Freezing of gait detection in Parkinson's disease via multimodal analysis of EEG and accelerometer signals.

Parkinson's disease (PD) patients with freezing of gait (FOG) can suddenly lose their forward moving ability leading to unexpected falls. To overcome FOG and avoid the falls, a real-time accurate FOG detection or prediction system is desirable to trigger on-demand cues. In this study, we designed and implemented an in-place movement experiment for PD patients to provoke FOG and meanwhile acquired multimodal physiological signals, such as electroencephalography (EEG) and accelerometer signals. A multimodal model using brain activity from EEG and motion data from accelerometers was developed to improve FOG detection performance. In the detection of over 700 FOG episodes observed in the experiments, the multimodal model achieved 0.211 measured by Matthews Correlation Coefficient (MCC) compared with the single-modal models (0.127 or 0.139).Clinical Relevance- This is the first study to use multimodal: EEG and accelerometer signal analysis in FOG detection, and an improvement was achieved.

Preparing to Stop Action Increases Beta Band Power in Contralateral Sensorimotor Cortex.

How do we prepare to stop ourselves in the future? Here, we used scalp EEG to test the hypothesis that people prepare to stop by putting parts of their motor system (specifically, here, sensorimotor cortex) into a suppressed state ahead of time. On each trial, participants were cued to prepare to stop one hand and then initiated a bimanual movement. On a minority of trials, participants were instructed to stop the cued hand while continuing quickly with the other. We used a guided multivariate source separation method to examine oscillatory power changes in presumed sensorimotor cortical areas. We observed that, when people prepare to stop a hand, there were above-baseline beta band power increases (12-24 Hz) in contralateral cortex up to a second earlier. This increase in beta band power in the proactive period was functionally relevant because it predicted, trial by trial, the degree of selectivity with which participants subsequently stopped a response but did not relate to movement per se. Thus, preparing to stop particular response channels corresponds to increased beta power from contralateral (sensorimotor) cortex, and this relates specifically to subsequent stopping. These results provide a high temporal resolution and frequency-specific electrophysiological signature of the preparing-to-stop state that is pertinent to future studies of mitigating provocation, including in clinical disorders. The results also highlight the utility of guided multivariate source separation for revealing the cortical dynamics underlying both movement and response suppression.

Estimation of the radiation dose for pediatric CBCT indications: a prospective study on ProMax3D.

BACKGROUND: An increasing number of CBCT units and a wide variability of radiation doses have been reported in dentistry lately. AIM: To estimate the effective, cumulative, and organ absorbed doses in children exposed to CBCT over 2 years. DESIGN: A prospective study was conducted in children who underwent CBCT diagnostic imaging with the ProMax3D machine. Organ and effective doses were calculated by Monte Carlo simulation using 5- and 8-year-old pediatric voxel phantoms. Extrapolation procedures were applied to estimate doses for other ages and CBCT protocols used in clinical conditions. RESULTS: The median effective dose was 137.9 µSv, and the median cumulative dose was 231.4 µSv. Statistically significant differences in the effective doses and cumulative doses were found for various indications of CBCT in children (P < 0.001). The median absorbed organ dose for brain and thyroid was significantly higher for the clinical condition that required large FOVs (2.5 mGy and 1.05 mGy, respectively) compared to medium (0.19 and 0.51 mGy) and small FOVs (0.07 and 0.24 mGy; P < 0.05). The radiation dose of salivary glands did not vary significantly with FOV. CONCLUSION: The results revealed the variation of CBCT doses and the influence of FOV size in pediatric exposure.

Guideline for obtaining valid consent for gastrointestinal endoscopy procedures.

Much has changed since the last guideline of 2008, both in endoscopy and in the practice of obtaining informed consent, and it is vital that all endoscopists who are responsible for performing invasive and increasingly risky procedures are aware of the requirements for obtaining valid consent. This guideline is restricted to GI endoscopy but we cover elective and acute or emergency procedures. Few clinical trials have been carried out in relation to informed consent but most areas are informed by guidance from the General Medical Counsel (GMC) and/or are enshrined in legislation. Following an iterative voting process a series of recommendations have been drawn up that cover the majority of situations that will be encountered by endoscopists. This is not exhaustive and where doubt exists we have described where legal advice is likely to be required. This document relates to the law and endoscopy practice in the UK-where there is variation between the four devolved countries this is pointed out and endoscopists must be aware of the law where they practice. The recommendations are divided into consent for patients with and without capacity and we provide sections on provision of information and the consent process for patients in a variety of situations. This guideline is intended for use by all practitioners who request or perform GI endoscopy, or are involved in the pathway of such patients. If followed, we hope this document will enhance the experience of patients attending for endoscopy in UK units.

An efficient strategy based on an individualized selection of registration methods. Application to the coregistration of MR and SPECT images in neuro-oncology.

An efficient registration strategy is described that aims to help solve delicate medical imaging registration problems. It consists of running several registration methods for each dataset and selecting the best one for each specific dataset, according to an evaluation criterion. Finally, the quality of the registration results, obtained with the best method, is visually scored by an expert as excellent, correct or poor. The strategy was applied to coregister Technetium-99m Sestamibi SPECT and MRI data in the framework of a follow-up protocol in patients with high grade gliomas receiving antiangiogenic therapy. To adapt the strategy to this clinical context, a robust semi-automatic evaluation criterion based on the physiological uptake of the Sestamibi tracer was defined. A panel of eighteen multimodal registration algorithms issued from BrainVisa, SPM or AIR software environments was systematically applied to the clinical database composed of sixty-two datasets. According to the expert visual validation, this new strategy provides 85% excellent registrations, 12% correct ones and only 3% poor ones. These results compare favorably to the ones obtained by the globally most efficient registration method over the whole database, for which only 61% of excellent registration results have been reported. Thus the registration strategy in its current implementation proves to be suitable for clinical application.

A framework using multimodal imaging for longitudinal monitoring of patients in neuro-oncology. Application to a SPECT/MRI study.

This paper proposes a framework to assess the potential value of 99mTc Sestamibi SPECT in addition to Gadolinium-enhanced MRI for the monitoring of patients with high grade gliomas under antiangiogenic treatment. It includes: 1) multimodal and monomodal high precision registration steps achieved thanks to a registration strategy which selects the best method among several ones for each dataset, 2) tumor segmentation steps dedicated to each modality and 3) a tumor comparison step which consists in the computation of some global (volume, intensity) and local (matching and mismatching) quantitative indices to analyze the tumor using different imaging modalities and at different times during the treatment. Each step is checked via 2D and 3D visualization. This framework was applied to a database of fifteen patients. For all patients, except one, the tumor volumes decrease globally and locally. Furthermore, a high correlation (r=0.77) was observed between MRI and Sestamibi tumor volumes. Finally, local indices show some possible mismatches between MRI Gadolinium uptake and Sestamibi uptake, which need to be further investigated.

A new strategy to improve coregistration of SPECT and MR images in patients with high grade glioma.

This paper proposes a new strategy to optimize the coregistration of Technetium-99m Sestamibi SPECT and MRI data in case of patients with high grade glioma. It consists in a personalized approach which selects, for each data set, the best registration method among several ones. To achieve this selection, a quantitative dedicated evaluation criterion based on the average intensities within specific anatomical structures corresponding to physiological areas of uptake of Sestamibi was defined. The strategy was applied to sixty-two data sets using nine registration methods based on mutual information and chamfer distance registration approaches, with different settings. It was implemented within the Anatomist/Brainvisa environment, using its basic registration functions. The visual evaluation by experts indicated that this strategy provides 60% good quality registrations, and 26% intermediate quality ones. Compared to the single use of the best global registration method, the number of registrations of good quality was multiplied by 1.4 when using the data specific strategy.

Excessive Na+/H+ exchange in disruption of dendritic Na+ and Ca2+ homeostasis and mitochondrial dysfunction following in vitro ischemia.

Neuronal dendrites are vulnerable to injury under diverse pathological conditions. However, the underlying mechanisms for dendritic Na(+) overload and the selective dendritic injury remain poorly understood. Our current study demonstrates that activation of NHE-1 (Na(+)/H(+) exchanger isoform 1) in dendrites presents a major pathway for Na(+) overload. Neuronal dendrites exhibited higher pH(i) regulation rates than soma as a result of a larger surface area/volume ratio. Following a 2-h oxygen glucose deprivation and a 1-h reoxygenation, NHE-1 activity was increased by ∼70-200% in dendrites. This elevation depended on activation of p90 ribosomal S6 kinase. Moreover, stimulation of NHE-1 caused dendritic Na(+)(i) accumulation, swelling, and a concurrent loss of Ca(2+)(i) homeostasis. The Ca(2+)(i) overload in dendrites preceded the changes in soma. Inhibition of NHE-1 or the reverse mode of Na(+)/Ca(2+) exchange prevented these changes. Mitochondrial membrane potential in dendrites depolarized 40 min earlier than soma following oxygen glucose deprivation/reoxygenation. Blocking NHE-1 activity not only attenuated loss of dendritic mitochondrial membrane potential and mitochondrial Ca(2+) homeostasis but also preserved dendritic membrane integrity. Taken together, our study demonstrates that NHE-1-mediated Na(+) entry and subsequent Na(+)/Ca(2+) exchange activation contribute to the selective dendritic vulnerability to in vitro ischemia.

Personal touch: personal health records for consumers of healthcare.

Personal health records (PHRs) consist of medical records that the consumer collects from each of their healthcare providers, plus any health information that the consumer adds. Sharing information from the PHR with providers enables the consumer and provider to work together. Use of data in the PHR can help reduce or eliminate duplicate procedures or processes. This helps save time and healthcare dollars. It can help the consumer receive better, more coordinated healthcare. In addition, PHRs will eventually have the impact of empowering consumers as never before to make informed healthcare choices and have a positive impact on the overall cost of healthcare. This article is part of a series of unpublished essays titled A Community View on How Personal Health Records Can Improve Patient Care and Outcomes in Many Healthcare Settings, a collaborative project of Northern Illinois Physicians For Connectivity and the Coalition for Quality and Patient Safety of Chicagoland. For further information on how you can obtain copies of the complete work, contact the principle Dr. Stasia Kahn at Stash5@sbcglobal.net.