Using an adaptive autoregressive model for the early detection of action potential duration alternans

Cardiostim 2012, Nice, France

Challenges in the early detection of psychosis in children and adolescents

The early detection and treatment of persons at-risk for psychosis is currently regarded a promising strategy in fighting the devastating consequences of psychotic disorders. The two current at-risk approaches, i.e., the "ultra high risk" and the "basic symptom" criteria, were mainly developed on adult samples. Initial evidence suggests, however, that they cannot simply be applied to children and adolescents. For ultra high risk criteria, there is indication of some attenuated psychotic symptoms being potentially non-specific in adolescents and of brief limited intermittent symptoms being difficult to clinically classify in children when observable behavioral correlates are missing. For basic symptoms, too, only preliminary indication of their usefulness in children and adolescents exists. Since developmental peculiarities in the assessment of basic symptoms should be considered, a child and youth version of the Schizophrenia Proneness Instrument (SPI-CY) was developed. In conclusion, research on the clinical-prognostic validity of the at-risk criteria and their potential adoption to the special needs of children and adolescents is needed. If a Prodromal Risk Syndrome for Psychosis or Attenuated Psychotic Symptoms Syndrome will be included into DSM-V, it has to be highlighted that its suitability for children and adolescents is only insufficiently known.

Dynamic contrast-enhanced and diffusion-weighted MRI for early detection of tumoral changes in single-dose and fractionated radiotherapy: evaluation in a rat rhabdomyosarcoma model

We aimed to examine different intratumoral changes after single-dose and fractionated radiotherapy, using diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI in a rat rhabdomyosarcoma model. Four WAG/Rij rats with rhabdomyosarcomas in the flanks received single-dose radiotherapy of 8 Gy, and four others underwent fractionated radiotherapy (five times 3 Gy). In rats receiving single-dose radiotherapy, a significant perfusion decrease was found in the first 2 days post-treatment, with slow recuperation afterwards. No substantial diffusion changes could be seen; tumor growth delay was 12 days. The rats undergoing fractionated radiotherapy showed a similar perfusion decrease early after the treatment. However, a very strong increase in apparent diffusion coefficient occurred in the first 10 days; growth delay was 18 days. DW-MRI and DCE-MRI can be used to show early tumoral changes induced by radiotherapy. Single-dose and fractionated radiotherapy induce an immediate perfusion effect, while the latter induces more intratumoral necrosis.

Feasibility of Using EMG for Early Detection of the Facial Nerve During Robotic Direct Cochlear Access

HYPOTHESIS Facial nerve monitoring can be used synchronous with a high-precision robotic tool as a functional warning to prevent of a collision of the drill bit with the facial nerve during direct cochlear access (DCA). BACKGROUND Minimally invasive direct cochlear access (DCA) aims to eliminate the need for a mastoidectomy by drilling a small tunnel through the facial recess to the cochlea with the aid of stereotactic tool guidance. Because the procedure is performed in a blind manner, structures such as the facial nerve are at risk. Neuromonitoring is a commonly used tool to help surgeons identify the facial nerve (FN) during routine surgical procedures in the mastoid. Recently, neuromonitoring technology was integrated into a commercially available drill system enabling real-time monitoring of the FN. The objective of this study was to determine if this drilling system could be used to warn of an impending collision with the FN during robot-assisted DCA. MATERIALS AND METHODS The sheep was chosen as a suitable model for this study because of its similarity to the human ear anatomy. The same surgical workflow applicable to human patients was performed in the animal model. Bone screws, serving as reference fiducials, were placed in the skull near the ear canal. The sheep head was imaged using a computed tomographic scanner and segmentation of FN, mastoid, and other relevant structures as well as planning of drilling trajectories was carried out using a dedicated software tool. During the actual procedure, a surgical drill system was connected to a nerve monitor and guided by a custom built robot system. As the planned trajectories were drilled, stimulation and EMG response signals were recorded. A postoperative analysis was achieved after each surgery to determine the actual drilled positions. RESULTS Using the calibrated pose synchronized with the EMG signals, the precise relationship between distance to FN and EMG with 3 different stimulation intensities could be determined for 11 different tunnels drilled in 3 different subjects. CONCLUSION From the results, it was determined that the current implementation of the neuromonitoring system lacks sensitivity and repeatability necessary to be used as a warning device in robotic DCA. We hypothesize that this is primarily because of the stimulation pattern achieved using a noninsulated drill as a stimulating probe. Further work is necessary to determine whether specific changes to the design can improve the sensitivity and specificity.

A field trial of infrared thermography as a non-invasive diagnostic tool for early detection of digital dermatitis in dairy cows

Infrared thermography (IRT) was used to detect digital dermatitis (DD) prior to routine claw trimming. A total of 1192 IRT observations were collected from 149 cows on eight farms. All cows were housed in tie-stalls. The maximal surface temperatures of the coronary band (CB) region and skin (S) of the fore and rear feet (mean value of the maximal surface temperatures of both digits for each foot separately, CBmax and Smax) were assessed. Grouping was performed at the foot level (presence of DD, n=99; absence, n=304), or at the cow level (all four feet healthy, n=24) or where there was at least one DD lesion on the rear feet, n=37). For individual cows (n=61), IRT temperature difference was determined by subtracting the mean sum of CBmax and Smax of the rear feet from that of the fore feet. Feet with DD had higher CBmax and Smax (P<0.001) than healthy feet. Smax was significantly higher in feet with infectious DD lesions (M-stage: M2+M4; n=15) than in those with non-infectious M-lesions (M1+M3; n=84) (P=0.03), but this was not the case for CBmax (P=0.12). At the cow level, an optimal cut-off value for detecting DD of 0.99°C (IRT temperature difference between rear and front feet) yielded a sensitivity of 89.1% and a specificity of 66.6%. The results indicate that IRT may be a useful non-invasive diagnostic tool to screen for the presence of DD in dairy cows by measuring CBmax and Smax.

Can a novel computerized cognitive screening test provide additional information for early detection of Alzheimer's disease?

BACKGROUND: Virtual reality testing of everyday activities is a novel type of computerized assessment that measures cognitive, executive, and motor performance as a screening tool for early dementia. This study used a virtual reality day-out task (VR-DOT) environment to evaluate its predictive value in patients with mild cognitive impairment (MCI). METHODS: One hundred thirty-four patients with MCI were selected and compared with 75 healthy control subjects. Participants received an initial assessment that included VR-DOT, a neuropsychological evaluation, magnetic resonance imaging (MRI) scan, and event-related potentials (ERPs). After 12 months, participants were assessed again with MRI, ERP, VR-DOT, and neuropsychological tests. RESULTS: At the end of the study, we differentiated two subgroups of patients with MCI according to their clinical evolution from baseline to follow-up: 56 MCI progressors and 78 MCI nonprogressors. VR-DOT performance profiles correlated strongly with existing predictive biomarkers, especially the ERP and MRI biomarkers of cortical thickness. CONCLUSIONS: Compared with ERP, MRI, or neuropsychological tests alone, the VR-DOT could provide additional predictive information in a low-cost, computerized, and noninvasive way.

EPA guidance on the early detection of clinical high risk states of psychoses

The aim of this guidance paper of the European Psychiatric Association is to provide evidence-based recommendations on the early detection of a clinical high risk (CHR) for psychosis in patients with mental problems. To this aim, we conducted a meta-analysis of studies reporting on conversion rates to psychosis in non-overlapping samples meeting any at least any one of the main CHR criteria: ultra-high risk (UHR) and/or basic symptoms criteria. Further, effects of potential moderators (different UHR criteria definitions, single UHR criteria and age) on conversion rates were examined. Conversion rates in the identified 42 samples with altogether more than 4000 CHR patients who had mainly been identified by UHR criteria and/or the basic symptom criterion ‘cognitive disturbances’ (COGDIS) showed considerable heterogeneity. While UHR criteria and COGDIS were related to similar conversion rates until 2-year follow-up, conversion rates of COGDIS were significantly higher thereafter. Differences in onset and frequency requirements of symptomatic UHR criteria or in their different consideration of functional decline, substance use and co-morbidity did not seem to impact on conversion rates. The ‘genetic risk and functional decline’ UHR criterion was rarely met and only showed an insignificant pooled sample effect. However, age significantly affected UHR conversion rates with lower rates in children and adolescents. Although more research into potential sources of heterogeneity in conversion rates is needed to facilitate improvement of CHR criteria, six evidence-based recommendations for an early detection of psychosis were developed as a basis for the EPA guidance on early intervention in CHR states.

Early detection of psychosis: helpful or stigmatizing experience? A qualitative study

AIM Despite the large scientific debate concerning potential stigmatizing effects of identifying an individual as being in an at-risk mental state (ARMS) for psychosis, studies investigating this topic from the subjective perspective of patients are rare. This study assesses whether ARMS individuals experience stigmatization and to what extent being informed about the ARMS is experienced as helpful or harmful. METHODS Eleven ARMS individuals, currently participating in the follow-up assessments of the prospective Basel Früherkennung von Psychosen (FePsy; English: Early Detection of Psychosis) study, were interviewed in detail using a semistructured qualitative interview developed for this purpose. Data were analysed using Interpretative Phenomenological Analysis. RESULTS Most individuals experiencing first symptoms reported sensing that there was 'something wrong with them' and felt in need of help. They were relieved that a specific term was assigned to their symptoms. The support received from the early detection centre was generally experienced as helpful. Many patients reported stigmatization and discrimination that appeared to be the result of altered behaviour and social withdrawal due to the prepsychotic symptoms they experienced prior to contact with the early detection clinic. CONCLUSIONS The results suggest that early detection services help individuals cope with symptoms and potential stigmatization rather than enhancing or causing the latter. More emphasis should be put on the subjective experiences of those concerned when debating the advantages and disadvantages of early detection with regard to stigma. There was no evidence for increased perceived stigma and discrimination as a result of receiving information about the ARMS.

Experiences with a voluntary surveillance system for early detection of equine diseases in Switzerland

Clinical observations made by practitioners and reported using web- and mobile-based technologies may benefit disease surveillance by improving the timeliness of outbreak detection. Equinella is a voluntary electronic reporting and information system established for the early detection of infectious equine diseases in Switzerland. Sentinel veterinary practitioners have been able to report cases of non-notifiable diseases and clinical symptoms to an internet-based platform since November 2013. Telephone interviews were carried out during the first year to understand the motivating and constraining factors affecting voluntary reporting and the use of mobile devices in a sentinel network. We found that non-monetary incentives attract sentinel practitioners; however, insufficient understanding of the reporting system and of its relevance, as well as concerns over the electronic dissemination of health data were identified as potential challenges to sustainable reporting. Many practitioners are not yet aware of the advantages of mobile-based surveillance and may require some time to become accustomed to novel reporting methods. Finally, our study highlights the need for continued information feedback loops within voluntary sentinel networks.

A supervised cooperative learning system for early detection of language disorders

The Quality of Life of a person may depend on early attention to his neurodevel-opment disorders in childhood. Identification of language disorders under the age of six years old can speed up required diagnosis and/or treatment processes. This paper details the enhancement of a Clinical Decision Support System (CDSS) aimed to assist pediatricians and language therapists at early identification and re-ferral of language disorders. The system helps to fine tune the Knowledge Base of Language Delays (KBLD) that was already developed and validated in clinical routine with 146 children. Medical experts supported the construction of Gades CDSS by getting scientific consensus from literature and fifteen years of regis-tered use cases of children with language disorders. The current research focuses on an innovative cooperative model that allows the evolution of the KBLD of Gades through the supervised evaluation of the CDSS learnings with experts¿ feedback. The deployment of the resulting system is being assessed under a mul-tidisciplinary team of seven experts from the fields of speech therapist, neonatol-ogy, pediatrics, and neurology.

Sentiment classification for early detection of health alerts in the chemical textile domain

In the chemical textile domain experts have to analyse chemical components and substances that might be harmful for their usage in clothing and textiles. Part of this analysis is performed searching opinions and reports people have expressed concerning these products in the Social Web. However, this type of information on the Internet is not as frequent for this domain as for others, so its detection and classification is difficult and time-consuming. Consequently, problems associated to the use of chemical substances in textiles may not be detected early enough, and could lead to health problems, such as allergies or burns. In this paper, we propose a framework able to detect, retrieve, and classify subjective sentences related to the chemical textile domain, that could be integrated into a wider health surveillance system. We also describe the creation of several datasets with opinions from this domain, the experiments performed using machine learning techniques and different lexical resources such as WordNet, and the evaluation focusing on the sentiment classification, and complaint detection (i.e., negativity). Despite the challenges involved in this domain, our approach obtains promising results with an F-score of 65% for polarity classification and 82% for complaint detection.

A simplified PCR test for early detection of dwarf off-types in micropropagated Cavendish bananas (Musa spp. AAA)

The dwarf somaclonal variant is a major problem affecting micropropagation of the banana cultivar Williams (Musa spp. AAA; subgroup Cavendish). This problem arises from genetic changes that occur during the tissue culture process. Early identification of this problem is difficult and propagators must wait until plants are ex vitro in order to visualise the dwarfism phenotype. In this study, we have improved a SCAR-based molecular diagnostic technique, developed by Damasco et al. [Acta Hortic. 461 (1997) 157], for the early identification of dwarf off-types. We have included a positive internal control in a multiplex PCR and adapted the technique for use with small amounts of fresh in vitro leaf material as PCR template. The control product is a 500 bp fragment from 18S rRNA and is amplified in all tissues irrespective of phenotype. The use of small in vitro leaf material removing the need for genomic DNA extraction. (C) 2004 Elsevier B.V. All rights reserved.