Neuroimaging a single thought: dorsolateral PFC activity associated with refreshing just-activated information.

Neuroimaging studies of human working memory (WM) show conflicting results regarding whether dorsolateral prefrontal cortex (PFC) contributes to maintaining information in consciousness or is recruited primarily when information must be manipulated. Using functional magnetic resonance imaging (fMRI), we looked at a minimal maintenance process--thinking back to a single, just-seen stimulus (refreshing). We found greater activity in left dorsolateral PFC (BA9) when participants refreshed a word compared to reading a word once or a second time. Furthermore, recognition memory was subsequently more accurate and faster for items that had been refreshed, demonstrating that a single thought that maintains activation can have consequences for long-term memory. Our fMRI results call into question any class of models of the functional organization of PFC and WM that associates simple and/or maintenance processes only with ventrolateral PFC or that associates dorsolateral PFC only with more complex processes such as manipulation.     

White matter damage impairs access to consciousness in multiple sclerosis

Global neuronal workspace theory predicts that damage to long-distance white matter (WM) tracts should impair access to consciousness during the perception of brief stimuli. To address this issue, we studied visual backward masking in 18 patients at the very first clinical stage of multiple sclerosis (MS), a neurological disease characterized by extensive WM damage, and in 18 matched healthy subjects. In our masking paradigm, the visibility of a digit stimulus increases non-linearly as a function of the interval duration between this target and a subsequent mask. In order to characterize quantitatively, for each subject, the transition between non-conscious and conscious perception of the stimulus, we used non-linear regression to fit a sigmoid curve to objective performance and subjective visibility reports as a function of target-mask delay. The delay corresponding to the inflexion point of the sigmoid, where visibility suddenly increases, was termed the "non-linear transition threshold" and used as a summary measure of masking efficiency. Objective and subjective non-linear transition thresholds were highly correlated across subjects in both groups, and were higher in patients compared to controls. In patients, variations in the non-linear transition threshold were inversely correlated to the Magnetization transfer ratio (MTR) values inside the right dorsolateral prefrontal WM, the right occipito-frontal fasciculus and the left cerebellum. This study provides clinical evidence of a relationship between impairments of conscious access and integrity of large WM bundles, particularly involving prefrontal cortex, as predicted by global neuronal workspace theory.     

2型糖尿病患者饮食决策平衡与大五人格特征的相关性研究

目的 探讨2型糖尿病患者饮食决策平衡现状及其与大五人格特征的相关性,以期为临床个体化健康饮食教育提供参考.方法 便利抽样法选取重庆市3所三级甲等医院内分泌科住院的192例2型糖尿病患者为研究对象,采用饮食决策平衡量表和大五人格量表简化版(neuroticism extraversion openness five fa...     

White matter brain and trigeminal nerve abnormalities in temporomandibular disorder

Temporomandibular disorder (TMD) is a prevalent chronic pain disorder that remains poorly understood. Recent imaging studies reported functional and gray matter abnormalities in brain areas implicated in sensorimotor, modulatory, and cognitive function in TMD, but it is not known whether there are white matter (WM) abnormalities along the trigeminal nerve (CNV) or in the brain. Here, we used diffusion tensor imaging, and found that, compared to healthy controls, TMD patients had 1) lower fractional anisotropy (FA) in both CNVs; 2) a negative correlation between FA of the right CNV and pain duration; and 3) diffuse abnormalities in the microstructure of WM tracts related to sensory, motor, cognitive, and pain functions, with a highly significant focal abnormality in the corpus callosum. Using probabilistic tractography, we found that the corpus callosum in patients had a higher connection probability to the frontal pole, and a lower connection probability to the dorsolateral prefrontal cortex, compared to controls. Finally, we found that 1) FA in tracts adjacent to the ventrolateral prefrontal cortex and tracts coursing through the thalamus negatively correlated with pain intensity; 2) FA in the internal capsule negatively correlated with pain intensity and unpleasantness; and 3) decreases in brain FA were associated with increases in mean diffusivity and radial diffusivity, markers of inflammation and oedema. These data provide novel evidence for CNV microstructural abnormalities that may be caused by increased nociceptive activity, accompanied by abnormalities along central WM pathways in TMD.     

Discriminating schizophrenia and bipolar disorder by fusing fMRI and DTI in a multimodal CCA+ joint ICA model

Diverse structural and functional brain alterations have been identified in both schizophrenia and bipolar disorder, but with variable replicability, significant overlap and often in limited number of subjects. In this paper, we aimed to clarify differences between bipolar disorder and schizophrenia by combining fMRI (collected during an auditory oddball task) and diffusion tensor imaging (DTI) data. We proposed a fusion method, "multimodal CCA+ joint ICA", which increases flexibility in statistical assumptions beyond existing approaches and can achieve higher estimation accuracy. The data collected from 164 participants (62 healthy controls, 54 schizophrenia and 48 bipolar) were extracted into "features" (contrast maps for fMRI and fractional anisotropy (FA) for DTI) and analyzed in multiple facets to investigate the group differences for each pair-wised groups and each modality. Specifically, both patient groups shared significant dysfunction in dorsolateral prefrontal cortex and thalamus, as well as reduced white matter (WM) integrity in anterior thalamic radiation and uncinate fasciculus. Schizophrenia and bipolar subjects were separated by functional differences in medial frontal and visual cortex, as well as WM tracts associated with occipital and frontal lobes. Both patients and controls showed similar spatial distributions in motor and parietal regions, but exhibited significant variations in temporal lobe. Furthermore, there were different group trends for age effects on loading parameters in motor cortex and multiple WM regions, suggesting that brain dysfunction and WM disruptions occurred in identified regions for both disorders. Most importantly, we can visualize an underlying function-structure network by evaluating the joint components with strong links between DTI and fMRI. Our findings suggest that although the two patient groups showed several distinct brain patterns from each other and healthy controls, they also shared common abnormalities in prefrontal thalamic WM integrity and in frontal brain mechanisms.     

A multimodal imaging study in U.S. veterans of Operations Iraqi and Enduring Freedom with and without major depression after blast-related concussion

Although the exact number of affected individuals is unknown, it has been estimated that approximately 20% of U.S. veterans of Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) have experienced mild traumatic brain injury (mTBI) (i.e., concussion), which is defined as a brief loss or alteration of consciousness from a blow or jolt to the head. Blast exposure is among the most common causes of concussion in OEF–OIF warriors. Although the mechanism is unknown, major depressive disorder (MDD) after head injury is common. The purpose of this study was to use diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) to examine the structural and functional neural correlates of MDD in OEF–OIF combat veterans with a self-reported history of blast-related concussion. We hypothesized that subjects in the MDD group (i.e., individuals with a history of blast-related concussion who were experiencing current MDD) relative to individuals in the non-MDD group (i.e., individuals with a history of blast-related concussion but no current or lifetime history of MDD) would show amygdala hyperactivity and disruption of white matter tracts connecting prefrontal and limbic brain regions. To test these hypotheses, 11 MDD and 11 non-MDD individuals underwent DTI and performed a validated emotional face matching task during fMRI. MDD relative to non-MDD individuals showed greater activity during fear matching trials in the amygdala and other emotion processing structures, lower activity during fear matching trials in emotional control structures such as the dorsolateral prefrontal cortex and lower fractional anisotropy (FA) in several white matter tracts including the superior longitudinal fasciculus (SLF). Greater depressive symptom severity correlated negatively with FA in the SLF. These results suggest a biological basis of MDD in OEF–OIF veterans who have experienced blast-related concussion, and may contribute to the development of treatments aimed at improving the clinical care of this unique population of wounded warriors.     

Working memory effects on semantic processing: priming differences in pars orbitalis

Both working memory (WM) and controlled (attention-mediated) semantic processing functions have been thought to operate as limited capacity systems, but the possible link between these processes has not been investigated. We found that increased WM load attenuated semantic priming (i.e., reduced the response time advantage for semantically primed relative to unprimed items) and changed fMRI signal intensities in brain regions usually associated with both WM (dorsolateral prefrontal cortex) and controlled semantic retrieval (inferior frontal gyrus [IFG], pars orbitalis). fMRI signal changes in dorsolateral prefrontal cortex were negatively correlated with signal changes in pars orbitalis. The findings suggest that controlled semantic processing and working memory share neural system resources.     

Young adults born preterm with very low birth weight demonstrate widespread white matter alterations on brain DTI

Preterm birth with very low birth weight (VLBW, ≤1500 g) is connected to reduced white matter (WM) integrity in childhood and adolescence. These changes in WM are correlated to motor, sensory and neuropsychological impairments. CNS myelination continues into the early twenties, but the consequences of this for WM integrity in VLBWs have not been explored. DTI and tract based spatial statistics (TBSS) was carried out to test for voxelwise differences in fractional anisotropy (FA), eigenvalues and mean diffusivity (MD) between a preterm VLBW group (n=49) and a control group born at term (n=59) at 18-22 years of age. TBSS was also used to explore the relationship between perinatal clinical data and general cognitive ability (total IQ), respectively, and the DTI metrics (FA and MD), with gender and age as a confounder. In the VLBW group several major WM tracts particularly in the posterior region had significantly reduced FA caused by an increase in the two lowest eigenvalues. MD was significantly increased in the VLBWs in 50% of the same regions as the FA changes, but encompassing also more peripheral WM. In the VLBW group, FA was found to correlate positively with birth weight and negatively with number of days in intensive care and on mechanical ventilator, particularly in the corpus callosum. FA was found to correlate positively with total IQ in the young preterm adults. In the controls there was no correlation between FA and total IQ. Our results indicate that the neurologic sequelae of preterm birth with VLBW are a lifelong condition inducing structural and functional impairments also in adulthood in VLBW survivors. The greatest risk of having reduced WM integrity in adulthood was found in the most immature VLBW neonates requiring mechanical ventilation and long-term intensive care.     

Personality Traits Associated with Occupational ‘Burnout’ in ABA Therapists

Background

Applied behaviour analysis (ABA) therapists typically work one‐to‐one with children with autism for extended periods of time, which often leads to high levels of job‐related stress, lower levels of job satisfaction, increased frequency of occupational ‘burnout’ and higher than average job turnover (Journal of Autism Development, 39 , 2009 and 42). This is particularly unfortunate, in that these vulnerable clients need stability and consistency in care, both of which are empirically related to clinical outcomes (Journal of Autism Development, 39 , 2009 and 42). It is reasonable to assume that some individuals, by virtue of their personal characteristics, are better suited to this type of work than are others.

Method

The purpose of the this study was to investigate associations between personality traits, using the five‐factor model of personality, and key job‐related variables, including burnout and job satisfaction, in a sample of therapists (n = 113) who work one‐to‐one with individuals diagnosed with autism.

Results

Significant correlations were found between Neuroticism and all three subscales of burnout (Exhaustion, Cynicism and Professional Efficacy). Extraversion and Conscientiousness were significantly negatively correlated with Cynicism and positively correlated with Professional Efficacy. Agreeableness was positively associated with Professional Efficacy. Job satisfaction was correlated positively with Extraversion and negatively with Neuroticism. Level of perceived personal and professional support partially mediated the effect of personality traits on job satisfaction.

Conclusions

These results may help to identify job applicants who are dispositionally less suited to this type of work, as well as currently employed therapists who are in need of support or intervention.     

Neuroanatomical correlates of personality in the elderly

Extraversion and neuroticism are two important and frequently studied dimensions of human personality. They describe individual differences in emotional responding that are quite stable across the adult lifespan. Neuroimaging research has begun to provide evidence that neuroticism and extraversion have specific neuroanatomical correlates within the cerebral cortex and amygdala of young adults. However, these brain areas undergo alterations in size with aging, which may influence the nature of these personality factor-brain structure associations in the elderly. One study in the elderly demonstrated associations between perisylvian cortex structure and measures of self transcendence [Kaasinen, V., Maguire, R.P., Kurki, T., Bruck, A., Rinne, J.O., 2005. Mapping brain structure and personality in late adulthood. NeuroImage 24, 315-322], but the neuroanatomical correlates of extraversion and neuroticism, or other measures of the Five Factor Model of personality have not been explored. The purpose of the present study was to investigate the structural correlates of neuroticism and extraversion in healthy elderly subjects (n=29) using neuroanatomic measures of the cerebral cortex and amygdala. We observed that the thickness of specific lateral prefrontal cortex (PFC) regions, but not amygdala volume, correlates with measures of extraversion and neuroticism. The results suggest differences in the regional neuroanatomic correlates of specific personality traits with aging. We speculate that this relates to the influences of age-related structural changes in the PFC.     

White matter integrity in patients with classic trigeminal neuralgia: a multi-node automated fiber tract quantification study

ObjectiveTo study the characteristics of point-by-point destruction of white matter tracts in patients using automated fiber tract quantification (AFQ).MethodsThirty-four classic trigeminal neuralgia (CTN) patients and 34 healthy control (HC) subjects underwent 3.0 T diffusion tensor magnetic resonance imaging and T1-weighted imaging. The fractional anisotropy (FA) and mean diffusivity (MD) of 100 nodes of 20 fiber tracts were analyzed by AFQ, and the correlations of the FA and MD with the visual analogue scale (VAS) pain score were assessed.ResultsThe FA values of the left thalamic radiation (middle segment), left corticospinal tract, callosum forceps minor, and right uncinate fasciculus were significantly lower in CTN patients than in the HC group. The MD of the left thalamic tract (middle segment), left corticospinal tract, right superior longitudinal fasciculus, and left superior longitudinal fasciculus (anterior segment) were significantly higher in the CTN group. Additionally, the VAS pain score in CTN patients was positively correlated with FA and negatively correlated with MD.ConclusionSpecific fiber tract nodes were damaged in CTN patients, which was related to the VAS pain score. Multi-node quantitative studies of fiber tract damage are valuable for understanding the white matter tract damage pattern in CTN patients.     

The responsive amygdala: Treatment-induced alterations in functional connectivity in pediatric complex regional pain syndrome

The amygdala is a key brain region with efferent and afferent neural connections that involve complex behaviors such as pain, reward, fear, and anxiety. This study evaluated resting state functional connectivity of the amygdala with cortical and subcortical regions in a group of chronic pain patients (pediatric complex regional pain syndrome) with age-sex matched control subjects before and after intensive physical-biobehavioral pain treatment. Our main findings include (1) enhanced functional connectivity from the amygdala to multiple cortical, subcortical, and cerebellar regions in patients compared with control subjects, with differences predominantly in the left amygdala in the pretreated condition (disease state); (2) dampened hyperconnectivity from the left amygdala to the motor cortex, parietal lobe, and cingulate cortex after intensive pain rehabilitation treatment within patients with nominal differences observed among healthy control subjects from time 1 to time 2 (treatment effects); (3) functional connectivity to several regions key to fear circuitry (prefrontal cortex, bilateral middle temporal lobe, bilateral cingulate, hippocampus) correlated with higher pain-related fear scores; and (4) decreases in pain-related fear associated with decreased connectivity between the amygdala and the motor and somatosensory cortex, cingulate, and frontal areas. Our data suggest that there are rapid changes in amygdala connectivity after an aggressive treatment program in children with chronic pain and intrinsic amygdala functional connectivity activity serving as a potential indicator of treatment response.     

Cortico-striatal connectivity and cognition in normal aging: a combined DTI and resting state fMRI study

Resting state fMRI studies have found that cognitive decline in aging is associated with alterations in functional connectivity of distributed neural systems in the brain. While functional connections have been shown to rely on the underlying structural connectivity, direct structural connections have been studied in only a few distributed cortical systems so far. It is well known that subcortical nuclei have structural connections to the entire cortex. We hypothesized that structural subcortico-cortical connections may provide integral routes for communication between cortical resting state networks, and that changes in the integrity of these connections have a role in cognitive aging. We combined anatomical MRI, diffusion tensor MRI, and resting state fMRI in 100 healthy elderly to identify fiber bundles connecting cortical resting state networks to subcortical nuclei. In identified tracts, white matter fiber bundle integrity measures were compared to composite cognitive measures on executive function, processing speed, and memory performance. The integrity (FA values) in selected fiber bundles correlated strongly with cognitive measures on executive function and processing speed. Correlation was most pronounced between executive function and fiber bundles connecting the putamen to the dorsal attention network (r=0.73, p<0.001). Our findings show that unique cortico-subcortical fiber bundles can be identified for a range of cortical resting state networks, and indicate that these connections play an important role in cortical resting state network communication and cognition.     

Effect of personality traits on rehabilitation effect after anterior cruciate ligament reconstruction: An observational study

BackgroundAnterior cruciate ligament (ACL) reconstruction requires an extended period of postoperative rehabilitation. Psychological factors can affect recovery after surgery. Study of psychological factors is still limited to self-motivation, fear and pain. Study of personality traits associated with early rehabilitation outcome after ACL reconstruction is scarce.ObjectiveWe aimed to explore the effect of personality traits on early rehabilitation after ACL reconstruction and provide a reference for clinicians in designing a personalized rehabilitation plan.MethodsThis prospective analysis investigated 155 patients at 3 and 6 months after ACL reconstruction. Follow-up involved administration of a general data questionnaire, the Chinese Big Five Personality Inventory Brief Version, the Tegner activity score, the International Knee Documentation Committee Subjective Knee Score, the Knee injury and Osteoarthritis Outcome Score, the Lysholm Score and a balance test.ResultsAmong the 155 patients included (124 males), Neuroticism was negatively correlated with subjective knee scores at 3 and 6 months after surgery (p<0.001). The odds of a poor balance test result was increased for each 1-point increase in Neuroticism score (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.28–2.36, p<0.001). We found a positive correlation between Conscientiousness score and subjective knee scores at 3 and 6 months after surgery (p<0.001). For every 1-point increase in Conscientiousness score, the odds of a poor balance test result were decreased (OR 0.29, 95% CI 0.16–0.54, p<0.001). Agreeableness and Openness to experience scores were positively correlated with subjective knee scores at 3 and 6 months after surgery (p<0.001). We found no correlation between Extraversion and subjective knee scores at 3 and 6 months after surgery (p>0.05) but a positive correlation with the Tegner activity score at 3 and 6 months after surgery (p<0.05).ConclusionWe found a significant correlation between the Big Five personality dimensions and the early rehabilitation effect after ACL reconstruction, which can provide a reference for clinicians in designing a personalized rehabilitation plan.     

Relating neocortical pathology to disability progression in multiple sclerosis using MRI

Cortical grey matter (cGM) develops a substantial burden of pathology in multiple sclerosis (MS). Previous cross-sectional studies have suggested a relationship between measures of cortical atrophy and disability. Our objective was to develop a method for automatically measuring the apparent cGM thickness as well as the integrity of the interface between cGM and subcortical white matter (GM/WM) both globally and regionally on T(1)-weighted MRI, and use this method in a longitudinal investigation of how these measures differed between patients with stable MS and patients with progressing disability. Measurements were made over the whole brain and for anatomically specified cortical regions, both cross-sectionally at baseline and longitudinally on two MRI scans performed on average 1 year apart. We found a higher average rate of apparent loss of cGM thickness across the whole brain in the group that progressed over the interscan interval compared to the group that remained stable (progressing = -3.13 +/- 2.88%/year, stable = 0.06 +/- 2.31%/year, P = 0.002). This difference was detected with regional measures in parietal and precentral cortex. In contrast, change in the GM/WM interface integrity did not show detectable regional differences, although the group of MS patients whose disability progressed showed a significant decrease in GM/WM interface integrity compared to the stable group (P = 0.003). Regional measures of apparent loss of cGM thickness enhance sensitivity to cortical pathological changes. A measure of integrity offers a new index of disease-associated cortical changes at the GM/WM interface. The results suggest that progression of disability in MS is associated with the progression of MRI-detectable cortical pathology.     

Neural mechanisms underlying the conditioned diminution of the unconditioned fear response

Recognizing cues that predict an aversive event allows one to react more effectively under threatening conditions, and minimizes the reaction to the threat itself. This is demonstrated during Pavlovian fear conditioning when the unconditioned response (UCR) to a predictable unconditioned stimulus (UCS) is diminished compared to the UCR to an unpredictable UCS. The present study investigated the functional magnetic resonance imaging (fMRI) signal response associated with Pavlovian conditioned UCR diminution to better understand the relationship between individual differences in behavior and the neural mechanisms of the threat-related emotional response. Healthy volunteers participated in a fear conditioning study in which trait anxiety, skin conductance response (SCR), UCS expectancy, and the fMRI signal were assessed. During acquisition trials, a tone (CS+) was paired with a white noise UCS and a second tone (CS-) was presented without the UCS. Test trials consisted of the CS+ paired with the UCS, CS- paired with the UCS, and presentations of the UCS alone to assess conditioned UCR diminution. UCR diminution was observed within the dorsolateral PFC, dorsomedial PFC, cingulate cortex, inferior parietal lobule (IPL), anterior insula, and amygdala. The threat-related activity within the dorsolateral PFC, dorsomedial PFC, posterior cingulate cortex, and IPL varied with individual differences in trait anxiety. In addition, anticipatory (i.e. CS elicited) activity within the PFC showed an inverse relationship with threat-related (i.e. UCS elicited) activity within the PFC, IPL, and amygdala. Further, the emotional response (indexed via SCR) elicited by the threat was closely linked to amygdala activity. These findings are consistent with the view that the amygdala and PFC support learning-related processes that influence the emotional response evoked by a threat.     

Preliminary findings on the relation between the personality trait of stress reaction and the central neural control of human vocalization

The objectives of this study were to examine whether the personality trait of stress reaction (SR), as assessed with the Multidimensional Personality Questionnaire-Brief Form (MPQ-BF), (1) influences prefrontal and limbic area activity during overt sentence reading and if (2) SR and associated individual differences in prefrontal and limbic activations correlate with sensorimotor cortical activity during overt sentence reading. Ten vocally healthy adults (22-57 years) participated in a functional MRI study using an event-related sparse sampling design to acquire brain activation data during sentence production tasks (covert, whispered, overt). The outcome measure was the blood oxygenation level-dependent signal change in prefrontal, limbic, and primary somatosensory (S1) and motor cortices (M1). Significant positive correlations were found between SR scores and S1, dorsolateral prefrontal cortex (both r =.73, p <.05), and periaqueductal gray (r =.88, p <.01) activity. M1 activity was positively correlated with SR (r =.64, p <.05) and negatively with social potency (r = -.70, p <.05). Our findings suggest that motor cortical control subserving voice and speech production varies with expression of selected personality traits. Future studies should investigate the functional significance of personality differences in the central neural control of vocalization.     

White matter integrity of the descending pain modulatory system is associated with interindividual differences in placebo analgesia

The ability for endogenous pain control varies considerably among individuals. The mechanisms underlying this interindividual difference are incompletely understood. We used placebo analgesia as a classic model of endogenous pain modulation in combination with diffusion tensor magnetic resonance imaging to test the hypothesis of a structural predisposition for the individual capacity of endogenous pain control. Specifically we determined white matter integrity within and between regions of the descending pain modulatory system. Twenty-four healthy participants completed a placebo paradigm and underwent diffusion tensor magnetic resonance imaging. The individual placebo analgesic effect was correlated with white matter integrity indexed by fractional anisotropy. The individual placebo analgesic effect was positively correlated with FA in the right dorsolateral prefrontal cortex, left rostral anterior cingulate cortex, and the periaqueductal grey. Probabilistic tractography seeded in these regions showed that stronger placebo analgesic responses were associated with increased mean fractional anisotropy values within white matter tracts connecting the periaqueductal grey with pain control regions such as the rostral anterior cingulate cortex and the dorsolateral prefrontal cortex. Our findings provide the first evidence that the white matter integrity within and between regions of the descending pain modulatory network is critically linked with the individual ability for endogenous pain control.     

基于DTI的三叉神经痛脑白质结构异常及其与临床特征的相关性

目的 采用基于纤维束的空间统计方法（TBSS）探讨原发性三叉神经痛（PTN）患者脑白质微结构异常。方法 对38例PTN患者（PTN组）和38名年龄、性别匹配的健康志愿者（对照组）行全脑DTI扫描,并用FSL软件进行分析,寻找FA值、平均扩散系数（MD）、径向扩散系数（RD）和轴向扩散系数（AD）存在组间统计学差异的脑区,并与视觉模拟评分（VAS）进行相关分析。结果 与对照组相比,PTN组胼胝体、放射冠、左侧上纵束、左侧下纵束及下额枕束FA值降低;且PTN组双侧丘脑后辐射、双侧内囊、双侧外囊、穹窿、右侧上纵束同时存在MD值和RD值升高,而AD升高脑区仅局限于双侧内囊前支、左侧内囊后支、双侧上放射冠和双侧上纵束。PTN患者左侧上纵束FA值与VAS呈负相关（r=-0.502,P=0.001）,左侧上纵束MD值与VAS评分呈正相关（r=0.437,P=0.006）。结论 丘脑、内囊MD值和RD值同向升高而不伴FA值降低可能是PTN的相对特征性DTI表现;左侧上纵束FA值和MD值对评估PTN患者疼痛水平有参考价值。