Imaging the Centromedian Thalamic Nucleus Using Quantitative Susceptibility Mapping.

The centromedian (CM) nucleus is an intralaminar thalamic nucleus that is considered as a potentially effective target of deep brain stimulation (DBS) and ablative surgeries for the treatment of multiple neurological and psychiatric disorders. However, the structure of CM is invisible on the standard T1- and T2-weighted (T1w and T2w) magnetic resonance images, which hamper it as a direct DBS target for clinical applications. The purpose of the current study is to demonstrate the use of quantitative susceptibility mapping (QSM) technique to image the CM within the thalamic region. Twelve patients with Parkinson's disease, dystonia, or schizophrenia were included in this study. A 3D multi-echo gradient recalled echo (GRE) sequence was acquired together with T1w and T2w images on a 3-T MR scanner. The QSM image was reconstructed from the GRE phase data. Direct visual inspection of the CM was made on T1w, T2w, and QSM images. Furthermore, the contrast-to-noise ratios (CNRs) of the CM to the adjacent posterior part of thalamus on T1w, T2w, and QSM images were compared using the one-way analysis of variance (ANOVA) test. QSM dramatically improved the visualization of the CM nucleus. Clear delineation of CM compared to the surroundings was observed on QSM but not on T1w and T2w images. Statistical analysis showed that the CNR on QSM was significantly higher than those on T1w and T2w images. Taken together, our results indicate that QSM is a promising technique for improving the visualization of CM as a direct targeting for DBS surgery

Over 10 dB Net Coding Gain Based on 20% Overhead Hard Decision Forward Error Correction in 100G Optical Communication Systems

\u3cp\u3eWe propose a product code with shortened BCH component codes for 100G optical communication systems. Simulation result shows that 10 dB net coding gain is promising at post-FEC BER of 1E-15.\u3c/p\u3

Deep Brain Stimulation-Induced Transient Effects in the Habenula

The habenula, located in the epithalamus, has been implicated in various psychiatric disorders including mood disorders and schizophrenia. This study explored the transient effects of deep brain stimulation in the habenula. Each of the four patients (two with bipolar disorder and two with schizophrenia) was tested with eight deep brain stimulation contacts. Patients were examined via transient electrical stimulation 1 month after deep brain stimulation surgery. The pulse width was 60 μs and the voltage ranged from 0 V to a maximum of 10 V, increasing in increments of 1 V. Each patient received stimulation at two frequencies, 60 and 135 Hz. A total of 221 out of 385 active trials elicited stimulation-induced effects. The three most common transient effects were numbness, heart rate changes, and pain. The incidence of numbness, heart rate changes, pain, and involuntary movements increased with the increase in stimulation voltage. Through contralateral stimulation, numbness was triggered in all parts of the body except the scalp. The obtained stimulus-response maps suggested a possible somatosensory organization of the habenula

Habenular Stimulation for Neurosurgery Resistant Obsessive-Compulsive Disorder: A Case Report.

BACKGROUND: Some patients suffer from persistent and severely disabling Obsessive-Compulsive Disorder (OCD) symptoms that cannot be alleviated by conventional treatments or neuroablative interventions targeting cortico-striatal loop circuits. Currently, it is unclear how to manage the clinical symptoms of these unique patients. We reasoned that deep brain stimulation (DBS) of the habenula (HB) could be a valuable subsequent treatment option for these otherwise medically intractable cases of severe OCD. The HB is an epithalamic structure critically involved in the encoding and responding to aversive stimulus events, cognitive and brain processes known to be impaired in many patients with OCD. Similarly, HB DBS can alleviate depression and anxiety, which often co-occur with OCD. Here, we explore the clinical benefits and risks of HB DBS treatment in a patient with severe and refractory OCD. CASE PRESENTATION: A 30-year-old male patient presented with persistent and severely disabling OCD symptoms that were refractory to previous psychological and pharmacological treatments as well as to neuroablative surgical interventions involving both capsulotomy and cingulotomy. After HB DBS, however, the severity of the patient's OCD symptoms was markedly reduced at 1-month follow-up, which was sustained until the final (at 12-month) follow-up. The patient also reported enduring improvements in depression, anxiety, and health-related quality of life after several months of HB DBS treatment. CONCLUSIONS: This case report provides the first clinical evidence suggesting that HB DBS could serve as a safe and effective alternative neurosurgical intervention for severe and refractory OCD. The present findings are promising and warrant further research into the role of the HB in pathophysiology and treatment of OCD

Non-iterative, fast SE(3) path smoothing

In this paper, we present a fast, non-iterative approach to smooth a noisy input on the Special Euclidean Group, SE(3) manifold. The translational part can be smoothed by a simple Gaussian convolution.We then proposed a novel approach to rotation smoothing. Unlike existing rotation smoothing methods using either iterative optimization methods or stochastic filtering methods, our method allows direct computation of the smoothing result and allows parallelization of the computation. Furthermore, we have done a comparative study on Jia and Evans’s method published in 2014 [1], and shown that our method can better smooth an input rotation sequence, with shorter computational time. The smoothed camera path is then used for video stabilisation, which shows fluid and smooth camera motion.Australian ARC Centre of Excellence for Robotic Vision (CE140100016

Abnormal Voxel-Wise Degree Centrality in Patients With Late-Life Depression: A Resting-State Functional Magnetic Resonance Imaging Study.

Objectives:Late-life depression (LLD) has negative impacts on somatic, emotional and cognitive domains of the lives of patients. Elucidating the abnormality in the brain networks of LLD patients could help to strengthen the understanding of LLD pathophysiology, however, the studies exploring the spontaneous brain activity in LLD during the resting state remain limited. This study aimed at identifying the voxel-level whole-brain functional connectivity changes in LLD patients. Methods:Fifty patients with late-life depression (LLD) and 33 healthy controls were recruited. All participants underwent a resting-state functional magnetic resonance imaging scan to assess the voxel-wise degree centrality (DC) changes in the patients. Furthermore, DC was compared between two patient subgroups, the late-onset depression (LOD) and the early-onset depression (EOD). Results:Compared with the healthy controls, LLD patients showed increased DC in the inferior parietal lobule, parahippocampal gyrus, brainstem and cerebellum (p < 0.05, AlphaSim-corrected). LLD patients also showed decreased DC in the somatosensory and motor cortices and cerebellum (p < 0.05, AlphaSim-corrected). Compared with EOD patients, LOD patients showed increased centrality in the superior and middle temporal gyrus and decreased centrality in the occipital region (p < 0.05, AlphaSim-corrected). No significant correlation was found between the DC value and the symptom severity or disease duration in the patients after the correction for multiple comparisons. Conclusions:These findings indicate that the intrinsic abnormality of network centrality exists in a wide range of brain areas in LLD patients. LOD patients differ with EOD patients in cortical network centrality. Our study might help to strengthen the understanding of the pathophysiology of LLD and the potential neural substrates underlie related emotional and cognitive impairments observed in the patients

Impulsivity and craving in subjects with opioid use disorder on methadone maintenance treatment.

BACKGROUND: Methadone maintenance treatment (MMT) is effective in decreasing opioid use or facilitating abstinence. Previous studies using small opioid use disorder samples suggest that cognitive impairments including impulsivity and executive functions may partially improve on MMT, but a range of deficits may persist. However, systematic assessments with larger samples are needed to confirm the profile of cognitive functions on MMT. METHODS: We assessed four types of impulsivity (delay discounting, reflection impulsivity, risk taking and motoric impulsivity), executive functioning (spatial working memory, paired associative learning and strategic planning) and drug cue-induced craving in a relatively large population (115 MMT patients, 115 healthy controls). The relationships between impulsivity, drug cue-induced craving and addiction-related variables were also assessed. RESULTS: Delay discounting, as well as drug cue-induced craving was increased in patients, while motoric impulsivity was lower than in controls. Paired associative learning was additionally impaired, which was explained by increased depression and anxiety levels in patients. Within the MMT group, the delay discounting and drug-cue induced craving scores were positively correlated with self-reported urgency, but unrelated to methadone dosage, duration on methadone, withdrawal symptoms, or presence of nicotine dependence. CONCLUSIONS: Our findings highlight increased delay discounting and cue-induced craving in MMT patients suggesting a potential role for trait effects in delay discounting. Although previous smaller studies have shown impaired executive function, in our large sample size on chronic MMT we only observed impaired associative learning related to depressive and anxiety symptoms highlighting a role for managing comorbid symptoms to further optimize cognitive function