Relationship between behavioral disturbances and characteristics of patients in special units for dementia

Abstract The aim of the present study was to examine the relationships between behavioral disturbances and patient characteristics of inpatients with dementia nationwide. The five patient characteristics used were age, gender, years of education, cognitive status, and walking ability. The subjects consisted of 730 inpatients selected by systematic sampling from 180 units that have specialized psychiatric beds for acute/long‐term care of dementia. Clinical staff members assessed the 730 patients with the Mini‐Mental State Examination (MMSE), and filled out a questionnaire for long‐term care insurance, including 19 items relating to behavioral disturbances and walking scale. Five meaningful factors were identified out of the 19 behavioral disturbances by factor analysis. Linear regression analysis revealed that the factor ‘psychotic/neurotic’ was not related to any patient characteristics; ‘aggression/negativistic’ was related to male gender and a lower MMSE score; and ‘dirty/destructive’ and ‘disorientation/fire management’ were related to a lower MMSE score and higher walking score. The factor ‘sexual behavior’ included only one behavior at a very low frequency. These findings suggest that different behavioral disturbance factors have different correlations with patient characteristics, while cognitive dysfunction has a relatively important role in behavioral disturbances of inpatients with dementia.     

Motor-induced brain activation in cortical, subcortical and cerebellar regions in schizophrenic inpatients. A whole brain fMRI fingertapping study

Motor symptoms including neurological soft signs have been found to be more prevalent in schizophrenic patients. In addition, catatonic symptoms and neuroleptic treatment as well may influence cortical and subcortical motor organization in schizophrenia. The results of previous neuroimaging studies exploring motor function in patients with schizophrenia are inhomogenous reporting on a decreased activity in cortical motor regions in some studies and normal activity in others. Using fMRI, we studied 40 subjects performing a unilateral self-paced fingertapping task. Analyzing a general linear model of four groups, we compared patients with schizophrenia according to DSM-IV treated with olanzapine (OL; 10) or haloperidol (HA; 10) to healthy controls (HC; 10) and untreated patients (UN; 10). Brainvoyager software was used for data analyzing. In all groups, the contralateral motor cortex was significantly activated. Significant activation of the ipsilateral cerebellum was found in the UN group, the control group and the OL group. The contralateral basal ganglia were activated in UN and in controls. Motor-induced cortical and subcortical brain activation in HC was significantly higher than in patients with schizophrenia. UN with schizophrenia showed a significant overactivation than the other groups. In conclusion, we revealed a diminished activation in the patient group treated with neuroleptic drugs. This study outlines the importance of further fMRI studies to investigate interindividual activation differences under different conditions especially focusing on basal ganglia.     

Abnormal cortical sensory activation in dystonia: an fMRI study.

Despite the obvious motor manifestations of focal dystonia, it is recognised that the sensory system plays an important role in this condition. This functional magnetic resonance imaging study examines the sensory representations of individual digits both within the subregions of the primary sensory cortex (SI) and in other nonprimary sensory areas. Patients with focal dystonia and controls were scanned during vibrotactile stimulation of both the index (digit 2) and little (digit 5) fingers of their dominant hand (which was the affected hand in all the dystonic subjects). The activation maps obtained were analysed for location, size, and magnitude of activation and three-dimensional (3-D) orientation of digit representations. Data from both groups were compared. There were significant differences in the average 3-D separation between the two digit representations in area 1 of SI between subject groups (9.6 +/- 1.2 mm for controls and 4.1 +/- 0.2 mm for dystonic subjects). There were also strong trends for reversed ordering of the representation of the two digits in both the secondary sensory cortex and posterior parietal area between the two groups. In addition, in dystonic subjects, there was significant under activation in the secondary somatosensory cortex (SII/area 40) for both digits and in the posterior parietal area for digit 5. These results indicate the presence of widespread activation abnormalities in the cortical sensory system in dystonia.     

阿尔茨海默病和血管性痴呆的精神行为症状

目的 探讨阿尔茨海默病(Alzheimer’s disease，AD)和血管性痴呆(vascular dementia，VD)患者的精神行为症状特点及对早期诊断的价值。方法 对80例AD和72例VD的精神行为症状进行分类、比较和分析。结果 VD患者焦虑(P＝0．0024)和抑郁(P＝0．0059)的发生率显著高于AD患者，AD患者则以无目的闲逛(P＝0．0018)明显多见；而情感失控和情绪不稳的发生率在两组痴呆患者中无明显差异。结论 AD和VD患者的精神行为改变各有其不同特点，这对二者的早期诊断和鉴别诊断有一定帮助。     

Brain activation pattern related to gait disturbances in Parkinson's disease

Gait disturbances represent a therapeutic challenge in Parkinson's disease (PD). To further investigate their underlying pathophysiological mechanisms, we compared brain activation related to mental imagery of gait between 15 PD patients and 15 age‐matched controls using a block‐design functional MRI experiment. On average, patients showed altered locomotion relatively to controls, as assessed with a standardized gait test that evaluated the severity of PD‐related gait disturbances on a 25‐m path. The experiment was conducted in the subjects as they rehearsed themselves walking on the same path with a gait pattern similar as that during locomotor evaluation. Imagined walking times were measured on a trial‐by‐trial basis as a control of behavioral performance. In both groups, mean imagined walking time was not significantly different from that measured during real gait on the path used for evaluation. The between‐group comparison of the mental gait activation pattern with reference to mental imagery of standing showed hypoactivations within parieto‐occipital regions, along with the left hippocampus, midline/lateral cerebellum, and presumed pedunculopontine nucleus/mesencephalic locomotor area, in patients. More specifically, the activation level of the right posterior parietal cortex located within the impaired gait‐related cognitive network decreased proportionally with the severity of gait disturbances scored on the path used for gait evaluation and mental imagery. These novel findings suggest that the right posterior parietal cortex dysfunction is strongly related to the severity of gait disturbances in PD. This region may represent a target for the development of therapeutic interventions for PD‐related gait disturbances. © 2012 Movement Disorder Society     

Voluntary activation and cortical activity during a sustained maximal contraction: an fMRI study

Motor fatigue is an exercise-induced reduction in the force-generating capacity. The underlying mechanisms can be separated into factors residing in the periphery or in the central nervous system. We designed an experiment in which we investigated central processes underlying motor fatigue by means of magnetic resonance imaging in combination with the twitch interpolation technique. Subjects performed a sustained maximal abduction (2 min) with the right index finger. Brain activation was recorded with an MR scanner, together with index finger abduction force, EMG of several hand muscles and interpolated twitches. Mean activity per volume was calculated for the primary motor cortex and the secondary motor areas (supplementary motor, premotor, and cingulate areas) as well as mean force and mean rectified EMG amplitude. Results showed a progressive decline in maximal index finger abduction force and EMG of the target muscles combined with an increase in brain activity in the contralateral primary motor cortex and secondary motor areas. Analysis of the twitches superimposed on the sustained contraction revealed that during the contraction the voluntary drive decreased significantly. In conclusion, our data showed that despite an increase in brain activity the voluntary activation decreased. This suggests that, although the CNS increased its input to the relevant motor areas, this increase was insufficient to overcome fatigue-related changes in the voluntary drive.     

fMRI changes in cortical activation during task performance with the unaffected hand partially reverse after ropinirole treatment in de novo Parkinson's disease

Background and purposePrevious fMRI studies indicated a relationship between changes of the cortical activation pattern and disease severity in Parkinson's disease (PD). Early diagnosis of Parkinson's disease offers the opportunity to evaluate the putative neuroprotective and disease-modifying effects of drugs at a clinical stage when they might be more effective. The aim of this study was to assess motor cortex reorganization at the earliest clinically detectable stage of PD and the effects on it of chronic dopaminergic treatment.MethodsWe evaluated with fMRI 11 de novo patients with right unilateral parkinsonism during execution of a controlled hand-tapping task by the unaffected left hand. In 7 of them fMRI examination with the same task was repeated after 6 months of ropinirole administration.ResultsAt baseline, as compared to control subjects, PD patients showed significant hypoactivation of right sensory-motor cortex (SM1) and hyperactivation of the left parietal superior and inferior gyri and frontal superior gyrus and of the right parietal superior gyrus and precuneus. Ropinirole treatment yielded a significant clinical improvement (mean UPDRS score subitem III 13.4 at baseline, 9.4 at follow-up; p < 0.001 at a paired t-test) which was combined with lower activation in the left parietal superior and inferior gyri and in right parietal and occipital superior gyri with respect to their baseline fMRI examination.ConclusionsOur results indicate that in PD patients changes in cortical activation precede the onset of motor symptoms in the clinically unaffected side and are partially reversed by chronic administration of long acting dopamine agonist ropinirole.     

Learning-related changes of brain activation in the visual ventral stream: an fMRI study of mirror reading skill

A previous neuroimaging study has indicated that the visual dorsal stream may contribute to accurate reading of mirror-reversed words. However, the role of the visual ventral stream in the learning of mirror reading skill remains ambiguous. In the present fMRI study, we investigated learning-related changes in brain activation in the visual ventral stream in a mirror reading task. Subjects participated in three successive runs of the mirror reading task, in each of which they were asked to read mirror-reversed words and normal words as accurately and as quickly as possible. The behavioral data for the mirror reading condition showed significant improvement in reaction time but not in performance accuracy across the three runs. The activation data showed different learning-associated patterns related to the right and left visual ventral streams. On the right side, activity related to the reading of mirror stimuli was significantly greater than that related to normal stimuli in the first run only, whereas on the left side it was greater in all runs. Additional correlation analysis between response time data and percentage signal changes only in the mirror reading condition showed significant correlation on the right visual ventral stream in the first run only, whereas that on the left visual ventral stream was found only in the third run. The dissociable response between the right and left visual ventral streams may reflect learning-related changes in reading strategy and may be critical in improving the speed of reading mirror-reversed words.     

Prefrontal transcranial direct current stimulation alters activation and connectivity in cortical and subcortical reward systems: A tDCS‐fMRI study

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique used both experimentally and therapeutically to modulate regional brain function. However, few studies have directly measured the aftereffects of tDCS on brain activity or examined changes in task‐related brain activity consequent to prefrontal tDCS. To investigate the neural effects of tDCS, we collected fMRI data from 22 human subjects, both at rest and while performing the Balloon Analog Risk Task (BART), before and after true or sham transcranial direct current stimulation. TDCS decreased resting blood perfusion in orbitofrontal cortex and the right caudate and increased task‐related activity in the right dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in response to losses but not wins or increasing risk. Network analysis showed that whole‐brain connectivity of the right ACC correlated positively with the number of pumps subjects were willing to make on the BART, and that tDCS reduced connectivity between the right ACC and the rest of the brain. Whole‐brain connectivity of the right DLPFC also correlated negatively with pumps on the BART, as prior literature would suggest. Our results suggest that tDCS can alter activation and connectivity in regions distal to the electrodes. Hum Brain Mapp 35:3673–3686, 2014. © 2014 Wiley Periodicals, Inc .     

网络游戏成瘾者相关脑区功能定位的fMRI研究

目的 采取线索--反应模式,利用功能磁共振成像(fMRI)技术探索与网络游戏成瘾相关的脑区功能定位.方法 网络游戏成瘾者和对照者各20例,在观看相关网络游戏视频录像和日常生活视频录像的同时进行fMRI扫描,进行问卷调查了解受试者观看视频录像后的心理状态并采集脑血氧水平依赖(BOLD)信号得到网络游戏和日常生活视频录像刺激的脑区激活数据,利用相减原则进行相关性分析产生相应的激活区,进行激活脑区的定位并比较激活强度.结果 成瘾者观看网络游戏和日常生活视频录像时所产生的情绪状态、渴望程度、喜欢程度和希望再次观看程度差异均有统计学意义(P<0.05),而对照者仅希望再次观看程度差异有统计学意义(P<0.05);与生活视频比较,对照者观看游戏视频时顶叶(左)和颞叶视皮层(左)的激活强度较高,差异有统计学意义(P<0.05),而成瘾者除伏核(左)和尾状核(左)外,余脑区观看观看游戏视频和生活视频时激活强度差异均有统计学意义(P<0.05).结论 利用fMRI技术可以对网络游戏成瘾者相关脑区进行功能定位,这些脑区可能参与了网络游戏成瘾的产生与维持.     

Somatosensory cortical activation in cervical dystonia and its modulation with botulinum toxin: an fMRI study

Converging data on focal dystonias suggest a widespread disorder of somatosensory processing. The aims of our study were, first, to assess somatosensory activation patterns in cervical dystonia (CD) beyond the representation of the affected body parts and, second, to search for task-related activation changes induced by botulinum toxin type-A (BoNT-A) therapy. Functional magnetic resonance imaging (MRI) during electrical median nerve stimulation was employed in seven CD patients and nine controls; the examination was repeated 4 weeks after BoNT-A application to dystonic neck muscles. The pretreatment activation map of patients showed activation in the contralateral primary somatosensory cortex, but missing activation in the secondary somatosensory cortex and insula, in contrast to controls and patients after treatment. Clinically significant effect of BoNT-A therapy was associated with a significant increase of BOLD response in the contralateral secondary somatosensory, insular, and inferior parietal cortices. The posttreatment somatosensory maps of patients did not significantly differ from controls. This study has brought evidence of widespread disruption of somatosensory processing in CD and its modification with BoNT-A therapy.     

An fMRI study of affective state and medication on cortical and subcortical brain regions during motor performance in bipolar disorder

Structural neuroimaging studies have identified abnormalities in the basal ganglia in patients with bipolar disorder. Findings have been mixed with regard to affective state and have not elaborated on the role of medication on functional brain activity. The aims of the present study were to use functional magnetic resonance imaging (fMRI) to test whether depressed and manic bipolar disorder patients differ in terms of activity in cortical and subcortical brain areas and to examine the effects of psychotropic medication. Twenty-four bipolar disorder subjects and 13 healthy comparison subjects participated in an fMRI study of manual reaction time. Both manic and depressed subjects exhibited abnormally elevated blood oxygen level dependent BOLD responses in cortical and subcortical areas. Manic bipolar subjects had significantly higher BOLD responses in the left globus pallidus and significantly lower BOLD responses in the right globus pallidus compared with depressed bipolar patients. Correlational analyses revealed significant relationships between the severity of mania and activity within the globus pallidus and caudate. Patients off antipsychotic or mood-stabilizing medication exhibited significantly higher BOLD responses throughout the motor cortex, basal ganglia and thalamus compared with patients on these medications. These results suggest that affective state in bipolar disorder may be related to a disturbance of inhibitory regulation within the basal ganglia and that antipsychotics and/or mood stabilizers normalize cortical and subcortical hyperactivity.     

Comparing cerebral perfusion in Alzheimer's disease and Parkinson's disease dementia: an ASL-MRI study

Emerging evidence suggests that Alzheimer''s disease (AD) and Parkinson''s disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing. Alzheimer''s disease and PDD perfusion was analyzed by whole-brain voxel-based analysis (to assess absolute blood flow), a priori specified region of interest analysis, and principal component analysis (to generate a network differentiating the two groups). Corrections were made for cerebral atrophy, age, sex, education, and MRI scanner software version. Analysis of absolute blood flow showed no significant differences between AD and PDD. Comparing each group with controls revealed an overlapping, posterior pattern of hypoperfusion, including posterior cingulate gyrus, precuneus, and occipital regions. The perfusion network that differentiated AD and PDD groups identified relative differences in medial temporal lobes (AD<PDD) and right frontal cortex (PDD<AD). In conclusion, the pattern of cerebral hypoperfusion is very similar in AD and PDD. This suggests closely linked mechanisms of neurodegeneration mediating the evolution of dementia in both conditions.     

Dementia in Parkinson's disease: a post-mortem study in a population of brain donors

OBJECTIVE: To identify factors associated with dementia in a cohort of Parkinson's disease (PD) brain donors and determine whether its presence may influence the clinical phenotype of the disease. METHODS: We included 67 consecutive patients with a clinical and pathological diagnosis of PD, who while alive, consented to donate their brains to the University of Miami Brain Endowment Bank(TM). Dementia and psychiatric complications of PD were diagnosed according to established criteria. Case histories were abstracted and reviewed and comparisons between PD patients with (PD-D, n = 34) and without (PD, n = 33) dementia were made. RESULTS: Age at death, age at disease onset and disease duration did not differ significantly between PD-D and PD patients. Other symptoms were similar in both groups. Visual hallucinations and bilateral symptoms at diagnosis were significantly higher in PD-D patients. No association between dementia and overall survival duration was found. Although the frequency of depression and psychosis was higher in the PD patients with dementia no statistical significance was reached. The overall lifetime prevalence of dementia in our group was 50.7%. CONCLUSIONS: Visual hallucinations and bilateral symptoms were associated with dementia in our cohort of PD brain donors. No association between dementia and survival duration was found. Understanding the influence of dementia on the clinical phenotype of the disease and predicting its development is essential for the successful management of PD.     

Altered resting state networks in mild cognitive impairment and mild Alzheimer's disease: an fMRI study

Activity and reactivity of the default mode network in the brain was studied using functional magnetic resonance imaging (fMRI) in 28 nondemented individuals with mild cognitive impairment (MCI), 18 patients with mild Alzheimer's disease (AD), and 41 healthy elderly controls (HC). The default mode network was interrogated by means of decreases in brain activity, termed deactivations, during a visual encoding task and during a nonspatial working memory task. Deactivation was found in the default mode network involving the anterior frontal, precuneus, and posterior cingulate cortex. MCI patients showed less deactivation than HC, but more than AD. The most pronounced differences between MCI, HC, and AD occurred in the very early phase of deactivation, reflecting the reactivity and adaptation of the network. The default mode network response in the anterior frontal cortex significantly distinguished MCI from both HC (in the medial frontal) and AD (in the anterior cingulate cortex). The response in the precuneus could only distinguish between patients and HC, not between MCI and AD. These findings may be consistent with the notion that MCI is a transitional state between healthy aging and dementia and with the proposed early changes in MCI in the posterior cingulate cortex and precuneus. These findings suggest that altered activity in the default mode network may act as an early marker for AD pathology.     

Human brain activation during passive listening to sounds from different locations: an fMRI and MEG study

Recent animal and human studies indicate the existence of a neural pathway for sound localization, which is similar to the "where" pathway of the visual system and distinct from the sound identification pathway. This study sought to highlight this pathway using a passive listening protocol. We employed fMRI to study cortical areas, activated during the processing of sounds coming from different locations, and MEG to disclose the temporal dynamics of these areas. In addition, the hypothesis of different activation levels in the right and in the left hemispheres, due to hemispheric specialization of the human brain, was investigated. The fMRI results indicate that the processing of sound, coming from different locations, activates a complex neuronal circuit, similar to the sound localization system described in monkeys known as the auditory "where" pathway. This system includes Heschl's gyrus, the superior temporal gyrus, the supramarginal gyrus, and the inferior and middle frontal lobe. The MEG analysis allowed assessment of the timing of this circuit: the activation of Heschl's gyrus was observed 139 ms after the auditory stimulus, the peak latency of the source located in the superior temporal gyrus was at 156 ms, and the inferior parietal lobule and the supramarginal gyrus peaked at 162 ms. Both hemispheres were found to be involved in the processing of sounds coming from different locations, but a stronger activation was observed in the right hemisphere.     

Object naming and action-verb generation in Parkinson's disease: A fMRI study

Introduction

Previous studies have demonstrated that non-demented Parkinson's disease (PD) patients have particular difficulty in producing verbs in a word generation situation. Two alternative explanations for this deficit have been proposed: the “motor” theory (verbs as action representawcttions) and the “grammatical” theory (verbs as lexical category). The aim of this study was to investigate the “motor” theory by exploring the neuronal substrates of action-related word production.

Methods

Event-related functional magnetic resonance with a 3 T magnetic resonance imaging (MRI) was used to explore brain activity during two overt oral language tasks, i.e., object naming (ON) and generation of action-verbs (GenA), in 14 non-demented PD patients using a common set of object drawings. The objects used were either man-made objects (MMO) or manipulable biological objects (MBO). Stimuli and tasks were randomized across subjects. Neuroimaging data were analyzed using SPM2.

Results

Reaction times in GenA_MBO were significantly longer than in the other three conditions (ON_MBO, ON_MMO, GenA_MMO). The distribution of brain activities associated with each condition resembled that reported in previous studies on healthy subjects using similar tasks; a comparison between GenA and ON revealed slight differences located above all in the premotor and prefrontal cortices, particularly as regards GeneA_MBO > ON_MMO. Furthermore, we found positive correlations between the severity of the motor deficit (as assessed by the Unified Parkinson's Disease Rating Scale - UPDRS score) and brain activity, particularly during GenA_MBO, in the pre- and post-central gyri bilaterally, left frontal operculum, left supplementary motor area (SMA) and right superior temporal cortex.

Conclusions

The direct comparison in our study of brain activity during the production of action-words and of object names did not reveal any major differences. However, our results point to a relationship between motor system dysfunction in PD and the extent of activation in verb generation, a task which implies in-depth processing of semantic representation of actions.