBV and PS. During surgery, samples from the centre and periphery of the tumour were obtained. Two correspondent regions of interest (ROIs) were drawn on CBV and PS maps. Central and peripheral CBV and PS mean values were calculated. PCT parameters were correlated to CD-34 and endoglin. Results There was a positive correlation between PS and CD-34. No correlation was found between PS values and endoglin, CBV values and CD-34 and endoglin values. Conclusion Our findings suggest that PCT may support conventional morphological imaging in predicting meningioma grading before surgery.

BACKGROUND AND PURPOSE: MR imaging tractography is increasingly used to perform noninvasive presurgical planning for brain gliomas. Recently, constrained spherical deconvolution tractography was shown to overcome several limitations of commonly used DTI tractography. The purpose of our study was to evaluate WM tract alterations of both the corticospinal tract and arcuate fasciculus in patients with high-grade gliomas, through qualitative and quantitative analysis of probabilistic constrained spherical deconvolution tractography, to perform reliable presurgical planning. MATERIALS AND METHODS: Twenty patients with frontoparietal high-grade gliomas were recruited and evaluated by using a 3T MR imaging scanner with both morphologic and diffusion sequences (60 diffusion directions). We performed probabilistic constrained spherical deconvolution tractography and tract quantification following diffusion tensor parameters: fractional anisotropy; mean diffusivity; linear, planar, and spherical coefficients. RESULTS: In all patients, we obtained tractographic reconstructions of the medial and lateral portions of the corticospinal tract and arcuate fasciculus, both on the glioma-affected and nonaffected sides of the brain. The affected lateral corticospinal tract and the arcuate fasciculus showed decreased fractional anisotropy ( z = 2.51, n = 20, P = .006; z = 2.52, n = 20, P = .006) and linear coefficient ( z = 2.51, n = 20, P = .006; z = 2.52, n = 20, P = .006) along with increased spherical coefficient ( z = −2.51, n = 20, P = .006; z = −2.52, n = 20, P = .006). Mean diffusivity values were increased only in the lateral corticospinal tract ( z = −2.53, n = 20, P = .006). CONCLUSIONS: In this study, we demonstrated that probabilistic constrained spherical deconvolution can provide essential qualitative and quantitative information in presurgical planning, which was not otherwise achievable with DTI. These findings can have important implications for the surgical approach and postoperative outcome in patients with glioma.

Studies with diffusion tensor imaging (DTI) analysis have produced conflicting information about the involvement of the cerebellar hemispheres in Parkinson's disease (PD). We, thus, used a new approach for the analysis of DTI parameters in order to ascertain the involvement of the cerebellum in PD.We performed a fiber tract-based analysis of cerebellar peduncles and cerebellar hemispheres in 16 healthy subjects and in 16 PD patients with more than 5 years duration of disease, using a 3T MRI scanner and a constrained spherical deconvolution (CSD) approach for tractographic reconstructions. In addition, we performed statistical analysis of DTI parameters and fractional anisotropy (FA) XYZ direction samplings.We found a statistically significant decrement of FA values in PD patients compared to controls (p 0.05). In addition, extrapolating and analyzing FA XYZ direction samplings for each patient and each control, we found that this result was due to a stronger decrement of FA values along the Y axis (antero-posterior direction) (p 0.01); FA changes along X and Z axes were not statistically significant (p 0.05). We confirmed also no statistically significant differences of FA and apparent diffusion coefficient (ADC) for cerebellar peduncles in PD patients compared to healthy controls.The DTI-based cerebellar abnormalities in PD could constitute an advance in the knowledge of this disease. We demonstrated a statistically significant reduction of FA in cerebellar hemispheres of PD patients compared to healthy controls. Our work also demonstrated that the use of more sophisticated approaches in the DTI parameter analysis could potentially have a clinical relevance.