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Olga Ciccarelli

Publications and source records attributed to Olga Ciccarelli.

At least 19 recordsLinked to original sources
PubMed2026

Prevalence of Slowly Expanding Lesions in Patients With Multiple Sclerosis: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Chronic active lesions (CALs) reflect chronic inflammation in multiple sclerosis (MS). Slowly expanding lesions (SELs) are CALs identified on conventional MRI by linear, concentric expansion over time, while paramagnetic rim lesions (PRLs) are CALs characterized by a paramagnetic rim on susceptibility-sensitive MRI. However, the prevalence of SELs and their overlap with PRLs remain unclear. The aims of this study were to (1) estimate the proportion of SELs among all T2 lesions and the proportion of patients with at least 1 SEL and (2) assess the proportion of SELs overlapping with PRLs. METHODS: We systematically searched PubMed, Scopus, Web of Science, and Embase on February 1, 2026, for studies evaluating SELs in MS. At least 2 authors independently assessed study eligibility. Primary outcomes were the pooled proportion of SELs among T2 lesions and the proportion of patients with at least 1 SEL. We estimated mean per-patient volumes of SELs and total T2 lesions and the proportion of SELs overlapping with PRLs. Random-effects generalized linear mixed-effects models and inverse-variance methods were used, with between-study heterogeneity assessed using τ2 and I2 and robustness using sensitivity analyses. Univariable meta-regression explored heterogeneity. PROSPERO: CRD42024603778. RESULTS: Of 5,980 records, 20 studies comprising 4,786 patients with MS were included (mean age: 43.6 ± 6.3 years; 63.7% female). Sample sizes varied by outcome. SELs accounted for 14% (95% CI 10-21) of all T2 lesions, and 78% (67-85) of patients had at least 1 SEL. After sensitivity analysis, per-patient mean volumes were 1.42 mL (0.79-2.06) for SELs and 10.6 mL (8.53-12.67) for total T2 lesions. In total, 11% (6-20) of SELs overlapped with PRLs. In subgroup analyses, proportions of SELs were similar in relapsing-remitting and progressive MS (15%), but the proportion of patients with at least 1 SEL was higher in progressive MS. Between-study heterogeneity was high across analyses with no significant sources identified. DISCUSSION: Although SELs represent a minority of T2 lesions, most patients have at least 1 SEL and a subset overlaps with PRLs, suggesting a partial correspondence between these 2 imaging markers of chronic inflammatory activity. Limitations include possible publication bias, high unexplained heterogeneity, differences in SEL identification methods, and differences in MRI time point number/timing.

Humans↗
PubMed2007

Two-dimensional population map of cortical connections in the human internal capsule.

PURPOSE: To exploit diffusion imaging tractography to produce a two-dimensional (xy) probabilistic population map of the cortical connections within the human internal capsule (IC). MATERIALS AND METHODS: Diffusion tensor imaging (DTI) was carried out on 11 healthy volunteers. We parceled an axial section of the IC according to its connections to the prefrontal, premotor, primary motor, primary somatosensory, posterior parietal, and occipital cortices using our locally developed probabilistic algorithm. RESULTS: A consistent topographical organization was generated that was consistent with our anatomical knowledge of the IC. In addition, our study shows that in humans the anterior half of the IC is occupied by the prefrontal cortex. CONCLUSION: This map may be of clinical use for correlating neurological deficit with hemispheric lesions, particularly those that affect sensorimotor function.

Adult↗
PubMed2006

Tract-based spatial statistics: voxelwise analysis of multi-subject diffusion data.

There has been much recent interest in using magnetic resonance diffusion imaging to provide information about anatomical connectivity in the brain, by measuring the anisotropic diffusion of water in white matter tracts. One of the measures most commonly derived from diffusion data is fractional anisotropy (FA), which quantifies how strongly directional the local tract structure is. Many imaging studies are starting to use FA images in voxelwise statistical analyses, in order to localise brain changes related to development, degeneration and disease. However, optimal analysis is compromised by the use of standard registration algorithms; there has not to date been a satisfactory solution to the question of how to align FA images from multiple subjects in a way that allows for valid conclusions to be drawn from the subsequent voxelwise analysis. Furthermore, the arbitrariness of the choice of spatial smoothing extent has not yet been resolved. In this paper, we present a new method that aims to solve these issues via (a) carefully tuned non-linear registration, followed by (b) projection onto an alignment-invariant tract representation (the "mean FA skeleton"). We refer to this new approach as Tract-Based Spatial Statistics (TBSS). TBSS aims to improve the sensitivity, objectivity and interpretability of analysis of multi-subject diffusion imaging studies. We describe TBSS in detail and present example TBSS results from several diffusion imaging studies.

Amyotrophic Lateral Sclerosis↗
PubMed2006

Pediatric liver transplantation using left hepatic segments from living related donors: surgical experience in 100 recipients at Saint-Luc University Clinics.

Living-related liver transplantation was developed in the context of deceased donor organ shortage, which is particularly acute for pediatric recipients. This retrospective study analyzes the surgical technique and complications in the first 100 pediatric liver transplantation using left segmental liver grafts from living donors, performed at Saint-Luc University Clinics between July 1993 and April 2002. Pre-operative evaluation in donors and recipients, analysis of the surgical technique, and postoperative complications were reviewed. After a median follow-up period of 2526 days, no donor mortality was encountered, with a minimal morbidity and no long-term sequelae. At one and five yr post-transplantation, the actuarial patient survival rates were 94% and 92%, the corresponding figures being 92% and 89% for graft survival. The incidences of portal vein and hepatic artery thromboses, and of biliary complications were 14%, 1%, and 27%, respectively. Living-related liver transplantation in children constitutes an efficient therapy for liver failure to face the increased demand for liver grafts. Donor morbidity was kept to acceptable incidence, and surgical technique in the recipient needs to be tailored to minimize postoperative complications.

Adolescent↗
PubMed2006

Functional anatomy of interhemispheric cortical connections in the human brain.

Interhemsipheric interaction between the human cerebral hemispheres is served by abundant white-matter fibres in the human corpus callosum (CC). Damage to these fibres has notable behavioural and cognitive sequelae that depend on the exact location of the fibre loss. Until now, correlations between fibre loss and neurological disorders have been limited to post-mortem studies. Here we used probabilistic diffusion magnetic resonance imaging tractography to produce a two-dimensional map of the CC in the mid-sagittal plane. We observed an antero-posterior topography of interhemispheric tracts within the CC, consistent with our current neuroanatomical understanding of post-mortem studies in human. Callosal tract to the left and right hemispheres had comparable volume. Gender, a factor that is often reported to affect CC shape and geometry, also had no effect on the volume of the tracts. Our map showed high consistency across individuals. We propose that this map might be useful in the study of the effects of damage to human CC in neurodegenerative and cognitive disorders.

Adult↗
PubMed2005

Anti-CD2 monoclonal antibody and tacrolimus in adult liver transplantation.

BACKGROUND: Blockade of costimulation and adhesion signaling is an attractive approach to interfere with graft rejection METHODS: Between January 1997 and May 1999, forty adults having benign liver diseases were included in a prospective, randomized study comparing tacrolimus plus low-dose short-term steroids without (n=20, TAC group) or with a 10-day course of antihuman CD2 monoclonal antibody (n=20, BTI group). RESULTS: At day 7, histological rejection expressed by mean Banff scores (2.3+/-1.6 vs. 5.4+/-1.6 in the TAC group; P<0.0001) and incidence of moderate to severe rejection (score>or=6) (0 vs. 10 [50%] in the TAC group; P<0.001) were significantly lower in the BTI group. Rejection was treated in 10% (two patients) of BTI patients during the first 3 months and in 15% during the whole follow-up and in 25% (five patients) of TAC patients (P=NS). None of the BTI-patients presented with an adverse event. Three-month, 1-year, and 5-year actual patient survival rates were 100%, 95%, and 95% in the BTI group and 100%, 100%, and 85% in the TAC group. Graft survival rates were 100%, 90%, and 90% in the BTI group and 95%, 95%, and 80% in the TAC group (P=NS). The mAb had no negative impact on infectious or tumor events. CONCLUSIONS: Antihuman CD2 monoclonal antibody is a safe immunosuppressive drug which has a favorable impact on early immunological follow-up of liver transplanted patients. The antibody had no impact on late patient and graft survival.

Adult↗
PubMed2005

The evolution of prefrontal inputs to the cortico-pontine system: diffusion imaging evidence from Macaque monkeys and humans.

The cortico-ponto-cerebellar system is one of the largest projection systems in the primate brain, but in the human brain the nature of the information processing in this system remains elusive. Determining the areas of the cerebral cortex which contribute projections to this system will allow us to better understand information processing within it. Information from the cerebral cortex is conveyed to the cerebellum by topographically arranged fibres in the cerebral peduncle - an important fibre system in which all cortical outputs spatially converge on their way to the cerebellum via the pontine nuclei. Little is known of their anatomical organization in the human brain. New in vivo diffusion imaging and probabilistic tractography methods now offer a way in which input tracts in the cerebral peduncle can be characterized in detail. Here we use these methods to contrast their organization in humans and macaque monkeys. We confirm the dominant contribution of the cortical motor areas to the macaque monkey cerebral peduncle. However, we also present novel anatomical evidence for a relatively large prefrontal contribution to the human cortico-ponto-cerebellar system in the cerebral peduncle. These findings suggest the selective evolution of prefrontal inputs to the human cortico-ponto-cerebellar system.

Adult↗
PubMed2005

Optic radiation changes after optic neuritis detected by tractography-based group mapping.

Postmortem data suggest that trans-synaptic degeneration occurs in the lateral geniculate nucleus after optic nerve injury. This study investigated in vivo the optic radiations in patients affected by optic neuritis using fast marching tractography (FMT), a diffusion magnetic resonance imaging (MRI) fiber tracking method, and group mapping techniques, which allow statistical comparisons between subjects. Seven patients, 1 year after isolated unilateral optic neuritis, and ten age and gender-matched controls underwent whole-brain diffusion tensor MR imaging. The FMT algorithm was used to generate voxel-scale connectivity (VSC) maps in the optic radiations in each subject in native space. Group maps of the left and right optic radiations were created in the patient and control group in a standardized reference frame using statistical parametric mapping (SPM99). The reconstructed optic radiations in the patient group were localized more laterally in the posterior part of the tracts and more inferiorly than in the control group. Patients showed reduced VSC values in both tracts compared with controls. These findings suggest that the group mapping techniques might be used to assess changes in the optic radiations in patients after an episode of optic neuritis. The changes we have observed may be secondary to the optic nerve damage.

Adult↗
PubMed2005

Liver transplantation with preservation of the inferior vena cava in case of symptomatic adult polycystic disease.

Adult polycystic liver disease (APLD) is a rare disorder of the liver parenchyma, the treatment of which is still controversial. Conservative surgery may have a significant morbidity and is often ineffective in the long run. Liver replacement may be indicated in case of incapacitating hepatomegaly. Patients (one male, five females) undergoing liver transplantation for symptomatic APLD is presented in this study. The particular nature of this series is the fact that successful transplantation was performed in all cases with preservation of the recipient's inferior vena cava and without use of veno-venous bypass despite massive hepatomegaly and previous extensive liver surgery (in three cases). There was minimal morbidity and no mortality. All patients have excellent quality of life with a median follow-up of 41 months (range: 12-58) as testified by a median Karnofsky score of 90% (range: 80-100%).

Adult↗
PubMed2004

Lateralization of ventral and dorsal auditory-language pathways in the human brain.

Recent electrophysiological investigations of the auditory system in primates along with functional neuroimaging studies of auditory perception in humans have suggested there are two pathways arising from the primary auditory cortex. In the primate brain, a 'ventral' pathway is thought to project anteriorly from the primary auditory cortex to prefrontal areas along the superior temporal gyrus while a separate 'dorsal' route connects these areas posteriorly via the inferior parietal lobe. We use diffusion MRI tractography, a noninvasive technique based on diffusion-weighted MRI, to investigate the possibility of a similar pattern of connectivity in the human brain for the first time. The dorsal pathway from Wernicke's area to Broca's area is shown to include the arcuate fasciculus and connectivity to Brodmann area 40, lateral superior temporal gyrus (LSTG), and lateral middle temporal gyrus. A ventral route between Wernicke's area and Broca's area is demonstrated that connects via the external capsule/uncinate fasciculus and the medial superior temporal gyrus. Ventral connections are also observed in the lateral superior and middle temporal gyri. The connections are stronger in the dominant hemisphere, in agreement with previous studies of functional lateralization of auditory-language processing.

Adult↗
PubMed2004

Functional-anatomical validation and individual variation of diffusion tractography-based segmentation of the human thalamus.

Parcellation of the human thalamus based on cortical connectivity information inferred from non-invasive diffusion-weighted images identifies sub-regions that we have proposed correspond to nuclei. Here we test the functional and anatomical validity of this proposal by comparing data from diffusion tractography, cytoarchitecture and functional imaging. We acquired diffusion imaging data in eleven healthy subjects and performed probabilistic tractography from voxels within the thalamus. Cortical connectivity information was used to divide the thalamus into sub-regions with highest probability of connectivity to distinct cortical areas. The relative volumes of these connectivity-defined sub-regions correlate well with volumetric predictions based on a histological atlas. Previously reported centres of functional activation within the thalamus during motor or executive tasks co-localize within atlas regions showing high probabilities of connection to motor or prefrontal cortices, respectively. This work provides a powerful validation of quantitative grey matter segmentation using diffusion tractography in humans. Co-registering thalamic sub-regions from 11 healthy individuals characterizes inter-individual variation in segmentation and results in a population-based atlas of the human thalamus that can be used to assign likely anatomical labels to thalamic locations in standard brain space. This provides a tool for specific localization of functional activations or lesions to putative thalamic nuclei.

Adult↗
PubMed2004

Hepatic haemangioendothelioma in adults: excellent outcome following liver transplantation.

Hepatic epithelioid haemangioendotheliomas (HEHEs) are rare, low-grade vascular tumours. Five adults with HEHEs and one adult with a vascular tumour showing combined features of haemangioma and haemangioendothelioma underwent liver transplantation. Two HEHE patients had extrahepatic metastases at the time of transplantation. Median survival time following diagnosis was 10.7 years (range 40 months to 195 months). One patient needed resection of a HEHE in the breast 13 years post-transplantation. All six patients are surviving free from disease 22 to 166 months after transplantation (median 77 months). One HEHE-patient who had been treated for 8 years for vertebral and cerebral localisations is free of disease without immunosuppression 56 months after transplantation. We can conclude that liver transplantation is a valuable treatment for hepatic haemangioendothelioma, even in cases of extrahepatic localisation of the disease.

Adult↗
PubMed2004

Characterizing function-structure relationships in the human visual system with functional MRI and diffusion tensor imaging.

A key objective in neuroscience is to improve our understanding of the relationship between brain function and structure. We investigated this in the posterior visual pathways of healthy volunteers by applying functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) with tractography. The optic radiations were segmented using the Probabilistic Index of Connectivity (PICo) tractography algorithm and extracted at several thresholds of connection confidence. The mean fractional anisotropy (FA) of the estimated tracts was found to correlate significantly with fMRI measures of visual cortex activity (induced by a photic stimulation paradigm). The results support the hypothesis that the visual cortical fMRI response is constrained by the external anatomical connections of the subserving optic radiations.

Adult↗
PubMed2003

Glycogenosis storage type I diseases and evolutive adenomatosis: an indication for liver transplantation.

We report on two cases of type I glycogen storage disease (GSD) complicated by malignant tumors. A 23-year-old man had GSD Ia with adenomatosis. He underwent transplantation for rapidly growing and radiologically changing adenomata. At histological examination, one adenoma had become a hepatocellular carcinoma. A 22-year-old, HBV-infected woman had GSD type Ib with adenomatosis. At follow-up, several tumors showed changing morphological characteristics. Pre-transplant laparotomy confirmed the presence of a metastatic cholangiocarcinoma. Liver transplantation should be considered in GSD type I patients with adenomatosis, especially when tumor characteristics change. Regular detailed Doppler ultrasound and magnetic nuclear resonance screening during childhood and adolescence are, therefore, mandatory in order for the timing of transplantation to be optimized.

Adenoma, Liver Cell↗
PubMed2003

Cavocaval adult liver transplantation and retransplantation without venovenous bypass and without portocaval shunting: a prospective feasibility study in adult liver transplantation.

BACKGROUND: The original method of liver transplantation (LT) included recipient inferior vena cava (IVC) resection and the use of extracorporeal venovenous bypass (VVB). Refinements in technique permit transplantation to be done with IVC preservation and without VVB use. MATERIAL AND METHODS: Between November 1993 and November 2000, 202 consecutive grafts were performed in 188 adults (>/=16 years of age). Twelve patients (6.4%) received two and three retransplants (re-LT). Split grafting was performed 19 times (19 of 202 grafts, 9.4%). Risk factors included United Network of Organ Sharing status I (n=30, 16%), previous right upper abdominal surgery (n=32, 17.1%), caudate lobe encirclement of IVC (n=65, 32.2%), IVC (n=24, 11.9%), and splanchnic venous modification (n=58, 30.9%), transjugular intrahepatic portosystemic stent shunt (n=34, 16.8%), giant (>5 kg) liver tumor (n=6, 3%), septic necrosis of the caudate lobe (n=1, 0.5%), and previous cavocaval (n=13, 6.4%) or classical LT (n=5, 2.5%). RESULTS: IVC preservation, avoidance of IVC cross clamping and of VVB use were possible in 98.9%, 93%, and 99.5% of 183 primary LT and in 89.5%, 84.2%, and 89.5% of 19 re-LT. Temporary portocaval shunting was never applied. Perioperative mortality was 1.2%. There was no allotransfusion in 73 (36%) grafts and 45 (22%) patients were immediately extubated. Permanent hepatic vein and caval problems were encountered in three (1.5%) grafts. One patient needed stent placement to treat IVC stenosis. Actual 3- and 12-month patient survival for whole, re-LT, and right-lobe split LT groups were 94.7%, 94.1%, 94.7%, 88.2%, 94.1%, and 89%. Three-month graft survival rates for these groups were 92.6%, 94.7%, and 84.2%. CONCLUSIONS: LT with IVC preservation and without VVB use and portocaval shunting is possible in nearly all primary transplants and in the majority of re-LT.

Adult↗
PubMed2003

Re-use of a liver allograft; an exceptional opportunity to enlarge the organ donor pool.

Liver allograft re-use is an exceptional way of enlarging the donor pool. We describe here a case of a re-used liver allograft, originating from an insulin-intoxicated donor and transplanted at first into a recipient presenting with hyperacute liver failure due to paracetamol intoxication. Because the original recipient developed an irreversible cerebral oedema, the allograft was re-implanted electively 55.5 h later into a patient with post-viral C cirrhosis and solitary hepatocarcinoma. Both donor and recipient operations were technically successful; liver function after the second use of the graft was normal.

Acetaminophen↗