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Biomedical subjects

M A Rocca

Publications and source records attributed to M A Rocca.

At least 19 recordsLinked to original sources
PubMed2006

MRI quantification of gray and white matter damage in patients with early-onset multiple sclerosis.

BACKGROUND AND OBJECTIVE: Contrary to what happens in adult-onset multiple sclerosis (MS), in a previous preliminary magnetic resonance imaging (MRI) study we showed only subtle normal-appearing brain tissue changes in patients with earlyonset MS. Our objective was to evaluate the presence and extent of tissue damage in the brain normalappearing white matter (NAWM) and gray matter (GM) from a larger population of patients with earlyonset MS. METHODS: Using diffusion tensor (DT) and magnetization transfer (MT) MRI, we obtained DT and MT ratio (MTR) maps of the NAWM and GM from 23 patients with early-onset MS and 16 sex- and age-matched healthy volunteers. RESULTS: Compared with healthy volunteers, patients with early-onset MS had significantly increased average MD (p = 0.02) and FA peak height (p = 0.007) and decreased average FA (p <0.0001) of the NAWM. Brain dual-echo lesion load was significantly correlated with average FA (r = -0.48, p = 0.02) and with FA peak height (r = 0.45, p = 0.03) of the NAWM. No MTR and diffusion changes were detected in the GM. CONCLUSIONS: This study confirms the paucity of the 'occult' brain tissue damage in patients with earlyonset MS. It also suggests that in these patients GM is spared by the disease process and that NAWM changes are likely to be secondary to Wallerian degeneration of fibers passing through macroscopic lesions.

Adolescent↗
PubMed2006

Functional MRI to study brain plasticity in clinical neurology.

Functional magnetic resonance imaging (fMRI) is being widely used to study recovery of function in patients with several neurological conditions, including multiple sclerosis, stroke and Alzheimer's disease. The application of this MR technique has shown that plastic cortical changes do occur after central nervous system (CNS) injury of different aetiology, that such changes are related to the extent of CNS damage and that they can contribute in limiting the clinical consequences of brain damage. Conversely, the failure or exhaustion of the adaptive properties of the cerebral cortex might be among the factors responsible for the accumulation of 'fixed' neurological deficits. New studies aimed at investigating the effect of therapies devoted to promote brain plasticity are now warranted.

Brain Diseases↗
PubMed2006

EFNS guidelines on the use of neuroimaging in the management of multiple sclerosis.

Magnetic resonance (MR)-based techniques are widely used for the assessment of patients with suspected and definite multiple sclerosis (MS). However, despite the publication of several position papers, which attempted to define the utility of MR techniques in the management of MS, their application in everyday clinical practice is still suboptimal. This is probably related, not only, to the fact that the majority of published guidelines focused on the optimization of MR technology in clinical trials, but also to the continuing development of modern, quantitative MR-based techniques, that have not as yet entered the clinical arena. The present report summarizes the conclusions of the 'EFNS Expert Panel of Neuroimaging of MS' on the application of conventional and non-conventional MR techniques to the clinical management of patients with MS. These guidelines are intended to assist in the use of conventional MRI for the diagnosis and longitudinal monitoring of patients with MS. In addition, they should provide a foundation for the development of more widespread but rational clinical applications of non-conventional MR-based techniques in studies of MS patients.

Brain↗
PubMed2006

Diffusion tensor magnetic resonance imaging at 3.0 tesla shows subtle cerebral grey matter abnormalities in patients with migraine.

BACKGROUND AND OBJECTIVE: Diffusion tensor (DT) magnetic resonance imaging (MRI) has the potential to disclose subtle abnormalities in the brain of migraine patients. This ability may be increased by the use of high field magnets. A DT MRI on a 3.0 tesla scanner was used to measure the extent of tissue damage of the brain normal appearing white (NAWM) and grey matter in migraine patients with T2 visible abnormalities. METHODS: Dual echo, T1 weighted and DT MRI with diffusion gradients applied in 32 non-collinear directions were acquired from 16 patients with migraine and 15 sex and age matched controls. Lesion load on T2 weighted images was measured using a local thresholding segmentation technique, and brain atrophy assessed on T1 weighted images using SIENAx. Mean diffusivity and fractional anisotropy histograms of the NAWM and mean diffusivity histograms of the grey matter were also derived. RESULTS: Brain atrophy did not differ between controls and patients. Compared with healthy subjects, migraine patients had significantly reduced mean diffusivity histogram peak height of the grey matter (p=0.04). No diffusion changes were detected in patients' NAWM. In migraine patients, no correlation was found between T2 weighted lesion load and brain DT histogram derived metrics, whereas age was significantly correlated with grey matter mean diffusivity histogram peak height (p=0.05, r=-0.52). CONCLUSIONS: DT MRI at high field strength discloses subtle grey matter damage in migraine patients, which might be associated with cognitive changes in these patients.

Adult↗
PubMed2006

MR imaging assessment of brain and cervical cord damage in patients with neuroborreliosis.

BACKGROUND AND PURPOSE: Neuroborreliosis is frequently indistinguishable from multiple sclerosis (MS) on both clinical and radiologic grounds. By using MR imaging, we assessed "occult" brain white matter (WM), brain gray matter (GM), and cervical cord damage in patients with neuroborreliosis in an attempt to achieve a more accurate picture of tissue damage in these patients, which might contribute to the diagnostic work-up. METHODS: We studied 20 patients with neuroborreliosis and 11 sex- and age-matched control subjects. In all subjects, we acquired dual echo, T1-weighted, diffusion tensor (DT) and magnetization transfer (MT) MR imaging scans of the brain and fast short-tau inversion recovery and MT MR imaging scans of the cervical cord. T2-visible lesion load was measured by using a local thresholding segmentation technique. Mean diffusivity and fractional anisotropy histograms of the brain and cervical cord MT ratio histograms were produced. Normalized brain volumes (NBV) were measured by using SIENAx. RESULTS: Brain T2-visible lesions were detected in 12 patients, whereas no occult damage in the normal-appearing WM and GM was disclosed by using MT and DT MR imaging. No macroscopic lesions were found in the cervical cord, which was also spared by occult pathology. NBV did not differ between patients with neuroborreliosis and control subjects. CONCLUSION: This study shows that, contrary to what happens in MS, occult brain tissue damage and cervical cord pathology are not frequent findings in patients with neuroborreliosis. These observations might be useful in the diagnostic work-up of patients with neuroborreliosis and T2 brain lesions undistinguishable from those of MS.

Adult↗
PubMed2005

A method for obtaining tract-specific diffusion tensor MRI measurements in the presence of disease: application to patients with clinically isolated syndromes suggestive of multiple sclerosis.

The aim of this study was to investigate whether neurological symptoms related to a specific axonal fiber tract in brain white matter were associated with a higher degree of tissue damage in that region, in patients at presentation with clinically isolated syndromes (CIS) suggestive of multiple sclerosis. To this end, a magnetic resonance imaging (MRI) method to segment and evaluate the fiber bundle of interest was implemented, taking care to circumvent the problems caused by pathology. Diffusion tensor (DT) MRI tractography was used to construct, from healthy volunteer data, a probability map for the pyramidal tract (PYT), and this map was applied to patients to calculate DT-derived metrics inside the PYT. In CIS patients with clinical symptoms related to motor function, the DT-derived mean diffusivity and the lesion volume in the PYT were found to be increased, while the fractional anisotropy was no different, when compared to those patients without motor symptoms. These results may be explained by several microstructural changes in the damaged tissue, such as changes in the permeability of axonal cell membranes, decreases of axonal density and edema. The approach taken to analyze a specific fiber tract was possible because the axons in the tract have a high orientational coherence, allowing tissue structure changes to be isolated from the tissue architecture. Its extension to other white matter fiber bundles is therefore limited to bundles with high orientational coherence.

Adult↗
PubMed2005

Quantification of cervical cord pathology in primary progressive MS using diffusion tensor MRI.

OBJECTIVE: To investigate the extent and severity of cervical cord damage using diffusion tensor MRI (DT-MRI) and histogram analysis in patients with primary progressive MS (PPMS). METHODS: Diffusion-weighted sensitivity-encoded (SENSE) echoplanar images of the cervical cord and brain dual-echo and diffusion-weighted scans were acquired from 24 patients with PPMS and 13 healthy controls. Cord and brain mean diffusivity and fractional anisotropy histograms were produced. An analysis of variance model, adjusting for cord volume, was used to compare cord DT-MRI parameters from controls and patients. RESULTS: Compared to healthy controls, PPMS patients had reduced cervical cord cross-sectional area and average cord fractional anisotropy (p = 0.007), and increased cord mean diffusivity (p = 0.024). No correlations were found between DT-MRI metrics of the cord and quantities obtained from conventional and DT-MRI of the brain. CONCLUSIONS: DT-MRI of the cervical cord can quantify the extent of diffuse cord pathology in patients with PPMS. Such cord diffusivity changes in patients with PPMS are likely to reflect irreversible axonal injury and reactive gliosis and seem to be independent of brain damage.

Adult↗
PubMed2005

Imaging spinal cord damage in multiple sclerosis.

During the past 2 decades, the considerable improvement of magnetic resonance (MR) technology and the development of new MR strategies capable of providing an in vivo overall assessment of multiple sclerosis (MS) pathology have allowed us to obtain important novel pieces of information on disease evolution in the brain. However, despite this, the correlation between brain MR imaging metrics and clinical disability are still suboptimal. A reason for this discrepancy might be the involvement of clinically eloquent structures, such as the spinal cord, which owing to technical challenges have not been extensively studied using MR imaging until very recently. An objective and accurate estimate of the presence and extent of spinal cord damage might indeed contribute to increasing the strength of the correlations between clinical and MRI metrics. This review summarizes the main results obtained from the application of conventional and modern MR-based techniques for the evaluation of spinal cord damage in MS.

Diffusion Magnetic Resonance Imaging↗
PubMed2005

Serum MMP-9/TIMP-1 and MMP-2/TIMP-2 ratios in multiple sclerosis: relationships with different magnetic resonance imaging measures of disease activity during IFN-beta-1a treatment.

Matrix metalloproteinase-9 (MMP-9) is involved in blood-brain barrier (BBB) disruption in active multiple sclerosis (MS), while MMP-2 seems to be associated with the chronic progressive phase of the disease. Recombinant interferon beta-1a (rIFNbeta-1a) is effective in restoring the BBB. We studied the relationships between serum MMP-9, MMP-2, TIMP-1 and TIMP-2 and different magnetic resonance imaging (MRI) measures of disease activity in MS patients during treatment with rIFNbeta-1a. Twenty-one relapsing-remitting (RR) MS patients underwent longitudinally simultaneous blood withdrawals and MRI (before and after standard dose (SD) and triple dose (TD) of gadolinium (Gd)) examinations before and during 48 weeks of rIFNbeta-1a (Rebif 22 mcg three times a week) treatment. Serum MMP-9, MMP-2, TIMP-1 and TIMP-2 were measured, MMP-9 to TIMP-1 and MMP-2 to TIMP-2 ratios were calculated and the numbers of Gd-SD, Gd-TD, new-Gd-SD, new-Gd-TD and new-T2 lesions counted. Serum MMP-9/TIMP-1 ratio (P < 0.0001), as well as the numbers of 'active' lesions (P ranging from 0.0004 to 0.005) decreased during treatment Moreover, serum MMP-9/TIMP-1 ratio proved to be a good positive predictor (estimate = 0.85; P < 0.05) of the numbers of MRI Gd-TD active lesions. These data confirm that serum MMP-9/TMIP-1 ratio may be viewed as a reliable marker and may be predictive of MRI activity in RR MS.

Adjuvants, Immunologic↗
PubMed2005

Imaging the optic nerve in multiple sclerosis.

Although multiple sclerosis (MS) frequently involves the optic nerves, imaging this structure is not yet performed routinely in clinical practice. The recent improvement of magnetic resonance (MR) technology and the development of new MR strategies, capable of providing an, in vivo, overall assessment of MS pathology has allowed objective metrics to be obtained for monitoring disease evolution, essentially in the brain. However, despite this progress, the correlation between brain MR metrics of the disease and clinical disability are still disappointing. An objective and accurate estimate of the presence and extent of optic nerve involvement might help to overcome this clinical/MRI paradox. This review summarizes the main results obtained from the application of conventional and modern MR-based techniques for the evaluation of optic nerve damage in MS.

Atrophy↗
PubMed2004

Magnetization transfer and diffusion tensor MRI show gray matter damage in neuromyelitis optica.

Using magnetization transfer (MT) and diffusion tensor (DT) MRI, the authors assessed the extent of tissue damage of the brain normal-appearing white and gray matter (NAGM) in patients with neuromyelitis optica (NMO). Compared to healthy controls, patients with NMO showed reduced MT ratio and increased mean diffusivity of the NAGM. This challenges the classic notion of a sparing of the brain tissue in the course of NMO.

Adult↗
PubMed2004

Multiparametric MRI in a patient with adult-onset leukoencephalopathy with vanishing white matter.

This is a multiparametric MR study of the first reported patient with adult-onset genetically confirmed vanishing white matter (VWM) disease. It shows that, despite the presence of a severe and diffuse damage of the brain WM, brain gray matter, and cervical cord tissue, the cortical adaptive capacities were relatively preserved. Interpatient variability of brain plasticity may contribute to the known phenotypic variation of patients with VWM disease.

Basal Ganglia↗
PubMed2004

Diffusion tensor and magnetization transfer MR imaging of early-onset multiple sclerosis.

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system (CNS) with the onset of symptoms typically occurring between the age of 20 and 40 years. However, in about 3% to 12% of the cases, the onset of the disease is before 16 years of age. This review summarizes the main results obtained by the application of conventional and non-conventional MRI techniques to the assessment of patients with early-onset MS, which showed that the overall amount of CNS damage in these subjects is mild, compared to that typically detected in the adult-form of the disease. This fits with the notion that an early onset of the disease is associated with a more favourable clinical evolution.

Adult↗
PubMed2004

MR imaging of Devic's neuromyelitis optica.

Devic's neuromyelitis optica (NMO) is a neurological condition characterized by a severe involvement of the optic nerves and spinal cord in a mono- or multi-phasic manner. Recent pathologic, cerebrospinal fluid and conventional magnetic resonance imaging (MRI) studies have shown abnormalities which might help in differentiating patients with NMO from those with multiple sclerosis. This review article summarizes the main results obtained using conventional MRI in NMO, which has contributed to the definition of internationally-accepted diagnostic criteria, and those obtained from the application of modem quantitative MR techniques which are significantly changing our views on NMO pathobiology.

Brain↗
PubMed2004

A functional MRI study of movement-associated cortical changes in patients with Devic's neuromyelitis optica.

Movement-associated cortical changes have been shown in several neurological conditions and were found to be associated to the extent of brain and cord damage. Devic's neuromyelitis optica (DNO) is characterized by a severe involvement of the cord and optic nerve, with sparing of the brain. To assess the actual role of cord pathology on the pattern of movement-associated cortical recruitment, we obtained functional magnetic resonance imaging (fMRI) from patients with DNO and investigated whether the extent of brain activation is correlated with the extent of cervical cord damage. We studied 10 right-handed DNO patients and 15 sex- and age-matched healthy controls. The MRI assessment consisted of the following: (a) fMRI during repetitive flexion extension of the last four fingers of the right and left hand, (b) brain and cervical cord conventional MRI, and (c) cervical cord magnetization transfer (MT) MRI. Compared to controls and for both tasks, DNO patients had an increased recruitment of several regions of the sensorimotor network (primary sensorimotor cortex, postcentral gyrus, middle frontal gyrus, rolandic operculum, secondary sensorimotor cortex, precuneus, and cerebellum) and of several other regions mainly in the temporal and occipital lobes, such as MT/V5, the fusiform gyrus, the cuneus, and the parahippocampal gyrus. For both tasks, strong correlations (r values ranging from -0.76 to -0.85) were found between relative activations of cortical sensorimotor areas and the severity of cervical cord damage. This study shows an abnormal pattern of movement-associated cortical activations in patients with DNO, which extends beyond the 'classical' sensorimotor network and also involves visual areas devoted to motion processing. The correlation found between fMRI changes and the extent of cord damage suggests that such functional cortical changes might have an adaptive role in limiting the clinical outcome of DNO structural pathology.

Adult↗
PubMed2004

Brain tissue loss occurs after suppression of enhancement in patients with multiple sclerosis treated with autologous haematopoietic stem cell transplantation.

To assess whether brain tissue loss occurs after profound and sustained suppression of magnetic resonance imaging (MRI) enhancement, we measured brain volume changes from 10 patients with rapidly evolving secondary progressive multiple sclerosis (MS) treated with autologous haematopoietic stem cell transplantation and followed up for 24 months. An average yearly decrease of brain volume of about 1.9% was observed despite only five enhancing lesions seen on triple dose follow up scans of two patients. This indicates that, in MS, progressive loss of tissue can occur independently of concomitant MRI-visible inflammation.

Artifacts↗