Shasha Li

Altered functional connectivity in default mode network in absence epilepsy: A resting‐state fMRI study

Dysfunctional default mode network (DMN) has been observed in various mental disorders, including epilepsy (see review Broyd et al. [ 2009 ]: Neurosci Biobehav Rev 33:279–296). Because interictal epileptic discharges may affect DMN, resting‐state fMRI was used in this study to determine DMN functional connectivity in 14 healthy controls and 12 absence epilepsy patients. To avoid interictal epileptic discharge effects, testing was performed within interictal durations when there were no interictal epileptic discharges. Cross‐correlation functional connectivity analysis with seed at posterior cingulate cortex, as well as region‐wise calculation in DMN, revealed decreased integration within DMN in the absence epilepsy patients. Region‐wise functional connectivity among the frontal, parietal, and temporal lobe was significantly decreased in the patient group. Moreover, functional connectivity between the frontal and parietal lobe revealed a significant negative correlation with epilepsy duration. These findings indicated DMN abnormalities in patients with absence epilepsy, even during resting interictal durations without interictal epileptic discharges. Abnormal functional connectivity in absence epilepsy may reflect abnormal anatomo‐functional architectural integration in DMN, as a result of cognitive mental impairment and unconsciousness during absence seizure. Hum Brain Mapp, 2011.

Functional magnetic resonance imaging study on dysphagia after unilateral hemispheric stroke: a preliminary study

Background: Swallowing dysfunction is common and disabling after acute stroke; however, the mechanism of dysphagia or recovery of swallowing from dysphagia remains uncertain. The purpose of this study was to explore cerebral activation of swallowing in dysphagia using functional MRI (fMRI) to compare the functional anatomy of swallowing in unilateral hemispheric stroke patients and healthy adults. Methods: In total, five left hemispheric stroke patients with dysphagia, five right hemispheric stroke patients with dysphagia and 10 healthy controls were examined with event related fMRI while laryngeal swallow related movements were recorded. Data were processed using the general linear model. Results: A multifocal cerebral representation of swallowing was identified predominantly in the left hemisphere, in a bilateral and asymmetrical manner. Cerebral activation during swallowing tasks was localised to the precentral, postcentral and anterior cingulate gyri, insula and thalamus in all groups. Activation of volitional swallowing in dysphagic unilateral hemispheric stroke patients might require reorganisation of the dominant hemispheric motor cortex, or a compensatory shift in activation to unaffected areas of the hemisphere. Conclusions: The results indicate that unilateral stroke of either cerebral hemisphere can produce dysphagia. Effective recovery is associated with cerebral activation related to cortical swallowing representation in the compensating or recruited areas of the intact hemisphere. Functional MRI is a useful method for exploring the spatial localisation of changes in neuronal activity during tasks that may be related to recovery. Therefore, the subsequent information gleaned from changes in neural plasticity could be useful for assessing the prognosis of dysphagic stroke.

Clinical utility of brain stimulation modalities following traumatic brain injury: current evidence.

Traumatic brain injury (TBI) remains the main cause of disability and a major public health problem worldwide. This review focuses on the neurophysiology of TBI, and the rationale and current state of evidence of clinical application of brain stimulation to promote TBI recovery, particularly on consciousness, cognitive function, motor impairments, and psychiatric conditions. We discuss the mechanisms of different brain stimulation techniques including major noninvasive and invasive stimulations. Thus far, most noninvasive brain stimulation interventions have been nontargeted and focused on the chronic phase of recovery after TBI. In the acute stages, there is limited available evidence of the efficacy and safety of brain stimulation to improve functional outcomes. Comparing the studies across different techniques, transcranial direct current stimulation is the intervention that currently has the higher number of properly designed clinical trials, though total number is still small. We recognize the need for larger studies with target neuroplasticity modulation to fully explore the benefits of brain stimulation to effect TBI recovery during different stages of recovery.

Structural and functional changes mapped in the brains of amyotrophic lateral sclerosis patients with/without dysphagia: A pilot study

The purpose of this study was to explore cerebral structural and functional changes in amyotrophic lateral sclerosis (ALS) patients with or without dysphagia compared with healthy adults. In total, five ALS patients with dysphagia, five ALS patients without dysphagia and 10 healthy controls were evaluated using diffusion tensor magnetic resonance imaging (DTI) and event-related functional magnetic resonance imaging (fMRI) while laryngeal swallow-related movements were recorded. The fMRI data were analysed using the general linear model to gain the differential statistical map (two-sample t-test) for each group. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were calculated within the masks that corresponded to the different statistical functional maps of intergroup comparisons. During the voluntary saliva swallowing, prominent activation of foci corresponded to the primary sensorimotor (SM) cortex in both ALS and controls, while decreased activation of the SM cortex was observed in ALS patients with dysphagia. DTI analysis revealed that FA was significantly reduced and MD was typically increased in the posterior limb of the internal capsule, thalamus, and anterior cingulate gyrus, as well as in the insula of ALS patients compared with controls. However, in ALS patients with dysphagia, FA and MD were more sensitive to these changes than ALS patients without dysphagia. This study highlights the potential of DTI and fMRI for monitoring structural degeneration and functional changes in patients with ALS. This study is the first to demonstrate that cerebral activation map changes correspond to distribution patterns of diffusion abnormalities. Combined non-invasive neuroimaging techniques may be useful tools to assess prognosis and study rehabilitation strategies for dysphagic ALS patients, especially for patients who are MRI-negative by conventional methods.

Randomized-controlled study of treating attention deficit hyperactivity disorder of preschool children with combined electro-acupuncture and behavior therapy

OBJECTIVE To study the effectiveness of electro-acupuncture with behavior therapy on preschool children with attention deficit hyperactivity disorder (ADHD). METHODS 180 preschool children with ADHD diagnosed by DSM-IV were classified into three subtypes: predominantly inattentive subtype (PI subtype, 60 cases), predominantly hyperactive-impulsive subtype (HI subtype, 60 cases) and combined subtype (CT subtype, 60 cases). In each subtype, the patients were recruited randomly into experimental group, which received electro-acupuncture and behavior therapy; and control group, which received sham electro-acupuncture and behavior therapy. The treatment efficacy was evaluated by measuring the change in core symptoms of ADHD according to the standard enacted by the national traditional Chinese medicine committee after 12 courses of treatment (lasted 12 weeks) and relapse rate was evaluated after a half-year follow up. RESULTS (1) In PI subtype, 11 cases showed effectiveness with treatment and 12 cases showed improvement with treatment among experimental group, while five cases showed effectiveness and 12 cases showed improvement among control group; in HI subtype, 10 cases showed effectiveness and 17 cases showed improvement among experimental group, while four cases showed effectiveness and 14 cases showed improvement among control group; in CI subtype, 12 cases showed effectiveness and 12 cases showed improvement among experimental group, while five cases showed effectiveness and 12 cases showed improvement among control group; The overall comparison manifested that the efficacy of experimental group was better than that of control group (p<0.05). (2) The core symptoms of experimental group were significantly decreased than that of control group at half-year follow up (p<0.05). CONCLUSION The treatment of ADHD in preschool children with electro-acupuncture combining behavior therapy has positive effect in reducing symptoms of ADHD. Adverse events are mild to patients. It is recommendable for this combined therapy, while multi-center RCT needs to be further studied.

Treatment of Posthemorrhagic Hydrocephalus in Premature Infants with Subcutaneous Reservoir Drainage

Aims: To investigate the effectiveness of subcutaneous reservoir drainage as a treatment for the different types of posthemorrhagic hydrocephalus in premature infants. Methods: 11 premature infants with posthemorrhagic hydrocephalus underwent subcutaneous reservoir embedment surgery, and cerebrospinal fluid (CSF) was drained via the reservoir intermittently for 8 weeks. During the period of drainage, ultrasound and computerized tomography were used to measure ventricle size. CSF examinations were performed routinely to assess the presence of intraventricular hemorrhage (IVH) and/or infection. Results: (1) Five infants were diagnosed as having obstructive hydrocephalus; 2 had nearly normal ventricle sizes with treatment and drainage was stopped after 8 weeks, 2 had nearly normal ventricle sizes after 4 more weeks of drainage, and 1 underwent ventriculoperitoneal shunt (V-P shunt) surgery due to failure of ventricle size reduction. (2) Six infants were diagnosed as having communicating hydrocephalus; 4 had further enlarged ventricle size after 8 weeks and underwent V-P shunt surgery, 1 had treatment aborted at week 8 of drainage, and only 1 had moderate reduction of ventricle size after 8 weeks. (3) None of the 11 infants had progressive IVH and/or intracranial infection during drainage. Conclusions: Subcutaneous reservoir drainage is a suitable and safe treatment for posthemorrhagic hydrocephalus in premature infants. It is more effective for obstructive hydrocephalus than for communicating hydrocephalus.

Altered Resting-State Functional and White Matter Tract Connectivity in Stroke Patients With Dysphagia

Background. Swallowing dysfunction is intractable after acute stroke. Our understanding of the alterations in neural networks of patients with neurogenic dysphagia is still developing. Objective. The aim was to investigate cerebral cortical functional connectivity and subcortical structural connectivity related to swallowing in unilateral hemispheric stroke patients with dysphagia. Methods. We combined a resting-state functional connectivity with a white matter tract connectivity approach, recording 12 hemispheric stroke patients with dysphagia, 12 hemispheric stroke patients without dysphagia, and 12 healthy controls. Comparisons of the patterns in swallowing-related functional connectivity maps between patient groups and control subjects included (a) seed-based functional connectivity maps calculated from the primary motor cortex (M1) and the supplementary motor area (SMA) to the entire brain, (b) a swallowing-related functional connectivity network calculated among 20 specific regions of interest (ROIs), and (c) structural connectivity described by the mean fractional anisotropy of fibers bound through the SMA and M1. Results. Stroke patients with dysphagia exhibited dysfunctional connectivity mainly in the sensorimotor-insula-putamen circuits based on seed-based analysis of the left and right M1 and SMA and decreased connectivity in the bilateral swallowing-related ROIs functional connectivity network. Additionally, white matter tract connectivity analysis revealed that the mean fractional anisotropy of the white matter tract was significantly reduced, especially in the left-to-right SMA and in the corticospinal tract. Conclusions. Our results indicate that dysphagia secondary to stroke is associated with disruptive functional and structural integrity in the large-scale brain networks involved in motor control, thus providing new insights into the neural remodeling associated with this disorder.

Vitamin D receptor gene polymorphisms and risk of osteoarthritis: A meta-analysis

The vitamin D receptor (VDR) gene polymorphisms have been reported to be involved in the development of many musculoskeletal disorders, including osteoarthritis (OA). However, results were inconsistent and there is no definite conclusion regarding the association between any VDR polymorphism and the risk of OA. In this study, we conducted a meta-analysis to determine whether BsmI, TaqI, and ApaI polymorphisms in the VDR gene are associated with OA susceptibility. Literature research was performed using PubMed and EMBASE databases. Studies illustrating the association between the three VDR polymorphisms and OA were included, and their qualities were assessed using Newcastle–Ottawa scale. Eight eligible studies, recruiting 1626 cases and 2024 controls were identified. Their methodological qualities were generally good, with scores ranging from 6 to 8 points. However, throughout all summary analyses, which were performed for multiple categories and on four contrasts (allele contrast, contrast of homozygotes, recessive and dominant models), none of the VDR BsmI, TaqI, and ApaI gene polymorphisms were found to be significantly associated with the risk of OA. On the other hand, there was no significant publication bias. Results from this meta-analysis suggested that the VDR BsmI, TaqI, and ApaI gene polymorphisms might not be important predictors of OA. More studies further investigating these associations, especially taking into account of gene–gene, gene–environment interactions, and other confounding factors are warranted.

Changes in beta(1) integrin in renal tubular epithelial cells after intrauterine asphyxia of rabbit pups.

Abstract Objective: We investigated the role of β1 integrin in acute renal tubular injury caused by intrauterine asphyxia of neonatal rabbits by exploring the distribution and expression changes in β1 integrin and its mRNA in renal tubular epithelial cells. Methods: A catheter was used to temporarily block the abdominal aortas of New Zealand pregnant rabbits in order to set up the intrauterine asphyxia animal model. The rabbit pups were randomly divided into control, asphyxia, and calpain inhibitor intervention groups and their renal tubular tissues were examined at 2 h after asphyxia. Immunofluorescence and in situ hybridization were used to examine the expression of β1 integrin and its mRNA, respectively. Western blot analysis was used to show the proteolysis of β1 integrin. Calpain inhibitor I was used to show the protective effect of keeping β1 integrin from being hydrolyzed after asphyxia. Results: (1) Normally, β1 integrin was located exclusively at the basal surface of renal tubular epithelial cells. After asphyxia a large amount of β1 integrin shifted from the basal surface to the cytoplasma and the lateral and apical surfaces and its expression decreased significantly, with simultaneous damage to renal tubular integrity and structure, many exfoliated cells and cell fragments obstructed the tubular lumen. (2) The mRNA of β1 integrin was mainly expressed in the cytoplasma. After asphyxia its expression increased significantly. (3) Proteolysis of β1 integrin was evident after asphyxia, but was significantly reduced in the calpain inhibitor intervention group. Calpain inhibitor I prevented the decrease and dislocation of β1 integrin and protected renal tubular integrity and structure. Conclusion: Intrauterine asphyxia caused proteolysis of β1 integrin, with reduced expression and depolarized distribution, leading to tubular lumen obstruction and renal tubule destruction. Damage to β1 integrin and the renal tubule was related to the activation of calpain, and calpain inhibitor curtailed these effects.

Nonhuman primate models of focal cerebral ischemia

Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.