Conventional magnetic resonance imaging features in patients with tropical spastic paraparesis

Conventional brain and spinal cord magnetic resonance images were performed in 21 patients with human T-cell lymphotropic virus (HTLV)-1 associated myelopathy/tropical spastic paraparesis, to assess the role of conventional magnetic resonance imaging (MRI) in the disease diagnosis. These patients had no other central nervous system conditions or related risk factors at the time of tropical spastic paraparesis diagnosis. Eleven (52.4%) patients showed nonspecific brain abnormalities on T2-weighted images. The majority (77.2%) of brain abnormalities were located in the deep white matter. A transient contrast-enhancing lesion was identified in the brain of only one patient. In the brain of another patient, 9.0% of the T2-hyperintense lesion load was hypointense on the correspondent T1-weighted images. No differences in terms of demographic, biological, or clinical variables were present between patients with abnormal brain images and those with normal brain magnetic resonance images. Spinal cord T2-weighted images were abnormal in three (14.3%) patients. In one of these three patients, a diffuse but transient edema was found along the entire tract of the spinal cord. White matter lesions were present in the central nervous system of 60% of the cases in this study. However, no correlations between magnetic resonance imaging and clinical findings, and no specificity of lesions were observed. Hence, conventional magnetic resonance imaging is a sensitive but not highly specific tool for diagnosis of tropical spastic paraparesis.     

临床治愈的抑郁症患者静息态脑功能磁共振研究

目的：利用静息态功能磁共振,结合局部一致性分析方法探讨临床治愈的抑郁患者局部脑功能的改变。方法：对19例临床治愈的抑郁症患者（患者组）和14名健康志愿者（正常对照组）进行功能磁共振扫描,通过双样本t检验比较两组被试者脑区局部一致性。结果：与正常对照组比较,患者组左背内侧前额叶（t=4.070,P<0.01）、左梭状回（t=3.855,P<0.01）局部一致性增高;左颞中回（t=-4.851,P<0.01）、左顶下小叶（t=-4.459,P<0.01）及右楔叶（t=-3.477,P<0.01）局部一致性降低。结论：临床治愈的抑郁症患者存在部分脑区的功能异常。     

Brain magnetic resonance imaging findings in patients with mitochondrial cytopathies

BACKGROUND: Mitochondrial cytopathies (MCs) are a heterogeneous group of clinical entities, some of which have classic phenotypes. Magnetic resonance imaging (MRI) has been reported to be helpful in the diagnosis of MC. OBJECTIVE: To correlate the most common brain MRI findings reported in patients with MC with the clinical findings in patients in different MC subgroups. DESIGN: Case series. SETTING: Patients with MCs seen at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubiran, Mexico City, Mexico. PATIENTS: Twenty-one patients with MC with the following phenotypes: chronic progressive external ophthalmoplegia (n = 7), Kearns-Sayre syndrome (n = 7), mitochondrial neurogastrointestinal encephalopathy (n = 6), and myoclonic epilepsy with ragged red fiber myopathy (n = 1). RESULTS: Brain MRI abnormalities were found in 20 (95%) of 21 patients. The most frequent abnormalities were widespread white matter hyperintensity in 19 patients (90%), supratentorial cortical atrophy in 18 patients (86%), and cerebellar atrophy in 13 patients (62%). Widespread white matter hyperintensity (P<.001) and supratentorial cortical atrophy (P = .001) were each correlated significantly with MC. Subsequent subgroup analyses showed that the absence of basal ganglia hyperintensity was correlated with Kearns-Sayre syndrome (P < .001) and the presence of supratentorial cortical atrophy was correlated with mitochondrial neurogastrointestinal encephalopathy (P = .005). CONCLUSIONS: The presence of widespread white matter hyperintensity and/or supratentorial cortical atrophy in brain MRI may help to establish the diagnosis of MC. The radiologist has a role to play in the workup of MC by confirming the diagnosis and possibly distinguishing different subgroups of MC.     

Gross motor patterns in children with cerebral palsy and spastic diplegia

Rolling, sitting, and crawling patterns were motoscopically analyzed in 72 children with cerebral palsy and spastic diplegia; the relation between these patterns and the severity of the locomotive disability was studied. In rolling, trunk rotation and elbow support were difficult for the most severely diplegic children. When sitting, most patients had a between-heel sitting pattern in which the thighs were adducted and the knees were flexed. When crawling, the reciprocal thigh movements were insufficient and accompanied by lateral bending of the trunk in many patients. In the more impaired patients, the thighs supported the weight in flexion and did not move reciprocally. Creeping on the elbows without reciprocal leg movements was demonstrated in the most severely affected children after 2 years of age.     

视神经脊髓炎患者33例脑部磁共振分析

目的 探讨视神经脊髓炎(neuromyelitis optica,NMO)患者脑部MRI影像学表现.方法 收集满足最新NMO诊断标准且脑部MRI表现不符合多发性硬化诊断标准的患者33例,均行脑部和脊髓MRI检查,分析其MRI影像学特点.结果 33例NMO中,脑部正常表现者5例(15.2%),异常表现28例(84.8%),其中脑内实质有明确病灶22例(66.7%),另6例(18.2%)脑内虽未见明确病灶,但深部脑白质显示了肉眼可视的对称性弥漫性脱髓鞘高信号影.22例明确病灶中,15例病灶数≥2个,7例为单个病灶.幕上近皮质、皮质下和深部脑白质区的点状非特异性病灶最多,少数为非典型的斑片状融合病灶.幕下脑干是易受累的部位(14/33,42.4%),特别是延髓(7/33,21.2%).结论 NMO患者出现脑内异常较为常见,有脑部的异常不能排除NMO的诊断.认识NMO脑内病灶对完善NMO诊断标准有帮助.     

Brain magnetic resonance imaging in Wolf-Hirschhorn syndrome

Wolf-Hirschhorn syndrome (WHS) is a rare genetic disorder, which is caused by partial deletion of the short arm of one chromosome 4. Brain magnetic resonance (MR) imaging findings are lacking. We report on brain findings in 10 children with WHS. We evaluated the MR imaging films of 10 subjects affected by WHS, which had been confirmed by genetic study. The age range at MR imaging was between 1 month and 9 years. In 9/10 cases enlargement of the third lateral ventricles was present. In 9/10 cases a global reduction of cerebral hemispheres white matter was present. In 10/10 cases diffuse thinning of the corpus callosum was visible; it was severe in 7/10 cases. In 5/10 cases small foci of T (2) hyper intense signal were visible within the subcortical white matter. In three of the six cases studied within the first year of life frontal periventricular cysts were present. In three of the four cases studied after the first year of life a squared shape of the frontal horns of the lateral ventricles was visible. The MR imaging findings reported in WHS cannot be considered pathognomonic of the syndrome, however, they may suggest WHS.     

Brain magnetic resonance imaging and manganese exposure

Due to its paramagnetic properties, manganese (Mn) can be effectively visualized by MRI. Mn accumulates selectively in the globus pallidus of basal ganglia, where it can produce high signals at brain magnetic resonance. These hyperintensities are bilateral, symmetrical, and visible in T1-weighted magnetic resonance imaging of different manganese overload conditions. A review of the literature shows identical findings in manganese exposed workers, hepatopatic patients, and patients undergoing total parenteral nutrition with excessive amount of manganese. Two indicators of exposure and hyperintensity were considered, represented respectively by the concentration of Mn in total blood (MnB), and the pallidal index (PI). These two indicators show a positive association, which indicates a possible continuum from normality to clinical stages both in workers occupationally exposed to Mn and in patients suffering from chronic liver disease. Since both MnB and PI show a high degree of variability, further research should be focused on the identification of more accurate indicators.     

单侧大脑中动脉狭窄的脑磁共振灌注成像研究

目的探讨大脑中动脉(MCA)不同狭窄程度时的脑磁共振灌注加权成像(PWI)表现。方法对31例经DSA诊断为单侧MCA狭窄或闭塞患者行脑磁共振PWI检查,并对不同程度MCA狭窄状态下患侧和健侧大脑半球的脑灌注参数局部脑血流量(rCBF)、局部脑血容量(rCBV)、局部平均通过时间(rMTT)、局部达峰时间(rTTP)进行定量分析。结果31例患者中,DSA诊断单侧MCA轻中度狭窄14例,其中脑灌注异常11例;患侧大脑半球rTTP较健侧显著延长(P0.01)。MCA重度狭窄或闭塞17例,均出现异常灌注;患侧大脑半球rTTP较健侧显著延长(P0.01),而患侧rCBF较健侧明显减少(P0.05),患侧rMTT健侧亦显著延长(P0.05)。结论通过脑灌注成像参数综合分析,磁共振PWI能准确评估MCA狭窄程度和脑组织血供情况,可为脑缺血的临床诊断提供重要价值。     

Brain magnetic resonance imaging and neuropsychologic evaluation of patients with idiopathic dilated cardiomyopathy

We compared brain magnetic resonance imaging and neuropsychologic performance in 20 neurologically asymptomatic patients suffering from idiopathic dilated cardiomyopathy (mean age 41 [range 18-49] years) and 20 age-matched controls (mean age 38 [range 28-49] years). Patients exhibited a significantly higher rate of cerebral infarcts (20% versus 0%, p less than 0.05) and cortical (50% versus 5%, p less than 0.01) and ventricular (55% versus 15%, p less than 0.02) atrophy than controls. Accordingly, semiquantitative volumetric measurements yielded a significantly increased ventricular-to-intracranial cavity ratio in the patients (6.2 +/- 2.9% versus 4.1 +/- 1.3%, p less than 0.01). This ratio and the cortical atrophy ratings correlated positively with disease duration (r = 0.63 and 0.54, p less than 0.05). Cognitive test performance was significantly worse in patients than in controls and was most impaired in those patients with morphologic cerebral abnormalities.     

Brain magnetic resonance imaging abnormalities in neuromyelitis optica

Objective – Brain abnormalities in neuromyelitis optica (NMO) attracted much attention. Our study was to identify the brain magnetic resonance imaging (MRI) abnormalities in Chinese NMO patients. Methods – Patients who fulfilled the latest diagnostic criteria of NMO proposed by Wingerchuk et al. [Neurology 66 (2006) 1485] and whose brain MRI did not meet the multiple sclerosis (MS) criteria of McDonald et al. [Ann Neurol 50 (2001) 121] were selected to perform MRI scanning of the brain, spinal cord and optic nerves. Results – Twenty‐eight of 33 patients (84.8%) had abnormal MRI findings. Twenty‐two patients (66.7%) presented with well‐defined brain parenchymal lesions and the other six patients (18.2%) with macroscopic symmetrical diffuse hyperintensities in deep white matter. Fifteen of 22 patients had more than one lesion (≥2 lesions) and the other seven patients had single lesion. In the supratentorium, most lesions were punctate or small round dot and non‐specific in juxtacortical, subcortical and deep white matter regions, a few were patchy atypical confluent lesions. Brainstem was easily involved (14/33, 42.4%) especially in medulla (7/33, 21.2%). Conclusions – This study demonstrates the characteristics of brain MRI abnormalities in Chinese NMO patients, which are helpful to the revision of diagnostic criteria for NMO.     

Brain magnetic resonance imaging findings in ECT-induced delirium

A prolonged (interictal) but reversible delirium was induced by electroconvulsive therapy (ECT) in 10 of 87 (11%) elderly depressed patients. Brain magnetic resonance imaging (MRI) revealed several structural abnormalities, particularly basal ganglia and moderate to severe subcortical white-matter lesions, in the patients who developed delirium. These findings are consistent with several lines of data that have implicated the basal ganglia and subcortical white matter in the development of delirium from other causes and suggest that lesions in these areas may predispose one to developing an interictal delirium during a course of ECT.     

工作记忆与脑的功能磁共振成像

工作记忆是临时信息编码、保持和提取的过程 ,是学习记忆研究的热点之一。功能磁共振作为一种新型无损伤技术 ,为研究工作记忆提供了一个新的途径。本文对功能磁共振的原理、实验设计和目前工作记忆功能磁共振检查的研究进展进行综述。     

工作记忆与脑的功能磁共振成像

工作记忆是临时信息编码、保持和提取的过程,是学习记忆研究的热点之一.功能磁共振作为一种新型无损伤技术,为研究工作记忆提供了一个新的途径.本文对功能磁共振的原理、实验设计和目前工作记忆功能磁共振检查的研究进展进行综述.     

Brain magnetic resonance imaging white-matter lesions and cerebrospinal fluid findings in patients with acute intermittent porphyria

BACKGROUND: Case reports display similarities between multiple sclerosis and acute intermittent porphyria (AIP). This study examines whether patients with AIP in general demonstrate white-matter lesions on brain magnetic resonance imaging (MRI) and/or abnormalities in plasma and/or cerebrospinal fluid (CSF) when examined outside attacks. We looked particularly for the presence of oligoclonal bands (OB) of immunoglobulin (Ig) in liquor. METHODS: Eight AIP gene carriers without previous episodes of porphyria, mean age 42.8 years (range 30-60), and 8 AIP gene carriers with previous episodes of porphyria, mean age 42.8 years (range 33-62), were examined with brain MRI, venous blood samples and lumbar punctures. RESULTS: Two male AIP gene carriers with previous episodes of porphyria, 58 and 35 years of age, had multiple white-matter, high-signal lesions on T(2)- weighted MRI sequences. Two AIP gene carriers without previous episodes of porphyria, 1 male and 1 female, had less than 5 such lesions. No OB were seen in the CSF in any patient, but 1 carrier had an increased level of protein in the CSF. Seven of 16 subjects (44%) had increased levels of HbA1c (>6.0), suggesting protracted hyperglycemia, and 3 further subjects had borderline levels (5.9). CONCLUSION: T(2)-weighted MRI sequences demonstrated multiple white-matter, high-signal lesions in 4 out of 16 AIP gene carriers (25%). No carrier demonstrated OB of Ig in CSF, making it unlikely that demyelinating lesions play a pivotal role in the pathogenesis of CNS symptoms in AIP. Only 1 AIP gene carrier had an increased level of protein in CSF; this contrasts with studies during acute attacks of porphyria. Seven subjects (44%) had abnormally high levels of HbA1c, in spite of the fact that no patient had a previous diagnosis of diabetes mellitus.     

Short‐term plasticity following motor sequence learning revealed by diffusion magnetic resonance imaging

Current noninvasive methods to detect structural plasticity in humans are mainly used to study long‐term changes. Diffusion magnetic resonance imaging (MRI) was recently proposed as a novel approach to reveal gray matter changes following spatial navigation learning and object‐location memory tasks. In the present work, we used diffusion MRI to investigate the short‐term neuroplasticity that accompanies motor sequence learning. Following a 45‐min training session in which participants learned to accurately play a short sequence on a piano keyboard, changes in diffusion properties were revealed mainly in motor system regions such as the premotor cortex and cerebellum. In a second learning session taking place immediately afterward, feedback was given on the timing of key pressing instead of accuracy, while participants continued to learn. This second session induced a different plasticity pattern, demonstrating the dynamic nature of learning‐induced plasticity, formerly thought to require months of training in order to be detectable. These results provide us with an important reminder that the brain is an extremely dynamic structure. Furthermore, diffusion MRI offers a novel measure to follow tissue plasticity particularly over short timescales, allowing new insights into the dynamics of structural brain plasticity.     

An age and gender dependency of metabolite concentrations in basal ganglia in children with spastic diplegia: proton magnetic resonance spectroscopy study

We determined metabolite profile in spastic diplegic children compared to controls in left basal ganglia of brain in using proton magnetic resonance spectroscopy in correlation with age and gender. Twenty-four patients with spastic diplegia and twenty-six healthy children were examined. The relative concentrations of N-acetylaspartate, choline, and myoinositol were measured in relation to creatine and different combinations of metabolites within 8-cm(3) brain voxel. Children with spastic diplegia showed reduced ratios of N-acetylaspartate/creatine, N-acetylaspartate/ choline, and N-acetylaspartate/myoinositol in the basal ganglia compared to the control group. Patients and controls subjects demonstrated a significant age-dependent increase in N-acetylaspartate/creatine, N-acetylaspartate/choline in the basal ganglia. No gender-dependent difference was shown in children with cerebral palsy for all tested metabolite ratios. Gender-related differences because of increased ratio N-acetylaspartate/choline in girls in controls were detected. These results indicate that maturation of brain exists in cerebral palsy and healthy children to a higher degree in healthy children.     

Functional magnetic resonance imaging in the assessment of motor centers in patients with brain tumors in motor area]

Magnetic resonance imaging (MRI) is become recognised as the most sensitive and specific imaging modality for the examination of central nervous system pathology. Blood oxygen level-dependent (BOLD) contrast imaging is a non-invasive functional MRI technique for localising active neuronal brain centres. The aim of our study was to determine usefulness of fMRI in detecting hand movements cortical activity in hemisphere with brain tumour and comparison with corresponding one. Six right-handed patients with brain tumours of central sulcus area, aged 20-50 years were examined using a commercial 1.5 T scanner. All patients underwent both conventional and functional magnetic resonance imaging (MRI) examinations. Simple hand movements were examined separately for right and left hand at a self-paced rate. Significant increase of signal intensity was found in: a) contralateral primary motor cortex in all cases during both motor tasks, b) ipsilateral primary motor cortex, supplementary motor cortex and premotor cortex of both hemispheres in a part of the cases c) displacement of the activity in the affected hemisphere in comparison to the opposite one was noticeable depending on the localisation and size of the tumour and accompanied oedema. Usefulness of functional MRI in detecting primary motor area in patients with brain tumours was proved. There is a difference between activation in affected cortex and corresponding normal cortex in the opposite hemisphere.     

Nuclear magnetic resonance imaging in patients with stroke

In contrast to CT, NMR imaging revealed a high percentage of abnormalities in the TIA-RIND population studied. The various patterns of abnormalities identified should provide further insight into the pathophysiology of ischemic cerebrovascular disease. Age and hypertension appeared to be the most significant clinical risk factors for TIA-RIND. Although periventricular hypodensities have been visualized by CT for many years, their clinical significance has only recently been appreciated. NMR shows the same periventricular changes as increased signal (long T2), but shows it in a more dramatic fashion. These periventricular abnormalities, seen both by CT and NMR, have been shown in some cases to be compatible with the pathologic diagnosis of SAE, or Binswanger's disease. Watershed abnormalities both with and without corresponding cerebral infarctions have been presented. At present, this appears to be a ubiquitous group of cerebrovascular disease with multiple underlying causes. NMR is superior to CT for demonstrating watershed infarctions, not only because it reveals ones missed by CT, but also because it shows a fuller extent of involvement than does CT. The evolution of cerebral infarctions as seen by CT and NMR has been presented. NMR demonstrates abnormalities earlier than CT. The region of infarction appears more extensive than by CT and chronic infarctions show an associated rim of prolonged T2 that may correspond to the ischemic penumbra or regions of ischemic demyelinization. CT phenomena, such as fogging and GME, have their NMR correlates. To date, all regions of GME shown by CT have also been demonstrated by NMR. Cortical infarctions, thought in many instances to be due to emboli have been frequently demonstrated by NMR. NMR imaging is clearly superior to CT for recognizing these lesions because it is not hampered by artifact from bone adjacent to cortex, as is CT. Similarly, posterior fossa and brainstem infarctions may be seen to advantage by NMR.