Demonstration of Recovery of a Patient with a Cerebellar Peduncle Injury due to Intracerebral Hemorrhage: a Diffusion Tensor Imaging Study.

背景：扩散张量成像可以对小脑脚进行三维显影。 目的：采用扩散张量成像,观察一位由于颅内出血所致小脑脚损伤患者在三个月内的功能恢复。 设计,时间和地点：病例研究,2008年10月至2009年3月期间在岭南大学医学院理疗康复教研室进行。 受试者：一位72岁女性患者,九名对照者,对照者同患者的年龄和性别相符。 方法：采用1.5T敏感性编码头线圈进行扩散张量成像。 主要观察指标：采用DTI-Studio软件评价小脑脚,包括小脑上脚,小脑中脚和小脑下脚。 结果：患者在发病三周后不能平坐,但可以独立行走,发病后4周可以完成大部分日常活动。3周扩散张量成像显示,所有小脑脚被血肿压迫。左小脑脚的后侧缩短,尤其是左小脑中脚在中部阻断。4月扩散张量成像显示,所有被压缩的小脑脚复原。此外,3周扩散张量成像结果还显示,除去右小脑中脚之外,所有小脑脚的各项异性值同正常对照值相比,降低了2个标准差。4月扩散张量成像结果显示,右小脑小脚的各项异性值有所增加,比正常对照值高出2个标准差。尽管如此,其他小脑脚的各项异性值仍保持在正常对照值之下的2个标准差。结果显示,发病后3周时的小脑脚的神经元损伤（所有小脑上脚,左小脑中脚和所有小脑下脚）在发病后4月内康复不明显。 结论：患者的功能性恢复最初是由于被压迫的小脑脚的减压所致,而不是受伤小脑脚的恢复。笔者认为采用扩散张量成像评价小脑脚对小脚损伤的疑似病例有帮助。     

Changes in a cerebellar peduncle lesion in a patient with Dandy-Walker malformation A diffusion tensor imaging study

We report a patient with severe ataxia due to Dandy-Walker malformation, who showed functional recovery over 10 months corresponding to a change in a cerebellar peduncle lesion. A 20-month-old female patient who was diagnosed with Dandy-Walker syndrome and six age- and sex-matched healthy control subjects were enrolled. The superior cerebellar peduncle, the middle cerebellar peduncle, and the inferior cerebellar peduncle were evaluated using fractional anisotropy and the apparent diffusion coefficient. The patients’ functional ambulation category was 0 at the initial visit, but improved to 2 at the follow-up evaluation, and Berg’s balance scale score also improved from 0 to 7. Initial diffusion tensor tractography revealed that the inferior cerebellar peduncle was not detected, that the fractional anisotropy of the superior cerebellar peduncle and middle cerebellar peduncle decreased by two standard deviations below, and that the apparent diffusion coefficient increased by two standard deviations over normal control values. However, on follow-up diffusion tensor tractography, both inferior cerebellar peduncles could be detected, and the fractional anisotropy of superior cerebellar peduncle increased to within two standard deviations of normal controls. The functional improvement in this patient appeared to correspond to changes in these cerebellar peduncles. We believe that evaluating cerebellar peduncles using diffusion tensor imaging is useful in cases when a cerebellar peduncle lesion is suspected.     

Diffusion tensor imaging study of the middle cerebellar peduncles in patients with schizophrenia

Recent evidence from neuroimaging studies suggests that neural dysfunction is involved in the pathophysiology of schizophrenia. Diffusion tensor imaging (DTI) is a technique that has the potential to detect subtle disruptions of neural connectivity. Fractional anisotropy (FA), which is measured by DTI, is a measure of the directionality of diffusion anisotropy. Decrease in FA indicates abnormalities of white matter due to increased water diffusion accompanied by an increase in extracellular space. In the literature, previous studies reported that patients with schizophrenia showed widespread lower FA in the white matter. These findings suggest that patients with schizophrenia have microstructural lesions in the cerebral white matter. We used DTI to determine whether neural connectivity was disturbed in the middle cerebellar peduncles in schizophrenic subjects. We found a significant FA reduction in the middle cerebellar peduncle in patients with schizophrenia. Therefore, neural disconnectivity between the cerebellum and cerebrum was considered present in patients with schizophrenia and may be involved in the pathology of schizophrenia. This review provides current findings regarding DTI study on the cerebellar peduncle in patients with schizophrenia.     

Neural disorganization in the superior cerebellar peduncle and cognitive abnormality in patients with schizophrenia: A diffusion tensor imaging study

Disconnection in the frontal–thalamic–cerebellar circuit is thought to be associated with cognitive abnormality in patients with schizophrenia. The superior cerebellar peduncle is involved in neural connectivity in the circuit. Because diffusion tensor imaging (DTI) can detect neural disconnection, we investigated whether there was neural disruption in the superior cerebellar peduncle in patients with schizophrenia. DTI was performed in 21 schizophrenic subjects and 21 age- and sex-matched healthy subjects. Cognitive cluster scores were attained by using the Positive and Negative Syndrome Scale (PANSS). Schizophrenic subjects had significantly lower fractional anisotropy (FA) in the right and left superior cerebellar peduncles than healthy subjects. Higher FA in the left superior cerebellar peduncle was associated with worse cognitive function in patients with schizophrenia. These findings suggest that there is neural disruption in the superior cerebellar peduncle in patients with schizophrenia, which may be involved in the cognitive abnormalities found in schizophrenia.     

Local tissue anisotropy decreases in cerebellopetal fibers and pyramidal tract in multiple system atrophy

Background One of the cardinal features in multiple system atrophy (MSA) is the white matter pathology: loss of myelin, astrocytosis, and glial cytoplasmic inclusions. The pathological changes of tissue microstructure can modify the diffusion behavior of water molecules, which can be assessed by diffusion tensor imaging (DTI). Objectives To explore the hypothesis of white matter degeneration in MSA. Methods We studied 11 patients with clinically probable MSA and 10 age–matched controls. DTI was performed in both groups to measure fractional anisotropy (FA) in various regions of interest: the inferior cerebellar peduncle (ICP), middle cerebellar peduncle (MCP), superior cerebellar peduncle (SCP), basis pontis, internal capsule, and corpus callosum. Results FA values in SCP and corpus callosum showed no significant difference between the MSA group and controls. By contrast, FA values decreased in the MSA group in the MCP, basis pontis and internal capsule. In addition, FA values in the MCP were negatively correlated with ataxia severity in the MSA group. Conclusion The areas showing decreased tissue anisotropy in DTI corresponded well with pathologically vulnerable areas in MSA. In addition, the local tissue anisotropy of MCP decreased in accordance with functional disability. These observations implied that DTI is a feasible method for in vivo evaluation of the white matter pathology in MSA.This work was supported by funds from the Japanese Ministry of Education, Science and Technology (Grant number 14770295).     

White matter integrity of the cerebellar peduncles as a mediator of effects of prenatal alcohol exposure on eyeblink conditioning

Fetal alcohol spectrum disorders (FASD) are characterized by a range of neurodevelopmental deficits that result from prenatal exposure to alcohol. These can include cognitive, behavioural, and neurological impairment, as well as structural and functional brain damage. Eyeblink conditioning (EBC) is among the most sensitive endpoints affected in FASD. The cerebellar peduncles, large bundles of myelinated nerve fibers that connect the cerebellum to the brainstem, constitute the principal white matter element of the EBC circuit. Diffusion tensor imaging (DTI) is used to assess white matter integrity in fibre pathways linking brain regions. DTI scans of 54 children with FASD and 23 healthy controls, mean age 10.1 ± 1.0 years, from the Cape Town Longitudinal Cohort were processed using voxelwise group comparisons. Prenatal alcohol exposure was related to lower fractional anisotropy (FA) bilaterally in the superior cerebellar peduncles and higher mean diffusivity (MD) in the left middle peduncle, effects that remained significant after controlling for potential confounding variables. Lower FA and higher MD in these regions were associated with poorer EBC performance. Moreover, effects of alcohol exposure on EBC decreased significantly after inclusion of these DTI measures in regression models, suggesting that these white matter deficits partially mediate the relation of prenatal alcohol exposure to EBC. The associations of greater alcohol consumption with these DTI measures are largely attributable to greater radial diffusivity, possibly indicating poorer myelination. Thus, these data suggest that fetal alcohol‐related deficits in EBC are attributable, in part, to poorer myelination in key regions of the cerebellar peduncles. Hum Brain Mapp 36:2470–2482, 2015. © 2015 Wiley Periodicals, Inc.     

White matter fiber tractography and color mapping of the normal human cerebellum with diffusion tensor imaging

Diffusion tensor imaging (DTI) color mapping and fiber tractography was used to study the white matter within the cerebellum along with the afferent and efferent tracts associated with the cerebellum in 24 normal human subjects. The most prominent structures that can be readily identified using these DTI techniques are the middle, inferior and superior cerebellar peduncles. Furthermore DTI shows transverse white matter fiber that cross between the two cerebellar hemispheres at the level of the vermis. At the hemispheric level fibers to the dentate, to the emboliform nuclei are clearly visible on DTI as is the afferent pathway represented by the middle cerebellar peduncle. Selective DTI fiber tractography provides very exquisite images of the cerebellar peduncles and of the fibers projecting to and from the cerebellar cortex. This study demonstrates that DTI is complementary to conventional MRI in that DTI elucidates the orientation of white matter fiber bundles that are associated with the cerebellum. Therefore we anticipate that DTI will become an important adjunct to conventional MRI for clinical and basic studies of cerebellar ataxias and congenital disorders involving the cerebellum and brain stem. This work provides a summary of the normal DTI appearance of the cerebellar white matter which will be useful for interpreting DTI results in clinical populations.     

Subtle disruption of the middle cerebellar peduncles in patients with schizophrenia

Diffusion tensor imaging (DTI) was used to investigate subtle disruption in the middle cerebellar peduncles in patients with schizophrenia. Fractional anisotropy (FA) was measured in 25 patients with schizophrenia and 21 healthy subjects using DTI. The FA of the right and left middle cerebellar peduncles was significantly lower in the schizophrenic patients compared to healthy subjects. FA in the left middle cerebellar peduncles was significantly correlated with the dosage of neuroleptics in patients with schizophrenia. There were no significant differences of mean diffusivity in the right and left middle cerebellar peduncles between patients with schizophrenia and healthy subjects. The findings of the study suggest that antipsychotics may improve the subtle disruption in the middle cerebellar peduncles in patients with schizophrenia.     

Orthogonal diffusion-weighted MRI measures distinguish region-specific degeneration in cerebellar ataxia subtypes

The cerebellar peduncles are excellent candidates for composite indicators of regional degeneration in posterior fossa structures, as the peduncles show histopathological changes in degenerative ataxia. We postulate that magnetic resonance imaging will reveal evidence of disease specific peduncle degeneration through macrostructural (cross-sectional area) and microstructural (fractional anisotropy, mean diffusivity) measures. This study presents a “proof of principle” using orthogonal diffusion tensor imaging cross-sections of the cerebellar peduncles to distinguish categories of cerebellar disease.     

Anterior and posterior inferior cerebellar artery infarction with sudden deafness and vertigo

We report a patient with anterior and posterior inferior cerebellar artery infarction, which manifested as profound deafness, transient vertigo, and minimal cerebellar signs. We suspect that ischaemia of the left internal auditory artery, which originates from the anterior inferior cerebellar artery, caused the deafness and transient vertigo. A small lesion in the middle cerebellar peduncle in the anterior inferior cerebellar artery territory and no lesion in the dentate nucleus in the posterior inferior cerebellar artery territory are thought to explain the minimal cerebellar signs despite the relatively large size of the infarction. Thus a relatively large infarction of the vertebral-basilar territory can manifest as sudden deafness with vertigo. Neuroimaging, including magnetic resonance imaging, is strongly recommended for patients with sudden deafness and vertigo to exclude infarction of the vertebral-basilar artery territory.     

Altered Microstructural Connectivity of the Superior Cerebellar Peduncle is Related to Motor Dysfunction in Children with Autistic Spectrum Disorders

Many studies have reported motor impairments in autistic spectrum disorders (ASD). However, the brain mechanism underlying motor impairment in ASD remains unclear. Recent neuroimaging studies have suggested that underconnectivity between the cerebellum and other brain regions contributes to the features of ASD. In this study, we investigated the microstructural integrity of the cerebellar pathways, including the superior, middle, and inferior cerebellar peduncles, of children with and without ASD by using diffusion tensor imaging (DTI) tractography to determine whether the microstructural integrity of the cerebellar pathways is related to motor function in children with ASD. Thirteen children with ASD and 11 age-, gender-, handedness-, and IQ-matched typically developing (TD) controls were enrolled in this study. DTI outcome measurements, such as fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD), for the cerebellar pathways were calculated. The Movement Assessment Battery for Children 2 (M-ABC 2) was used for assessing motor functions. There were no significant differences between the two groups in RD. However, compared to the TD subjects, patients with ASD had a significantly lower FA in the right superior cerebellar peduncle and lower AD in the left superior cerebellar peduncle, in addition to a significantly lower score in ball skills and the total test score of M-ABC 2. There was a significant positive correlation between the total test score of M-ABC 2 and FA in the right superior cerebellar peduncle in the ASD group. These findings suggest that the altered microstructural integrity of the superior cerebellar peduncle may be related to motor impairment in ASD.     

扩散张量成像技术对急性脑梗死的诊断价值

目的应用MR扩散张量成像(DTI)及扩散张量纤维束成像(DTT)技术对急性脑梗死患者进行检查,研究患者肢体活动障碍的表现及预后与皮质脊髓束的关系及ADC图对急性脑梗死的诊断价值。方法对33例急性脑梗死患者(发病时间<72h)行常规MRI检查及DTI检查,并进行皮质脊髓束三维DTT成像及b=1000的ADC成像,将患者运动障碍的程度分为无瘫痪,治疗后瘫痪恢复,治疗后瘫痪不恢复3种情况,将常规MRI图、DTI中的ADC图影像表现及DTT图皮质脊髓束形态表现与患者临床肌力表现及治疗结果相比较。结果无瘫痪13例,治疗后瘫痪恢复者9例,治疗后瘫痪不恢复者11例,DTT图显示皮质脊髓束分别为无受压,受压无中断及中断破坏。所有病例ADC图均表现为低或稍低信号。结论DTI及DTT技术,对判断脑梗死患者运动障碍的程度及预后有重要价值。     

Recovery of the corticospinal tract after injury by transtentorial herniation: a case report

Little is known about recovery of the corticospinal tract (CST) after injury by transtentorial herniation (TH). We present with a patient who showed recovery of the CST after injury by TH, using diffusion tensor tractography (DTT) and transcranial magnetic stimulation (TMS). A 69-year-old female underwent craniotomy and drainage of an intracerebral hemorrhage in the left corona radiata and basal ganglia. Brain CT showed left TH and brain MRI revealed a leukomalactic lesion at the left cerebral peduncle. The patient presented with complete paralysis of the right extremities at ICH onset, but slowly recovered some function to the point of being able to move the affected extremities against gravity at about 6 months after onset. Three-week DTT showed disruption of the left CST below the cerebral peduncle; however, this disruption was recovered on 1-year DTT. Three-week TMS showed no motor evoked potential for the affected hemisphere; in contrast, motor evoked potentials that were compatible with regenerated CST were obtained from the affected hand muscle at 6 months. Using DTT and TMS in a patient with ICH, we demonstrated recovery of the CST after injury by TH.     

Diffusion tensor imaging comparison of progressive supranuclear palsy and corticobasal syndromes

BackgroundCorticobasal syndrome (CBS) and progressive supranuclear palsy syndrome (PSPS) are atypical parkinsonian syndromes that are both associated with white matter tract degeneration. However, little is known about how patterns of degeneration compare across these two syndromes.MethodsTwenty-seven subjects, nine with CBS and eighteen with probable or definite PSPS (9 pathologically confirmed) were prospectively recruited and underwent 3.0 T diffusion tensor imaging. A whole-brain voxel-based analysis was performed on fractional anisotropy (FA) and mean diffusivity (MD) images to compare both groups to each other and to 50 healthy controls.ResultsThe two syndromes showed overlapping regions of reduced FA and increased MD in the body of the corpus callosum, middle cingulum bundle, and premotor and prefrontal white matter, with reduced FA also observed in the superior cerebellar peduncles in both syndromes. However, CBS showed a more supratentorial and posterior pattern of degeneration with greater involvement of the splenium of the corpus callosum, premotor, motor and parietal lobes than PSPS. Findings in CBS were also highly asymmetric. Conversely, PSPS showed a more symmetric and infratentorial pattern of degeneration, with greater involvement of the superior cerebellar peduncles and midbrain than CBS.ConclusionsCBS and PSPS are both associated with striking white matter tract degeneration. Despite differences in the supratentorial and infratentorial distribution of degeneration, and in asymmetry, both tend to target a common structural network. Measurements of white matter tract diffusion could therefore be useful disease biomarkers in both of these syndromes.     

Brain fiber tract plasticity in experimental spinal cord injury: diffusion tensor imaging

Diffusion tensor imaging (DTI) and immunohistochemistry were performed in spinal cord injured rats to understand the basis for activation of multiple regions in the brain observed in functional magnetic resonance imaging (fMRI) studies. The measured fractional anisotropy (FA), a scalar measure of diffusion anisotropy, along the region encompassing corticospinal tracts (CST) indicates significant differences between control and injured groups in the 3 to 4 mm area posterior to bregma that correspond to internal capsule and cerebral peduncle. Additionally, DTI-based tractography in injured animals showed increased number of fibers that extend towards the cortex terminating in the regions that were activated in fMRI. Both the internal capsule and cerebral peduncle demonstrated an increase in GFAP-immunoreactivity compared to control animals. GAP-43 expression also indicates plasticity in the internal capsule. These studies suggest that the previously observed multiple regions of activation in spinal cord injury are, at least in part, due to the formation of new fibers.     

Prognostic factors for motor outcome in patients with compressed corticospinal tract by intracerebral hematoma

Little is known about prognostic factors associated with motor outcome when the corticospinal tract (CST) was compressed by hematoma. Using diffusion tensor tractography (DTT), we attempted to investigate prognostic factors for motor outcome in patients whose affected CST was compressed by hematoma. The study included 51 consecutive severe hemiparetic patients with a hematoma involving the corona radiata and basal ganglia. Integrities of the affected CSTs were preserved to the cerebral cortex and were found to be compressed by a hematoma on DTT. Patients were classified into four groups according to the region which the CST was originated from the precentral gyrus (type A), postcentral gyrus (type B), posterior parietal cortex (type C), and premotor cortex (type D). We measured the ratios of DTT parameters between affected/unaffected hemispheres.The motor function of the affected extremities at 6-month after onset was better with the following order: DTT type A, type B, type C, and type D patients. The 6-month motor function for DTT type A patients was higher than that of DTT type D patients (p=0.008). The fractional anisotropy ratio between the affected and unaffected CST was positively correlated with the 6-month motor function of the affected extremities (Pearson's correlation coefficient, p=0.025, r=0.313). We found that motor outcome differed according to the originated area of the affected CST and the degree of injury of the affected CST in patients whose affected CST was compressed by hematoma.     

DTI及DTT技术在弥漫性轴索伤预后判断中的作用

目的探讨磁共振弥散张量成像（DTI）及弥散张量纤维束成像（DTT）技术在弥漫性轴索损伤(DAI)患者预后判断中的作用。 方法选取解放军联勤保障部队第九八八医院神经外科自2016年1月至2018年1月收治的34例DAI患者,于外伤后1周内行3.0T常规头颅MRI检查,同期行DTI及DTT成像。根据纤维束数量及形态预测患者预后并分为3级：Ⅰ级意识恢复伴或不伴有残疾,Ⅱ级植物生存,Ⅲ级为临床死亡。同时于患者伤后即行脑干听觉诱发电位（BAEP）监测,并于1周内完成,并根据Cant标准预测预后并分为3级：Ⅰ级意识恢复伴或不伴有残疾,Ⅱ级植物生存,Ⅲ级为临床死亡。根据实际结果对比2种方法的符合率,分析其预测的优劣。 结果根据DTI及DTT预测显示,Ⅰ级15例,Ⅱ级13例,Ⅲ级6例;根据BAEP监测结果预测,Ⅰ级8例,Ⅱ级18例,Ⅲ级8例;其中在Ⅲ级结局的预测中BAEP准确率明显高于DTI及DTT,而在Ⅰ及Ⅱ级结局预测中DTI及DTT的准确率明显高于BAEP。 结论DTI及DTT和BAEP在对DAI的病情判断及结局预测中各有优势,临床上二者应结合应用。     

Vascular anomaly of the posterior circulation associated with intracranial lipoma-like lesion in the cerebral peduncle manifesting as oculomotor nerve palsy

Intracranial lipomas are rare and often located in the midline of the brain. Intracranial lipomas are often associated with malformations of the brain such as dysgenesis of the corpus callosum, but rarely with vascular malformations. A man presented with left-sided facial pain at the age of 31. He developed left oculomotor nerve palsy at the age of 38 years and was referred to our hospital at the age of 48. Radiological findings revealed vascular anomalies of the left posterior cerebral and superior cerebellar arteries with intracranial lipoma-like lesion in the cerebral peduncle. Surgical treatment was complicated by the lesion location, so we administered conservative therapy. Despite treatment with corticosteroids, his symptoms have not improved. This unique case documents the presentation of vascular anomalies of the left posterior cerebral and superior cerebellar arteries associated with lipoma in the cerebral peduncle.     

硬脑膜下血肿清除前后皮质脊髓束的状态：弥散张量成像证据

Abstract Subdural hematoma can cause compression or damage to the neural tracts in the brain; however, very little is known about this injury. We report on a patient with subdural hematoma who was evaluated by diffusion tensor imaging prior to and after trephination and drainage of subdural hematoma. A 58-year-old male patient and ten age-matched normal control subjects were evaluated. The patient showed mild hemiparesis for 3 weeks prior to surgery. His hemiparesis recovered to a nearly normal state at 5 weeks post-surgery when the follow up diffusion tensor image was acquired. Two diffusion tensor image parameters, fractional anisotropy and apparent diffusion coefficient, were measured along the corticospinal tract. Pre-operative diffusion tensor image showed that the corticospinal tract of the affected hemisphere seemed to be injured or compressed. However, the follow up diffusion tensor image showed recovery of this corticospinal tract to a normal state. It would appear that diffusion tensor images are a useful tool for evaluation of the effects of subdural hematomas on neural tracts. Key Words: subdural hematoma; diffusion tensor imaging; hemiparesis; corticospinal tract     

儿童第四脑室-小脑脚-脑干区肿瘤的手术治疗

目的 研究第四脑室-小脑脚-脑干区肿瘤的形态学特点，以及安全地切除此部位肿瘤的手术方法。方法 儿童（15岁以下）第四脑室-小脑脚-脑干区肿瘤（室管膜瘤和星形细胞瘤）23例。术前头颅MRI证实瘤体起源于小脑脚或侧隐窝，分别向第四脑室，脑干，CPA和斜坡生长。采用枕下正中外侧拐入路，术中分区域切除肿瘤，结果 全切除肿瘤12例，近全切除9例，大部切除2例，无手术死亡，术后病理证实室管膜瘤13例，恶性室管膜瘤2例，星形细胞瘤8例。结论 起源于小脑脚或侧隐窝的肿瘤，以脑干为中心呈半弧形生长，肿瘤侵袭范围包括第四脑室，小脑脚，脑干，CPA和斜坡，合适的手术入路和术中分区域切除肿瘤的技术，可以做到安全地全切除和/或近全切除肿瘤。