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G Scotti

Publications and source records attributed to G Scotti.

At least 19 recordsLinked to original sources
PubMed2006

The contribution of voxel-based morphometry in staging patients with mild cognitive impairment.

OBJECTIVE: To assess whether different patterns of regional gray matter loss in patients with mild cognitive impairment (MCI) are associated with different risks of conversion to Alzheimer disease (AD), using MRI and voxel-based morphometry (VBM). METHODS: The authors recruited 22 patients with MCI, 22 patients with probable AD, and 20 healthy subjects (HS). T1 volumes from each subject were postprocessed according to an optimized VBM protocol. All patients were clinically followed up (mean [SD] time = 28.7 [5.7] months), and patients with MCI were reclassified into two groups (converters and nonconverters to AD). RESULTS: When comparing patients with AD to HS, widespread areas of reduced gray matter density were found predominantly in temporal, frontal, and parietal lobes and in the insula. Comparing MCI converters and nonconverters with HS, the converters showed more widespread areas of reduced gray matter density than nonconverters, with a pattern of abnormalities similar to that seen in patients with AD. Conversely, when comparing the same groups with patients with AD, MCI nonconverters showed a pattern of gray matter density similar to that of HS. Areas of decreased gray matter density were also found in MCI converters compared with nonconverters. CONCLUSIONS: Different patterns of gray matter density distribution in patients with mild cognitive impairment may be associated to different rates of conversion to Alzheimer disease.

Aged↗
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

Angiographic follow-up of cerebral aneurysms treated with Guglielmi detachable coils: an analysis of 162 cases with 173 aneurysms.

BACKGROUND AND PURPOSE: The endovascular approach, with the use of Guglielmi detachable coils (GDC), has been increasingly used to treat ruptured and unruptured cerebral aneurysms in recent years. Our objective was to assess the mid- to long-term radiologic outcome of cerebral aneurysms treated with GDC embolization. METHODS: One hundred and sixty-two patients with a total of 173 aneurysms embolized with GDCs underwent angiographic follow-up 1 to 54 months after the procedure and were reviewed retrospectively. Each angiogram was reviewed by 2 neuroradiologists and 1 neurosurgeon, each of whom made a comparison between the initial and follow-up angiograms. Morphologic outcomes were scored as follows: unchanged, progressive thrombosis, and reopening or regrowth. RESULTS: Of the 173 aneurysms with GDC embolization, 142 had total or nearly total occlusion, 23 subtotal occlusion, and 8 partial occlusion on the initial angiograms. The incidence of reopening was 17.1% (13/76) in less than 3 months and 6.2% (6/97) between 3 and 6 months after the procedure. Four aneurysms (2.3%) were found to be recurrent in the second follow-up angiography within 1 year after the procedure. The 1-year cumulative recurrent rate was 13.3%. Among 56 aneurysms with a third follow-up angiography in the period of 12 to 54 months after the procedure, 4 (7.1%) displayed a slight enlargement; the long-term cumulative recurrent rate was 20.4%. CONCLUSION: The direct and primary causes for aneurysmal recurrence are incomplete and loose packing. The first angiographic follow-up is recommended to be performed at 3 months or earlier for incompletely occluded aneurysms and at 6 months for totally or nearly totally occluded aneurysms. In case of total or nearly total occlusion that remains stable at follow-up, the interval for monitoring should be prolonged appropriately. Retreatment with balloon- or stent-assisted coil embolization is recommended for reopened aneurysms.

Adolescent↗
PubMed2005

A whole brain MR spectroscopy study from patients with Alzheimer's disease and mild cognitive impairment.

Brain damage in Alzheimer's disease (AD) and mild cognitive impairment (MCI) is widespread with involvement of large portions of the neocortex and the subcortical white matter. A quantitative measure of neuronal damage of the entire brain might be valuable in the context of large-scale, longitudinal studies of these patients. This study investigated the extent of neuroaxonal injury of patients with AD and MCI using a novel unlocalized proton magnetic resonance spectroscopy ((1)H-MRS) technique, which allows quantification of the concentration of N-acetylaspartate from the whole of the brain tissue (WBNAA). Conventional brain MRI and WBNAA were obtained from 28 AD patients, 27 MCI patients and 25 age-matched controls. Normalized brain volume (NBV) was also measured using an automated segmentation technique. WBNAA and NBV showed a significant heterogeneity between groups (P < 0.001). WBNAA concentration was different between controls and MCI patients (P = 0.003), but not between MCI and AD patients (P = 0.33). NBV differed both between controls and MCI patients (P = 0.02) and between MCI and AD patients (P = 0.03). A multivariate regression model retained WBNAA as the best MRI predictor of the Mini Mental State Examination score (P = 0.001). Significant neuronal damage, which is related to the extent of cognitive decline, can be quantified in the whole brain tissue of patients with AD, using a novel (1)H-MRS approach. The demonstration in patients with MCI of MR structural and metabolic findings, intermediate between those of healthy volunteers and those of AD patients, indicates that neuronal damage is already evident and widespread in individuals with MCI before they are clinically demented.

Aged↗
PubMed2005

Brain tissue damage in dementia with Lewy bodies: an in vivo diffusion tensor MRI study.

The aim of the present study was to apply diffusion tensor MRI (DT-MRI), a quantitative MRI measure which reflects tissue organization, to dementia with Lewy bodies (DLB). DT-MRI scans were obtained from 15 patients with probable DLB and 10 sex- and age-matched healthy controls. Abnormalities were found in the corpus callosum, pericallosal areas and the frontal, parietal, occipital and, less prominently, temporal white matter of patients compared with controls. Abnormalities were also found in the caudate nucleus and the putamen. The average grey matter volume was lower in patients than in controls. These findings of concomitant grey matter atrophy and white matter abnormalities (as detected by DT-MRI) in regions with a high prevalence of long connecting fibre tracts might suggest the presence of neurodegeneration involving associative cortices. The modest involvement of the temporal lobe fits with the relative preservation of global neuropsychological measures and memory tasks in the early stage of DLB. The selective involvement of parietal, frontal and occipital lobes might explain some of the clinical and neuropsychological features of DLB, providing a possible distinctive marker for this disease. The abnormalities found in the subcortical grey matter may indicate that DLB and Parkinson's disease share a similar nigrostriatal involvement caused by common pathophysiological mechanisms.

Aged↗
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↗
PubMed2003

Cord damage elicits brain functional reorganization after a single episode of myelitis.

OBJECTIVE: To assess, using fMRI, the brain pattern of movement-associated cortical activations in patients with a previous remitting episode of acute cervical myelitis of possible demyelinating origin and to investigate whether the extent of cortical reorganization is associated with the extent of cervical cord pathology measured using magnetization transfer (MT) MRI. METHODS: From 14 right-handed patients in a chronic and stable phase after an isolated myelitis (male/female = 7/7, mean age = 35.3 years, median disease duration = 21.2 months) involving the cervical cord and 15 sex- and age-matched healthy control subjects, we obtained 1) fMRI during repetitive flexion-extension of the last four fingers of the right hand, 2) brain diffusion tensor MRI, and 3) brain and cervical cord conventional and MT MRI. FMRI data were analyzed using Statistical Parametric Mapping software. Brain mean diffusivity, fractional anisotropy, and MT ratio (MTR) histograms of the normal-appearing white and gray matter and cervical cord MTR histograms were produced. RESULTS: Patients with myelitis had lower average cord MTR (p < 0.0001) and cord MTR histogram peak position (p = 0.002) than control subjects. Compared with healthy volunteers, patients with myelitis showed increased recruitment of the ipsilateral hemisphere in the primary sensorimotor cortex (p < 0.0001), supplementary motor area (p = 0.002), and middle frontal gyrus (MFG) (p < 0.0001). Average cervical cord MTR was inversely correlated with relative activations of the ipsilateral MFG (r = -0.80) and of the ipsilateral postcentral gyrus (r = -0.80). The relative activation of the ipsilateral MFG was also correlated with cervical cord MTR peak position (r = -0.92). CONCLUSIONS: An abnormal pattern of movement-associated cortical activations was found in patients with a previous episode of cervical myelitis. These functional cortical changes might have an adaptive role in limiting the clinical outcome of structural cord damage.

Acute Disease↗
PubMed2003

Evidence for widespread axonal damage at the earliest clinical stage of multiple sclerosis.

Although axonal pathology is recognized as one of the major pathological features of multiple sclerosis, it is less clear how early in its course it occurs and how it correlates with MRI-visible lesion loads. To assess this early axonal pathology, we quantified the concentration of whole-brain N-acetylaspartate (WBNAA) in a group of patients at the earliest clinical stage of the disease and compared the results with those from healthy controls. Conventional brain MRI and WBNAA using unlocalized proton magnetic resonance spectroscopy were obtained from 31 patients at presentation with clinically isolated syndromes suggestive of multiple sclerosis and paraclinical evidence of dissemination in space, and from 16 matched controls. An additional conventional MRI scan was obtained in all patients 4-6 months later to detect dissemination of lesions in time. The mean WBNAA concentration was significantly lower in patients compared with the controls (P < 0.0001). It was not significantly different between patients with and without enhancing lesions at the baseline MRI or between patients with and without lesion dissemination in time. No correlation was found between WBNAA concentrations and lesion volumes. Widespread axonal pathology, largely independent of MRI-visible inflammation and too extensive to be completely reversible, occurs in patients even at the earliest clinical stage of multiple sclerosis. This finding lessens the validity of the current concept that the axonal pathology of multiple sclerosis is the end-stage result of repeated inflammatory events, and argues strongly in favour of early neuroprotective intervention.

Adult↗
PubMed2002

Evidence for widespread movement-associated functional MRI changes in patients with PPMS.

BACKGROUND: Previous work has suggested that functional reorganization of cortical motor areas might have a role in limiting the motor deficits in patients with MS. OBJECTIVE: To test whether movement-associated cortical changes in MS might extend beyond the "classic" motor areas and involve sites for multimodal integration. METHODS: fMRI was used to assess patterns of brain activations associated with 3 different motor tasks in 30 right-handed patients with primary progressive MS (PPMS) and variable degrees of motor impairment, which were compared with those from 15 right-handed, sex- and age-matched control subjects. RESULTS: Compared with control subjects, patients with MS showed increased activation of brain regions within both traditional motor planning and execution regions (including the supplementary motor area and the cingulate motor area), the insula (a region implicated in sensory processing), and several multimodal cortical regions in the temporal, parietal, and occipital lobes. In patients, the extent of the fMRI activations was strongly correlated with MR lesion burden (r ranging from 0.70 to 0.86, p < 0.001). CONCLUSIONS: This study shows that movement-associated cortical activation in patients with PPMS is widely distributed and also involves multimodal "nonmotor" cortical networks. It also suggests that adaptive cortical reorganization might be one of the mechanisms limiting the clinical impact of MS in the progressive phases of the disease.

Adult↗
PubMed2002

Functional magnetic resonance imaging correlates of fatigue in multiple sclerosis.

Although fatigue is a common and troublesome symptom of multiple sclerosis (MS), its pathogenesis is poorly understood. In this study, we used functional magnetic resonance imaging (fMRI) to test whether a different pattern of movement-associated cortical and subcortical activations might contribute to the development of fatigue in patients with MS. We obtained fMRI during the execution of a simple motor task with completely normally functioning hands from 15 MS patients with fatigue (F), 14 MS patients without fatigue (NF), and 15 sex- and age-matched healthy volunteers. F and NF MS patients were also matched for major clinical and MRI variables. FMRI data were analyzed using statistical parametric mapping. In all patients, severity of fatigue was rated using the Fatigue Severity Scale (FSS). Compared to healthy subjects, MS patients showed more significant activations of the contralateral primary somatomotor cortex, the contralateral ascending limb of the Sylvian fissure, the contralateral intraparietal sulcus (IPS), the contralateral supplementary motor area, and the ipsilateral and contralateral cingulate motor area (CMA). Compared to F MS patients, NF patients showed more significant activations of the ipsilateral cerebellar hemisphere, the ipsilateral rolandic operculum, the ipsilateral precuneus, the contralateral thalamus, and the contralateral middle frontal gyrus. In contrast, F MS patients had a more significant activation of the contralateral CMA. Significant inverse correlations were found between FSS scores and relative activations of the contralateral IPS (r = -0.63), ipsilateral rolandic operculum (r = -0.61), and thalamus (r = -0.62). This study provides additional evidence that fatigue in MS is related to impaired interactions between functionally related cortical and subcortical areas. It also suggests that fMRI might be a valuable tool to monitor the efficacy of treatment aimed at reducing MS-related fatigue.

Adult↗
PubMed2002

Correlations between structural CNS damage and functional MRI changes in primary progressive MS.

In patients with primary progressive multiple sclerosis (PPMS), we investigated whether brain and cervical cord structural changes in lesions and normal-appearing brain tissue (NABT), measured using conventional, magnetization transfer (MT), and diffusion tensor (DT) MRI, are correlated with movement-associated cortical activations measured using functional magnetic resonance imaging (fMRI). From 26 right-handed PPMS patients and 15 right-handed, sex- and age-matched healthy controls, we obtained: (a) brain and cervical cord dual-echo scans and MT ratio (MTR) maps; (b) brain mean diffusivity (D(-)) maps, and (c) f-MRI (flexion-extension of the last four fingers of the right hand). All PPMS patients had no previous symptoms affecting their right upper limbs, which were functionally normal. Healthy volunteers showed more significant activation in the ipsilateral cerebellar hemisphere than PPMS patients. PPMS patients showed greater activation bilaterally in the superior temporal gyrus, ipsilaterally in the middle frontal gyrus, and, contralaterally in the insula/claustrum. In PPMS patients, moderate to strong correlations (r values ranging from 0.59 to 0.68) were found between relative activations of cortical areas located in a widespread network for sensory-motor and multimodal integration and the severity of structural changes of the NABT (as measured using MT and DT MRI) and the severity of cervical cord damage (as measured using MT MRI). This study shows that the pattern of cortical activation of PPMS patients is different from that of normal controls even when performing a motor task with clinically unaffected limbs. It also suggests that cortical reorganization might be able to limit the consequences of MS injury in the brain and cervical cord.

Adult↗
PubMed2002

White matter damage in Alzheimer's disease assessed in vivo using diffusion tensor magnetic resonance imaging.

OBJECTIVE: To investigate the extent and the nature of white matter tissue damage of patients with Alzheimer's disease using diffusion tensor magnetic resonance imaging (DT-MRI). BACKGROUND: Although Alzheimer's disease pathology mainly affects cortical grey matter, previous pathological and MRI studies showed that also the brain white matter of patients is damaged. However, the nature of Alzheimer's disease associated white matter damage is still unclear. METHODS: Conventional and DT-MRI scans were obtained from 16 patients with Alzheimer's disease and 10 sex and age matched healthy volunteers. The mean diffusivity (D), fractional anisotropy (FA), and inter-voxel coherence (C) of several white matter regions were measured. RESULTS: D was higher and FA lower in the corpus callosum, as well as in the white matter of the frontal, temporal, and parietal lobes from patients with Alzheimer's disease than in the corresponding regions from healthy controls. D and FA of the white matter of the occipital lobe and internal capsule were not different between patients and controls. C values were also not different between patients and controls for any of the regions studied. Strong correlations were found between the mini mental state examination score and the average overall white matter D (r=0.92, p<0.001) and FA (r=0.78; p<0.001). CONCLUSIONS: White matter changes in patients with Alzheimer's disease are likely to be secondary to wallerian degeneration of fibre tracts due to neuronal loss in cortical associative areas.

Aged↗
PubMed2001

Quantification of tissue damage in AD using diffusion tensor and magnetization transfer MRI.

The authors measured mean diffusivity (D) and magnetization transfer ratio (MTR) of the brain from 18 patients with AD and 16 healthy control subjects. The peak heights of cortical gray matter (cGM) D (p < 0.001) and MTR (p < 0.001) histograms were lower and average cGM D (p < 0.01) higher in patients with AD than in control subjects. A composite MR score based on brain volume and cGM MTR peak height was correlated with patient cognitive impairment (r = 0.65, p = 0.003). This preliminary study presents a novel approach to quantify AD-related tissue damage in-vivo.

Aged↗
PubMed2001

Diagnosis and differential diagnosis of acute transverse myelopathy. The role of neuroradiological investigations and review of the literature.

Acute transverse myelopathy (ATM) is a clinical definition of an acute neurologic condition that reflects impairment of spinal cord function. The term "myelopathy" has a different meaning from "myelitis", even if the words are often confused. Both terms indicate spinal cord involvement by some pathological event; but while myelopathy does not imply any etiological factor, myelitis refers to inflammatory diseases of the spinal cord. Acute spinal pathology can be associated with intra-axial or extra-axial lesions; extra-axial spinal pathology, however, has more often a chronic and progressive presentation. In this paper, we discuss primarily intra-axial lesions with attention on the role of neuroradiological investigations in diagnosis and differential diagnosis. Magnetic resonance imaging is the modality of choice for diagnosis; it shows signal abnormalities, usually T2 hyperintensity, focal or extensive, gadolinium enhancement and sometimes cord swelling. Despite its high sensitivity, about 40% of acute transverse myelopathies remain undemonstrated. Concerning etiology (multiple sclerosis (MS), vasculitis, infection, autoimmune disorders) no clearly different and specific patterns have been found; however small multiple enhancing lesions are more suggestive of MS (or lupus) while extensive, multilevel abnormalities reflect vasculitis as in antiphospholipid antibody syndrome.

Diagnosis, Differential↗
PubMed2001

Differential diagnosis of posterior fossa multiple sclerosis lesions--neuroradiological aspects.

Various infratentorial pathological conditions can mimic multiple sclerosis (MS) both clinically and radiologically. We review the inflammatory, vascular, neoplastic and metabolic conditions which show features similar to those of MS on magnetic resonance imaging (MRI). Behcet's disease, Lyme disease, progressive multifocal leukoencephalopathy, neurosarcoidosis, Whipple's disease, listeria rhombencephalitis, Bickerstaff's brainstem encephalitis, vasculitis due to systemic lupus erythematosus, and acute disseminated encephalomyelitis produce inflammatory lesions similar to those of MS in the brainstem and cerebellum. Neoplastic diseases, in particular pontine gliomas and lymphomas, can mimic MS. Vascular ischaemic lesions, either due to infarction produced by occlusion of a major posterior circulation artery or due to small vessel vasculopathy, can lead to posterior fossa lesions. The MRI changes of central pontine myelinolysis can also mimic MS. Diffuse axonal injury, radiation and chemotherapy induce lesions that resemble MS, however the clinical history will exclude these possibilities. Finally, we discuss a few conditions which are similar to MS in clinical presentation but have different MRI appearances, such as brainstem cavernomas, posterior fossa tumoural lesions, aneurysms and vascular loops producing neurovascular conflicts. Analysis of the MRI findings with clinical history and laboratory data helps to narrow down the diagnosis of the infratentorial pathology.

Brain↗
PubMed2001

Spinal cord involvement in primary angiitis of the central nervous system: a report of two cases.

SUMMARY: We report two patients with suspected primary angiitis of the CNS who underwent serial contrast-enhanced MR imaging of the spinal cord. MR abnormalities were multiple and enhancing, and located within the cervical and thoracic cord. Brain MR findings and brain biopsy specimens were positive for primary angiitis of the CNS. On follow-up MR studies, obtained after steroid and immunosuppressive therapy, a significant decrease in the number and size of the enhancing and nonenhancing abnormalities was observed, along with clinical improvement. Numerous small and enhancing abnormalities with a primarily posterior location, seen at the onset of the disease and resolved on follow-up studies, may be considered suggestive of a diagnosis of primary angiitis of the CNS.

Adult↗
PubMed2000

Comparison of MRI pulse sequences for investigation of lesions of the cervical spinal cord.

Small spinal cord lesions, even if clinically significant, can be due to the low sensitivity of some pulse sequences. We compared T2-weighted fast (FSE), and conventional (CSE) spin-echo and short-tau inversion-recovery (STIR)-FSE overlooked on MRI sequences to evaluate their sensitivity to and specificity for lesions of different types. We compared the three sequences in MRI of 57 patients with cervical spinal symptoms. The image sets were assessed by two of us individually for final diagnosis, lesion detectability and image quality. Both readers arrived at the same final diagnoses with all sequences, differentiating four groups of patients. Group 1 (30 patients, 53%), with a final diagnosis of multiple sclerosis (MS). Demyelinating lesions were better seen on STIR-FSE images, on which the number of lesions was significantly higher than on FSE, while the FSE and CSE images showed approximately equal numbers of lesions; additional lesions were found in 9 patients. The contrast-to-noise ratio (CNR) of 17 demyelinating lesions was significantly higher on STIR-FSE images than with the other sequences. Group 2, 19 patients (33%) with cervical pain, 15 of whom had disc protrusion or herniation: herniated discs were equally well delineated with all sequences, with better myelographic effect on FSE. In five patients with intrinsic spinal cord abnormalities, the conspicuity and demarcation of the lesions were similar with STIR-FSE and FSE. Group 3, 4 patients (7%) with acute myelopathy of unknown aetiology. In two patients, STIR-FSE gave better demarcation of lesions and in one a questionable additional lesions. Group 4, 4 patients (7%) with miscellaneous final diagnoses. STIR-FSE had high sensitivity to demyelinating lesions, can be considered quite specific and should be included in spinal MRI for assessment of suspected demyelinating disease.

Adolescent↗