Mario Cirillo

Distributed changes in default-mode resting-state connectivity in multiple sclerosis.

Background: The default-mode network (DMN) has been increasingly recognized as relevant to cognitive status. Objectives: To explore DMN changes in patients with relapsing–remitting (RR) multiple sclerosis (MS) and to relate these to the cognitive status. Methods: Eighteen cognitively impaired (CI) and eighteen cognitively preserved (CP) RRMS patients and eighteen healthy controls (HCs), matched for age, sex and education, underwent neuropsychological evaluation and anatomical and resting-state functional MRI (rs-fMRI). DMN functional connectivity was evaluated from rs-fMRI data via independent component analysis. T2 lesion load (LL) was computed by a semi-automatic method and global and local atrophy was estimated by SIENAX and SPM8 voxel-based morphometry analyses from 3D-T1 images. Results: When the whole group of RRMS patients was compared with HCs, DMN connectivity was significantly weaker in the anterior cingulate cortex, whereas it was significantly weaker in the core but stronger at the periphery of the posterior cingulate cortex. These findings were more evident in CP than CI patients. Observed DMN changes did not correlate with global atrophy or T2-LL, but were locally associated with regional grey matter loss. Conclusion: Relapsing–remitting multiple sclerosis patients show a consistent dysfunction of DMN at the level of the anterior node. DMN distribution changes in the posterior node may reflect a possible compensatory effect on cognitive performance.

Regional Gray Matter Atrophy in Patients with Parkinson Disease and Freezing of Gait

BACKGROUND AND PURPOSE: FOG is a troublesome symptom of PD. Despite growing evidence suggesting that FOG in PD may be associated with cognitive dysfunction, the relationship between regional brain atrophy and FOG has been poorly investigated. MATERIALS AND METHODS: Optimized VBM was applied to 3T brain MR images of 24 patients with PD and 12 HC. Patients were classified as either FOG− or FOG+ (n = 12) based on their responses to a validated FOG Questionnaire and clinical observation. All patients with PD also underwent a detailed neuropsychological evaluation. RESULTS: The VBM analysis in patients with FOG+ showed a reduced GM volume in the left cuneus, precuneus, lingual gyrus, and posterior cingulate cortex compared with both patients with FOG− and HC. We did not detect any significant change of GM volume when comparing HC versus all patients with PD (FOG− and FOG+). FOG clinical severity was significantly correlated with GM loss in posterior cortical regions. Finally, patients with FOG+ scored lower on tests of frontal lobe function. CONCLUSIONS: Our findings provide the first evidence that the development of FOG in patients with PD is associated with posterior GM atrophy, which may play a role in the complex pathophysiology of this disabling symptom.

Disrupted default mode network connectivity in migraine without aura

BackgroundResting-state functional magnetic resonance imaging (RS-fMRI) has demonstrated disrupted default mode network (DMN) connectivity in a number of pain conditions, including migraine. However, the significance of altered resting-state brain functional connectivity in migraine is still unknown. The present study is aimed to explore DMN functional connectivity in patients with migraine without aura (MwoA) and investigate its clinical significance.MethodsTo calculate and compare the resting-state functional connectivity of the DMN in 20 patients with MwoA, during the interictal period, and 20 gender- and age-matched HC, Brain Voyager QX was used. Voxel-based morphometry was used to assess whether between-group differences in DMN functional connectivity were related to structural differences. Secondary analyses explored associations between DMN functional connectivity, clinical and neuropsychological features of migraineurs.ResultsIn comparison to HC, patients with MwoA showed decreased connectivity in prefrontal and temporal regions of the DMN. Functional abnormalities were unrelated to detectable structural abnormalities or clinical and neuropsychological features of migraineurs.ConclusionsOur study provides further evidence of disrupted DMN connectivity in patients with MwoA. We hypothesize that a DMN dysfunction may be related to behavioural processes such as a maladaptive response to stress which seems to characterize patients with migraine.

Widespread Microstructural White Matter Involvement in Amyotrophic Lateral Sclerosis: A Whole-Brain DTI Study

BACKGROUND AND PURPOSE: The extensive application of advanced MR imaging techniques to the study of ALS has undoubtedly improved our knowledge of disease pathophysiology, even if the actual spread of the neurodegenerative process throughout the central nervous system is not fully understood. The present study aimed to detect WM patterns of microstructural abnormalities to better investigate the pathologic process in ALS, within but also beyond CSTs, in a whole-brain analysis. MATERIALS AND METHODS: DTI was performed in 19 patients with ALS and 20 matched healthy controls, by using whole-brain TBSS and VOI analyses. RESULTS: We observed a significant decrease of FA in the body of CC of the ALS group (P < .05). At the VOI level, both FA decrease and RD increase in the body of CC significantly correlated with the UMN score (P = .003 and P = .02). Additionally, significant voxelwise positive correlations between FA and the ALSFRS-R were detected in the WM tracts underneath the left premotor cortex (P < .05). CONCLUSIONS: The correlations between reduction of FA and increase of RD in the body of CC with the UMN score indicate that the WM degeneration in the CC is strictly related to the ALS pyramidal impairment, while the correlation between FA and ALSFRS-R in the associative tracts underneath the left premotor cortex might reflect the progressive spread of the disease from the motor toward the extramotor areas.

Interictal cortical reorganization in episodic migraine without aura: an event-related fMRI study during parametric trigeminal nociceptive stimulation

The aim of our study was to explore the pain processing network in patients with migraine during trigeminal nociceptive stimulation. Sixteen patients with episodic migraine without aura and 16 healthy controls performed functional magnetic resonance imaging during thermal stimuli (at 41, 51 and 53°C). Patients with migraine showed a greater activation in the perigenual part of anterior cingulate cortex at 51°C and less activation in the bilateral somatosensory cortex at 53°C compared to healthy controls. There were no differences in experimental pain perception between groups. Our findings demonstrate a functional reorganization of cerebral areas known to be involved in pain processing in patients with migraine.

A rare symptomatic presentation of ecchordosis physaliphora: neuroradiological and surgical management

We report a case of ecchordosis physaliphora, an uncommon benign lesion originating from embryonic notochordal remnants, intradurally located in the prepontine cistern, that unusually presented associated with symptoms. MRI detected and precisely located the small mass. At surgery, a cystic gelatinous nodule was found ventral to the pons, contiguous with the dorsal wall of the clivus via a small pedicle. Histological examination diagnosed the lesion as an ecchordosis physaliphora. Here we focus on the analysis of the neuroradiological aspects that play a crucial role from both a diagnostic and a therapeutic standpoint.

Functional overlap and divergence between ALS and bvFTD.

Amyotrophic lateral sclerosis (ALS) and behavioral variant frontotemporal dementia (bvFTD) lie on a clinical, pathologic, and genetic continuum. Neuroimaging techniques have proven to be potentially useful to unravel the shared features of these syndromes. Using resting-state functional magnetic resonance imaging (RS-fMRI), we investigated functional connectivity of brain networks in 15 ALS and 15 bvFTD patients in early stages of disease and 15 healthy controls, looking expressly for connectivity pattern divergence or overlap between the 2 disorders. Compared with controls, we found decreased RS-fMRI signals within sensorimotor, right frontoparietal, salience, and executive networks in both patient groups. Within the default mode network (DMN), divergent connectivity patterns were observed, with RS-fMRI signals in the posterior cingulate cortex enhanced in bvFTD patients and suppressed in ALS patients. Our findings confirm that ALS and bvFTD not only broadly share common RS-fMRI connectivity patterns, probably representing different phenotypical expressions of the same neurodegenerative process, but also differ in the DMN, probably reflecting a different stage of neurodegeneration.

Fatigue in multiple sclerosis: The contribution of occult white matter damage

Background: A functional cortico-subcortical disconnection has been recognized in fatigued multiple sclerosis (MS) patients. Normal appearing white matter (NAWM) damage might contribute to the abovementioned disconnectivity. Objectives: To assess the relationship between fatigue and microstructural NAWM damage in relapsing-remitting (RR) MS. Methods: Sixty RRMS patients and 29 healthy controls (HC) underwent a magnetic resonance imaging (MRI) protocol including diffusion tensor imaging (DTI). Patients with a mean Fatigue Severity Scale (FSS) score ⩾ 4 were considered fatigued (fatigued MS (F-MS)). Tract-based spatial statistics were applied for voxel-wise analysis of DTI indices. A correlation analysis was performed between FSS score and DTI indices in the entire MS group. Results: Thirty MS patients were F-MS. Compared to HC, F-MS patients showed a more extensive NAWM damage than not fatigued MS (NF-MS) patients, with additional damage in the following tracts: frontal and occipital juxtacortical fibers, external capsule, uncinate fasciculus, forceps minor, superior longitudinal fasciculus, cingulum, and pons. No differences were found between F-MS and NF-MS patients. Fatigue severity correlated to DTI abnormalities of corona radiata, cingulum, corpus callosum, forceps minor, superior longitudinal fasciculus, inferior fronto-occipital fasciculus, thalamus and anterior thalamic radiation, cerebral peduncle, and midbrain. Conclusions: Fatigue is associated to a widespread microstructural NAWM damage, particularly in associative tracts connected to frontal lobes.

Clinical and cognitive correlations of regional gray matter atrophy in progressive supranuclear palsy

BACKGROUND Progressive supranuclear palsy is the most common neurodegenerative bradykinetic-rigid syndrome after Parkinsons disease. Several volumetric studies have revealed a widespread cortical and subcortical gray matter atrophy, however the correlations between the pattern of gray matter loss and clinical-cognitive features have been poorly investigated. METHODS By using 3-T magnetic-resonance imaging and voxel-based morphometry we compared gray matter volume in 15 patients with progressive supranuclear palsy, 15 patients with Parkinsons disease and 15 healthy controls. All patients underwent a clinical and neuropsychological evaluation. RESULTS In agreement with previous studies, patients with progressive supranuclear palsy, compared to patients with Parkinsons disease and healthy controls, showed a reduced gray matter volume in several cortical and subcortical areas including cerebellum, frontal, temporal and parahippocampal cortical structures. We did not find any significant gray matter volume changes when comparing patients with Parkinsons disease vs healthy controls. Among different significant correlations between motor-cognitive features and gray matter loss, we detected a significant correlation between fronto-cerebellar gray matter atrophy and executive cognitive impairment in patients with progressive supranuclear palsy. CONCLUSIONS Our findings confirm that gray matter loss in patients with progressive supranuclear palsy involves several brain areas and suggest that cerebellar atrophy may play a role in the pathogenesis of cognitive dysfunction in patients with progressive supranuclear palsy due to a disruption of its modulation on executive functions.

Basilar artery hypoplasia

A rare case of segmental hypoplasia of the basilar artery is described in a 49-year-old man with transient vertebrobasilar ischemia, explored by magnetic resonance imaging (MRI) and digital angiography (DA). The embryology, clinical relevance and magnetic resonance findings of this arterial anomaly are discussed, with a review of six previously reported cases. Segmental aplasia was suggested in our case by magnetic resonance, and subsequently confirmed not only by time-of-flight magnetic resonance, but also by DA. Only ultrathin-slice T2-weighted images revealed the real finding of basilar artery hypoplasia. This sequence, not employed in previously reported cases, is mandatory to allow a clear differential diagnosis between basilar artery aplasia and hypoplasia.