Limbic grey matter changes in early Parkinson's disease

The purpose of this study was to investigate local and network‐related changes of limbic grey matter in early Parkinson's disease (PD) and their inter‐relation with non‐motor symptom severity. We applied voxel‐based morphometric methods in 538 T1 MRI images retrieved from the Parkinson's Progression Markers Initiative website. Grey matter densities and cross‐sectional estimates of age‐related grey matter change were compared between subjects with early PD (n = 366) and age‐matched healthy controls (n = 172) within a regression model, and associations of grey matter density with symptoms were investigated. Structural brain networks were obtained using covariance analysis seeded in regions showing grey matter abnormalities in PD subject group. Patients displayed focally reduced grey matter density in the right amygdala, which was present from the earliest stages of the disease without further advance in mild‐moderate disease stages. Right amygdala grey matter density showed negative correlation with autonomic dysfunction and positive with cognitive performance in patients, but no significant interrelations were found with anxiety scores. Patients with PD also demonstrated right amygdala structural disconnection with less structural connectivity of the right amygdala with the cerebellum and thalamus but increased covariance with bilateral temporal cortices compared with controls. Age‐related grey matter change was also increased in PD preferentially in the limbic system. In conclusion, detailed brain morphometry in a large group of early PD highlights predominant limbic grey matter deficits with stronger age associations compared with controls and associated altered structural connectivity pattern. This provides in vivo evidence for early limbic grey matter pathology and structural network changes that may reflect extranigral disease spread in PD. Hum Brain Mapp 38:3566–3578, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.     

Subcortical grey matter changes in untreated,early stage Parkinson's disease without dementia

BackgroundPrevious MRI studies have investigated cortical or subcortical grey matter changes in patients with Parkinson's disease (PD), yielding inconsistent findings between the studies. We therefore sought to determine whether focal cortical or subcortical grey matter changes may be present from the early disease stage.MethodsWe recruited 49 untreated, early stage PD patients without dementia and 53 control subjects. Voxel-based morphometry was used to evaluate cortical grey matter changes, and automated volumetry and shape analysis were used to assess volume changes and shape deformation of the subcortical grey matter structures, respectively.ResultsVoxel-based morphometry showed neither reductions nor increases in grey matter volume in patients compared to controls. Compared to controls, PD patients had significant reductions in adjusted volumes of putamen, nucleus accumbens, and hippocampus (corrected p < 0.05). Vertex-based shape analysis showed regionally contracted area on the posterolateral and ventromedial putamen bilaterally in PD patients (corrected p < 0.05). No correlations were found between cortical and subcortical grey matter and clinical variables representing disease duration and severity.ConclusionsOur results suggest that untreated, early stage PD without dementia is associated with volume reduction and shape deformation of subcortical grey matter, but not with cortical grey matter reduction. Our findings of structural changes in the posterolateral putamen and ventromedial putamen/nucleus accumbens could provide neuroanatomical basis for the involvement of motor and limbic striatum, further implicating motor and non-motor symptoms in PD, respectively. Early hippocampal involvement might be related to the risk for developing dementia in PD patients.     

Temporal lobe changes in early,untreated Parkinson's disease

The purpose of this study was to determine if focal cortical abnormalities may occur in early Parkinson's disease (PD). We studied 26 untreated patients with early PD and 14 healthy control subjects, with cognitive screening and magnetic resonance imaging (MRI). Voxel‐based morphometry was used to assess for the presence of localized cortical grey matter (GM) and/or subcortical white matter (WM) changes. Patient and control groups showed no differences in age or gender distribution. Females had a greater GM% than males (P = 0.001). Comparison of patients and controls revealed no difference in local GM volumes. In PD, however, there was decreased WM volume in the anterior right fusiform gyrus and superior temporal gyrus. There were no correlations between the California Verbal Learning Test long delay free recall, Judgment of Line Orientation, Trail Making A or B and either the GM or WM localized volumes. These results suggest that right anterior temporal lobe changes occur in untreated patients with PD. The earliest changes may occur in subcortical white matter rather than temporal cortex. © 2009 Movement Disorder Society     

Regional cortical grey matter loss in Parkinson's disease without dementia is independent from visual hallucinations

In our previous functional magnetic resonance imaging study, Parkinson's disease (PD) patients with visual hallucinations (VH) showed reduced activations in ventral/lateral visual association cortices preceding image recognition, compared with both PD patients without VH and healthy controls. The primary aim of the current study was to investigate whether functional deficits are associated with grey matter volume changes. In addition, possible grey matter differences between all PD patients and healthy controls were assessed. By using 3‐Tesla magnetic resonance imaging (MRI) and voxel‐based morphometry (VBM), we found no differences between PD patients with (n = 11) and without VH (n = 13). However, grey matter decreases of the bilateral prefrontal and parietal cortex, left anterior superior temporal, and left middle occipital gyrus were found in the total group of PD patients, compared with controls (n = 14). This indicates that previously demonstrated functional deficits in PD patients with VH are not associated with grey matter loss. The strong left parietal reduction in both nondemented patient groups was hemisphere specific and independent of the side of PD symptoms. © 2010Movement Disorder Society.     

The effects of HIV and aging on subcortical shape alterations: A 3D morphometric study

Standard volumetric neuroimaging studies have demonstrated preferential atrophy of subcortical structures among individuals with HIV. However, to our knowledge, no study has investigated subcortical shape alterations secondary to HIV and whether advancing age impacts that relationship. This study employed 3D morphometry to examine the independent and interactive effects of HIV and age on shape differences in nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen, and thalamus in 81 participants ranging in age from 24 to 76 including 59 HIV+ individuals and 22 HIV‐seronegative controls. T1‐weighted MRI underwent a preprocessing pipeline followed by automated subcortical segmentation. Parametric statistical analyses were used to determine independent effects of HIV infection and age on volume and shape in each region of interest (ROI) and the interaction between age and HIV serostatus in predicting volume/shape in each ROI. Significant main effects for HIV were found in the shape of right caudate and nucleus accumbens, left pallidum, and hippocampus. Age was associated with differences in shape in left pallidum, right nucleus accumbens and putamen, and bilateral caudate, hippocampus, and thalamus. Of greatest interest, an age × HIV interaction effect was found in the shape of bilateral nucleus accumbens, amygdala, caudate, and thalamus as well as right pallidum and putamen such that increasing age in HIV participants was associated with greater shape alterations. Traditional volumemetric analyses revealed main effects for both HIV and age but no age × HIV interaction. These findings may suggest that age and HIV infection conferred additional deleterious effects on subcortical shape abnormalities beyond the independent effects of these factors. Hum Brain Mapp 38:1025–1037, 2017. © 2016 Wiley Periodicals, Inc.     

Right external globus pallidus changes are associated with altered causal awareness in youth with depression

Cognitive impairment is a functionally disabling feature of depression contributing to maladaptive decision-making, a loss of behavioral control and an increased disease burden. The ability to calculate the causal efficacy of ones actions in achieving specific goals is critical to normal decision-making and, in this study, we combined voxel-based morphometry (VBM), shape analysis and diffusion tensor tractography to investigate the relationship between cortical–basal ganglia structural integrity and such causal awareness in 43 young subjects with depression and 21 demographically similar healthy controls. Volumetric analysis determined a relationship between right pallidal size and sensitivity to the causal status of specific actions. More specifically, shape analysis identified dorsolateral surface vertices where an inward location was correlated with reduced levels of causal awareness. Probabilistic tractography revealed that affected parts of the pallidum were primarily connected with the striatum, dorsal thalamus and hippocampus. VBM did not reveal any whole-brain gray matter regions that correlated with causal awareness. We conclude that volumetric reduction within the indirect pathway involving the right dorsolateral pallidum is associated with reduced awareness of the causal efficacy of goal-directed actions in young depressed individuals. This causal awareness task allows for the identification of a functionally and biologically relevant subgroup to which more targeted cognitive interventions could be applied, potentially enhancing the long-term outcomes for these individuals.     

Correlation between quantitative EEG and MRI in idiopathic generalized epilepsy

The objective of this study was to investigate the relationship between the focal discharges sometimes observed in the electroencephalogram of patients with idiopathic generalized epilepsies and subtle structural magnetic resonance imaging abnormalities. The main hypothesis to be assessed is that focal discharges may arise from areas of structural abnormality which can be detected by quantitative neuroimaging. Focal discharges were used for quantitative electroencephalogram source detection. Neuroimaging investigations consisted of voxel‐based morphometry and region of interest volumetry. For voxel‐based morphometry, volumetric MRI were acquired and processed. The images of each patient were individually compared with a control group. Statistical analysis was used to detect differences in gray matter volumes. Region of interest‐based morphometry was automatically performed and used essentially to confirm voxel‐based morphometry findings. The localization of the focal discharges on the electroencephalogram was compared to the neuroimaging results. Twenty‐two patients with idiopathic generalized epilepsies were evaluated. Gray matter abnormalities were detected by voxel‐based morphometry analysis in 77% of the patients. There was a good concordance between EEG source detection and voxel‐based morphometry. On average, the nearest voxels detected by these methods were 19 mm (mm) apart and the most statistically significant voxels were 34 mm apart. This study suggests that in some cases subtle gray matter abnormalities are associated with focal epileptiform discharges observed in the electroencephalograms of patients with idiopathic generalized epilepsies. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.     

Voxel-based morphometry of auditory and speech-related cortex in stutterers

Stutterers demonstrate unique functional neural activation patterns during speech production, including reduced auditory activation, relative to nonstutterers. The extent to which these functional differences are accompanied by abnormal morphology of the brain in stutterers is unclear. This study examined the neuroanatomical differences in speech-related cortex between stutterers and nonstutterers using voxel-based morphometry. Results revealed significant differences in localized grey matter and white matter densities of left and right hemisphere regions involved in auditory processing and speech production.     

Grey matter differences in bipolar disorder: a meta-analysis of voxel-based morphometry studies

Selvaraj S, Arnone D, Job D, Stanfield A, Farrow TFD, Nugent AC, Scherk H, Gruber O, Chen X, Sachdev PS, Dickstein DP, Malhi GS, Ha TH, Ha K, Phillips ML, McIntosh AM. Grey matter differences in bipolar disorder: a meta‐analysis of voxel‐based morphometry studies. Bipolar Disord 2012: 14: 135–145. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objective: Several neuroimaging studies have reported structural brain differences in bipolar disorder using automated methods. While these studies have several advantages over those using region of interest techniques, no study has yet estimated a summary effect size or tested for between‐study heterogeneity. We sought to address this issue using meta‐analytic techniques applied for the first time in bipolar disorder at the level of the individual voxel. Methods: A systematic review identified 16 voxel‐based morphometry (VBM) studies comparing individuals with bipolar disorder with unaffected controls, of which eight were included in the meta‐analysis. In order to take account of heterogeneity, summary effect sizes were computed using a random‐effects model with appropriate correction for multiple testing. Results: Compared with controls, subjects with bipolar disorder had reduced grey matter in a single cluster encompassing the right ventral prefrontal cortex, insula, temporal cortex, and claustrum. Study heterogeneity was widespread throughout the brain; though the significant cluster of grey matter reduction remained once these extraneous voxels had been removed. We found no evidence of publication bias (Eggers p = 0.63). Conclusions: Bipolar disorder is consistently associated with reductions in right prefrontal and temporal lobe grey matter. Reductions elsewhere may be obscured by clinical and methodological heterogeneity.     

A manual and automated MRI study of anterior cingulate and orbito-frontal cortices, and caudate nucleus in obsessive-compulsive disorder: comparison with healthy controls and patients with schizophrenia

Functional imaging and neuropsychological data suggest that interconnected brain structures including the orbito-frontal cortex (OFC), anterior cingulate cortex (ACC) and caudate nucleus (CN) are involved in the pathophysiology of obsessive-compulsive disorder (OCD), but structural imaging studies investigating these regions have yielded inconclusive results. This may be due to inconsistencies in the identification of anatomical boundaries and methodologies utilised (i.e. automated vs. manual tracing). This magnetic resonance imaging study used manual tracing to measure volumes of selected brain regions (OFC, ACC and CN) in OCD patients and compared them with samples of healthy (HC) and psychiatric (schizophrenia; SCZ) controls (n=18 in each group). Concurrently, automated voxel-based analysis was also used to detect subtle differences in cerebral grey and white matter. For the OCD vs. HC comparison, there were no significant volumetric differences detected using the manual or the automated method (although the latter revealed a deficit in the subcortical white matter of the right temporal region). A direct comparison of the two patient groups showed no significant differences using the manual method. However, a moderate effect size was detected for OFC grey matter (reduced in SCZ), which was supported by findings of reduced OFC volume in the automated analysis. Automated analyses also showed reduced volumes in the dorsal (white matter) and ventral ACC (grey and white matter), as well as the left posterior cingulate (grey and white matter) in SCZ. The findings suggest that in contrast to findings in SCZ, there are very few (if any) gross structural anomalies in OCD.     

Microstructural changes in white matter associated with freezing of gait in Parkinson's disease

In Parkinson's disease (PD), freezing of gait (FOG) is associated with widespread functional and structural gray matter changes throughout the brain. Previous study of freezing‐related white matter changes was restricted to brainstem and cerebellar locomotor tracts. This study was undertaken to determine the spatial distribution of white matter damage associated with FOG by combining whole brain and striatofrontal seed‐based diffusion tensor imaging. Diffusion‐weighted images were collected in 26 PD patients and 16 age‐matched controls. Parkinson's disease groups with (n = 11) and without freezing of gait (n = 15) were matched for age and disease severity. We applied tract‐based spatial statistics to compare fractional anisotropy and mean diffusivity of white matter structure across the whole brain between groups. Probabilistic tractography was used to evaluate fractional anisotropy and mean diffusivity of key subcortico‐cortical tracts. Tract‐based spatial statistics revealed decreased fractional anisotropy in PD with FOG in bilateral cerebellar and superior longitudinal fascicle clusters. Increased mean diffusivity values were apparent in the right internal capsule, superior frontal cortex, anterior corona radiata, the left anterior thalamic radiation, and cerebellum. Tractography showed consistent white matter alterations in striatofrontal tracts through the putamen, caudate, pallidum, subthalamic nucleus, and in connections of the cerebellar peduncle with subthalamic nucleus and pedunculopontine nucleus bilaterally. We conclude that FOG is associated with diffuse white matter damage involving major cortico‐cortical, corticofugal motor, and several striatofrontal tracts in addition to previously described cerebello‐pontine connectivity changes. These distributed white matter abnormalities may contribute to the motor and non‐motor correlates of FOG. © 2015 International Parkinson and Movement Disorder Society     

Increased prefrontal volume in PD with levodopa‐induced dyskinesias: A voxel‐based morphometry study

Levodopa‐induced dyskinesias represent disabling complications from long‐term therapy with dopaminergic drugs for treating Parkinson's disease (PD). Although several neuroimaging studies have reported altered striatofrontal function that contributes to the emergence of these motor complications, the neuroanatomical correlates of this disorder are still unknown. Optimized voxel‐based morphometry (VBM) was applied to the MRI brain images of 36 PD patients with levodopa‐induced dyskinesias, 36 PD patients without levodopa‐induced dyskinesias, and 32 age‐ and sex‐matched controls. The VBM analysis comparing dyskinetic and nondyskinetic groups provided evidence of increased gray matter volume of the bilateral inferior frontal gyrus in dyskinetic patients, a finding that was more evident in patients with early‐onset PD. No significant differences were detected in the dyskinetic and nondyskinetic groups when compared with the controls. Our findings suggest that the presence of dyskinesias in patients with PD is characterized by an aberrant neural plasticity that could play a role in the pathophysiology of these motor complications. © 2011 Movement Disorder Society     

基于形变的形态学测量对首次发病未服药抑郁症患者大脑灰质异常的研究

目的:探讨首次发病未服药抑郁症患者（major depressive disorder）大脑灰质结构改变以及抑郁症早期诊断的影像学指标。方法:对38例抑郁症患者（抑郁症组）和65名年龄、性别相匹配的健康对照（对照组）进行3D T 1加权结构像磁共振成像扫描,采用基于形变的形态学测量（deformation-...     

Region‐specific disturbed iron distribution in early idiopathic Parkinson's disease measured by quantitative susceptibility mapping

In Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron‐mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter‐group differences of susceptibility and R2^* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty‐four early PD patients and 35 gender and age‐matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427–442; Stage I). However, increased R2^* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS‐III scores in early PD. This finding supports the potential value of QSM as a non‐invasive quantitative biomarker of early PD. Hum Brain Mapp 36:4407–4420, 2015. © 2015 Wiley Periodicals, Inc .     

Relationship between CAG repeat length and brain volume in premanifest and early Huntington’s disease

Huntington’s disease (HD) is caused by an expanded CAG repeat on the gene encoding for the protein huntingtin. There are conflicting findings about the extent to which repeat length predicts signs of the disease or severity of disease progression in adults. This study examined the relationship between CAG repeat length and brain volume in a large cohort of pre- and post-motor onset HD gene carriers, using voxel-based morphometry (VBM), an approach which allowed us to investigate the whole brain without defining a priori regions of interest. We also used VBM to examine group differences between 20 controls, 21 premanifest, and 40 early HD subjects. In the 61 mutation-positive subjects higher CAG repeat length was significantly associated with reduced volume of the body of the caudate nucleus bilaterally, left putamen, right insula, right parahippocampal gyrus, right anterior cingulate, and right occipital lobe, after correcting for age. The group contrasts showed significant reduction in grey matter volume in the early HD group relative to controls in widespread cortical as well as subcortical areas but there was no evidence of difference between controls and premanifest subjects. Overall we have demonstrated that increased CAG repeat length is associated with atrophy in extra-striatal as well as striatal regions, which has implications for the monitoring of disease-modifying therapies in the condition. denotes equal senior author     

White matter abnormalities in Parkinson's disease patients with glucocerebrosidase gene mutations

Glucocerebrosidase gene mutations represent a genetic risk factor for the development of Parkinson's disease. This study investigated brain alterations in Parkinson's disease patients carrying heterozygous glucocerebrosidase gene mutations using structural and diffusion tensor magnetic resonance imaging. Among 360 Parkinson's disease patients screened for glucocerebrosidase gene mutations, 19 heterozygous mutation carriers (5.3%) were identified. Of these, 15 patients underwent a neuropsychological evaluation and a magnetic resonance imaging scan. Sixteen age‐ and sex‐matched healthy controls and 14 idiopathic Parkinson's disease patients without glucocerebrosidase gene mutations were also studied. Tract‐based spatial statistics was used to perform a white matter voxel‐wise analysis of diffusion tensor magnetic resonance imaging metrics. Mean fractional anisotropy values were obtained from white matter tracts of interest. Voxel‐based morphometry was used to assess gray‐matter atrophy. Cognitive deficits were found in 9 mutation carrier patients (60%). Compared with controls, Parkinson's disease patients carrying glucocerebrosidase gene mutations showed decreased fractional anisotropy in the olfactory tracts, corpus callosum, and anterior limb of the internal capsule bilaterally, as well as in the right anterior external capsule, and left cingulum, parahippocampal tract, parietal portion of the superior longitudinal fasciculus, and occipital white matter. Mutation carrier patients also had decreased fractional anisotropy of the majority of white matter tracts compared with Parkinson's disease patients with no mutations. No white matter abnormalities were found in Parkinson's disease patients without glucocerebrosidase gene mutations. No gray matter difference was found between patients and controls. In Parkinson's disease patients, verbal fluency scores correlated with white matter abnormalities. Parkinson's disease patients carrying glucocerebrosidase gene mutations experience a distributed pattern of white matter abnormalities involving the interhemispheric, frontal corticocortical, and parahippocampal tracts. White matter pathology in these patients may have an impact on the clinical manifestations of the disease, including cognitive impairment. © 2013 Movement Disorder Society     

Voxel‐Based Morphometric Analysis in Hypothyroidism Using Diffeomorphic Anatomic Registration via an Exponentiated Lie Algebra Algorithm Approach

The present study aimed to investigate whether brain morphological differences exist between adult hypothyroid subjects and age‐matched controls using voxel‐based morphometry (VBM) with diffeomorphic anatomic registration via an exponentiated lie algebra algorithm (DARTEL) approach. High‐resolution structural magnetic resonance images were taken in ten healthy controls and ten hypothyroid subjects. The analysis was conducted using statistical parametric mapping. The VBM study revealed a reduction in grey matter volume in the left postcentral gyrus and cerebellum of hypothyroid subjects compared to controls. A significant reduction in white matter volume was also found in the cerebellum, right inferior and middle frontal gyrus, right precentral gyrus, right inferior occipital gyrus and right temporal gyrus of hypothyroid patients compared to healthy controls. Moreover, no meaningful cluster for greater grey or white matter volume was obtained in hypothyroid subjects compared to controls. Our study is the first VBM study of hypothyroidism in an adult population and suggests that, compared to controls, this disorder is associated with differences in brain morphology in areas corresponding to known functional deficits in attention, language, motor speed, visuospatial processing and memory in hypothyroidism.     

Bilateral high-frequency stimulation of the internal globus pallidus in advanced Parkinson's disease

We report here the results of an open prospective study in 9 patients suffering from severe Parkinson's disease with on/off fluctuations and restricted off-period mobility, who underwent bilateral implantation of stimulating electrodes in the internal pallidum. At 3-month follow-up, the total Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the medication-off state was reduced from 54.1 ± 14.8 to 23.9 ± 11.7 (44.2%) when stimulation was turned on. Comparison of UPDRS subscores revealed significant improvements for tremor, rigidity, bradykinesia, gait and posture, and dyskinesias. The results of the clinical scoring could be confirmed by significant changes in the quantitative assessment of hand function and walking. Bilateral pallidal stimulation reduced the amount and severity of on/off fluctuations. Additional follow-up at 6 months (n = 6), 9 months (n = 6), and 12 months (n = 4) did not show a decline in effectiveness of stimulation. There was no permanent morbidity associated with the procedure. A subtle reduction of verbal fluency, which was not evident to the patients, was the only cognitive side effect of the procedure in neuropsychological testing. Chronic bilateral high-frequency stimulation of the internal pallidum seems to be a neurologically safe and highly effective treatment for “off” symptoms, dyskinesias, and motor fluctuations in advanced stages of Parkinson's disease.     

Dorsal pallidal neurons directly link the nidopallium and midbrain in the zebra finch (Taeniopygia guttata)

The dorsal pallidum in birds is considered similar, if not homologous, to the globus pallidus (GP) of mammals. The dorsal pallidum projects to both thalamic and midbrain targets similar to the direct and indirect pathways arising from the internal and external segments of the GP. In the present study, retrograde and anterograde tracing studies revealed a previously undescribed projection of the avian dorsal pallidum. This arises from a specific dorsomedial component, which terminates in the intercollicular nucleus and partly surrounds the avian equivalent of the central nucleus of the inferior colliculus. The respiratory‐vocal dorsomedial nucleus of the intercollicular complex, however, does not receive these projections. The somata of the pallidal neurons retrogradely labeled from injections in the intercollicular nucleus were large and generally multipolar and had extensive, sparsely branching central processes (presumptive dendrites) that together extended up to 2 mm dorsally into the intermediate and caudomedial nidopallium. The size and morphology of these neurons were similar to those of large pallidal neurons labeled by calretinin immunoreactivity, which could be co‐localized to the same cells. Thus, rather than being directly involved in the control of movement, the large dorsomedial neurons of the caudal dorsal pallidum may be involved in sensory processing, in that they provide an unusual direct link between sensory (auditory/somatosensory) regions of the nidopallium and sensory regions of the intercollicular nucleus of the midbrain. J. Comp. Neurol. 525:1731–1742, 2017. © 2016 Wiley Periodicals, Inc.     

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. Voxel‐based morphometry results showed that DLB patients had greater gray matter atrophy in the right superior frontal gyrus, the right premotor area and the right inferior frontal lobe compared to PDD. Furthermore, the anterior cingulate and prefrontal volume correlated with performance on the Continuous Performance Test while the right hippocampus and amygdala volume correlated with Visual Memory Test in the DLB group. In conclusion, DLB patients had more fronto‐temporal gray matter atrophy than PDD patients and these reductions correlated with neuropsychological impairment. © 2009 Movement Disorder Society