Biomedical subjects

D Bartrés-Faz

Publications and source records attributed to D Bartrés-Faz.

15 recordsLinked to original sources

PubMed2006

Increased cerebral activity in Parkinson's disease patients carrying the DRD2 TaqIA A1 allele during a demanding motor task: a compensatory mechanism?

Previous studies suggest that neuroimaging techniques are useful for detecting the effects of functional genetic polymorphisms on brain function in healthy subjects or in patients presenting with psychiatric or neurodegenerative conditions. Former evidence showed that individuals carrying risk alleles displayed broader patterns of brain activity during behavioural and cognitive tasks, despite being clinically comparable to non-carriers. This suggests the presence of compensatory brain mechanisms. In the present study, we investigated this effect in Parkinson's disease (PD) patients carrying the DRD2 TaqIA A1 allelic variant. This variant may confer an increased risk of developing the disease and/or influence the clinical presentation. During a complex sequential motor task, we evidenced by functional magnetic resonance imaging that A1 allele carriers activated a larger network of bilateral cerebral areas than non-carriers, including cerebellar and premotor regions. Both groups had similar clinical and demographic measures. In addition, their motor performance during the functional magnetic resonance experiment was comparable. Therefore, our conclusions, pending replication in a larger sample, seem to reflect the recruitment of compensatory cerebral resources during motor processing in PD patients carrying the A1 allele.

Adaptation, Physiological↗

PubMed2002

Apolipoproteins E and C1 and brain morphology in memory impaired elders.

Previous research has shown that polymorphisms of the apolipoproteins E ( APOE) and APOC1 represent genetic risk factors for dementia and for cognitive impairment in the elderly. The brain mechanisms by which these genetic variations affect behavior or clinical severity are poorly understood. We studied the effect of APOE and APOC1 genes on magnetic resonance imaging measures in a sample of 50 subjects with age-associated memory impairment. The APOE E4 allele was associated with reduced left hippocampal volumes and APOE*E3 status was associated with greater frontal lobe white matter volumes. However, no APOE effects were observed when analyses accounted for other potential confounding variables. The effects of APOC1 on hippocampal volumes appeared to be more robust than those of the APOE polymorphism. However, no modulatory effects on brain morphology outside the medial temporal lobe region were observed when demographic variables, clinical status, and other anatomical brain measurements were taken into consideration. Our results suggest that the role of the APOC1 polymorphism in brain morphology of the cognitively impaired elderly should be examined in further studies.

Aged↗

PubMed2002

Relation of Apo E and ACE genes to cognitive performance in chronic alcoholic patients.

Apolipoprotein E epsilon4 and ACE genes have been related to several conditions involving cognitive impairment, including Alzheimer's disease, normal ageing and cerebrovascular disease. However, it has not been established whether their genotypes are associated with alcoholism or its cognitive functioning. Genotypic distributions of 140 chronic alcoholic patients were compared with a non-alcoholic sample, and the cognitive performance of a subsample of the alcoholic subjects was assessed with standard neuropsychological tests. No differences in allele or genotype distributions of Apo E or ACE genes were found when comparing controls and alcoholics (Apo E epsilon2/2; patients 1.4%, controls 0% p < 0.06; epsilon2/epsilon3; patients 9.3%, controls 6.6% p < 0.29; epsilon2/epsilon4; patients 0%, controls 1% p < 0.31; epsilon3/epsilon3 patients 71.4%, controls 72% p < 0.89; epsilon3/epsilon4; patients 15.7%, controls 19.2%, p < 0.36; epsilon4/epsilon4; patients 2.1%, controls 1.2% p < 0.44; ACE D/D; patients 35%, controls 28.5% p < 0.14; I/D; patients 47.5%, controls 51.1% p < 0.51; I/I; patients 14.5%, controls 20.4% p < 0.19). In terms of cognitive performance, epsilon4/epsilon3 patients did better on visuoconstructive (p < 0.001) and visual memory (p < 0.04) functions compared with epsilon2/epsilon3 bearers. Furthermore, ACE D/D patients performed better on a test of abstract reasoning (p < 0.03) compared with the ACE I/I homozygous group. The cognitive results suggest that Apo E or ACE genotypes may modify the effects of ethanol on cognitive deterioration in alcoholic patients. However, the data do not support an association between the Apo E epsilon4 allele and reduced cognitive performance in alcoholism.

Adult↗

PubMed2001

APOE and APOC1 genetic polymorphisms in age-associated memory impairment.

We studied the distribution of two genetic polymorphisms (APOE and APOC1) in a sample of 100 subjects fulfilling the NIMH criteria for age-associated memory impairment (AAMI) and 124 controls. We found significant associations both for APOE and APOC1 loci and their combinations with the AAMI condition. The findings in our sample suggest that memory-impaired subjects as described by the NIMH may be genetically differentiated from normally aging subjects in relation to these two polymorphisms and indicate the interest of considering variations in the APOC1 gene for further studies in cognitive aging.

Aged↗

PubMed2001

Neuropsychological and genetic differences between age-associated memory impairment and mild cognitive impairment entities.

OBJECTIVE: To neuropsychologically and genetically compare age-associated memory impairment (AAMI) and mild cognitive impairment (MCI) entities and to determine what proportion of AAMI diagnosed individuals could also receive a MCI diagnosis. To compare the distribution of a previously known genetic risk factor for Alzheimer's disease (apolipoprotein E common polymorphism) associated with these two conditions with a sample of the normal aging. DESIGN: Neuropsychological and genetic assessments in AAMI and MCI individuals. Genetic assessment in AAMI, MCI, and control subjects. SETTING: General health centers and geriatric homes from northeastern Spain (Catalunya). PARTICIPANTS: One hundred and four subjects presenting subjective memory complaints were selected and the AAMI and MCI criteria were applied. One hundred and twenty-four healthy Spanish subjects age 50 and older were defined as controls. MEASUREMENTS: Memory, language, and frontal lobe functions were assessed using standard neuropsychological tests. The apolipoprotein E (apo E) polymorphism was obtained by using polymerase chain reaction (PCR) and HhaI restriction endonuclease. RESULTS: Sixty-seven percent of previously diagnosed AAMI individuals could also be identified as MCI subjects. These MCI cases differed from those only-AAMI individuals both in neuropsychological and genetic analyses, performing worse not only on memory but also on language and frontal lobe tests and presenting high and low prevalences of the apo E epsilon 3/epsilon 4 and epsilon 3/epsilon 3 genotypes, respectively. The general AAMI sample of 93 individuals also differed from controls in the apo E genotype and allele distributions but these differences were no longer present after subtracting the MCI cases (63 subjects). These findings reflect that the differences between the memory impaired sample and the control sample regarding the apo E polymorphism were mainly attributable to MCI individuals and not to those who received only a diagnosis of AAMI alone. CONCLUSIONS: Our findings suggest that among AAMI subjects, those who also fulfill the MCI criteria present a neuropsychological and genetic profile closer to that previously related to Alzheimer's disease than those individuals only eligible for a diagnosis of AAMI. However, our findings also suggest that using only the AAMI criteria still appears to select a population that differs genetically from the normal older population.

Age Distribution↗

PubMed2001

Correlation of atrophy measures on MRI with neuropsychological sequelae in children and adolescents with traumatic brain injury.

To examine the relationship between neuropsychological sequelae and atrophy parameters from magnetic resonance imaging (MRI) following paediatric moderate-to-severe traumatic brain injury (TBI), 19 head injured children and adolescents were studied at least 6 years after injury. Three-dimensional MRI scans were obtained. A semi-automatic computerized method was used to estimate ventricular volumes and the corpus callosum area. Tests of intellectual, memory, visuospatial, frontal lobe, and motor speed functioning were administered to all patients and to 19 matched normal control subjects. Patients' performance significantly differed from controls in general intellectual function, visual memory, visuospatial and frontal lobe tests. The corpus callosum area correlated strongly with several measures involving processing speed and visuospatial function. Ventricular enlargement was less related to neuropsychological outcome. In conclusion, quantitative measurement of the corpus callosum on MRI reflects neuropsychological outcome better than ventricular dilation in paediatric patients.

Adolescent↗

PubMed2000

Angiotensin I converting enzyme polymorphism in humans with age-associated memory impairment: relationship with cognitive performance.

We compared the distribution of an insertion (I)/deletion (D) polymorphism coding for the angiotensin I converting enzyme (ACE) gene in 100 subjects fulfilling NIMH criteria for Age-associated memory impairment (AAMI) and 124 controls. We found significantly reduced prevalences of the ACE I/I genotype together with increases of the ACE D allele in the AAMI group. We further compared the neuropsychological performance of the AAMI group according to their ACE genotype. Those AAMI subjects presenting the ACE I/I genotype exhibited better performance on a measure of frontal lobe function. Our results suggest that the lack of the ACE I/I genotype and the presence of the ACE D allele are associated with memory impairment in the elderly.

Age Factors↗

PubMed1999

Apo E influences declarative and procedural learning in age-associated memory impairment.

Age-associated memory impairment (AAMI) is a clinical entity which was originally described to define memory problems linked to normal aging. Apolipoprotein E and ACE genes have both been associated with cognitive impairment in aging and dementia. The purpose of this study was to investigate memory and executive functions in AAMI according to the genetic background. We found that subjects carrying the Apo E epsilon4 allele exhibit lower memory performance on tests of both declarative and procedural memory. We did not find differences on frontal lobe tests. These findings give further support to the hypothesis concerning a genetic susceptibility for cognitive impairment in aging.

Aged↗

PubMedDate not supplied

MRI and genetic correlates of cognitive function in elders with memory impairment.

The present study investigated the relationship between genetic variation, MRI measurements and neuropsychological function in a sample of 58 elders exhibiting memory decline. In agreement with previous reports, we found that the epsilon4 allele of the apolipoprotein E (APOE) and the D allele of the angiotensin converting enzyme (ACE) polymorphisms negatively modulated the cognitive performance. Further, we found an association between the A allele of the apolipoprotein C1 (APOC1) polymorphism and poorer memory and frontal lobe function. No clear associations emerged between MRI measures of white matter lesions (WML) or hippocampal sulcal cavities (HSC) and the cognitive performance after controlling for age effects. Further, the degree of WML or HSC lesions was in general not predisposed genetically except for the presence of the A allele of the APOC1 polymorphism that was related to a higher severity of HSC scores. Our results suggest that WML or HSC do not represent important brain correlates of genetic influences on cognitive performance in memory impaired subjects.

Aged↗

PubMedDate not supplied

[Cognitive changes in normal aging: nosology and current status].

INTRODUCTION AND OBJECTIVES: During the last 15 years several diagnostic categories have appeared to describe a group of adults with cognitive impairment compared to their age-matched standardized norms but without dementia. In this work, the main studies relating to these categories are reviewed and compared in order to establish if they define similar or different aged populations. DEVELOPMENT: Differences in prevalence or in prognostic values among studies are probably due to the selection of diagnostic categories or the differences in the application of inclusion/exclusion criteria. Genetic and neuroimaging data have contributed to reinforce the validity of the proposed classifications to identify the age related cognitive decline. CONCLUSIONS: The criteria used seems to be very important in the inclusion of subjects closer to normal aging or to dementia. In this respect further longitudinal studies and a consensus from previous described categories are need to reliably identify aged population with lower cognitive function compared to their age norms but different from patients in the initial stages of dementia.

Aged↗

PubMedDate not supplied

[The application of transcranial magnetic stimulation in neuropsychological investigation].

OBJECTIVE: In this review we describe the main studies in which transcranial magnetic stimulation (TMS) has been used in the study of superior cognitive function. DEVELOPMENT: The various studies published in the literature show that TMS can modulate neuropsychological processes such as attention, different types of memory such as working memory, declarative memory, memory of procedures and language. In most cases TMS acts on the different cognitive abilities blocking or making them difficult. Thus TMS may be used as a method of causing transient lesions bringing the relationship brain-conduct to a dimension of cause and avoiding certain limitations of the classical method for creating lesions. The positive effects of TMS in certain tasks involving language and memory has also been shown. The latter offer new possibilities of future application in cognitive rehabilitation. CONCLUSIONS: TMS has an obvious effect on neuropsychological functions. Over the past ten years studies in this field have increased progressively. At the present time the results obtained by using TMS in cognitive neuroscience are of a basic type, limited to experimental laboratory work. It has mainly been used on normal persons. However, it cannot be long before it is used clinically in neuropsychological patients.

Attention↗

PubMedDate not supplied

[Transcranial magnetic stimulation: contribution to psychiatry and to the study of brain-behavior relationship].

Transcranial Magnetic Stimulation (TMS) is a safe noninvasive technique to modulate cortical excitability. The introduction of repetitive TMS (rTMS) provides a new tool for studying psychopathologic disorders and higher cognitive functions. One of the most salient potential effects of rTMS is its possible therapeutic effect on different psychiatric disorders like depression, mania, obsessive compulsive disorder, post-traumatic stress disorder and schizophrenia. The mechanisms by which exerts its therapeutic effects are still unknown. However, the combination of this new methodology with functional neuroimaging techniques may help clarify what cerebral dysfunctions underly certain psychiatric conditions at the same time that it provides novel insights into brain cortico-cortical and cortico-subcortical connectivity.

Brain↗

PubMedDate not supplied

[Study of the long term sequelae of traumatic brain injury: evaluation of declarative and procedural memory, and its neuroanatomic substrate].

INTRODUCTION AND OBJECTIVES: The hippocampus and the striatum have been proposed as respectively cerebral substrates of declarative and procedural memory. Both structures are vulnerable to traumatic brain injury. Although declarative and procedural memory have been reported to be impaired in traumatic brain injury (TBI), volumetric measures have so far failed to associate this impairment with atrophy of hippocampal and striatal structures. In our study, we investigated the profile of declarative and procedural memory in children who suffered from moderate to severe traumatic brain injury during childhood (injury test interval: 9.42+/-1.98 years). PATIENTS AND METHODS: Nineteen patients and matched controls were evaluated on tests of declarative memory and motor learning. Results showed that TBI subjects exhibit poorer performance in both tasks. Moreover, structural magnetic resonance images were obtained from TBI subjects. In order to relate neuropsychological performance with hippocampal and neostriatal volumetric data, correlation analyses were performed. RESULTS: Significant positive correlations were obtained between hippocampal volume and memory for objects. Striatal volume correlated positively with motor learning and with verbal memory. CONCLUSIONS: It thus seems that plasticity does not completely compensate for the memory deficits resultant from neural loss in the immature brain.

Adolescent↗

PubMedDate not supplied

[White matter changes and cognitive performance in aging].

OBJECTIVE: In this paper we review the main magnetic resonance studies to show a possible relationship between changes in the white matter of the brain or leukoaraiosis, and the neuropsychological profile of elderly persons without dementia. DEVELOPMENT: The articles published to date show contradictory data, and in nearly half the cases reviewed no clear relationship could be established between leukoaraiosis and conduct. However, by using sensitive cognitive tests it is possible to detect and association between the presence and degree of change in the white matter and decline in frontal function such as speed of processing information, visuomotor function, verbal fluency, classification and mental sequences. Other cognitive areas such as language, memory or visuospatial, visuoconstructive and visuoperceptive functions appear less frequently related to the presence or intensity of lesions of the white matter of the brain. From a neuropsychological point of view, periventricular localization of the leukoaraiosis seems to be more important than subcortical localization. CONCLUSIONS: The neuropsychological functions most frequently associated with the presence of leukoaraiosis are those dependent on the frontal lobes, and are a disconnection favoured by the presence of the white matter of the brain, the most probable underlying physiopathological mechanism. Although there is evidence showing a genetic effect in the appearance of the white matter of the brain, study of the genes associated with cognitive deterioration in normal ageing has not given conclusive findings.

Aging↗

PubMedDate not supplied

[Apolipoproteins and cognitive deterioration].

Main studies which have shown an association between the variation in apolipoprotein genes and human neuropsychological impairement are reviewed in this work. Data from literature indicate a special relevance of apolipoprotein E (ApoE) in relation to Central Nervous System (CNS) functions, basically memory. ApoE epsilon 4 is a well documented risk factor for late-onset Alzheimer's Disease (AD). Memory changes in older adults and in AD are also associated with ApoE genotype. Furthermore, ApoE may play a role in formation or degeneration of some neural structures related to memory. In some studies a relation between ApoE's alleles and cerebral vascular disorders like ischemic, haemorrhagic, Vascular (VD) and Multi-infarct (MD) Dementias is also reported. The role of the remaining apolipoproteins in cognitive impairment is still unknown, and these molecules have been considered as risk factors associated with environmental factors in CNS pathologies, essentially the vascular ones.

Aged↗