Regional vulnerability of hippocampal subfields and memory deficits in Parkinson's disease.

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.

Frontal and associative visual areas related to visual hallucinations in dementia with Lewy bodies and Parkinson's disease with dementia.

Visual Hallucinations (VH) are among the core features of Dementia with Lewy Bodies (DLB), but are also very frequent in demented patients with Parkinson's Disease (PDD). The purpose of this study was to investigate the pattern of gray matter and cognitive impairment underlying VH in DLB and PDD. We applied voxel-based morphometry and behavioral assessment to 12 clinically diagnosed DLB patients and 15 PDD patients.

Differential progression of brain atrophy in Parkinson's disease with and without visual hallucinations.

Objective: To determine the course of cognitive deficits and the regional progression of brain atrophy in patients with Parkinson's disease (PD) with and without visual hallucinations (VH).

Methods: The authors performed MRI and neuropsychological assessment at entry to the study and at follow-up (mean+/-SD=29.91+/-5.

Correlations between gray matter reductions and cognitive deficits in dementia with Lewy Bodies and Parkinson's disease with dementia.

There is controversy regarding whether Dementia with Lewy Bodies (DLB) and Parkinson's disease with dementia (PDD) may or not be different manifestations of the same disorder. The purpose of the present study was to investigate possible correlations between brain structure and neuropsychological functions in clinically diagnosed patients with DLB and PDD. The study sample consisted of 12 consecutively referred DLB patients, 16 PDD patients, and 16 healthy control subjects recruited from an outpatient setting, who underwent MRI and neuropsychological assessment.

Neuroanatomical substrate of visuospatial and visuoperceptual impairment in Parkinson's disease.

To determine magnetic resonance imaging patterns of gray matter (GM) atrophy underlying visuospatial and visuoperceptual impairment in Parkinson's disease (PD), we applied voxel-based morphometry to 36 nondemented PD patients and correlated their whole brain GM density with performance on three visuospatial and visuoperceptual tests. In addition, group comparisons between patients and 20 healthy controls were also performed. Correlations between visuospatial performance and GM density were found in the superior parietal lobules and the superior occipital gyrus of PD patients.

Structural brain correlates of verbal fluency in Parkinson's disease.

Verbal fluency tests are often used to assess cognitive dysfunction in Parkinson's disease. These tests have been found to be impaired even in initial stages of this illness. We applied voxel-based morphometry to investigate the neuroanatomic substrates of semantic and phonemic fluency impairment.

Hippocampal head atrophy predominance in Parkinson's disease with hallucinations and with dementia.

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.

Brain response to complex visual stimuli in Parkinson's patients with hallucinations: a functional magnetic resonance imaging study.

Visual hallucinations (VH) in Parkinson's disease (PD) have been associated with gray matter reductions in visual associative areas and with abnormal patterns of brain activation in posterior and frontal regions. However, all previous fMRI studies have used simple visual stimuli. The objective of our study was, therefore, to compare the pattern of brain activation during a one-back face detection task.

Cognitive changes in Parkinson's disease patients with visual hallucinations.

Objective: To evaluate the decline in specific neuropsychological functions in nondemented Parkinson's disease (PD) patients with a history of visual hallucinations (VH).

Methods: Twenty PD patients with VH, 20 PD patients without VH and 18 normal controls were followed up over a 1-year period and assessed for cognitive decline.

Results: Forty-five percent of nondemented hallucinating PD patients developed dementia during the 1-year period between baseline and follow-up evaluations.

Neuropsychological deficits in Parkinson's disease patients with visual hallucinations.

Recent neuropathological and neuroimaging studies suggest the involvement of several temporal regions in Parkinson's disease (PD) patients with visual hallucinations (VH). We examined 24 nondemented PD patients with VH, 21 PD patients without VH, and 21 healthy controls using a battery of tests assessing different aspects of temporal lobe function. PD patients with VH showed poorer performance in language, verbal learning, semantic fluency, and visuoperceptive functions compared to controls and PD patients without VH.

Longitudinal evaluation of cerebral morphological changes in Parkinson's disease with and without dementia.

Objective: To 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.

Methods: The initial sample comprised thirteen non-demented PD patients and sixteen demented patients. Longitudinal cognitive assessment and structural MRI were performed.

Amygdalar and hippocampal MRI volumetric reductions in Parkinson's disease with dementia.

Parkinson's disease (PD) involves neuropathological changes in the limbic system that lead to neuronal loss and volumetric reductions of several nuclei. We investigated possible volumetric reductions of the amygdala and hippocampus associated to PD. We carried out magnetic resonance imaging (MRI) volumetric studies in 16 patients with PD and dementia (PDD), 16 patients with PD without dementia (PD), and 16 healthy subjects.

Corpus callosum atrophy in adolescents with antecedents of moderate perinatal asphyxia.

Background: The corpus callosum (CC) is a cerebral structure that reflects cognitive status in several neurological pathologies. Visual inspection of MRI has shown that hypoxic-ischemic encephalopathy(HIE) causes callosal damage.

Primary Objective: To quantify the CC surface in a sample of patients with antecedents of HIE and a group of matched controls.