PubMed Health⌕ Search

Biomedical subjects

G Scotti

Publications and source records attributed to G Scotti.

At least 19 recordsLinked to original sources
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↗
PubMed2000

Introduction of GDC embolization in the clinical practice as treatment synergical to surgery: impact on overall outcome of patients with subarachnoid hemorrhage.

The GDC endovascular approach represent an effective alternative to surgery for treatment of intracranial aneurysms. Anyway no data are available about the impact of endovascular embolization with GDC on overall outcome of patients with subarachnoid hemorrhage. We analyse retrospectively a series of 234 patients admitted for ruptured intracranial aneurysm. Results were then compared with results of three surgical series from the literature. The 95.7% of patients underwent aneurysm treatment; 56.4% of patients were classified as good recovery, 12.8% presented moderate disability, 10.3% were severely disabled, 3% were in persistent vegetative state and 17.5% were dead. Patients older than 60 years accounted for 37% of all cases and good outcome in this group accounted for 54.7%. Good results were obtained in 90.1%, 61.7% and 22.8% of patients with Hunt-Hess grade I-II, III and IV-V respectively. Finally good outcome was observed in 82.8% of patients with aneurysms of the posterior circulation. Introduction of GDC embolization in clinical practice contributed to the extension of indication for aneurysm treatment leading to a reduction of overall mortality. GDC utilisation does not affect the overall percentage of patients with good outcome reflecting an increase of severely disabled patients. Endovascular treatment seems an effective theraputic choice in selected grade I-II patients. Results in grade III patients suggest that surgery may be advantageous because of washing and decompression of the basal cisterns while results in grade IV and V patients are unsatisfactory. GDC embolization clearly improves the prognosis of patients with posterior circulation aneurysms and probably is an advantageous theraputic choice in elderly patients.

Adolescent↗
PubMed2000

Stent-graft treatment of a common carotid artery pseudoaneurysm.

PURPOSE: To report a case demonstrating successful endovascular treatment of a right common carotid artery pseudoaneurysm using a commercially prepared balloon-expandable covered stent. METHODS AND RESULTS: A 50-year-old man was evaluated for syncopal episodes. He had a history of severe trauma sustained in a motor vehicle accident 3 years before symptom onset. Doppler ultrasound scanning detected a pseudoaneurysm at the origin of the right common carotid artery. The defect measured 25 mm x 20 mm with a 22-mm-long neck on angiography and computed tomography; there was no evidence of carotid stenosis or associated vascular pathology. Via a percutaneous femoral access, 2 Jostent peripheral stent-grafts were placed at the level of the aneurysm, safely achieving complete repair of the arterial wall defect. The patient was asymptomatic at his 12-month evaluation. Color flow duplex scans showed continued exclusion of the pseudoaneurysm. CONCLUSIONS: Wide-necked aneurysms in the extracranial carotid arteries may be treated with stent-grafts, which can achieve complete and permanent reconstruction of the arterial wall by excluding the aneurysm.

Aneurysm, False↗
PubMed2000

Three-dimensional time-of-flight MR angiography in the evaluation of intracranial aneurysms treated with Guglielmi detachable coils.

BACKGROUND AND PURPOSE: Intravascular treatment of intracranial aneurysms is a relatively new therapeutic technique and long-term controlled angiographic trials are needed to assess persistence of aneurysm occlusion. Our purpose was to evaluate the effectiveness of 3D time-of-flight (3D-TOF) MR angiography as a noninvasive screening tool in the follow-up of cerebral aneurysms treated with Guglielmi detachable coils (GDCs). METHODS: Forty-nine patients with 50 intracranial aneurysms previously treated with GDCs were studied with both DSA and 3D-TOF MR angiography. In 14 cases, a second follow-up examination was performed, for a total of 64 aneurysms evaluated. In 25 aneurysms, both pre- and postcontrast MR angiographic studies were obtained. RESULTS: In seven of 64 aneurysms, the MR angiographic studies were considered to be unreliable owing to the presence of artifacts that obscured part of the parent artery and did not allow an accurate evaluation of the aneurysm neck. These seven aneurysms, however, all were shown to be completely occluded at digital subtraction angiography (DSA). In the remaining 57 aneurysms, DSA revealed complete occlusion in 39 and the presence of residual patency in 18, whereas MR angiography showed complete occlusion in 38 and residual patency in 19. Enhanced MR angiography proved to be useful in evaluating residual patency in large and giant aneurysms and in better depicting the distal branch arteries. CONCLUSION: Although artifacts related to the presence of coils are evident on a considerable number of imaging studies, our findings indicate that MR angiography is useful in the evaluation of residual patency of cerebral aneurysms treated with GDCs and may eventually prove valuable in the follow-up of those cases in which a good initial correlation with DSA was demonstrated.

Angiography, Digital Subtraction↗
PubMed1999

Emergency endovascular treatment of a life-threatening hemorrhage from traumatic rupture of the left extracranial vertebral artery.

Hemorrhagic complications from transection of cervical arteries in blunt traumas are rare. We report a case of potentially fatal hemorrhage from rupture of the left vertebral artery in a closed trauma, successfully treated by endovascular injection of glue. Endovascular embolization may be considered as an alternative to surgical exploration in the treatment of traumatic lesions of vertebral arteries.

Accidents↗
PubMed1999

Post-traumatic dissecting aneurysm of extracranial internal carotid artery: endovascular treatment with stenting.

Traumatic internal carotid dissection occurs frequently in motor vehicle accidents, typically extracranially, close to the skull base. Dissection may lead to stenosis or occlusion of the vessel, possibly with a pseudoaneurysm, symptoms ranging from neck pain to neurological deficits. In symptomatic patients and in cases of pseudoaneurysm, when conservative medical treatment fails, surgery or endovascular treatment are indicated. We report a post-traumatic dissecting aneurysm of the extracranial internal carotid artery successfully treated with stenting via a transfemoral approach.

Accidents, Traffic↗
PubMed1999

Method for intracellular magnetic labeling of human mononuclear cells using approved iron contrast agents.

A method for intracellular iron labeling of human mononuclear cells (lymphocytes and monocytes) for magnetic resonance imaging (MRI) using simple incubation of cells with approved MRI iron contrast agents is presented. Labeled cells can be detected by MRI in vitro, and this suggests the possibility that the technique could become a marker for in vivo lymphocyte and monocyte trafficking studies in acute inflammatory lesions such as those in Multiple Sclerosis.

Cell Survival↗