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Biomedical subjects

U Nocentini

Publications and source records attributed to U Nocentini.

At least 19 recordsLinked to original sources
PubMed2006

Cognitive dysfunction in patients with relapsing-remitting multiple sclerosis.

Cognitive dysfunction is considered one of the clinical markers of multiple sclerosis (MS). However, in the literature there are inconsistent reports on the prevalence of cognitive dysfunction, and separate data for the relapsing-remitting (RR) type of the disease are not always presented. In this study, we submitted 461 RRMS patients to a battery of neuropsychological tests to investigate their impairment in various cognitive domains. As a consequence of the exclusion criteria, the sample is not fully representative of the entire population of RRMS patients. In this selected sample, when only the eight scores of a core battery (Mental Deterioration Battery) were considered (with respective cutoffs), it emerged that 31% of the patients were affected by some degree of cognitive deficit. In particular, 15% had mild, 11.2% moderate and 4.8% had severe impairment. Information processing speed was the most frequently impaired area, followed by memory. When two other tests (SDMT and MCST) were added and cognitive domains were considered, it emerged that 39.3% of the patients were impaired in two or more domains. When four subgroups were obtained by means of cluster analysis and then compared, it emerged that information processing speed and memory deficits differentiated the still cognitively unimpaired from the mildly impaired MS patients. Significant associations were found between cognitive and clinical characteristics. However, due to the large sample size, clinically irrelevant relationships may also have emerged. Even with the limitations imposed by the sample selection and the possible underestimation of the prevalence and severity of cognitive dysfunction, these results seem to provide further evidence that information processing speed deficit may be an early and important marker of cognitive impairment in MS patients.

Adult↗
PubMed2002

Diffusion of water in large demyelinating lesions: a follow-up study.

We studied five patients with multiple sclerosis with one plaque of demyelination more than 2 cm in diameter, using conventional and diffusion-weighted MRI, soon after the onset of symptoms and over 1-36 months. The orientationally averaged diffusion coefficient was increased in all the acute lesions, and increased further during follow-up in three. There was a strong correlation between and the degree of low signal on T1-weighted images. The quantitative information provided by allowed delineation of different diffusion patterns in large MS lesions, that may reflect heterogeneity of the anatomical substrate.

Adult↗
PubMed2001

Defective Fas ligand production in lymphocytes from MS patients.

In the present transectional study, Fas ligand (Fas-L) levels, either in membrane or in soluble form, in cells from multiple sclerosis (MS) patients were investigated. Expression of Fas was evaluated after PHA stimulation of peripheral blood mononuclear cells from MS patients with relapsing-remitting or secondary-progressive disease, and in healthy donors. There was statistically significant decreased expression (p = 0.001), as well as release of Fas-L, (p = 0.045) in lymphocytes from MS patients, in comparison with healthy donors. Moreover, levels of Fas-L production were inversely correlated with the EDSS scores of patients in an highly significant way. Impairment of Fas-L release in stimulated PBMC from MS patients might influence the ability to eliminate autoreactive clones in vivo.

Adult↗
PubMed2001

Interhemispheric transfer time in a patient with a partial lesion of the corpus callosum.

The interhemispheric transfer time (ITT) of basic visuo-motor integration was investigated in a patient who had a lesion of the corpus callosum that spared the splenium and rostrum. Overall, 4291 simple reaction times were collected during unimanual responses to tachistoscopically presented lateralized simple visual stimuli at 4 degrees, 6 degrees and 10 degrees. Despite retaining some abilities that typically require the integration of information between hemispheres (e.g. haptic naming, tachistoscopic lateralized consonant reading) the patient performed similarly to completely callosotomized patients in a basic visuo-motor ITT task (overall 25.5 ms) at any eccentricity. These findings suggest that specific callosal channels mediate the basic visuo-motor ITT and these do not include the rostrum and/or the splenium of the corpus callosum.

Brain Injuries↗
PubMed2001

The effects of left- versus right-hemisphere lesions on the sensitivity to intra- and interconceptual semantic relationships.

Studies on split-brain, normal and brain-damaged subjects suggest differences in the processing of semantic relationships by the two hemispheres. Various authors have conceived of this distinction in terms of the paradigmatic/syntagmatic dissociation, and the connotative and denotative meanings of words, and as reflecting different types of links between words. Drews has suggested that a left-hemisphere lesion would affect the processing of intraconceptual relationships, while a right-hemisphere lesion would impair the processing of interconceptual relationships. The goal of this study was to test this hypothesis, using a number of intra- and interconceptual semantic relationships. Pairs of common words were submitted to left-hemisphere brain-damaged and right-hemisphere brain-damaged subjects. The task required subjects to indicate whether or not there was any relationship between the words. The results only partially support the hypothesis. The right/left opposition applied to only one of three types of intraconceptual relationships (whole-part relation) and to one of two types of interconceptual relationship (same location relation). This partially unexpected result is discussed in reference to other studies.

Aged↗
PubMed2001

Patterns of cognitive impairment in secondary progressive stable phase of multiple sclerosis: correlations with MRI findings.

Cognitive impairment is commonly described in multiple sclerosis (MS), but conflicting results have been reported about its pattern by previous studies focused on heterogeneous patient groups. The aim of this study was to investigate the cognitive skills of a homogeneous group of secondary progressive MS patients, and to examine the relationship of this impairment to MRI parameters. Forty-four MS patients underwent a series of neuropsychological tests devised to explore the main cognitive domains, and T1- and T2-weighted brain MRI. Results showed the presence of deficits of attention, memory, planning abilities, problem-solving and conceptual reasoning (frontal functions) in a subgroup of MS patients. Correlations between the performance in some 'frontal' tests and the extent of frontal lobe MRI lesional area were present, but rather unspecific, the same performance being also correlated with the nonfrontal lesional area. These findings suggest that in MS, overall macroscopic and microscopic brain damage is more important than the corresponding focal brain disease, even in determining deficits of selective cognitive domains.

Adult↗
PubMed2000

Demyelinating plaques in relapsing-remitting and secondary-progressive multiple sclerosis: assessment with diffusion MR imaging.

BACKGROUND AND PURPOSE: Conventional MR imaging does not provide specific information that can be reliably associated with the pathologic substrate and clinical status of patients with multiple sclerosis (MS). Our goals were 1) to determine whether the orientationally averaged water diffusion coefficient ( ) can be used to distinguish between plaques of different severity in these patients and 2) to assess possible correlations between values and disease duration, Expanded Disability Status Scale (EDSS) score, and signal intensity on T1-weighted MR images. METHODS: Twenty patients (10 with relapsing-remitting MS and 10 with secondary-progressive MS) and 11 healthy volunteers underwent a combined conventional and diffusion-weighted MR study of the brain. , a parameter that is proportional to the trace of the diffusion tensor, was computed by averaging the apparent diffusion coefficients measured in the x, y, and z directions. measurements were obtained for selected areas of white matter plaques. Differences in among the three groups were tested using analysis of variance. RESULTS: was significantly higher (1.445 +/- 0.129 x 10(-3) mm2/s) in secondary-progressive lesions than in relapsing-remitting lesions (0.951 +/- 0.08), and both values were higher than in normal white matter (0.732 +/- 0.02). There was a significant negative correlation between and the degree of hypointensity on T1-weighted images, and a positive correlation between and both EDSS score and disease duration. CONCLUSION: Our findings suggest that is useful for distinguishing MS lesions of different severities, which are associated with different degrees of clinical disability.

Adolescent↗
PubMed1999

Impaired apoptosis in mitogen-stimulated lymphocytes of patients with multiple sclerosis.

We investigated the sensitivity to cell death of peripheral blood mononuclear cells (PBMCs) from patients with multiple sclerosis (MS). PBMCs from MS patients, following PHA stimulation, were less sensitive to cell death than those from healthy donors (mean +/- s.e.m., 22.5 +/- 1.9 in MS patients vs 36.5 +/- 2.8 in healthy controls; p = 0.0003). However, when Fas-agonist antibody was added, the increase in respect to apoptosis induced by mitogen alone was even higher in MS patients than in controls. In addition, PHA-activated PBMCs from MS patients showed higher surface expression of Fas than controls, while Bcl-2 expression was decreased. This finding raised the question of whether an impaired generation of apoptotic signals may be contributing to the immune component of MS.

Adult↗
PubMed1999

Age-related evolution of the contribution of the right hemisphere to language: absence of evidence.

The age difference observed between Wernicke's and Broca's aphasics has been understood by some authors as an indication of a progressive diminution of the contribution of the right hemisphere to language throughout the life span. To test this hypothesis, 24 right-hemisphere-damaged (RHD) and 24 normal control adults were submitted to six tasks looking at different aspects of language abilities. Results showed that RHDs performed less well than normal subjects on 3 of these tasks, but that this difference was not linked with age (younger than 55 versus older than 65 years). Consequently, these results do not support models of functional brain organization suggesting a decreasing contribution of the right hemisphere to language abilities with age.

Acoustic Stimulation↗
PubMed1997

A callosal disconnection syndrome of vascular origin.

OBJECTIVE: To study the after-effects of a selective lesion of the corpus callosum on the capacity in transferring spatial information on arm posture derived from kinesthesia and vision. DESIGN: Neuropsychological and psychophysical evaluations of a patient with callosal damage. SETTING: Institute of Neurology, University of "Tor Vergata", Rome, Italy and Research Centre, IRCCS "S. Lucia", Rome, Italy. PATIENT: P.V., a 59 years old man suffering from a vascular lesion of the left half of corpus callosum and left callosal radiations. MEASURES: Sensori-motor and cognitive tasks. Exo- and egocentric pointing abilities tasks. RESULTS: Impairments due to a disconnection between the two cerebral hemispheres were pointed out. About pointing abilities, errors were greater when each hand pointed to the remembered location of the other hand. Errors decreased dramatically with eyes open for right hand pointing to remembered location of left and right hand, and left hand pointing to remembered location of left hand. Open eyes left hand pointing to remembered location of right hand remained as poor as with eyes closed. CONCLUSIONS: The results appear compatible with the following network: visual information from striate and extrastriate cortex is passed forward to parietal cortex bilaterally (even in PV due to the splenium sparing). Kinesthetic information from parietal cortex of left and right hemisphere converge on a single visuokinesthetic center, lateralized to the left hemisphere. Information about limb position in three-dimensional space is then encoded in body-centered coordinates and passed forward to motor and premotor cortex in the frontal lobe. These frontal regions are those disconnected in PV.

Brain Ischemia↗
PubMed1996

Implicit memory in parkinsonian patients: evidence for deficient skill learning.

The aim of this study was to investigate procedural learning in idiopathic Parkinson's disease (PD) patients. For this purpose, 18 nondemented PD patients and 20 age-matched healthy subjects were trained to learn a visuoperceptual skill (mirror reading) and a cognitive skill with a motor demand (puzzle assembly task). In 3-day sessions, the patients were requested to perform with repeated and unrepeated stimuli, in order to distinguish between pure procedural learning and skill learning at least partially supported by explicit memory retrieval. In the mirror reading task, the PD patients showed normal improvement in reading times for repeated words but no improvement at all for unrepeated stimuli. In the puzzle assembly task, PD patients did not show any significant learning either for repeated or unrepeated stimuli. These results, which document deficient learning of procedures in parkinsonians, are discussed in the light of conflicting data reported regarding implicit memory in PD.

Aged↗
PubMed1990

Contralateral and ipsilateral disorders of visual attention in patients with unilateral brain damage.

To explain the prevalence of unilateral spatial neglect in patients with right brain damage, Heilman et al have suggested that the attentional neurons of the right parietal lobe might have bilateral receptive fields, whereas the homologous cells of the left hemisphere would have strictly contralateral receptive fields. One implication of this theory is that patients with right brain damage should show a prevalence of disorders of visual attention not only in the half space contralateral to the damaged hemisphere, but also in the ipsilateral one. To check this theory, 50 control subjects, 102 right and 125 left brain-damaged patients were given a drawing completion task in which patients were requested to complete the missing parts of a star, a cube and a house. Omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere were taken separately into account. Results did not confirm the hypothesis, since right brain-damaged patients failed to complete the contralateral sides of the models much more frequently than patients with left brain injury, but no difference was found between the two hemispheric groups when ipsilateral disorders of visual attention were taken into account. Furthermore, no correlation was found between omissions of lines lying on the sides of the models contralateral and ipsilateral to the damaged hemisphere. This finding suggests that contralateral and ipsilateral disorders of visual attention are not due to the same mechanism in right brain-damaged patients. The alternative hypothesis viewing ipsilateral disorders as resulting from a widespread lowering of general attention (and only contralateral neglect reflecting a specific disorder of visual attention) was supported by results obtained on a verbal memory test, used to evaluate the general cognitive and attention level of the patients. Patients with clear-cut ipislateral inattention obtained very low scores on this test, whereas patients with severe contralateral neglect, but not ipislateral inattention scored within the normal range on the verbal memory test.

Attention↗
PubMed1990

Cognitive functions in adult Down's syndrome.

Cognitive profiles of performances were obtained from a selected group of adult Down syndrome (DS) subjects (n = 20; mean age: 34.5 years; s.d.: 7.7) by means of an ad hoc neuropsychological battery. With the aim of examining, from a neuropsychological point of view, the modifications that increasing age produces in this group of patients, cognitive performances of younger DS subjects (mean age: 28 years; s.d.: 4.77) were compared with analogous performances obtained by the older ones (mean age: 39.8 years; s.d.: 5.11). Subsequently, to clarify qualitative aspects of cognitive patterns in the subgroups of young and old DS subjects, two different groups of control patients were utilised. Neuropsychological data collected from a group of adult mentally retarded subjects were compared with cognitive performances demonstrated by young DS subjects, while the old group of DS subjects was analyzed in comparison with a group of patients affected by initial form of Alzheimer disease (AD). Altogether, the results of our study do not seem to support, from a neuropsychological point of view, the hypothesis that mental decline observed in DS subjects reproduces the cognitive patterns of impairment observed in AD patients.

Adult↗
PubMed1989

Can the pattern of neuropsychological improvement obtained with cholinergic drugs be used to infer a cholinergic mechanism in other nootropic drugs?

1. Enhancement of episodic memory and reduction of intrusion errors are considered as the most characteristic outcome of cholinergic drugs administration in AD patients. 2. Since the nootropic drugs Piracetam and Oxiracetam are deemed to act through a cholinergic mechanism, we checked whether AD patients treated with these drugs would show the same pattern of neuropsychological improvement. 3. Results were negative, since (a) episodic memory showed a similar degree of improvement both in patients treated with these drugs and in patients treated with placebo; (b) the number of intrusions tended to increase, rather than to decrease, after the treatment period.

Alzheimer Disease↗
PubMed1989

Defective concept formation in parkinsonians is independent from mental deterioration.

An extensive neuropsychological battery (the Mental Deterioration Battery) was utilized to distinguish, within a sample of 24 idiopathic Parkinsonians, those showing signs of diffuse mental deterioration (n = 9) from those without deterioration (n = 15). Performances of control subjects on a wide range of tests exploring mnesic, visuo-constructive, linguistic and general intellectual functions (n = 21) did not differ from analogous performances of Parkinsonians without signs of diffuse mental deterioration. The Wisconsin Card Sorting Test was then used to verify the hypothesis that a selective impairment of cognitive functions subsumed by the integrity of frontal lobes could be demonstrated in Parkinsonian patients. Our results provide evidence that in this task, defective performances are obtained by Parkinsonians and even by patients without signs of diffuse cognitive impairment. These findings seem to confirm that a deficit in concept formation, maintenance and shifting is largely independent of the dementia frequently noticed in Parkinson's disease.

Aged↗
PubMed1989

Differential aspects of cognitive impairment in patients suffering from Parkinson's and Alzheimer's disease: a neuropsychological evaluation.

Neuropsychological profiles of cognitive impairment demonstrated by a group of Parkinson patients and by a group of Alzheimer patients both affected by a comparable level of mental deterioration were obtained by means of a neuropsychological battery. The results pointed out differential patterns of cognitive impairment exhibited by the two pathological groups. Particularly, Alzheimer's patients appear to be mainly impaired in mnesic functions, while Parkinsonian subjects show a pattern of performances indicative of a prevalent impairment of the functions underlied by frontal lobes. These data are in agreement with the hypothesis that different anatomical-functional cerebral structures are mainly involved in determining cognitive deterioration in the two diseases.

Alzheimer Disease↗
PubMed1986

Cognitive improvement in clinical trials with nootropic drugs: when can it be expected and how to clarify its meaning.

In order to have a correct evaluation of the activity of a nootropic drug, the criteria adopted for the choice of patients to be included in the clinical trials and the methods used to clarify the meaning of changes observed on cognitive tasks are reported. The results of a clinical trial with the nootropic oxiracetam carried out in line with the above-mentioned criteria and methods are related.

Clinical Trials as Topic↗