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Biomedical subjects

P Vendrell

Publications and source records attributed to P Vendrell.

33 records · Page 2Linked to original sources
PubMed1991

Left-ear extinction in patients with MRI periventricular lesions.

A dichotic listening test was administered to 22 elderly vascular patients with periventricular white matter changes on magnetic resonance imaging. We found four patients with a moderate-to-severe extent of these changes who showed a pattern of left-ear extinction. These findings suggest that periventricular lesions in patients with vascular risk factors may be associated with a functional disconnection of the interhemispheric auditory pathways.

Aged↗
PubMed1991

Cognitive correlates of ventricular enlargement in vascular patients with leuko-araiosis.

We studied the cognitive significance of ventricular enlargement in 40 vascular patients with leuko-araiosis on MRI. We obtained significant differences between patients and normal controls without vascular risk-factors regarding ventricular measures. Ventricular size of the patients correlated with several neuropsychological tests measuring abstract reasoning, comprehension of language, constructional skills, speed and attention. These results suggest that ventricular enlargement in vascular patients reflects global deterioration of complex cognitive functions. Information proceeding from ventricular size is complementary to that coming from the degree of leuko-araiosis and probably has more clinical significance. Both leuko-araiosis and ventricular size may be neuroimaging parameters capable of reflecting the cognitive deterioration in vascular patients without large lesions.

Aged↗
PubMed1990

Leuko-araiosis on magnetic resonance imaging and speed of mental processing.

The clinical significance of white matter abnormalities seen in brain imaging studies, termed leuko-araiosis (LA), still remains uncertain. Leuko-araiosis has been associated with a global decline in cognitive performance, although little is known about the cognitive functions that LA may account for. We present the correlates between LA severity on magnetic resonance imaging and mental deterioration in a selected sample of 41 elderly patients with vascular risk factors. We found that LA was related to performance on tasks measuring the speed of information processing and, in particular, on those that involve complex processes. This impairment can be important in producing reduction in daily living activities as it is in the support to the relationship found with some commonly used behavioral rating scales. Leuko-araiosis is also related to the presence of some primitive reflexes, suggesting that their disinhibition may be due to diffuse corticofugal fibers damage.

Aged↗
PubMed1990

Auditory ear extinction in lacunar syndromes.

A dichotic listening test was administered to 28 patients with lacunar syndromes in order to contribute to the investigation of the subcortical route of interhemispheric auditory pathways. Topographic study showed that lesions in the external capsule or in the anterior limb of the internal capsule in both hemispheres produced left ear extinction. The possibility that some of the auditory fibres travel through the external capsule, as well as the anterior limb of the internal capsule, before crossing the contralateral cerebral lobe is suggested.

Adult↗
PubMed1990

Wallerian degeneration of the pyramidal tract in capsular infarction studied by magnetic resonance imaging.

Using magnetic resonance imaging, we studied 24 patients with ischemic infarction of the internal capsule. Magnetic resonance imaging detected wallerian degeneration of the pyramidal tract below the capsular lesion in 11 patients (45.8%); all 11 had clinical evidence of pyramidal tract damage. In six additional patients magnetic resonance imaging findings, present only on axial slices, were considered to indicate possible wallerian degeneration. When motor deficit was associated with posterior limb lesions, magnetic resonance imaging detected wallerian degeneration of the pyramidal tract in 78.6% (11) of 14 patients.

Aged↗
PubMed1989

Differential recovery in naming in bilingual aphasics.

Language performance in a sample of 30 Catalan-Spanish bilingual aphasics was studied using three nominal tasks (naming, pointing, and translation). We compared performance between the two languages before and after therapy and also compared the improvements made in each language. Therapy was carried out in only one language, namely Catalan. Significant differences between the two languages were initially seen in the naming and translation tasks while after treatment significant differences were observed in the naming and pointing tasks. Analysis of covariance was carried out to control the influence of the initial performance on improvements. Performance in the naming task improved more in the treated language (Catalan) than in the nontreated language. We conclude that both differential impairment and recovery of languages in bilingual aphasics is seen not only in rare cases but also in studies of larger samples.

Adult↗
PubMed1988

Slowed information processing in multiple sclerosis.

Sixteen patients with a definitive diagnosis of multiple sclerosis (MS) and an equal number of matched controls were administered tests of memory and information processing speed. Results indicated a significant long-term verbal memory impairment in patients with MS, with spared short-term memory and memory scanning. Speed of information processing was evaluated with the Paced Auditory Serial Addition Test. The results for the two highest rates of presentation revealed significantly impaired processing in the MS group. Performance at the higher rates and retrieval of information from long-term memory were significantly correlated. These results suggest that slowed information processing is a deficit that contributes to long-term memory impairment in patients with MS.

Adult↗
PubMed1988

Multiple memory deficits in patients with multiple sclerosis. Exploring the working memory system.

Some patients with multiple sclerosis (MS) demonstrate impaired memory. A group of 16 patients with MS who were mildly to moderately affected (Kurtzke Expanded Disability Status Scale Score = 3.8) were studied, and they were compared with a matched control group on tests of "working memory." The working memory system was explored by evaluating the amount of information that can temporarily be held in a buffer system during encoding. Results indicated that patients with MS have difficulty in processing information at the level of a hypothesized articulatory loop in working memory. This deficit was correlated with their retrieval of verbal information from long-term memory, as well as how accurately they processed verbal information presented at a rapid rate. There was no significant relationship between ratings of MS severity or number of plaques visualized on magnetic resonance imaging scans and the degree of working memory deficit.

Adult↗
PubMed1986

Does reversed laterality really exist in dextrals? A case study.

We report a case of a right-handed patient who, after a massive left-hemisphere infarction, had neuropsychological disturbances compatible with a right-hemisphere lesion. This has been previously called 'reversed laterality'. Two new aspects of this pattern are described: the right hemisphere is as capable as the left in processing complex syntactic and higher psycholinguistic stimuli; reversed laterality is not complete, ideomotor praxis is the only function that does not follow an inverted representation. The existence of different forms of cerebral organization in dextrals is discussed.

Agraphia↗
PubMedDate not supplied

[Attention deficit hyperactivity disorder. Cerebral asymmetry observed on magnetic resonance].

INTRODUCTION: Anatomical and functional neuroimaging data from subjects with Attention Deficit Hyperactivity Disorder (ADHD) have consistently implicated a reversal of cerebral asymmetry and suggested a fronto-striatal dysfunction in this disorder. OBJECTIVE: The aim of this study is to investigate the brain asymmetries in a homogeneous and non-medicated sample of adolescents with ADHD who had been previously studied in our laboratory. PATIENTS AND METHODS: T1-weighted magnetic resonance images were obtained for 11 adolescents with ADHD and 19 control subjects. Frontal and posterior brain regions, caudate nucleus, and ventricular system were quantitatively measured. RESULTS: A reversed pattern of asymmetry for the caudate nucleus (right > left) was found in ADHD when compared to the control group. We also found a reversed pattern of asymmetry for the frontal lobe (right < left) and a smaller right frontal volume (prefrontal specifically) in the ADHD subjects most severely impaired. Right caudate and frontal measures were inversely correlated. CONCLUSIONS: ADHD is associated with fronto-striatal abnormalities, which may be explicable via extant neurodevelopmental theories. Enlargement of the right caudate nucleus may suggest the failure of a process of synaptic 'pruning' by which attentional functions could be improperly transferred from the basal ganglia to frontal regions during development.

Adolescent↗
PubMedDate not supplied

[Functional magnetic resonance in the evaluation of the activity of the anterior cingulate cortex using Stroop's paradigm].

INTRODUCTION: Stroop s paradigm has been used to evaluate the anterior attention system which regulates the inhibitory capacity of automatic responses. Functional neuroimaging techniques have shown a preponderant role for the anterior cingulate cortex in carrying out this paradigm. OBJECTIVE: To evaluate the activity of the anterior cingulate cortex in view of its clinical importance in the study of neurological and psychiatric disorders. PATIENTS AND METHODS: Eleven healthy volunteers took part in the study. The functional images were analyzed using the software SPM99 and by second order individual and group analysis. RESULTS: Initial local analysis showed activation in the right anterior cingulated cortex (Brodmann s area 32) and left central (areas 31 and 23); caudate nucleus (right body and left tail) and thalamus (bilateral). Overall there was significant activation of the left hemisphere, in areas 44 (Broca s area), 7, 40 (supra marginal gyrus and insular cortex, and in the right hemisphere in area 19. In spite of this there was great individual variation. CONCLUSIONS: The overall results are concordant with complex functional connections for attention and the control of automatic responses. In our study the anterior cingulated cortex was not selectively activated. The activation of the thalamus and caudate nucleus may be explained by their involvement in the frontostriatal circuits. The lack of individual consistency may be due to different personal cognitive styles of resolving conflicts. According to our results, Stroop s paradigm would not be clinically useful for showing good or bad functioning of the anterior cingulated cortex.

Adolescent↗
PubMedDate not supplied

[Neuropsychological consequences of perinatal asphyxia].

Perinatal asphyxia has been classically related to important neurological diseases such as cerebral palsy, but it it also stated that a high percentage of child with a good outcome did not show any sequelae. We reviewed cerebral lesions demonstrated by post-mortem analysis and the structural MRI contributions to the anatomo-functional correlates. The most frequent neuropsychological disturbances showed by these patients in the general intelligence, perceptive functions, memory and emotional and social behavior were also summarized.

Asphyxia Neonatorum↗