Publications (6)19.94 Total impact
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Article: Regional vulnerability of hippocampal subfields and memory deficits in parkinson's disease.
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ABSTRACT: Neuropathological studies show the hippocampus is affected in Parkinson's disease (PD), with the second subfield of the cornu armonis (CA2) being the most involved. Our aims were to assess in vivo volumes of different hippocampal subfields in patients with PD with and without visual hallucinations using MRI and test their association with verbal learning and long-term recall. A total of 18 nondemented PD patients, 18 nondemented PD patients with visual hallucinations and 18 neurologically unimpaired elderly controls matched by age and gender were enrolled in this study. We assessed the volumes of seven hippocampal subfields on MRI, including the cornu armonis (CA) sectors, subiculum, presubiculum and the dentate gyrus (DG) using a novel technique that enables automated volumetry. The CA2-3 and CA4-DG subfields were significantly smaller in both groups of patients, while the subiculum was only reduced in PD patients with visual hallucinations, compared to controls. Significant correlations were found between learning performance and CA2-3 as well as CA4-DG volumes in the whole patient sample. These data show there is regional atrophy of specific hippocampal subfields in PD, which is more severe and further extends to the subiculum in patients with visual hallucinations. Our findings indicate that learning deficits are associated with volume loss in subfields that act as input regions in the hippocampal circuit, suggesting that degeneration in these regions could be responsible for cognitive dysfunction in PD. © 2013 Wiley Periodicals, Inc.Hippocampus 04/2013; · 5.18 Impact Factor -
Article: Hippocampal head atrophy predominance in Parkinson’s disease with hallucinations and with dementia
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ABSTRACT: We studied regional gray matter density in the hippocampus in Parkinson’s disease (PD) patients. We obtained magnetic resonance scans in 44 PD patients (PD patients with dementia (PDD) = 9, non-demented PD patients with visual hallucinations (PD + VH) = 16, and PD patients without dementia and without visual hallucinations (PD - VH) = 19) and 56 controls matched for age and years of education. A region of interest (ROI) of the hippocampus following voxel-based morphometry (VBM) procedures was used to perform group comparisons, single-case individual analysis and correlations with learning scores. Group comparisons showed that PDD patients and PD+VH patients had significant hippocampal gray matter loss compared to controls. In PDD patients, hippocampal gray matter loss involved the entire hippocampus and in PD+VH this reduction was mainly confined to the hippocampal head. 78 % of PDD patients, 31 % of PD+VH patients and 26 % of PD-VH patients had hippocampal head gray matter loss when compared to controls. These results suggest that in PD the neurodegenerative process in the hippocampus starts in the head of this structure and later spreads to the tail and that, in addition, memory impairment assessed by Rey’s Auditory Verbal Learning Test (RAVLT) correlates with hippocampal head gray matter loss.Journal of Neurology 04/2012; 255(9):1324-1331. · 3.47 Impact Factor -
Article: Hippocampal head atrophy predominance in Parkinson's disease with hallucinations and with dementia.
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ABSTRACT: We studied regional gray matter density in the hippocampus in Parkinson's disease (PD) patients. We obtained magnetic resonance scans in 44 PD patients (PD patients with dementia (PDD) = 9, non-demented PD patients with visual hallucinations (PD + VH) = 16, and PD patients without dementia and without visual hallucinations (PD - VH) = 19) and 56 controls matched for age and years of education. A region of interest (ROI) of the hippocampus following voxel-based morphometry (VBM) procedures was used to perform group comparisons, single-case individual analysis and correlations with learning scores. Group comparisons showed that PDD patients and PD+VH patients had significant hippocampal gray matter loss compared to controls. In PDD patients, hippocampal gray matter loss involved the entire hippocampus and in PD+VH this reduction was mainly confined to the hippocampal head. 78 % of PDD patients, 31 % of PD+VH patients and 26 % of PD-VH patients had hippocampal head gray matter loss when compared to controls. These results suggest that in PD the neurodegenerative process in the hippocampus starts in the head of this structure and later spreads to the tail and that, in addition, memory impairment assessed by Rey's Auditory Verbal Learning Test (RAVLT) correlates with hippocampal head gray matter loss.Journal of Neurology 10/2008; 255(9):1324-31. · 3.47 Impact Factor -
Article: Cerebral atrophy in Parkinson's disease patients with visual hallucinations.
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ABSTRACT: Although visual hallucinations (VH) are relatively frequent in Parkinson's disease (PD) patients, their neural substrates are only known from neuropathological and functional magnetic resonance studies. The aim of this study was to investigate possible structural brain changes on MRI in non-demented PD patients with VH using voxel-based morphometry. Eighteen PD patients with VH were compared to 20 patients with PD without VH and 21 healthy controls. Compared with both controls and the non-hallucinating PD group, PD patients with VH had grey matter volume reductions in the lingual gyrus and superior parietal lobe. Structural changes in these areas involved in higher visual processing may be important in understanding the VH and visual deficits in PD patients.European Journal of Neurology 08/2007; 14(7):750-6. · 3.69 Impact Factor -
Article: Longitudinal evaluation of cerebral morphological changes in Parkinson's disease with and without dementia
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ABSTRACT: ObjectiveTo investigate the pattern of brain atrophy across time in a sample of Parkinson's disease (PD) patients with and without dementia using voxelbased morphometry (VBM) analysis. MethodsThe initial sample comprised thirteen non–demented PD patients and sixteen demented patients. Longitudinal cognitive assessment and structural MRI were performed. The mean follow–up period was 25 months (SD = 5.2). From this initial group, eight PD patients with dementia (5 men and 3 women) and eleven PD patients without dementia (7 men and 4 women) were reevaluated. MRI 3D structural images were acquired and analyzed by means of the optimized VBM procedure with Statistical Parametric Mapping (SPM2). ResultsVBM analysis showed a progressive grey matter volume decrease in patients with PD without dementia in limbic, paralimbic and neocortical associative temporooccipital regions. In patients with dementia the loss mainly involved neocortical regions. ConclusionVBM revealed a significant loss of grey matter volume in PD patients with and without dementia with disease progression. The decrease in limbic and paralimbic regions is widespread in non–demented patients. Neocortical volume reduction is the most relevant finding in patients with dementia. This suggests that the neocortex is a substrate for dementia in Parkinson disease.Journal of Neurology 10/2005; 252(11):1345-1352. · 3.47 Impact Factor -
Article: [Cerebral activation during Stroop's test in a case of early focal brain injury].
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ABSTRACT: Functional magnetic resonance imaging (fMRI) offers an important advantage over other functional neuroimaging techniques used with children because of its harmlessness. Previous studies conducted with adults with alexia suggested two ways the brain can reorganise reading after a brain injury affecting the left hemisphere, one contralateral and the other ipsilateral. We describe a study carried out using fMRI of a 10 year old girl with an injury to the left hemisphere caused by a fishing harpoon when she was 6 years old. As a result of the accident the girl presented a right hemiparesia. The girl s parents and teachers also reported difficulties in the acquisition of reading writing and arithmetic, as well as a certain degree of attentional deficit. An fMRI exploration was performed while the girl was doing the Stroop test. The structural MR images showed left hemisphere cortical lesions in the orbital and angular gyrus regions, in addition to the caudate and putamen nuclei, and in the inferior longitudinal bundle. The fRMI revealed a strong overactivation of the right dorsolateral frontal cortex, in the evaluation of interference, and activations of the right angular and bilateral supramarginal gyri, in the evaluation of word reading. The functional study suggests the existence of a reorganisation of reading that is both intra and inter hemispheric.Revista de neurologia 36(4):343-6. · 0.65 Impact Factor
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2007
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University of Barcelona
- Departament de Psiquiatria i Psicobiologia Clínica
Barcelona, Catalonia, Spain
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