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1.
The diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) is extremely difficult.Diffusion-weighted imaging has been shown to be the most sensitive technique for the detection of signal alterations in sCJD patients.The present study analyzed the diagnostic value of diffusion-weighted imaging and fluid-attenuated inversion recovery sequence in the early stage of sCJD in one female patient and correlated the clinical symptoms during disease course and magnetic resonance manifestations.Thalamic and basal ganglia hyperintensities were observed on magnetic resonance images in a very early stage,i.e.,when the clinical typical manifestations of the disease were not present.With the progression of the disease,cortical and basal ganglia hyperintensities were observed on magnetic resonance images,showing an obvious cerebral atrophy.These findings suggest that diffusion-weighted imaging and fluid-attenuated inversion recovery sequence are helpful in diagnosing sCJD.  相似文献   

2.
Vertebral artery orifice stenting may improve blood supply of the posterior circulation of the brain to regions such as the cerebellum and brainstem. However, previous studies have mainly focused on recovery of cerebral blood flow and perfusion in the posterior circulation after interventional therapy. This study examined the effects of functional recovery of local brain tissue on cerebellar function remodeling using blood oxygen level-dependent functional magnetic reso- nance imaging before and after interventional therapy. A total of 40 Chinese patients with severe unilateral vertebral artery orifice stenosis were enrolled in this study. Patients were equally and randomly assigned to intervention and control groups. The control group received drug treat- ment only. The intervention group received vertebral artery orifice angioplasty and stenting + identical drug treatment to the control group. At 13 days after treatment, the Dizziness Handicap Inventory score was compared between the intervention and control groups. Cerebellar function remodeling was observed between the two groups using blood oxygen level-dependent functional magnetic resonance imaging. The improvement in dizziness handicap and cerebellar function was more obvious in the intervention group than in the control group. Interventional therapy for severe vertebral artery orifice stenosis may effectively promote cerebellar function remodeling and exert neuroprotective effects.  相似文献   

3.
Subcortical vascular mild cognitive impairment(svMCI)is a common prodromal stage of vascular dementia.Although mounting evidence has suggested abnormalities in several single brain network metrics,few studies have explored the consistency between functional and structural connectivity networks in svMCI.Here,we constructed such networks using resting-state f MRI for functional connectivity and diffusion tensor imaging for structural connectivity in 30 patients with svMCI and 30 normal controls.The functional networks were then parcellated into topological modules,corresponding to several well-defined functional domains.The coupling between the functional and structural networks was finally estimated and compared at the multiscale network level(whole brain and modular level).We found no significant intergroup differences in the functional–structural coupling within the whole brain;however,there was significantly increased functional–structural coupling within the dorsal attention module and decreased functional–structural coupling within the ventral attention module in the svMCI group.In addition,the svMCI patients demonstrated decreased intramodular connectivity strength in the visual,somatomotor,and dorsal attention modules as well as decreased intermodular connectivity strength between several modules in the functional network,mainly linking the visual,somatomotor,dorsal attention,ventral attention,and frontoparietal control modules.There was no significant correlation between the altered module-level functional–structural coupling and cognitive performance in patients with svMCI.These findings demonstrate for the first time that svMCI is reflected in a selective aberrant topological organization in multiscale brain networks and may improve our understanding of the pathophysiological mechanisms underlying svMCI.  相似文献   

4.
Alzheimer's disease (AD) is the most common type of dementia, comprising an estimated 60-80% of all dementia cases. It is clinically characterized by impairments of memory and other cognitive functions. Previous studies have demonstrated that these impairments are associated with abnormal structural and functional connections among brain regions, leading to a disconnection concept of AD. With the advent of a combination of non-invasive neuroimaging (structural magnetic resonance imaging (MRI), diffusion MRI, and functional MRI) and neurophysiological techniques (electroencephalography and magnetoencephaJography) with graph theoretical analysis, recent studies have shown that patients with AD and mild cognitive impairment (MCI), the prodromal stage of AD, exhibit disrupted topological organization in large-scale brain networks (i.e., connectomics) and that this disruption is significantly correlated with the decline of cognitive functions. In this review, we summarize the recent progress of brain connectomics in AD and MCI, focusing on the changes in the topological organization of large-scale structural and functional brain networks using graph theoretical approaches. Based on the two different perspectives of information segregation and integration, the literature reviewed here suggests that AD and MCI are associated with disrupted segregation and integration in brain networks. Thus, these connectomics studies open up a new window for understanding the pathophysiological mechanisms of AD and demonstrate the potential to uncover imaging biomarkers for clinical diagnosis and treatment evaluation for this disease.  相似文献   

5.
Cognitive impairments are commonly observed in patients with multiple sclerosis and are associated with lower levels of quality of life. No consensus has been reached on how to tackle effectively cognitive decline in this clinical population non-pharmacologically. This exploratory case-control study aims to investigate the effectiveness of a hypothesis-based cognitive training designed to target multiple domains by promoting the synchronous co-activation of different brain areas and thereby improve cognition and induce changes in functional connectivity in patients with relapsing-remitting multiple sclerosis. Forty-five patients(36 females and 9 males, mean age 44.62 ± 8.80 years) with clinically stable relapsing-remitting multiple sclerosis were assigned to either a standard cognitive training or to control groups(sham training and nonactive control). The standard training included twenty sessions of computerized exercises involving various cognitive functions supported by distinct brain networks. The sham training was a modified version of the standard training that comprised the same exercises and number of sessions but with increased processing speed load. The non-active control group received no cognitive training. All patients underwent comprehensive neuropsychological and magnetic resonance imaging assessments at baseline and after 5 weeks. Cognitive and resting-state magnetic resonance imaging data were analyzed using repeated measures models. At reassessment, the standard training group showed significant cognitive improvements compared to both control groups in memory tasks not specifically targeted by the training: the Buschke Selective Reminding Test and the Semantic Fluency test. The standard training group showed reductions in functional connectivity of the salience network, in the anterior cingulate cortex, associated with improvements on the Buschke Selective Reminding Test. No changes were observed in the sham training group. These findings suggest that multi-domain training that stimulates multiple brain areas synchronously may improve cognition in people with relapsing-remitting multiple sclerosis if sufficient time to process training material is allowed. The associated reduction in functional connectivity of the salience network suggests that training-induced neuroplastic functional reorganization may be the mechanism supporting performance gains. This study was approved by the Regional Ethics Committee of Yorkshire and Humber(approval No. 12/YH/0474) on November 20, 2013.  相似文献   

6.
The aim of the present study was to investigate the importance of and correlation between clinical presentations and magnetic resonance imaging (MRI) of two different cases of nonalcoholic Wernicke encephalopathy. Case l : A 63-year-old man with a diagnosis of incomplete mechanical intestinal obstruction. His abdominal symptoms were improved by gastrointestinal decompression, but blurred vision, hypoacusis, dizziness, and unsteady gait were noted. His illness deteriorated to confusion on day seven. MRI showed hyperintense lesions in the medial thalami, tectum of the midbrain, and the periaqueduct region on T2- and diffusion-weighted images. Thiamine therapy was commenced immediately with good results. Case 2: A 22-year-old woman was admitted for sudden-onset confabulation and unsteady gait after hyperemesis gravidarum. She had no history of alcohol or any medication. Brain MRI was normal. The patient experienced relief after Vitamin B1 treatment. These results suggest that brain MRI can define characteristic abnormalities in Wernicke encephalopathy, and that diffusion-weighted imaging may improve the diagnosis sensitivity. In addition, the MRI images may be correlated to the clinical stage and severity of the disease. Nevertheless, the clinical features are essential for correct diagnosis.  相似文献   

7.
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.  相似文献   

8.
BACKGROUND: Functional MRI (fMRI) demonstrates the localization of hand representation in the motor cortex, thereby providing feasible noninvasive mapping of functional activities in the human brain.
OBJECTIVE: To observe cortical activation within different cortical motor regions during repetitive hand movements in healthy subjects through the use of fMRI.
DESIGN: An observational study, with each subject acting as his own control.
SETTING: Department of Radiology, the First Affiliated Hospital of Nanchang University.
PARTICIPANTS: Seven healthy volunteers, 4 males and 3 females, aged 19 to 38 years, participated in the study. All subjects were right-handed, with no neurological or psychological disorders. Informed written consent was obtained from all subjects, and the study was approved by the Institutional Review Board of the First Affiliated Hospital of Nanchang University.
METHODS: The study was performed at the Department of Radiology between June-August 2005. A 1.5 Tesla Siemens MRI scanner (Symphony, Germany) was used to acquire T1-weighted structural images, which were oriented parallel to the line running through the anterior and the posterior commissures. Subjects were instructed on a task and were allowed to practice briefly prior to the imaging procedure. The motor activation task consisted of the right hand performing a clenching movement. The T1-W images were acquired from six alternating epochs of rest and activation from all seven healthy subjects. Data were collected with echoplanar imaging of brain oxygen level dependent (BOLD) sequence. Each series comprised six cycles of task performance (30 seconds), alternating with rest (30 seconds) periods, and 3-second time intervals. The differences between active and baseline fMRI imaging were calculated using the student t-test. Differential maps were overlaid on the high resolution TI-W structural image for neuroanatomical correlation of activation areas.
MAIN OUTCOME MEASURES: The omega-shaped hand knob  相似文献   

9.
The anatomical organization of the corticopontocerebellar tract(CPCT) in the human brain remains poorly understood.The present study investigated probabilistic tractography of the CPCT in the human brain using diffusion tensor tractography with functional magnetic resonance imaging.CPCT data was obtained from 14 healthy subjects.CPCT images were obtained from functional magnetic resonance imaging and diffusion tensor tractography,revealing that the CPCT originated from the primary sensorimotor cortex and descended to the pontine nucleus through the corona radiata,the posterior limb of the internal capsule,and the cerebral peduncle.After crossing the pons through the transverse pontine fibers,the CPCT entered the cerebellum via the middle cerebral peduncle.However,some variation was detected in the midbrain(middle cerebral peduncle and/or medial lemniscus) and pons(ventral and/or dorsal transverse pontine fibers).The CPCT was analyzed in 3 dimensions from the cerebral cortex to the cerebellum.These results could be informative for future studies of motor control in the human brain.  相似文献   

10.
Cubital tunnel syndrome is often accompanied by paresthesia in ulnar nerve sites and hand muscle atrophy. When muscle weakness occurs, or after failure of more conservative treatments, anterior transposition is used. In the present study, the ulnar nerve and its blood vessels were examined in the elbows of 18 adult cadavers, and the external diameter of the nutrient vessels of the ulnar nerve at the point of origin, the distances between the origin of the vessels and the medial epicondyle of the humerus, and the length of the vessels accompanying the ulnar nerve in the superior ulnar collateral artery, the inferior ulnar collateral artery, and the posterior ulnar recurrent artery were measured. Anterior transposition of the vascularized ulnar nerve was performed to treat cubital tunnel syndrome. The most appropriate distance that the vascularized ulnar nerve can be moved to the subcutaneous tissue under tension-free conditions was 1.8 ± 0.6 cm(1.1–2.5 cm), which can be used as a reference value during the treatment of cubital tunnel syndrome with anterior transposition of the vascularized ulnar nerve.  相似文献   

11.
The case of a 64-year-old woman affected by slowly progressive visual agnosia is reported aiming to describe specific cognitive-brain relationships. Longitudinal clinical and neuropsychological assessment, combined with magnetic resonance imaging (MRI), spectroscopy, and positron emission tomography (PET) were used. Sequential neuropsychological evaluations performed during a period of 9 years since disease onset showed the appearance of apperceptive and associative visual agnosia, alexia without agraphia, agraphia, finger agnosia, and prosopoagnosia, but excluded dementia. MRI showed moderate diffuse cortical atrophy, with predominant atrophy in the left posterior cortical areas (temporal, parietal, and lateral occipital cortical gyri). 18FDG-PET showed marked bilateral posterior cortical hypometabolism; proton magnetic resonance spectroscopic imaging disclosed severe focal N-acetyl-aspartate depletion in the left temporoparietal and lateral occipital cortical areas. In conclusion, selective metabolic alterations and neuronal loss in the left temporoparietooccipital cortex may determine progressive visual agnosia in the absence of dementia.  相似文献   

12.
Background: The diagnosis of the behavioural variant of frontotemporal dementia (bvFTD) can be challenging. At present there is a paucity of prospective work addressing the specificity of current diagnostic criteria for bvFTD with respect to long-term outcome (i.e., false positives versus true positives).

Methods: Here we report two individuals who met current clinical criteria for bvFTD and who underwent detailed long-term clinical and neuropsychological follow-up. In addition, both had serial volumetric MRI and functional metabolic (FDG-PET) imaging separated by 5 years.

Results: One case had a slow clinical decline as well as both progressive atrophy and hypometabolism in a frontotemporal distribution, consistent with a neurodegenerative FTD syndrome. However, the second developed neither atrophy nor hypometabolism and remained clinically stable, a decade from symptom onset.

Conclusion: We propose that these cases illustrate that while there may be a slow evolution in bvFTD, it is possible that some cases who meet current criteria may not have a neurodegenerative syndrome. If correct, this hypothesis has important implications for the current diagnostic criteria. A potential hierarchy for diagnostic certainty in bvFTD is suggested.  相似文献   

13.
目的后部皮质萎缩(posterior cortical atrophy,PCA)是以视觉障碍为突出表现,并伴进行性认知功能受损的神经系统退行性疾病。PCA的临床表现以视觉加工、计算力下降、阅读书写能力受损为主,患者的视觉认知损害突出,而情景记忆、语言能力和自知力相对保留。本文结合我院收治PCA病例,总结PCA的临床及影像学特征,以期为该病的早期诊治提供参考。方法收集2013年至2018年于宣武医院神经内科确诊的后部皮质萎缩8例患者的临床表现、神经心理学检查、影像学资料等各项检查结果并进行回顾性分析。结果8例PCA患者起病均为隐袭起病,病情进展缓慢,其中有5例符合背侧型后部皮质萎缩特点,临床表现为巴林特综合征、视空间功能障碍以及格茨曼综合征特点,头MRI显示顶枕叶皮质萎缩为主;另3例符合腹侧型后部皮质萎缩特点,临床表现主要为面孔失认、视觉忽视,头MRI显示双侧颞枕叶皮质萎缩为主,而内侧颞叶和海马萎缩程度相对较轻。8例患者均行SPECT检查,显示大脑后部包括顶叶、颞枕叶皮质血流低灌注现象。3例患者行18F FDG PET检查显示大脑后部枕叶、顶叶、颞叶皮质葡萄糖代谢降低。结论对于存在视觉障碍和后部皮质相关认知功能损害的患者,临床医生要考虑到PCA的诊断,特别注意进行视觉相关的全面的神经心理学评估及PET检查,以辅助进行PCA的诊断。  相似文献   

14.
OBJECTIVES: To define the clinical, neuropsychological, and radiological features of bilateral parietal lobe atrophy. METHODS: Four patients underwent a comprehensive longitudinal neuropsychological assessment, as well as MRI and HMPAO-SPECT. RESULTS: The consistent findings in the patients were early visuospatial problems, agraphia of a predominantly peripheral (or apraxic) type, and difficulty with bimanual tasks, all of which outweighted deficits in memory and language until later in the course of the illness. As the disease progressed, impairments in the phonological aspects of language and in auditory-verbal short term memory were often striking, perhaps reflecting spread from the parietal lobe to perisylvian language areas. Three patients went on to develop a global dementia and fulfilled the criteria for a clinical diagnosis of probable Alzheimer's disease; the fourth patient has only recently been identified. Neuroimaging disclosed bilateral parietal lobe atrophy (MRI) and hypoperfusion (SPECT), which was out of proportion to that seen elsewhere in the brain. One patient has died and had pathologically confirmed Alzheimer's disease with particular concentration in both superior parietal lobes. CONCLUSIONS: Bilateral biparietal atrophy is a recognisable clinical syndrome which can be the presenting feature of Alzheimer's disease. Although the label "posterior cortical atrophy" has been applied to such cases, review of the medical literature suggests that this broad rubric actually consists of two main clinical syndromes with features reflecting involvement of the occipitotemporal (ventral) and biparietal (dorsal) cortical areas respectively.  相似文献   

15.
The objective of this paper is to compare and contrast the clinical, neuropsychological, and neuroimaging findings in patients with mild cognitive impairment (MCI) associated with underlying Alzheimer's disease (AD) versus Lewy body disease (LBD) pathology. MCI refers to a clinical syndrome with impairment in one or more cognitive domains, with essentially normal performance of activities of daily living. Patients with the amnesic subtype of MCI often develop the dementia syndrome and neuroimaging findings characteristic of AD [e.g., hippocampal atrophy on magnetic resonance imaging (MRI), temporoparietal and posterior cingulate hypometabolism on fluorodeoxyglucose positron emission tomography (FDG-PET), positive uptake on amyloid PET, normal striatonigral uptake on dopamine transporter scanning (DAT), etc.]. In contrast, the MCI syndrome associated with LBD pathology regardless of the coexisting presence or absence of parkinsonism is usually characterized by impairment in the executive and/or visuospatial domains, and the cognitive features are often preceded by REM sleep behavior disorder by many years. There is minimal hippocampal atrophy on MRI, minimal if any cortical uptake on amyloid-PET, and one would predict that hypometabolism would be maximal in the occipital cortex on FDG-PET and uptake would be decreased on DAT. The early data suggests that differentiating underlying AD vs LBD in the MCI phase will be feasible.  相似文献   

16.
Waldenstrom's macroglobulinemia (WM) is an uncommon low-grade lymphoma. Cognitive impairment due to central nervous system infiltration by lymphoplasmocytoid cells (Bing-Neel syndrome) has been rarely reported. We describe a 54-year-old man who was referred to a memory disorder clinic with a 9-month history of clinically obvious nonfluent aphasia and WM. He underwent extensive neuropsychological testing, clinical examination and structural and functional brain imaging. The diagnosis of the diffuse form of the Bing-Neel syndrome was supported by abnormal lymphoid cells found in the cerebrospinal fluid. Structural and functional brain imaging revealed impairment of brain areas due to white matter changes and subsequent functional deficits mimicking the neuropsychological syndrome encountered in progressive nonfluent aphasia. The diffuse form of Bing-Neel syndrome and neurological deficits are assumed to be the result of leptomeningeal infiltration by malignant cells and/or neoplastic vascular obstruction.  相似文献   

17.
Posterior cortical atrophy (PCA) is a syndrome that involves distinct neuropsychological deficits. This paper presents the clinical and neuropsychological findings recorded in four patients with PCA and reviews the characteristics of the syndrome and other conditions that need to be considered in the differential diagnosis. The cardinal symptoms of PCA are deficits of higher visual and spatial functions (mostly taking the form of Balint's syndrome), variably associated with disorders of visual perception, topographical disorientation, visual object agnosia and prosopagnosia, and deficits affecting reading, copying, drawing, and calculation. PCA is mostly associated with histopathological changes similar to those found in dementia of Alzheimer type (DAT), which are located predominantly in posterior brain regions. Memory and language functions tend to be preserved better and for a longer time in PCA than in the normal variant of DAT. SPECT and PET show deficits of perfusion and metabolism in both parietal and occipital lobes. The diagnosis of PCA is based on neuropsychological and imaging findings.  相似文献   

18.
This study reports FDG-PET findings in Wernicke-Korsakoff patients. Twelve patients suffering amnesia arising from the Korsakoff syndrome were compared with 10 control subjects without alcohol-related disability. Subjects received [18F]-fluorodeoxyglucose (FDG-PET) imaging as well as neuropsychological assessment and high-resolution MR imaging with volumetric analysis. Volumetric MRI analysis had revealed thalamic and mamillary body atrophy in the patient group as well as frontal lobe atrophy with relative sparing of medial temporal lobe structures. Differences in regional metabolism were identified using complementary region of interest (ROI) and statistical parametric mapping (SPM) approaches employing either absolute methods or a reference region approach to increase statistical power. In general, we found relative hypermetabolism in white matter and hypometabolism in subcortical grey matter in Korsakoff patients. When FDG uptake ratios were examined with occipital lobe metabolism as covariate reference region, Korsakoff patients showed widespread bilateral white matter hypermetabolism on both SPM and ROI analysis. When white matter metabolism was the reference covariate, Korsakoff patients showed relative hypometabolism in the diencephalic grey matter, consistent with their known underlying neuropathology, and medial temporal and retrosplenial hypometabolism, interpreted as secondary metabolic effects within the diencephalic-limbic memory circuits. There was also evidence of a variable degree of more general frontotemporal neocortical hypometabolism on some, but not all, analyses.  相似文献   

19.
Machiafava-Bignami disease (MBD) occurs in the alcoholic patients. It is characterized clinically by interhemispheric disconnection syndrome, resulting from demyelination and necrosis of the corpus callosum. We performed a neuropsychological study of an alcoholic patient, diagnosed as MBD by X-ray computed tomography (CT) and magnetic resonance imaging (MRI). 123I IMP-SPECT of the patient revealed the reduction of the blood flow in both cerebral hemispheres without laterality though both the X-ray CT and MRI showed no abnormality in the cerebral hemispheres. In neuropsychological studies, we observed not only interhemispheric disconnection syndrome such as an unilateral left agraphia and left apraxia but also left hemispatial neglect demonstrated in right-hand performance and motor impersistence. Because there were no abnormal lesions in the right hemisphere, these symptoms might be attributable to the lesions of corpus callosum.  相似文献   

20.
The syndrome of alexia without agraphia occurs rarely in multiple sclerosis (MS). We report a patient with right homonymous hemianopsia and alexia without agraphia as his initial manifestations of relapsing-remitting MS. Magnetic resonance imaging (MRI) demonstrated a hyperintense lesion in the left occipital subcortical white matter (WM) and an enhancing lesion in the splenium of the corpus callosum. The clinical presentation and MRI findings were consistent with disconnection of the functional right occipital visual cortex from structures responsible for language comprehension in the left hemisphere. The diagnosis of MS was confirmed by subsequent development of additional periventricular WM lesions.  相似文献   

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