Parkinsonian gait improves with bilateral subthalamic nucleus deep brain stimulation during cognitive multi-tasking

BackgroundGait impairment in Parkinson's disease reduces mobility and increases fall risk, particularly during cognitive multi-tasking. Studies suggest that bilateral subthalamic deep brain stimulation, a common surgical therapy, degrades motor performance under cognitive dual-task conditions, compared to unilateral stimulation.ObjectiveTo measure the impact of bilateral versus unilateral subthalamic deep brain stimulation on walking kinematics with and without cognitive dual-tasking.MethodsGait kinematics of seventeen patients with advanced Parkinson's disease who had undergone bilateral subthalamic deep brain stimulation were examined off medication under three stimulation states (bilateral, unilateral left, unilateral right) with and without a cognitive challenge, using an instrumented walkway system.ResultsConsistent with earlier studies, gait performance declined for all six measured parameters under cognitive dual-task conditions, independent of stimulation state. However, bilateral stimulation produced greater improvements in step length and double-limb support time than unilateral stimulation, and achieved similar performance for other gait parameters.ConclusionsContrary to expectations from earlier studies of dual-task motor performance, bilateral subthalamic deep brain stimulation may assist in maintaining temporal and spatial gait performance under cognitive dual-task conditions.     

Assessment of structural brain changes in patients with type 2 diabetes mellitus using the MRI-based brain atrophy and lesion index

Patients with type 2 diabetes mellitus(T2 DM) often have cognitive impairment and structural brain abnormalities.The magnetic resonance imaging(MRI)-based brain atrophy and lesion index can be used to evaluate common brain changes and their correlation with cognitive function,and can therefore also be used to reflect whole-brain structural changes related to T2 DM.A total of 136 participants(64 men and 72 women,aged 55–86 years) were recruited for our study between January 2014 and December 2016.All participants underwent MRI and Mini-Mental State Examination assessment(including 42 healthy control,38 T2 DM without cognitive impairment,26 with cognitive impairment but without T2 DM,and 30 T2 DM with cognitive impairment participants).The total and sub-category brain atrophy and lesion index scores in patients with T2 DM with cognitive impairment were higher than those in healthy controls.Differences in the brain atrophy and lesion index of gray matter lesions and subcortical dilated perivascular spaces were found between non-T2 DM patients with cognitive impairment and patients with T2 DM and cognitive impairment.After adjusting for age,the brain atrophy and lesion index retained its capacity to identify patients with T2 DM with cognitive impairment.These findings suggest that the brain atrophy and lesion index,based on T1-weighted and T2-weighted imaging,is of clinical value for identifying patients with T2 DM and cognitive impairment.Gray matter lesions and subcortical dilated perivascular spaces may be potential diagnostic markers of T2 DM that is complicated by cognitive impairment.This study was approved by the Medical Ethics Committee of University of South China(approval No.USC20131109003) on November 9,2013,and was retrospectively registered with the Chinese Clinical Trial Registry(registration No.Chi CTR1900024150) on June 27,2019.     

Cognition and gait show a distinct pattern of association in the general population

BackgroundWith brain aging, cognition and gait deteriorate in several domains. However, the interrelationship between cognitive and gait domains remains unclear. We investigated the independent associations between cognitive and gait domains in a community-dwelling population.MethodsIn the Rotterdam Study, 1232 participants underwent cognitive and gait assessment. Cognitive assessment included memory, information processing speed, fine motor speed, and executive function. Gait was summarized into seven independent domains: Rhythm, Variability, Phases, Pace, Tandem, Turning, and Base of Support. With multivariate linear regression, independent associations between cognitive and gait domains were investigated.ResultsInformation processing speed associated with Rhythm, fine motor speed with Tandem, and executive function with Pace. The effect sizes corresponded to a 5- to 10-year deterioration in gait.ConclusionsCognition and gait show a distinct pattern of association. These data accentuate the close, but complicated, relation between cognition and gait, and they may aid in unraveling the broader spectrum of the effects of brain aging.     

Mild cognitive impairment and event-related potentials in patients with cerebral atrophy and leukoaraiosis

Objective  The influence of cerebral atrophy and leukoaraiosis (LA) on the degree and profile of cognitive impairment remains unclear. Design  The aim of the study was to assess neuropsychological features of cognitive performance and parameters of event-related potentials (ERP) in subjects with generalised cerebral atrophy and LA. Setting  Department of Neurology, University of Medicine. Patients and participants  Forty-two patients with LA and/or cerebral atrophy and twenty controls. Measurements and results  Neuropsychological testing (NT) included Mini Mental State Examination (MMSE), Auditory Verbal Learning Test (AVLT) and Trail Making Test (TMT). Auditory ERPs were performed and parameters of the N2 and P3 components were compared in the patients and controls. Relationships were analysed between radiological indices of atrophy and LA, and NT and ERP results. Results of NT suggested generalised mild cognitive impairment in all the patients. P3 and N2 latencies were longer in the patients than in controls, especially in the LA subgroup. Correlations were found for indices of atrophy, AVLT and ERP parameters. There was a predominant influence of age upon ERP parameters and radiological indices. Conclusions  Cerebral atrophy and LA result in deficits in memory and attention. NT and ERP may be used as complementary methods in the assessment of cognitive impairment in patients with cerebral atrophy and LA.     

Structural MRI correlates of the MMSE and pentagon copying test in Parkinson's disease

BackgroundCognitive impairment in Parkinson's disease (PD) is common and recent studies have focused on addressing the most suitable screening tool for its assessment. MMSE is commonly used in clinical practice and longitudinal studies found a relationship between the MMSE pentagon copying item and progression to dementia, but its neuroanatomical correlates have been poorly investigated. The aim of this study is to investigate the MRI structural correlates of the global MMSE and the pentagon item scores in PD patients in the absence of dementia.MethodsWe selected a sample of 92 PD patients and 36 controls. MMSE was used as a global measure of cognitive status, and the pentagon copying test as a measure of visuospatial performance. FreeSurfer software was used to assess intergroup differences in cortical thickness (CTh) and global atrophy measures, as well as their relationship with cognitive performance.ResultsCompared to controls, patients showed significant differences in measures of global atrophy, which correlated with performance on MMSE and the pentagon item. Regional differences in CTh were seen between PD patients and controls bilaterally in the temporo-parietal-occipital region. Patients with impaired performance compared with those of normal performance also showed CTh reductions in these regions.ConclusionOur results suggest MMSE and the pentagon item reflect brain changes which at a regional level involve mainly posterior regions. Correlates of the pentagon item were seen in the same regions where PD patients exhibited significant thinning, and involved more areas and bigger cluster sizes than the correlates of MMSE global scores.     

Cortical thinning associated with mild cognitive impairment in Parkinson's disease

The aim of this study was to investigate patterns of cortical atrophy associated with mild cognitive impairment in a large sample of nondemented Parkinson's disease (PD) patients, and its relation with specific neuropsychological deficits. Magnetic resonance imaging (MRI) and neuropsychological assessment were performed in a sample of 90 nondemented PD patients and 32 healthy controls. All underwent a neuropsychological battery including tests that assess different cognitive domains: attention and working memory, executive functions, memory, language, and visuoperceptual‐visuospatial functions. Patients were classified according to their cognitive status as PD patients without mild cognitive impairment (MCI; n = 43) and PD patients with MCI (n = 47). Freesurfer software was used to obtain maps of cortical thickness for group comparisons and correlation with neuropsychological performance. Patients with MCI showed regional cortical thinning in parietotemporal regions, increased global atrophy (global cortical thinning, total gray matter volume reduction, and ventricular enlargement), as well as significant cognitive impairment in memory, executive, and visuospatial and visuoperceptual domains. Correlation analyses showed that all neuropsychological tests were associated with cortical thinning in parietotemporal regions and to a lesser extent in frontal regions. These results provide neuroanatomic support to the concept of MCI classified according to Movement Disorders Society criteria. The posterior pattern of atrophy in temporoparietal regions could be a structural neuroimaging marker of cognitive impairment in nondemented PD patients. All of the neuropsychological tests reflected regional brain atrophy, but no specific patterns were seen corresponding to impairment in distinct cognitive domains. © 2014 International Parkinson and Movement Disorder Society     

血管性认知障碍不同亚型患者认知功能及MRI检查的对比研究

目的探讨血管性认知障碍各亚型患者之间及其与认知功能正常者之间的认知功能及脑组织影像学表现的差异。方法采用简易智能状态检查量表、认知能力筛查量表和简易智能-认知能力联合检查量表对62例血管性认知障碍患者(无痴呆型血管性认知障碍34例、血管性痴呆18例、混合性痴呆10例)和50例正常对照者的认知功能进行评价,通过磁共振成像分析其容积测量值、脑叶萎缩、皮质下白质疏松和腔隙性脑梗死等影像学参数的差异。结果与对照组比较,血管性认知障碍各亚组患者认知功能评分呈逐步递减趋势(均P<0.05),但血管性痴呆与混合性痴呆患者之间差异无统计学意义(P>0.05)。血管性认知障碍各亚组患者双侧前额角容积、第三脑室容积测量值以及额叶、颞叶、顶叶、枕叶萎缩,皮质下白质疏松和腔隙性脑梗死评分均高于对照组(P<0.05),其影像学异常改变在进展为痴呆后更为明显。混合性痴呆患者的特征性表现为双侧海马容积、内嗅叶皮质容积减小,颞叶萎缩(均P<0.05),但无明显的腔隙性脑梗死(P>0.05)。结论血管性认知障碍患者的影像学异常改变可部分反映不同亚型的病理改变,但对认知障碍程度的反映尚缺乏敏感性,能否联合认知功能评分共同作为血管性认知障碍临床预测指标尚待进一步研究。     

Cognition in multiple sclerosis: relevance of lesions,brain atrophy and proton MR spectroscopy

The overall burden of brain MRI-visible lesions does not fully account for cognitive impairment in multiple sclerosis (MS). Several MRI studies have highlighted the importance of brain damage in the normal-appearing brain tissue. Brain atrophy (global, cortical, white and deep grey matter) is related to cognitive deficits in MS patients and this holds true since the earliest disease stages. Non-conventional MRI techniques such as proton MR spectroscopy have related metabolic changes in specific brain areas to specific cognitive deficits. Overall, data provided by MRI support the notion that cognitive disturbances need to be considered for a more complete clinical characterisation of patients with MS, including those with “benign” MS.     

Cortical and Subcortical Grey Matter Abnormalities in White Matter Hyperintensities and Subsequent Cognitive Impairment

Grey matter (GM) alterations may contribute to cognitive decline in individuals with white matter hyperintensities (WMH) but no consensus has yet emerged. Here, we investigated cortical thickness and grey matter volume in 23 WMH patients with mild cognitive impairment (WMH-MCI), 43 WMH patients without cognitive impairment, and 55 healthy controls. Both WMH groups showed GM atrophy in the bilateral thalamus, fronto-insular cortices, and several parietal-temporal regions, and the WMH-MCI group showed more extensive and severe GM atrophy. The GM atrophy in the thalamus and fronto-insular cortices was associated with cognitive decline in the WMH-MCI patients and may mediate the relationship between WMH and cognition in WMH patients. Furthermore, the main results were well replicated in an independent dataset from the Alzheimer''s Disease Neuroimaging Initiative database and in other control analyses. These comprehensive results provide robust evidence of specific GM alterations underlying WMH and subsequent cognitive impairment.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12264-021-00657-0.     

Relation between MRI features and dementia in cerebrovascular disease patients with leukoaraiosis: A longitudinal study

We examined selective MRI features (localization and degree of white matter abnormalities, cortical and subcortical atrophy) in relation to cognitive decline in patients with cerebrovascular disease (CVD) and leukoaraiosis (LA). We enrolled 6 female and 18 male CVD patients (mean age 66.2 ± 6.6 years) whose Magnetic Resonance Images (MRI) revealed LA and who displayed a history of stroke or TIA; none showed signs of cortical infarcts or normal pressure hydrocephalus. Two blind raters independently scored MRI scans with a high level of agreement. All patients underwent extensive clinico-neuropsychological assessment upon admission to the study and 19 were followed for an average of 48 ± 7.6 months. Twelve patients were initially classified as non-demented and 12 as demented. Three years later, one in the former group had become demented and mental impairment had worsened for 6 patients in the latter group; these 7 subjects were labeled as “decliners”. Ventricular indexes were significantly higher in the demented group and correlated with severity of mental impairment, while the degree of LA was similar in demented and non-demented subjects. Neither white matter lesions nor sulcal and ventricular enlargement differed statistically between decliners and non-decliners.     

Corpus callosum damage and cognitive dysfunction in benign MS

Corpus callosum (CC), the largest compact white matter fiber bundle of the human brain involved in interhemispheric transfer, is frequently damaged in the course of multiple sclerosis (MS). Cognitive impairment is one of the factors affecting quality of life of patients with benign MS (BMS). The aim of this study was to investigate the relationship between the cognitive profile of BMS patients and the extent of tissue damage in the CC. Brain conventional and DT MRI scans were acquired from 54 BMS patients and 21 healthy controls. Neuropsychological tests (NPT) exploring memory, attention, and frontal lobe cognitive domains were administered to the patients. DT tractography was used to calculate the mean diffusivity (MD) and fractional anisotropy (FA) of the CC normal appearing white matter (NAWM). An index of CC atrophy was also estimated. Nine (17%) BMS patients fulfilled criteria for cognitive impairment. Compared with controls, BMS had significantly different CC diffusivity and volumetry (P < 0.001). Compared with cognitively preserved patients, those with CI had significantly higher CC lesion volume (LV) (P = 0.02) and NAWM MD (P = 0.02). The scores obtained at PASAT were significantly correlated with CC T2 LV, and NAWM FA and MD (r values ranging from ?0.31 to 0.66, P values ranging from 0.04 to <0.001). Cognitive impairment in BMS is associated with the extent of CC damage in terms of both focal lesions and diffuse fiber bundle injury. MRI assessment of topographical distribution of tissue damage may represent a rewarding strategy for understanding the subtle clinical deficits of patients with BMS. Hum Brian Mapp 2009. © 2008 Wiley‐Liss, Inc.     

Structural MRI correlates of cognitive impairment in patients with multiple sclerosis

In a multicenter setting, we applied voxel‐based methods to different structural MR imaging modalities to define the relative contributions of focal lesions, normal‐appearing white matter (NAWM), and gray matter (GM) damage and their regional distribution to cognitive deficits as well as impairment of specific cognitive domains in multiple sclerosis (MS) patients. Approval of the institutional review boards was obtained, together with written informed consent from all participants. Standardized neuropsychological assessment and conventional, diffusion tensor and volumetric brain MRI sequences were collected from 61 relapsing‐remitting MS patients and 61 healthy controls (HC) from seven centers. Patients with ≥2 abnormal tests were considered cognitively impaired (CI). The distribution of focal lesions, GM and WM atrophy, and microstructural WM damage were assessed using voxel‐wise approaches. A random forest analysis identified the best imaging predictors of global cognitive impairment and deficits of specific cognitive domains. Twenty‐three (38%) MS patients were CI. Compared with cognitively preserved (CP), CI MS patients had GM atrophy of the left thalamus, right hippocampus and parietal regions. They also showed atrophy of several WM tracts, mainly located in posterior brain regions and widespread WM diffusivity abnormalities. WM diffusivity abnormalities in cognitive‐relevant WM tracts followed by atrophy of cognitive‐relevant GM regions explained global cognitive impairment. Variable patterns of NAWM and GM damage were associated with deficits in selected cognitive domains. Structural, multiparametric, voxel‐wise MRI approaches are feasible in a multicenter setting. The combination of different imaging modalities is needed to assess and monitor cognitive impairment in MS. Hum Brain Mapp 37:1627‐1644, 2016. © 2016 Wiley Periodicals, Inc.     

Callosal atrophy correlates with temporal lobe volume and mental status in Alzheimer's disease

BACKGROUND: Recent studies have reported significant atrophy of the corpus callosum (CC) in Alzheimer's Disease (AD). However, it is currently unknown whether CC atrophy is associated with specific cortical volume changes in AD. Moreover, possible atrophy in extra-callosal commissures has not been examined to date. The purpose of the present study was to quantify atrophy in two cerebral commissures [the CC and the anterior commissure (AC)], to correlate this measure with cognitive status, and to relate commissural size to independent measures of temporal lobe volume in AD patients. METHODS: A sample of AD patients and of age- and education-matched normal control subjects (NCs) underwent MRI and a cognitive test battery including the Dementia Rating Scale and Mini Mental State examination. Mid-sagittal regional areas within CC and AC were measured along with superior, middle and inferior temporal lobes volumes. RESULTS: Alzheimer's Disease patients had significantly smaller callosa than did NCs. The callosal regions most affected in AD included the midbody, isthmus and genu. The isthmus and midbody areas of the CC were positively correlated with cognitive performance and with superior temporal lobe volume in AD patients. The mid-sagittal area of the AC and the superior temporal volumes did not differ between AD patients and NCs. CONCLUSIONS: The study demonstrated that the regional morphology of the CC correlates with current cognitive status and temporal lobe atrophy in AD. As well, the lack of difference for the AC suggests that commissural atrophy in AD is regionally specific.     

Electrophysiological and clinical correlates of corpus callosum atrophy in patients with multiple sclerosis

Abstract

Multiple sclerosis (MS) is an idiopathic inflammatory demyelinating disorder of the central nervous system (CNS) characterized by demyelination and axonal degeneration. Corpus callosum (CC) is commonly involved during the disease process leading to atrophy (93%). Currently, there are no established markers of disease progression and the interplay of processes leading to brain atrophy in MS remains unknown. The primary aim of this study was to assess the frequency of CC atrophy in MS patients. Furthermore, the relationship between expanded disability status scale (EDSS) and transcranial magnetic stimulation (TMS) evoked motor potentials (MEP) were assessed to capture disease effects by independent parameters. Seventy-nine MS patients and 50 controls were included and their CC volumes were assessed. Out of 79 patients, 31 patients (39·2%) had CC atrophy. The distribution of EDSS scores among the group with CC atrophy [13 (32%) patients with EDSS 0–2; 11 (58%) patients with EDSS 2–4; 19 (24%) patients with EDSS ≥4] was not statistically significant (p>0·05). MEP latency was abnormal in 34 (43%) patients, 67 (85%) patients had abnormal MEP amplitude and CMCT was abnormal in 32 (41%) patients. The relation between EDSS and MEP was statistically significant among the patient population including the subgroup of patients with CC atrophy (p<0.05). Our results lacked to provide an association between disability and CC atrophy, but there was a correlation between CC atrophy and TMS evoked motor potentials. Early evolution of axonal degeneration and brain atrophy should be considered in terms of follow-up measures to provide long-term efficiency impacting disability, progression and brain atrophy.     

Survival in Parkinson's disease. Relation with motor and non-motor features

BackgroundSurvival in patients with Parkinson's disease is reduced as compared to the general population. We aimed to identify motor and non-motor features that predict mortality in Parkinson's disease.MethodsA broad range of motor and non-motor features were assessed in a hospital-based cohort of 414 patients with Parkinson's disease, who underwent five annual follow-up examinations including vital status assessment. Multivariable Cox's proportional hazards regression analysis was used to evaluate the association between baseline characteristics and mortality risk. Stepwise regression with backward elimination was carried out to determine the best model to predict mortality in Parkinson's disease.ResultsAfter a mean follow-up period of 4.3 years, 49 (11.8%) patients had died. In the stepwise regression model, predictors of mortality in Parkinson's disease were higher age, male sex, cognitive impairment, higher postural instability gait disorder score, and the presence of psychotic symptoms.ConclusionsHigher age, male sex, cognitive impairment, higher postural instability gait disorder score, and the presence of psychotic symptoms are independent predictors of decreased survival in Parkinson's disease. Mortality in Parkinson's disease thus seems to be affected mainly by non-dopaminergic and non-motor features.     

Dual-task clinical and functional MRI correlates in Parkinson's disease with postural instability and gait disorders

BackgroundDual-task is a challenge for Parkinson's disease patients with postural instability and gait disorders (PD-PIGD).ObjectiveThis study investigated clinical, cognitive and functional brain correlates of dual-task deficits in PD-PIGD patients using quantitative gait analysis, neuropsychological evaluations and functional MRI (fMRI).MethodsTwenty-three PD-PIGD patients performed a clinical assessment of gait/balance abilities. Single and dual-task Timed-Up-and-Go tests were monitored using an optoelectronic system to study turning velocity. Patients underwent executive-attentive function evaluation and two fMRI tasks: motor-task (foot anti-phase movements), and dual-task (foot anti-phase movements while counting backwards by threes starting from 100). Twenty-three healthy subjects underwent neuropsychological and fMRI assessments.ResultsDual-task in PD-PIGD patients resulted in worse gait performance, particularly during turning. Performing the dual-task relative to the motor-fMRI task, healthy subjects showed widespread increased recruitment of sensorimotor, cognitive and cerebellar areas and reduced activity of inferior frontal and supramarginal gyri, while PD-PIGD patients showed increased recruitment of inferior frontal gyrus and supplementary motor area and reduced activity of primary motor, supramarginal and caudate areas. Dual-task gait alterations in patients correlated with balance and executive deficits and with altered dual-task fMRI brain activity of frontal areas.ConclusionsThis study suggested the correlation between dual-task gait difficulties, postural instability and executive dysfunction in PD-PIGD patients. FMRI results suggest that an optimized recruitment of motor and cognitive networks is associated with a better dual-task performance in PD-PIGD. Future studies should evaluate the effect of specific gait/balance and dual-task trainings to improve gait parameters and optimize brain functional activity during dual-tasks.     

MRI study of caudate nucleus volume in Parkinson's disease with and without dementia with Lewy bodies and Alzheimer's disease

OBJECTIVE: To compare whole brain and caudate volume on MRI in subjects with Parkinson's disease without cognitive impairment (PD), Parkinson's disease with dementia with Lewy bodies (PD + DLB), Alzheimer's disease (AD) and normal control subjects. To examine the relationship between caudate volume and cognitive impairment, depression and movement disorder. METHOD: Whole brain and caudate volumes were segmented from volumetric 1.5-tesla magnetic resonance imaging (MRI) scans of older subjects with PD (n = 28; mean age 75.5 years), PD + DLB (n = 20; 73.0 years), AD (n = 27; 77.5 years) and normal controls (n = 35; 74.9 years). RESULTS: Subjects with AD had significantly reduced whole brain and caudate volume compared to controls and those with PD. Caudate atrophy in AD was proportionate to whole brain atrophy. There were no significant differences in whole brain or caudate volume between controls, PD and PD + DLB. There were no significant correlations between caudate volume and either global cognitive function, executive performance or processing speed. CONCLUSIONS: Caudate atrophy occurs in AD but not PD without dementia. Caudate atrophy is not regionally specific but part of generalised brain volume loss. Structural changes in the caudate, as assessed by in vivo MRI, do not appear to contribute to the cognitive impairment observed amongst patients with PD, PD + DLB or AD. Results indicate that the executive and attentional dysfunctions associated with PD and DLB are unlikely to be a direct and specific consequence of caudate atrophy as assessed on MRI.     

Correlating brain volume and callosal thickness with clinical and laboratory indicators of disease severity in children with HIV-related brain disease

Background

Objective MRI markers of central nervous system disease severity may precede subjective features of HIV encephalopathy in children. Previous work in HIV-infected adults shows that brain atrophy was associated with low CD4 and with neuropsychological impairment. Significant thinning of the corpus callosum (CC), predominantly anteriorly, was also found in HIV-infected adults and correlated with CD4 levels. These findings have not been tested in children.

Purpose

The aim of this study was to determine if brain volume and midsagittal CC linear measurements (thickness and length) on MRI in children with HIV-related brain disease correlate with clinical and laboratory parameters of disease severity.

Methods

Retrospective MRI analysis in children with HIV-related brain disease used a volumetric analysis software and a semi-automated tool to measure brain volume and callosal thickness/length, respectively. Each measure was correlated with clinical parameters of disease severity including Griffiths Mental Development scores (GMDS), absolute CD4 counts (cells/mm³), nadir CD4 (the lowest CD4 recorded, excluding baseline), duration of HAART, and decreased brain growth.

Results

Thirty-three children with HIV-related brain disease were included. Premotor segment of the CC mean thickness correlated with age (p?=?0.394). Motor CC maximum thickness correlated significantly with general developmental quotient (p?=?0.0277); CC length correlated with a diagnosis of acquired microcephaly (p?=?0.0071) and to CD4 level closest to date of the MRI scan (p?=?0.04).

Conclusions

Length of the CC and the “motor CC segment” may represent surrogate clinical biomarkers of central nervous system disease severity and with decreased level of immunity in HIV-infected patients that precede established HIV encephalopathy.     

Voxel-based morphometry reveals extra-nigral atrophy patterns associated with dopamine refractory cognitive and motor impairment in parkinsonism

ObjectivesTo determine overall patterns of brain atrophy associated with memory, executive function (EF) and dopamine non-responsive motor measures in older parkinsonian patients.DesignForty-three older PD patients (≥65 years) and matched controls underwent a neurological examination (Unified Parkinson's Disease Rating Scale, separated into dopamine responsive and dopamine non-responsive signs) and neuropsychological testing (memory: California Verbal Learning Test (CVLT)) and a composite of index of executive function (EF): Stroop Interference, Trail Making Test Part B, and digit ordering. All underwent volumetric MRI scans analyzed using voxel-based morphometry (VBM). Group comparisons, and the correlations between MRI gray and white matter volume and motor and cognitive measures were controlled for age, sex and intracranial volume. Cerebellar volume was independently measured using a validated extraction method.ResultsPatients and controls were matched for demographics and global cognitive measures. VBM indicated significant gray matter (GM) atrophy in the cerebellum in PD and was confirmed independently. Poor memory was associated with GM atrophy in the left (uncus, middle temporal and fusiform gyri) and right temporal lobes and left putamen. Dopamine non-responsive motor signs and EF were associated with caudate atrophy. EF was also associated with GM atrophy in the middle temporal gyri, the left precuneus and cerebellum.ConclusionsCortical and striatal atrophy were associated with dopamine non-responsive motor signs and cognitive impairment and provide a morphologic correlate for progression of PD. Cerebellar atrophy was found in older PD patients.     

Association between homocysteine and third ventricle dilatation,mesencephalic area atrophy in Parkinson’s disease with cognitive impairment

ObjectivesThis study aimed to explore the association of homocysteine (Hcy) with third ventricle (V3) dilatation and mesencephalic area (MA) atrophy as determined by transcranial sonography (TCS) in Parkinson’s disease (PD) with cognitive impairment.MethodsThe final statistical analysis included 101 PD patients and 20 age- and sex-matched controls. Using the Movement Disorder Society (MDS) level II criteria for PD with cognitive impairment, we categorized the PD patients into PD with normal cognition group (PD) and PD with cognitive impairment group (PDC). All subjects underwent TCS and laboratory analysis.ResultsThe V3 width (r = 0.349, P = 0.005) and the MA (r = −0.484, P < 0.001) were significantly correlated with the Hcy concentration in the PDC patients. Binary logistic regression analysis revealed that age (OR [95% CI] = 1.114 [0.991–1.251], P = 0.002), and Hcy level (OR [95% CI] = 0.931 [0.752–1.153], P = 0.411) were independent risk factors for V3 dilatation. Hcy level (OR [95% CI] = 0.557 [0.323–0.967], P = 0.035) were independent risk factors for MA atrophy. After adjustment for confounding factors, the odds ratio of V3 dilatation was 3.50 (95% CI 1.054–11.399, P = 0.031) and the odds ratio of MA atrophy was 4.67 (95% CI 1.395–15.602, P = 0.012) in the patients with higher Hcy level compared with the lower level.ConclusionsThe results revealed a close association between the V3 width, MA and Hcy concentration in PD patients with cognitive impairment. We hypothesized that increased Hcy concentration played a significant role in the development of brain atrophy in PD with cognitive impairment.