Abstract 22: Acute neuroradiograhic predictors of rehabiliation costs.

Objective: To examine acute neuroradiographic and injury predictors of rehabilitation costs in a large traumatic brain injury (TBI) population. Design: Multiple regression-based within-group design. Setting: Urban university-based neurotrauma center and rehabilitation hospital. Participants: 293 persons presenting to a level 1 trauma center with a primary diagnosis of moderate or severe TBI who required inpatient rehabilitation. Interventions: Not applicable. Main Outcome Measures: Multiple variables derived from demographics, injury characteristics, ratings of various computed tomography (CT) scan indicators of neuropathology, and charges for rehabilitation services. Results: Several key variables that are predictive of rehabilitation outcome (including age, cause of injury, admission Glasgow Coma Scale [GCS] score) and several CT-derived neuroradiographic variables were entered into a multiple regression model to predict the total dollar charges for all rehabilitation services. The variables that emerged as statistically significant were (in order of amount of variance accounted for in the predictive model: presence of subarachnoid hemorrhage (SAH) (F change=17.89; P<.0001), admission GCS total score (F change=13.59; P<.0001), presence of frontal lobe contusion (F change=8.26; P<.004), presence of left parietal contusion (F change=7.15; P<.008), presence of right epidural hemorrhage (F change=4.51; P=.035), and presence of a punctate hemorrhage (F change=4.89; P=.028). Conclusions: Charges for TBI rehabilitation are an important consideration. The ability to predict the relative cost of rehabilitation can facilitate planning and may be helpful in more accurately determining the allocation of resources. The presence of SAH was an important predictor of charges and may reflect a risk factor for secondary brain injury not captured by other measures.     

Incidental effects of emotional valence in single word processing: an fMRI study

The present study aimed at identifying the neural responses associated with the incidental processing of the emotional valence of single words using event-related functional magnetic resonance imaging (fMRI). Twenty right-handed participants performed a visual lexical decision task, discriminating between nouns and orthographically and phonologically legal nonwords. Positive, neutral and negative word categories were matched for frequency, number and frequency of orthographic neighbors, number of letters and imageability. Response times and accuracy data differed significantly between positive and neutral, and positive and negative words respectively, thus, replicating the findings of a pilot study. Words showed distributed, mainly left hemisphere activations, indicating involvement of a neural network responsible for semantic word knowledge. The neuroimaging data further revealed areas in left orbitofrontal gyrus and bilateral inferior frontal gyrus with greater activation to emotional than to neutral words. These brain regions are known to be involved in processing semantic and emotional information. Furthermore, distinct activations associated with positive words were observed in bilateral middle temporal and superior frontal gyrus, known to support semantic retrieval, and a distributed network, namely anterior and posterior cingulate gyrus, lingual gyrus and hippocampus when comparing positive and negative words. The latter areas were previously associated with explicit and not incidental processing of the emotional meaning of words and emotional memory retrieval. Thus, the results are discussed in relation to models of processing semantic and episodic emotional information.     

How Imaging Glutamate, γ‐Aminobutyric Acid,and Dopamine Can Inform the Clinical Treatment of Alcohol Dependence and Withdrawal

Neuroimaging studies have dramatically advanced our understanding of the neurochemical basis of alcohol dependence, a major public health issue. In this paper, we review the research generated from neurochemical specific imaging modalities including magnetic resonance spectroscopy, positron emission tomography, and single‐photon emission computed tomography in studies of alcohol dependence and withdrawal. We focus on studies interrogating γ‐aminobutyric acid (GABA), glutamate, and dopamine, as these are prominent neurotransmitter systems implicated in alcohol dependence. Highlighted findings include diminished dopaminergic functioning and modulation of the GABA system by tobacco smoking during alcohol withdrawal. Then, we consider how these findings impact the clinical treatment of alcohol dependence and discuss directions for future experiments to address existing gaps in the literature, for example, sex differences and smoking comorbidity. These and other considerations provide opportunities to build upon the current neurochemistry imaging literature of alcohol dependence and withdrawal, which may usher in improved therapeutic and relapse prevention strategies.     

Prediction of pediatric unipolar depression using multiple neuromorphometric measurements: A pattern classification approach

BackgroundDiagnosis of pediatric neuropsychiatric disorders such as unipolar depression is largely based on clinical judgment – without objective biomarkers to guide diagnostic process and subsequent therapeutic interventions. Neuroimaging studies have previously reported average group-level neuroanatomical differences between patients with pediatric unipolar depression and healthy controls. In the present study, we investigated the utility of multiple neuromorphometric indices in distinguishing pediatric unipolar depression patients from healthy controls at an individual subject level.MethodsWe acquired structural T₁-weighted scans from 25 pediatric unipolar depression patients and 26 demographically matched healthy controls. Multiple neuromorphometric indices such as cortical thickness, volume, and cortical folding patterns were obtained. A support vector machine pattern classification model was ‘trained’ to distinguish individual subjects with pediatric unipolar depression from healthy controls based on multiple neuromorphometric indices and model predictive validity (sensitivity and specificity) calculated.ResultsThe model correctly identified 40 out of 51 subjects translating to 78.4% accuracy, 76.0% sensitivity and 80.8% specificity, chi-square p-value = 0.000049. Volumetric and cortical folding abnormalities in the right thalamus and right temporal pole respectively were most central in distinguishing individual patients with pediatric unipolar depression from healthy controls.ConclusionsThese findings provide evidence that a support vector machine pattern classification model using multiple neuromorphometric indices may qualify as diagnostic marker for pediatric unipolar depression. In addition, our results identified the most relevant neuromorphometric features in distinguishing PUD patients from healthy controls.     

Structural covariance in schizophrenia and first-episode psychosis: An approach based on graph analysis

Schizophrenia is a neurodevelopmental disorder that produces abnormalities across different brain regions. Measuring structural covariance with MRI is a well-established approach to investigate common changes in distinct systems. We investigated structural covariance in schizophrenia in a large Brazilian sample of individuals with chronic schizophrenia (n = 143), First Episode Psychosis (n = 32), and matched healthy controls (n = 82) using a combination of graph analysis and computational neuroanatomy.Firstly, we proposed the connectivity-closeness and integrity-closeness centrality measures and them compared healthy controls with chronic schizophrenia regarding these metrics. We then conducted a second analysis on the mapped regions comparing the pairwise difference between the three groups.Our results show that compared with controls, both patient groups (in pairwise comparisons) had a reduced integrity-closeness in pars orbitalis and insula, suggesting that the relationship between these areas and other brain regions is increased in schizophrenia. No differences were found between the First Episode Psychosis and Schizophrenia groups. Since in schizophrenia the brain is affected as a whole, this may mirror that these regions may be related to the generalized structural alteration seen in schizophrenia.     

Neuroimaging of Parkinson's disease: Expanding views

Advances in molecular and structural and functional neuroimaging are rapidly expanding the complexity of neurobiological understanding of Parkinson's disease (PD). This review article begins with an introduction to PD neurobiology as a foundation for interpreting neuroimaging findings that may further lead to more integrated and comprehensive understanding of PD. Diverse areas of PD neuroimaging are then reviewed and summarized, including positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy and imaging, transcranial sonography, magnetoencephalography, and multimodal imaging, with focus on human studies published over the last five years. These included studies on differential diagnosis, co-morbidity, genetic and prodromal PD, and treatments from l-DOPA to brain stimulation approaches, transplantation and gene therapies. Overall, neuroimaging has shown that PD is a neurodegenerative disorder involving many neurotransmitters, brain regions, structural and functional connections, and neurocognitive systems. A broad neurobiological understanding of PD will be essential for translational efforts to develop better treatments and preventive strategies. Many questions remain and we conclude with some suggestions for future directions of neuroimaging of PD.     

颈总动脉血流机械动力学与脑小血管病负荷的相关性研究

目的 探讨急性腔隙性脑梗死患者脑小血管病(cSVD)负荷与颈总动脉机械动力学指标环壁张力(WT)的相关性. 方法 前瞻性连续入组芜湖市第一人民医院神经内科自2010年9月至2012年12月收治的首发急性腔隙性脑梗死患者227例.对所有患者行常规MRI序列和磁敏感加权成像扫描,依据患者MRI上无症状腔隙性脑梗死、脑白质病变、脑微出血以及扩大的血管周围间隙的出现和程度评测患者cSVD负荷.同时超声测量患者颈动脉内径并计算WT.使用Logistic回归分析患者颈动脉WT与cSVD负荷的相关性. 结果 6例患者cVSD负荷评分0分,37例患者cVSD负荷评分1分,103例患者cVSD负荷评分2分,61例患者cVSD负荷评分3分,20例患者cVSD负荷评分4分.将患者按照上述cSVD负荷评分成5组(0～4分组),每组的收缩期WT依次为:(5.79±0.24)×104 dyne/cm2、(5.70±0.49)×104 dyne/cm2、(5.89±0.71)×104 dyne/cm2、(7.12±1.19)×104 dyne/cm2、(6.63±0.76)× 104 dyne/cm2、舒张期WT依次为:(3.37±0.31)×104 dyne/cm2、(3.29±0.26)×104 dyne/cm2、(3.50±0.43)×104 dyne/cm2、(3.99±0.49)×104 dyne/cm2、(4.30±0.85)× 104 dyne/cm2.单因素分析结果显示,年龄、高血压病史、糖尿病病史、颈总动脉收缩期和舒张期末内径、收缩期WT以及舒张期WT在5组患者间分布差异有统计学意义(P＜0.05).回归分析结果显示,收缩期WT[优势比(OR):1.555,95％可信区间(CI):1.203～2.479,P=0.038]及舒张期WT (OR:5.287,95％ CI:2.713～10.302,P=0.001)与cVSD负荷有显著关联. 结论 急性腔隙性脑梗死患者WT是影响cSVD负荷的独立危险因素.     

Permanent endovascular balloon occlusion of the vertebral artery as an adjunct to the surgical resection of selected cervical spine tumors: A single center experience

Background and purpose

Complete surgical resection of cervical spine tumors is often challenging when there is tumor encasement of major neck vessels. Pre-operative endovascular sacrifice of the major vessels can facilitate safe tumor resection. The use of transarterial detachable coils has been described in this setting, but it can be time-consuming and costly to occlude a patent parent vessel using this method. Our aim was to evaluate the safety and effectiveness of our endovascular detachable balloon occlusion technique, performed without prior balloon test occlusion in the pre-operative management of these tumors.

Methods

We retrospectively reviewed 18 consecutive patients undergoing pre-operative unilateral permanent endovascular balloon occlusion of tumor-encased vertebral arteries in our institution. Procedure-related ischemic or thromboembolic complication was defined as focal neurologic deficit attributable to the endovascular occlusion which occurs before subsequent surgical resection.

Results

Successful pre-operative endovascular vertebral artery sacrifice using detachable balloons was achieved in 100% (n = 18) of cases without prior balloon test occlusion. Procedural complication rate was 5.6% as one patient developed transient focal neurology secondary to a delayed cerebellar infarct at home on day 11 and subsequently made a full recovery. There were no cases of distal balloon migration. Complete macroscopic resection of tumor as reported by the operating surgeon was achieved in 89% of cases.

Conclusion

Pre-operative endovascular sacrifice of the vertebral artery using detachable balloons and without prior balloon test occlusion is a safe procedure with low complication rates and good surgeon reported rates of total resection.     

卒中样表现的脑转移瘤19例临床影像学特点及机制探讨

目的：探讨卒中样表现的脑转移瘤的临床影像学特点及发生机制。方法回顾性分析19例卒中样表现的脑转移瘤患者的临床与影像学资料。结果本组19例脑转移瘤中肺癌16例,肝癌2例,胰腺癌1例,在原发灶发现之前呈卒中样表现,有突发局灶性神经症状体征,影像学具有脑转移瘤的特点。结论部分脑转移瘤原发灶隐蔽,有卒中样表现;除肿瘤影响到脑功能外,可能与继发脑血管损害有关,确诊需依靠全面的影像学检查以及病理学检查。