The ATTRACT study: screening for the early identification of axial psoriatic arthritis in a cohort of Italian psoriatic patients.

OBJECTIVE: There is growing interest in the early identification of patients with axial psoriatic arthritis (axPsA). We aimed to evaluate whether a dermatology-based screening strategy could help to identify axPsA patients. METHODS: The dermatologist-centered screening (DCS) questionnaire was administrated by Dermatologists to consecutive patients fulfilling the inclusion criteria (1. age ≥ 18 years and 2. clinical diagnosis of psoriasis made by a dermatologist) to identify patients eligible (affirmative answers 1-3c of the DCS) for rheumatological evaluation. Clinical, laboratory, genetic, and imaging data were collected from all referred patients. RESULTS: Among the 365 patients screened, 265 fulfilled the inclusion criteria and 124/265 (46.8%) were eligible for rheumatological referral. Diagnosis of axPsA, with or without peripheral PsA (pPsA), was made in 36/124 (29.0%) patients; pPsA without axial involvement was found in 21/124 (16.9%) patients. Back pain at screening was recorded in 174 (66%) patients, with 158 (60%) reporting a back pain duration longer than 3 months, and 140 (53%) reporting back pain onset before the age of 45. Active inflammatory and/or structural post-inflammatory changes in the sacroiliac joints and/or spine were observed in all axPsA patients.Patients with PsA showed a numerically longer duration of back pain and higher CRP levels in comparison with patients with Pso without PsA. CONCLUSION: The DCS tool proved to be a valuable screening strategy for detecting and characterizing patients with axPsA in a real-life cohort of psoriasis patients in a dermatological setting and helped to identify a substantial number of patients affected by undiagnosed pPsA.

Cardiac Masses and Pseudomasses: An Overview about Diagnostic Imaging and Clinical Background.

A cardiac lesion detected at ultrasonography might turn out to be a normal structure, a benign tumor or rarely a malignancy, and lesion characterization is very important to appropriately manage the lesion itself. The exact relationship of the mass with coronary arteries and the knowledge of possible concomitant coronary artery disease are necessary preoperative information. Moreover, the increasingly performed coronary CT angiography to evaluate non-invasively coronary artery disease leads to a rising number of incidental findings. Therefore, CT and MRI are frequently performed imaging modalities when echocardiography is deemed insufficient to evaluate a lesion. A brief comprehensive overview about diagnostic radiological imaging and the clinical background of cardiac masses and pseudomasses is reported.

Integrity of Corpus Callosum Is Essential for theCross-Hemispheric Propagation of Sleep Slow Waves:A High-Density EEG Study in Split-Brain Patients.

The slow waves of non-rapid eye movement (NREM) sleep reflect experience-dependent plasticity and play a direct role in the restorative functions of sleep. Importantly, slow waves behave as traveling waves, and their propagation is assumed to occur through cortico-cortical white matter connections. In this light, the corpus callosum (CC) may represent the main responsible for cross-hemispheric slow-wave propagation. To verify this hypothesis, we performed overnight high-density (hd)-EEG recordings in five patients who underwent total callosotomy due to drug-resistant epilepsy (CPs; two females), in three noncallosotomized neurologic patients (NPs; two females), and in a sample of 24 healthy adult subjects (HSs; 13 females). In all CPs slow waves displayed a significantly reduced probability of cross-hemispheric propagation and a stronger inter-hemispheric asymmetry. In both CPs and HSs, the incidence of large slow waves within individual NREM epochs tended to differ across hemispheres, with a relative overall predominance of the right over the left hemisphere. The absolute magnitude of this asymmetry was greater in CPs relative to HSs. However, the CC resection had no significant effects on the distribution of slow-wave origin probability across hemispheres. The present results indicate that CC integrity is essential for the cross-hemispheric traveling of slow waves in human sleep, which is in line with the assumption of a direct relationship between white matter integrity and slow-wave propagation. Our findings also revealed a residual cross-hemispheric slow-wave propagation that may rely on alternative pathways, including cortico-subcortico-cortical loops. Finally, these data indicate that the lack of the CC does not lead to differences in slow-wave generation across brain hemispheres.SIGNIFICANCE STATEMENT The slow waves of NREM sleep behave as traveling waves, and their propagation has been suggested to reflect the integrity of white matter cortico-cortical connections. To directly assess this hypothesis, here we investigated the role of the corpus callosum in the cortical spreading of NREM slow waves through the study of a rare population of totally callosotomized patients. Our results demonstrate a causal role of the corpus callosum in the cross-hemispheric traveling of sleep slow waves. Additionally, we found that callosotomy does not affect the relative tendency of each hemisphere at generating slow waves. Incidentally, we also found that slow waves tend to originate more often in the right than in the left hemisphere in both callosotomized and healthy adult individuals.

Differentiation between infectious spondylodiscitis versus inflammatory or degenerative spinal changes: How can magnetic resonance imaging help the clinician?

Spondylodiscitis is a complex disease whose diagnosis and management are still challenging. The differentiation between infectious and non-infectious aetiology is mandatory to avoid delays in the treatment of life-threatening infectious conditions. Imaging methods, in particular magnetic resonance imaging (MRI), play a key role in differential diagnosis. MRI provides detailed anatomical information, especially regarding the epidural space and spinal cord, and may allow differential diagnosis by assessing the characteristics of certain infectious and inflammatory/degenerative lesions. In this article, we provide an overview of the radiological characteristics and differentiating features of non-infectious inflammatory spinal disorders and infectious spondylodiscitis, focussing on MRI results and presenting relevant clinical and pathological features that help early diagnosis.

Craniocervical junction involvement in musculoskeletal diseases: an area of close collaboration between rheumatologists and radiologists.

The involvement of the cervical spine in musculoskeletal diseases can be crucial in terms of prognosis and morbidity. Early diagnosis of possible involvement of the craniocervical junction is essential to avoid the onset of neurological complications with poor prognosis. Among inflammatory diseases, rheumatoid arthritis affects the cervical spine frequently (in about 25% of patients). Atlantoaxial inflammatory changes are also detectable in spondyloarthritis. The involvement of the cervical spine in diffuse idiopathic skeletal hyperostosis is recognized as the cause of various clinical manifestations that may involve the pharynx, larynx and esophagus. The cervical spine may be specifically frequently implicated in crystal-associated arthropathies. Spinal cord infections are infrequent diseases that account for 3-4% of all spine infections. This pictorial review attempts to provide insights to interpret the radiological appearances of the craniocervical junction on conventional radiography, computed tomography and magnetic resonance imaging in relation to various musculoskeletal disease processes.

Low incidence of nephrotoxicity following intravenous administration of iodinated contrast media: a prospective study.

OBJECTIVES: To estimate the incidence of contrast-induced acute kidney injury (CI-AKI) after intravenous (iv) iodinated contrast material (ICM) exposure. METHODS: This prospective cohort study included all consecutive patients who underwent radiological investigations using low-osmolar iopamidol 370 mg/ml in a regional hospital over a period of 36 months, without any exclusion criteria. The estimated glomerular filtration rate (eGFR) was evaluated using the MRDR equation before (2-10 days) and after (24-36 h) radiological investigations. CI-AKI was defined as a ≥ 25% decrease in eGFR from baseline. CI-AKI incidence was estimated using a binomial distribution. The association between CI-AKI and demographic and clinical characteristics was modeled using logistic regression. RESULTS: The study included 1541 patients with a median age of 68 (1st-3rd quartiles 58-76) years with various comorbidities, 30% of whom had pre-existing CKD. Patients affected by stage III or IV chronic kidney disease (CKD) received an infusion of 0.9% normal saline (1.0-1.5 ml/kg/h) before and after iso-osmolar iodixanol administration. CI-AKI was observed in 33 patients (2.1%, 95% CI 1.5-3.0). The logistic regression analysis showed that antibiotic and statin therapies were significantly associated with CI-AKI. The probability of developing CI-AKI decreased by 80% in patients taking statins (OR = 0.20, 95% CI 0.03; 0.68) and increased approximately three times in patients with antibiotic therapy compared with those who did not take statins and antibiotics (OR = 2.92, 95% CI 1.21; 6.36). CONCLUSIONS: Our data suggest that low-osmolar iopamidol carries a low incidence of nephrotoxicity, even in subjects with various comorbid conditions or reduced renal function. KEY POINTS: • IV administration of ICM carries a low incidence of nephrotoxicity, which was transient in observed patients. • Statin therapy is negatively associated with AKI in patients exposed to ICM. • Pre-existing impairment of renal function is not associated with AKI in patients exposed to ICM.

Contrast-enhanced ultrasound in delayed splenic vascular injury and active extravasation diagnosis.

INTRODUCTION: We describe the use of contrast-enhanced ultrasound (CEUS) in the diagnosis of delayed splenic vascular injury (DSVI) and active extravasation (DAE) during spleen injury follow-up. CEUS might be used instead of contrast-enhanced computed tomography (CECT) during spleen injury follow-up in order to reduce radiation exposure. OBJECTIVE: Assess diagnostic comparability between CEUS and CECT in the evaluation of DSVI and DAE during spleen injury follow-up. SUBJECTS AND METHODS: A total of 139 trauma patients (101 males, 38 females; mean age 48.6 years) with CECT diagnosed spleen injury were prospectively evaluated. They performed CEUS and CECT follow-up. All CEUS studies were performed using the same ultrasound scan, convex probe, mechanical index and ultrasound contrast agent dose. Twelve patients performed digital subtraction angiography (DSA) during follow-up, and the diagnostic performance comparability between CEUS and DSA was evaluated. RESULTS: CEUS showed 17 delayed spleen injury complications, and in 122 patients no complication was suspected. CECT diagnosed 16 delayed spleen injury complications in these 17 patients and showed a small DSVI in another patient. A total of 122 follow-up CT scans were negative. CEUS and CECT diagnostic comparability was 98.6%. Compared to DSA, CEUS showed a sensitivity of 100% and a positive predictive value of 91.7%. CONCLUSIONS: CEUS can be used during spleen injury follow-up instead of CECT. Positive CEUS examinations could perform CECT and, when necessary, DSA in order to confirm and treat spleen injury complications.

The Prognostic Role of Volumetric MRI Evaluation in the Surgical Treatment of Glioblastoma.

Background: Glioblastoma is the most common primary brain neoplasm in adults, with a poor prognosis despite a constant effort to improve patient survival. Some neuroradiological volumetric parameters seem to play a predictive role in overall survival (OS) and progression-free survival (PFS). The aim of this study was to analyze the impact of the volumetric areas of contrast-enhancing tumors and perineoplastic edema on the survival of patients treated for glioblastoma. Methods: A series of 87 patients who underwent surgery was retrospectively analyzed; OS and PFS were considered the end points of the study. For each patient, a multidisciplinary revision was conducted in collaboration with the Neuroradiology and Neuro-Oncology Board. Manual and semiautomatic measurements were adopted to perform the radiological evaluation, and the following quantitative parameters were retrospectively analyzed: contrast enhancement preoperative tumor volume (CE-PTV), contrast enhancement postoperative tumor volume (CE-RTV), edema/infiltration preoperative volume (T2/FLAIR-PV), edema/infiltration postoperative volume (T2/FLAIR-RV), necrosis volume inside the tumor (NV), and total tumor volume including necrosis (TV). Results: The median OS value was 9 months, and the median PFS value was 4 months; the mean values were 12.3 and 6.9 months, respectively. Multivariate analysis showed that the OS-related factors were adjuvant chemoradiotherapy (p < 0.0001), CE-PTV < 15 cm3 (p = 0.03), surgical resection > 95% (p = 0.004), and the presence of a "pseudocapsulated" radiological morphology (p = 0.04). Conclusions: Maximal safe resection is one of the most relevant predictive factors for patient survival. Semiautomatic preoperative MRI evaluation could play a key role in prognostically categorizing these tumors.

Interhemispheric functional connectivity: an fMRI study in callosotomized patients.

Introduction: Functional connectivity (FC) is defined in terms of temporal correlations between physiological signals, which mainly depend upon structural (axonal) connectivity; it is commonly studied using functional magnetic resonance imaging (fMRI). Interhemispheric FC appears mostly supported by the corpus callosum (CC), although several studies investigating this aspect have not provided conclusive evidence. In this context, patients in whom the CC was resected for therapeutic reasons (split-brain patients) provide a unique opportunity for research into this issue. The present study was aimed at investigating with resting-state fMRI the interhemispheric FC in six epileptic patients who have undergone surgical resection of the CC. Methods: The analysis was performed using fMRI of the Brain Software Library; the evaluation of interhemispheric FC and the recognition of the resting-state networks (RSNs) were performed using probabilistic independent component analysis. Results: Generally, bilateral brain activation was often observed in primary sensory RSNs, while in the associative areas, such as those composing the default mode and fronto-parietal networks, the activation was often unilateral. Discussion: These results suggest that even in the absence of the CC, some interhemispheric communication is still present. This residual FC might be supported through extra-callosal pathways that are likely subcortical, making it possible for some interhemispheric integration. Further studies are needed to confirm these conclusions.

Point-Of-Care low-field MRI in acute Stroke (POCS): protocol for a multicentric prospective open-label study evaluating diagnostic accuracy.

INTRODUCTION: Fast and accurate diagnosis of acute stroke is crucial to timely initiate reperfusion therapies. Conventional high-field (HF) MRI yields the highest accuracy in discriminating early ischaemia from haemorrhages and mimics. Rapid access to HF-MRI is often limited by contraindications or unavailability. Low-field (LF) MRI (<0.5T) can detect several types of brain injury, including ischaemic and haemorrhagic stroke. Implementing LF-MRI in acute stroke care may offer several advantages, including extended applicability, increased safety, faster administration, reduced staffing and costs. This multicentric prospective open-label trial aims to evaluate the diagnostic accuracy of LF-MRI, as a tool to guide treatment decision in acute stroke. METHODS AND ANALYSIS: Consecutive patients accessing the emergency department with suspected stroke dispatch will be recruited at three Italian study units: Azienda Sanitaria Locale (ASL) Abruzzo 1 and 2, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS) Humanitas Research Hospital. The estimated sample size is 300 patients. Anonymised clinical and LF-MRI data, along with conventional neuroimaging data, will be independently assessed by two external units: Marche Polytechnic University and 'G. Martino' Polyclinic University Hospital. Both units will independently adjudicate the best treatment option, while the latter will provide historical HF-MRI data to develop artificial intelligence algorithms for LF-MRI images interpretation (Free University of Bozen-Bolzano). Agreement with conventional neuroimaging will be evaluated at different time points: hyperacute, acute (24 hours), subacute (72 hours), at discharge and chronic (4 weeks). Further investigations will include feasibility study to develop a mobile stroke unit equipped with LF-MRI and cost-effectiveness analysis. This trial will provide necessary data to validate the use of LF-MRI in acute stroke care. ETHICS AND DISSEMINATION: The study was approved by the Research Ethics Committee of the Abruzzo Region (CEtRA) on 11 May 2023 (approval code: richyvgrg). Results will be disseminated in peer-reviewed journals and presented in academic conferences. TRIAL REGISTRATION NUMBER: NCT05816213; Pre-Results.

Functional topography of human corpus callosum: an FMRI mapping study.

The concept of a topographical map of the corpus callosum (CC) has emerged from human lesion studies and from electrophysiological and anatomical tracing investigations in other mammals. Over the last few years a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI) activation in white matter, particularly the CC. In this study the scope for describing CC topography with fMRI was explored by evoking activation through simple sensory stimulation and motor tasks. We reviewed our published and unpublished fMRI and diffusion tensor imaging data on the cortical representation of tactile, gustatory, auditory, and visual sensitivity and of motor activation, obtained in 36 normal volunteers and in 6 patients with partial callosotomy. Activation foci were consistently detected in discrete CC regions: anterior (taste stimuli), central (motor tasks), central and posterior (tactile stimuli), and splenium (auditory and visual stimuli). Reconstruction of callosal fibers connecting activated primary gustatory, motor, somatosensory, auditory, and visual cortices by diffusion tensor tracking showed bundles crossing, respectively, through the genu, anterior and posterior body, and splenium, at sites harboring fMRI foci. These data confirm that the CC commissure has a topographical organization and demonstrate that its functional topography can be explored with fMRI.

Functional topography of the corpus callosum as revealed by fMRI and behavioural studies of control subjects and patients with callosal resection.

The concept of a topographical map of the corpus callosum (CC), the main interhemispheric commissure, has emerged from human lesion studies and from anatomical tracing investigations in other mammals. Over the last few years, a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI) activation in also the CC. This short review summarizes the functional and behavioral studies performed in groups of healthy subjects and in patients undergone to partial or total callosal resection, and it is focused on the work conducted by the authors. Functional data have been collected by diffusion tensor imaging and tractography (DTI and DTT) and functional magnetic resonance imaging (fMRI), both techniques allowing to expand and refine our knowledge of the commissure. Neuropsychological test were also administered, and simple behavioral task, as imitation perspective and mental rotation ability, were analyzed. These researches added new insight on the topographic organization of the human CC. By combining DTT and fMRI it was possible to observe that the callosal crossing points of interhemispheric fibers connecting homologous primary sensory cortices, correspond to the CC sites where the fMRI activation elicited by peripheral stimulation was detected. In addition, CC activation during imitation and mental rotation performance was also reported. These studies demonstrated the presence of specific callosal fiber tracts that cross the commissure in the genu, body, and splenium, at sites showing fMRI activation, consistently with cortical activated areas. Altogether, these findings lend further support to the notion that the CC displays a functional topographic organization, also related to specific behavior.

Cardiac rhabdomyomas and cerebral lesions in 4 pediatric patients with tuberous sclerosis.

Rhabdomyoma is the most common primary cardiac tumor in pediatric patients. A strong association exists between cardiac rhabdomyomas and tuberous sclerosis (TS), an autosomal dominant disease, characterized by diffuse lesions in the nervous system, such as cortical-subcortical tubers and subependymal nodules. In TS, cardiac rhabdomyomas typically are diagnosed in childhood, but they could be detected in the neonatal period with echocardiography and magnetic resonance imaging and may precede cerebral lesions. Therefore, the precocious detection of cardiac rhabdomyomas in pediatric patients can suggest the diagnosis of TS and the early detection of cerebral lesions, improving the management of the related symptoms. We reported the cases of 4 pediatric patients, in which the detection of cardiac rhabdomyomas lead to the early discovery of cerebral lesions and the diagnosis of the TS.

Glioblastoma: A Retrospective Analysis of the Role of the Maximal Surgical Resection on Overall Survival and Progression Free Survival.

BACKGROUND: Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults; despite advances in the understanding of GBM pathogenesis, significant achievements in treating this disease are still lacking. The aim of this study was to evaluate the prognostic significance of the extent of surgical resection (EOR), beyond the neoplastic mass, on the overall survival (OS). METHODS: A retrospective review of a single-institution glioblastoma patient database (January 2012-September 2021) was undertaken. The series is composed of 64 patients who underwent surgery at the University Department of Neurosurgery of Ancona; the series was divided into four groups based on the amount of tumor mass excision with the fluid-attenuated inversion recovery (FLAIR) abnormalities (SUPr-supratotal resection, GTR-gross total resection, STR-subtotal resection, BIOPSY). The hypothesis was that the maximal resection of FLAIR abnormalities may improve the overall survival compared to the resection of the visible T1 contrast-enhanced neoplastic area only. RESULTS: In the univariate analysis, SUPr and GTR are correlated with the overall survival (p = 0.001); the percentage of total neoplastic removal threshold conditioning outcome was 90% (p = 0.027). These results were confirmed by the multivariate analysis. CONCLUSIONS: Maximal surgical resection, when feasible, involving areas of FLAIR abnormalities represents an advantageous approach for the OS in GBM patients.

Visual integration across fixation: automatic processes are split but conscious processes remain unified in the split-brain.

The classic view holds that when "split-brain" patients are presented with an object in the right visual field, they will correctly identify it verbally and with the right hand. However, when the object is presented in the left visual field, the patient verbally states that he saw nothing but nevertheless identifies it accurately with the left hand. This interaction suggests that perception, recognition and responding are separated in the two isolated hemispheres. However, there is now accumulating evidence that this interaction is not absolute; for instance, split-brain patients are able to detect and localise stimuli anywhere in the visual field verbally and with either hand. In this study we set out to explore this cross-hemifield interaction in more detail with the split-brain patient DDC and carried out two experiments. The aim of these experiments is to unveil the unity of deliberate and automatic processing in the context of visual integration across hemispheres. Experiment 1 suggests that automatic processing is split in this context. In contrast, when the patient is forced to adopt a conscious, deliberate, approach, processing seemed to be unified across visual fields (and thus across hemispheres). First, we looked at the confidence that DDC has in his responses. The experiment involved a simultaneous "same" versus "different" matching task with two shapes presented either within one hemifield or across fixation. The results showed that we replicated the observation that split brain patients cannot match across fixation, but more interesting, that DDC was very confident in the across-fixation condition while performing at chance-level. On the basis of this result, we hypothesised a two-route explanation. In healthy subjects, the visual information from the two hemifields is integrated in an automatic, unconscious fashion via the intact splenium, and this route has been severed in DDC. However, we know from previous experiments that some transfer of information remains possible. We proposed that this second route (perhaps less visual; more symbolic) may become apparent when he is forced to use a deliberate, consciously controlled approach. In an experiment where he is informed, by a second stimulus presented in one hemifield, what to do with the first stimulus that was presented in the same or the opposite hemifield, we showed that there was indeed interhemispheric transfer of information. We suggest that this two-route model may help in clarifying some of the controversial issues in split-brain research.

Pediatric Moyamoya Disease and Syndrome in Italy: A Multicenter Cohort.

Background: Moyamoya is a rare progressive cerebral arteriopathy, occurring as an isolated phenomenon (moyamoya disease, MMD) or associated with other conditions (moyamoya syndrome, MMS), responsible for 6-10% of all childhood strokes and transient ischemic attacks (TIAs). Methods: We conducted a retrospective multicenter study on pediatric-onset MMD/MMS in Italy in order to characterize disease presentation, course, management, neuroradiology, and outcome in a European country. Results: A total of 65 patients (34/65 women) with MMD (27/65) or MMS (38/65) were included. About 18% (12/65) of patients were asymptomatic and diagnosed incidentally during investigations performed for an underlying condition (incMMS), whereas 82% (53/65) of patients with MMD or MMS were diagnosed due to the presence of neurological symptoms (symptMMD/MMS). Of these latter, before diagnosis, 66% (43/65) of patients suffered from cerebrovascular events with or without other manifestations (ischemic stroke 42%, 27/65; TIA 32%, 21/65; and no hemorrhagic strokes), 18% (12/65) of them reported headache (in 4/12 headache was not associated with any other manifestation), and 26% (17/65) of them experienced multiple phenotypes (≥2 among: stroke/TIA/seizures/headache/others). Neuroradiology disclosed ≥1 ischemic lesion in 67% (39/58) of patients and posterior circulation involvement in 51% (30/58) of them. About 73% (47/64) of patients underwent surgery, and 69% (45/65) of them received aspirin, but after diagnosis, further stroke events occurred in 20% (12/61) of them, including operated patients (11%, 5/47). Between symptom onset and last follow-up, the overall patient/year incidence of stroke was 10.26% (IC 95% 7.58-13.88%). At last follow-up (median 4 years after diagnosis, range 0.5-15), 43% (26/61) of patients had motor deficits, 31% (19/61) of them had intellectual disability, 13% (8/61) of them had epilepsy, 11% (7/61) of them had behavioral problems, and 25% (13/52) of them had mRS > 2. The proportion of final mRS > 2 was significantly higher in patients with symptMMD/MMS than in patients with incMMS (p = 0.021). Onset age <4 years and stroke before diagnosis were significantly associated with increased risk of intellectual disability (p = 0.0010 and p = 0.0071, respectively) and mRS > 2 at follow-up (p = 0.0106 and p = 0.0009, respectively). Conclusions: Moyamoya is a severe condition that may affect young children and frequently cause cerebrovascular events throughout the disease course, but may also manifest with multiple and non-cerebrovascular clinical phenotypes including headache (isolated or associated with other manifestations), seizures, and movement disorder. Younger onset age and stroke before diagnosis may associate with increased risk of worse outcome (final mRS > 2).

Brain and spine MRI features of Hunter disease: frequency, natural evolution and response to therapy.

BACKGROUND: Hunter disease is a rare X-linked mucopolysaccharidosis. Despite frequent neurological involvement, characterizing the severe phenotype, neuroimaging studies are scarce. OBJECTIVES: To determine frequency and severity of neuroradiological mucopolysaccharidosis-related features; to correlate them with clinical phenotype; to evaluate their natural evolution and the impact of intravenous enzymatic replacement therapy (ERT). METHODS: Sixty nine brain MRI examinations of 36 Italian patients (mean-age 10.4 years; age-range 2.2-30.8; severe phenotype in 22 patients) were evaluated. Twenty patients had multiple MRIs (median follow-up 3.1 years, range 1-16.9): among them 15 had MRIs before and after ERT, six had repeated MRIs without being on ERT and five while on ERT. Perivascular, subarachnoid and ventricle space enlargement, white matter abnormality (WMA) burden, pituitary sella/skull/posterior fossa abnormalities, periodontoid thickening, spinal stenosis, dens hypoplasia, myelopathy, vertebral and intervertebral disc abnormalities were graded by means of dedicated scales. RESULTS: Perivascular spaces enlargement (89%), WMAs (97%), subarachnoid space enlargement (83%), IIIrd-ventricle dilatation (100%), pituitary sella abnormalities (80%), cranial hyperostosis (19%), craniosynostosis (19%), enlarged cisterna magna (39%), dens hypoplasia (66%), periodontoid thickening (94%), spinal stenosis (46%), platyspondylia (84%) and disc abnormalities (79%) were frequently detected. WMAs, IIIrd-ventricle dilatation and hyperostosis correlated with the severe phenotype (p < 0.05). Subarachnoid spaces and ventricle enlargement, WMAs and spinal stenosis progressed despite ERT, while other MR features showed minimal or no changes. CONCLUSIONS: The spectrum of brain and spine MRI abnormalities in Hunter disease is extremely wide and requires a thorough evaluation. WMAs, atrophy/communicating hydrocephalus and spinal stenosis progress over time and might represent possible disease severity markers for new treatment efficacy assessment.

Unilateral visual loss due to ischaemic injury in the right calcarine region: a functional magnetic resonance imaging and diffusion tension imaging follow-up study.

To study the functional recovery of a patient with cerebrovascular injury using combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). A 24-year-old woman with left hemianopsia underwent fMRI and DTI in a 1.5-tesla machine both in the acute phase and 1 month after an ischaemic stroke involving the right calcarine cortex. Acute-phase fMRI demonstrated that peripheral left visual field stimulation did not activate the right primary visual cortex, whereas stimulation 1 month later activated the visual cortex bilaterally. Analysis of acute-phase DTI data disclosed that a reduction of fractional anisotropy in the right optic radiation had almost resolved after 1 month. Fibre direction was normal at either time point. fMRI and DTI can demonstrate functional damage and recovery in patients with neuro-ophthalmological lesions.

Is the Imitative Competence an Asymmetrically Distributed Function?

This study reconsiders behavioral and functional data from studies investigating the anatomical imitation (AI) and the related mental rotation (MR) competence, carried out by our group in healthy subjects, with intact interhemispheric connections, and in split-brain patients, completely or partially lacking callosal connections. The results strongly point to the conclusion that AI and MR competence requires interhemispheric communication, mainly occurring through the corpus callosum, which is the largest white matter structure in the human brain. The results are discussed in light of previous studies and of future implications.

Role of corpus callosum in sleep spindle synchronization and coupling with slow waves.

Sleep spindles of non-REM sleep are transient, waxing-and-waning 10-16 Hz EEG oscillations, whose cortical synchronization depends on the engagement of thalamo-cortical loops. However, previous studies in animal models lacking the corpus callosum due to agenesis or total callosotomy and in humans with agenesis of the corpus callosum suggested that cortico-cortical connections may also have a relevant role in cortical (inter-hemispheric) spindle synchronization. Yet, most of these works did not provide direct quantitative analyses to support their observations. By studying a rare sample of callosotomized, split-brain patients, we recently demonstrated that the total resection of the corpus callosum is associated with a significant reduction in the inter-hemispheric propagation of non-REM slow waves. Interestingly, sleep spindles are often temporally and spatially grouped around slow waves (0.5-4 Hz), and this coordination is thought to have an important role in sleep-dependent learning and memory consolidation. Given these premises, here we set out to investigate whether total callosotomy may affect the generation and spreading of sleep spindles, as well as their coupling with sleep slow waves. To this aim, we analysed overnight high-density EEG recordings (256 electrodes) collected in five patients who underwent total callosotomy due to drug-resistant epilepsy (age 40-53, two females), three non-callosotomized neurological patients (age 44-66, two females), and in a sample of 24 healthy adult control subjects (age 20-47, 13 females). Individual sleep spindles were automatically detected using a validated algorithm and their properties and topographic distributions were computed. All analyses were performed with and without a regression-based adjustment accounting for inter-subject age differences. The comparison between callosotomized patients and healthy subjects did not reveal systematic variations in spindle density, amplitude or frequency. However, callosotomized patients were characterized by a reduced spindle duration, which could represent the result of a faster desynchronization of spindle activity across cortical areas of the two hemispheres. In contrast with our previous findings regarding sleep slow waves, we failed to detect in callosotomized patients any clear, systematic change in the inter-hemispheric synchronization of sleep spindles. In line with this, callosotomized patients were characterized by a reduced extension of the spatial association between temporally coupled spindles and slow waves. Our findings are consistent with a dependence of spindles on thalamo-cortical rather than cortico-cortical connections in humans, but also revealed that, despite their temporal association, slow waves and spindles are independently regulated in terms of topographic expression.