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Olga Ciccarelli

Publications and source records attributed to Olga Ciccarelli.

27 records · Page 2Linked to original sources
PubMed2003

A study of the mechanisms of normal-appearing white matter damage in multiple sclerosis using diffusion tensor imaging--evidence of Wallerian degeneration.

Diffusion tensor imaging (DTI) investigates brain tissue microstructure in vivo. In multiple sclerosis (MS) Wallerian degeneration of axons traversing focal lesions is a potential mechanism of damage in normal-appearing white matter. In vivo evidence for this hypothesis is limited. The present study investigated the relationship between DTI-derived indices in the normal-appearing corpus callosum (CC) and the lesion loads (LLs) in connected cerebral regions. DTI was performed in 39 MS patients and in 21 age-matched controls. Fractional anisotropy (FA) and mean diffusivity (MD) were estimated in the genu, body and splenium of CC. Patients showed lower FA and higher MD in the CC than controls and both correlated with the total LL (r = -0.56 and r = 0.54, p < 0.0001). The LL of individual cerebral lobes correlated with both FA and MD in the corresponding callosal regions, with the body showing the strongest correlations with frontal and parietal LL (p < 0.0001). The strong correlations between DTI indices in the CC and the extent of lesions in connected brain regions support the hypothesis that Wallerian degeneration of axons transected by remote, but connected focal lesions, is an important pathogenic mechanism of damage in MS.

Adult↗
PubMed2003

Localizing significance of temporal intermittent rhythmic delta activity (TIRDA) in drug-resistant focal epilepsy.

OBJECTIVE: Temporal intermittent rhythmic delta activity (TIRDA) is an EEG pattern characterized by sinusoidal trains of activity, ranging from 1 to 3.5 Hz, and well localized over the temporal regions. It is considered to be an indicator of temporal lobe epilepsy (TLE), but full agreement between different authors has still not been reached. The aim of this study was therefore to assess the role of TIRDA in localizing the epileptogenic zone, which was estimated using anatomo-electro-clinical correlations obtained from non-invasive pre-surgical investigations, in a large group of patients affected by drug-resistant partial epilepsy. METHODS: The occurrence of TIRDA was investigated using a prolonged Video-EEG recording of 129 patients affected by drug-resistant partial epilepsy that underwent a non-invasive pre-surgical protocol. Patients were divided into 3 groups: TLE only, extratemporal epilepsy, and multilobar epilepsy including temporal lobe. According to the epileptogenic zone identified using anatomo-clinical-radiological correlations, 3 different subgroups of TLE were identified: mesial, lateral, and mesio-lateral. Statistical analysis was performed in order to evaluate the relationship between TIRDA and the epileptogenic zone, and neuroradiological, neuropathological, EEG interictal and ictal findings. RESULTS: The pattern of TIRDA was observed in 52 out of the 129 (40.3%) patients studied. Significant correlations were found between TIRDA and: (i) mesial and mesio-lateral TLE; (ii) mesial temporal sclerosis; (iii) interictal epileptiform discharge localized over the anterior temporal regions; and (iv) 5-9 Hz temporal ictal discharge. CONCLUSIONS: Our research shows that TIRDA plays a role in localizing the epileptogenic zone, suggesting that this pattern might be considered as an EEG marker of an epileptogenesis that involves the mesial structures of the temporal lobe. However, further studies investigating the relationship between intracranial EEG monitoring and simultaneous scalp EEG recording are needed in order to confirm our findings and improve our understanding of the significance of TIRDA.

Adolescent↗
PubMed2002

A longitudinal study of abnormalities on MRI and disability from multiple sclerosis.

BACKGROUND: In patients with isolated syndromes that are clinically suggestive of multiple sclerosis, such as optic neuritis or brain-stem or spinal cord syndromes, the presence of lesions as determined by T2-weighted magnetic resonance imaging (MRI) of the brain increases the likelihood that multiple sclerosis will develop. We sought to determine the relation between early lesion volume, changes in volume, and long-term disability. METHODS: Seventy-one patients in a serial MRI study of patients with isolated syndromes were reassessed after a mean of 14.1 years. Disability was measured with the use of Kurtzke's Expanded Disability Status Scale (EDSS; possible range, 0 to 10, with a higher score indicating a greater degree of disability). RESULTS: Clinically definite multiple sclerosis developed in 44 of the 50 patients (88 percent) with abnormal results on MRI at presentation and in 4 of 21 patients (19 percent) with normal results on MRI. The median EDSS score at follow-up for those with multiple sclerosis was 3.25 (range, 0 to 10); 31 percent had an EDSS score of 6 or more (including three patients whose deaths were due to multiple sclerosis). The EDSS score at 14 years correlated moderately with lesion volume on MRI at 5 years (r=0.60) and with the increase in lesion volume over the first 5 years (r=0.61). CONCLUSIONS: In patients who first present with isolated syndromes suggestive of multiple sclerosis, the increases in the volume of the lesions seen on magnetic resonance imaging of the brain in the first five years correlate with the degree of long-term disability from multiple sclerosis. This relation is only moderate, so the volume of the lesions alone may not be an adequate basis for decisions about the use of disease-modifying treatment.

Adolescent↗
PubMed2002

Initial demonstration of in vivo tracing of axonal projections in the macaque brain and comparison with the human brain using diffusion tensor imaging and fast marching tractography.

Diffusion tensor imaging (DTI), a magnetic resonance imaging technique, is used to infer major axonal projections in the macaque and human brain. This study investigates the feasibility of using known macaque anatomical connectivity as a "gold-standard" for the evaluation of DTI tractography methods. Connectivity information is determined from the DTI data using fast marching tractography (FMT), a novel tract-tracing (tractography) method. We show for the first time that it is possible to determine, in an entirely noninvasive manner, anatomical connection pathways and maps of an anatomical connectivity metric in the macaque brain using a standard clinical scanner and that these pathways are consistent with known anatomy. Analogous human anatomical connectivity is also presented for the first time using the FMT method, and the results are compared. The current limitations of the methodology and possibilities available for further studies are discussed.

Animals↗
PubMed2002

Investigating cervical spinal cord structure using axial diffusion tensor imaging.

This study describes a new technique for Diffusion Tensor Imaging (DTI) that acquires axial (transverse) images of the cervical spinal cord. The DTI images depict axonal fiber orientation, enable quantification of diffusion characteristics along the spinal cord, and have the potential to demonstrate the connectivity of cord white matter tracts. Because of the high sensitivity to motion of diffusion-weighted magnetic resonance imaging and the small size of the spinal cord, a fast imaging method with high in-plane resolution was developed. Images were acquired with a single-shot EPI technique, named ZOOM-EPI (zonally magnified oblique multislice echo planar imaging), which selects localized areas and reduces artefacts caused by susceptibility changes between soft tissue and the adjacent vertebrae. Cardiac gating was used to reduce pulsatile flow artefacts from the surrounding cerebrospinal fluid. Voxel resolution was 1.25 x 1.25 mm(2) in-plane with 5-mm slice thickness. Both the mean diffusivity (MD) and the fractional anisotropy (FA) indices of the cervical spinal cord were measured. The FA index demonstrated high anisotropy of the spinal cord with an average value of 0.61 +/- 0.05 (highest value of 0.66 +/- 0.03 at C3), comparable to white matter tracts in the brain. The diffusivity components parallel and orthogonal to the longitudinal axes of the cord were lambda( parallel) = (1648 +/- 123) x 10(-6) mm(2)s(-1) and lambda( perpendicular) = (570 +/- 47) x 10(-6) mm(2) s(-1), respectively. The high axial resolution allowed preliminary evaluation of fiber connectivity using the fast-marching tractography algorithm, which generated traces of fiber paths consistent with the well-known cord anatomy.

Algorithms↗
PubMed2002

Disability and lesion load in MS: a reassessment with MS functional composite score and 3D fast FLAIR.

The correlation between T2 lesion load (LL) detected on conventional MR sequences and disability assessed by the Expanded Disability Status Scale (EDSS) in multiple sclerosis (MS) is, at best, moderate. The present study was performed to determine whether the correlation between disability and LL is improved by (i) use of the more sensitive three-dimensional fast fluid-attenuated inversion recovery (3D-fast FLAIR) sequence; (ii) application of the newly devised MS functional composite (MSFC) score. Forty-one patients with clinically definite or probable MS were studied. All had been followed prospectively for 14 years since their first symptom. EDSS and MSFC score were assessed. Imaging was performed with 3D-fFLAIR, fast spin-echo (FSE), and T1 weighted SE sequences. 3D-fFLAIR detected a 34% higher LL than FSE, but did not improve the correlation between T2 LL and EDSS (r = 0.51 and r = 0.53); the correlation was stronger with T1 LL (r = 0.57). The MSFC score did not significantly correlate with T2 LL or T1 LL. The robust correlation in this cohort between T2 LL and EDSS may reflect the homogeneous disease duration and the wide spread of disability. This correlation was not improved by the increased detection of T2 lesions with the 3D-fFLAIR sequence. The stronger correlation between T1 LL with EDSS is consistent with the finding that this subgroup of lesions represent areas of more severe tissue damage. The MSFC score did not improve the clinico-radiological paradox that is found in MS, despite including information on cognitive function.

Adolescent↗
PubMedDate not supplied

Long-term medical complications and quality of life in adult recipients surviving 10 years or more after liver transplantation.

BACKGROUND AND STUDY AIMS: Little information is available about long-term results after adult liver transplantation. This study analyses long-term medical complications, changes of immunosuppression, recurrence of primary disease and quality of life 10 years after liver transplantation. MATERIAL AND METHODS: During the period February 1984-April 1994, 324 LT were performed in 282 adults (>15 years). One hundred forty-seven (52%) patients survived more than 10 years. Data regarding health status of 103 patients exclusively followed-up in our institution were analyzed. RESULTS: Actual 1, 5, 10 years survival rates of the 282 recipients were 76.6%, 64.9% and 52% respectively. Forty eight (46.6%) of the 103 studied patients had normal liver tests in their tenth year of the follow-up. Seventy-one (69%) patients were on a CyA, TAC or MMF monotherapy; 31 (30%) patients had CyA levels of less than 100ng/ml. Forty five patients had recurrent allograft disease. Twenty-four (40.6%) of 59 liver biopsy available at 10th year were normal. Thirty five (34%) patients developed chronic renal failure; nine (8.7%) of them had end-stage renal disease. New onset hypertension (>140/100 mmHg) developed in 49 (47.6%) patients; fourteen (13.6%) developed diabetes (glucose blood level > 140 mg/dl) and twenty five (24.2%) patients had serious cardiovascular events. Thirteen (12.6%) patients had a BMI>28 and thirty six (35%) patients had elevated serum cholesterol (>220 mg/dl). Cataract was present in 8 (7.7%) patients. De novo malignancy developed in 23 (22.3%) patients. One patient each developed nasopharyngeal lymphoproliferative disease and myeloma. Quality of life of this patient cohort was excellent as shown by a Karnofsky score of more than 80% in 96.6% of patients. CONCLUSION: The high rate of medical complications and especially of malignant tumours in this long-term follow-up study indicate that further optimization and especially minimization of immunosuppressive therapy as well as development of newer therapies in order to prevent recurrent allograft diseases are the priority for the future development of transplant medicine.

Adult↗
PubMedDate not supplied

Extension of the adult hepatic allograft pool using split liver transplantation.

BACKGROUND: The ever increasing number of, especially, adults waiting for a liver transplantation necessitates to develop techniques allowing to extend the available donor liver pool. MATERIALS AND METHODS: Between November 1988 and December 2004, 37 (6.6%) of 559 adults underwent split liver transplantation at Saint-Luc Hospitals. There were 36 were right and one left split procedures; 27 split grafts were obtained ex-situ and 10 in-situ. Results of these series are analysed and compared to literature data of split liver transplantation. RESULTS: Three and 12 months patient survival rates were 89.2% and 78.4% respectively. Five years actuarial patient survival was 75.7%. Early (< 3 months) and late (> 3 months) mortality rates were 10.8% (4 pat.) and 21.6% respectively. Early mortality was significantly higher in case of urgent split liver transplantation (3/5 patients vs. 2/32 elective patients--p 0.001). At present 25 patients are alive, with a mean Karnofsky score of 90%. Three and 12 months graft survival rates were 91.7% and 87.1% respectively. Three and one grafts were lost due to primary and early graft non-function. In-situ split grafts had shorter mean warm, cold, total ischemia and operating times as well as less need for blood transfusion; all these differences were however not statistically significant. Surgical complications occurred in 19 (51%) patients. All but one complication occurred early (< 3 months). There were sixteen biliary complications in 13 (35.1%) patients: 9 anastomotic stenoses, 3 anastomotic and 4 transection margin leakages. Six vascular complications occurred in 6 (15.2%) patients: three arterial and 3 portal vein thromboses. Seven (18.9%) patients had a postoperative bleeding. CONCLUSIONS: Graft and patient survival rates of split liver transplantation can be compared to those of classic liver transplantation. However the care of these patients is demanding due to the high number of technical complications. Results of split liver transplantation must be further improved in order to foster it's more widespread use necessary to overcome the actual shortage of liver allografts.

Adult↗