49 research outputs found

    A Usage-Based Model of Early Grammatical Development

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    The representations and processes yield-ing the limited length and telegraphic style of language production early on in acqui-sition have received little attention in ac-quisitional modeling. In this paper, we present a model, starting with minimal lin-guistic representations, that incrementally builds up an inventory of increasingly long and abstract grammatical representations (form+meaning pairings), in line with the usage-based conception of language ac-quisition. We explore its performance on a comprehension and a generation task, showing that, over time, the model bet-ter understands the processed utterances, generates longer utterances, and better ex-presses the situation these utterances in-tend to refer to.

    Localisation Of The Subthalamic Nucleus In Parkinson’s Disease with Neural Beta and Gamma Activity of Local Field Potentials

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    Introduction: To refine the MRI-based target during DBS surgery, microelectrode recordings (MER) are often performed to detect target-specific single unit activity. This requires additional recording time and increases the risk for haemorrhage. In the future it may therefore be relevant to be able to determine the implantable lead's position based on local field potential (LFP) recordings from the lead itself which reflect activity of a larger neural population. This study aims to evaluate the nature of oscillatory activity in the subthalamic nucleus (STN) by means of intraoperative LFP-recordings, its relationship with microelectrode recordings and its potential use to locate the STN and its sensorimotor sub-area in patients with Parkinson’s disease during deep brain stimulation (DBS) surgery.Methods: 25 patients with Parkinson’s disease are included in this study. MER and LFPs are recorded every 0.5 mm from multiple microelectrodes during DBS surgery in 48 STNs. A novel optimization approach to map the measurement points on an atlas STN based on the MER properties is used to enable a detailed spatial representation of these points. Power and coherence in different LFP frequencies at all points are assessed in reference to the point's location inside or outside the STN and its sensorimotor sub-area.Results: Coherence between LFPs and the envelope of spiking activity significantly increases when entering the STN. There is also a pronounced increase in the LFP power in the gamma band, which persists throughout the entire STN in 100% of the cases. In 70% of the cases LFPs have a significantly higher power in the high beta frequency band in the sensorimotor STN, defined by the mapping algorithm, compared to the non-sensorimotor STN.Conclusions: LFP gamma oscillations provide a useful tool for locating the STN intraoperatively and LFP beta oscillations can become useful to discriminate the sensorimotor area within the STN

    Effects of structured involvement of the primary care team versus standard care after a cancer diagnosis on patient satisfaction and healthcare use: the GRIP randomised controlled trial

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    Background: The growing number of cancer survivors and treatment possibilities call for more personalised and integrated cancer care. Primary care seems well positioned to support this. We aimed to assess the effects of structured follow-up of a primary care team after a cancer diagnosis. Methods: We performed a multicentre randomised controlled trial enrolling patients curatively treated for breast, lung, colorectal, gynaecologic cancer or melanoma. In addition to usual cancer care in the control group, patients randomized to intervention were offered a “Time Out consultation” (TOC) with the general practitioner (GP) after diagnosis, and subsequent follow-up during and after treatment by a home care oncology nurse (HON). Primary outcomes were patient satisfaction with care (questionnaire: EORTC-INPATSAT-32) and healthcare utilisation. Intention-to-treat linear mixed regression analyses were used for satisfaction with care and other continuous outcome variables. The difference in healthcare utilisation for categorical data was calculated with a Pearson Chi-Square or a Fisher exact test and count data (none versus any) with a log-binomial regression. Results: We included 154 patients (control n = 77, intervention n = 77) who were mostly female (75%), mainly diagnosed with breast cancer (51%), and had a mean age of 61 (SD ± 11.9) years. 81% of the intervention patients had a TOC and 68% had HON contact. Satisfaction with care was high (8 out of 10) in both study groups. At 3 months after treatment, GP satisfaction was significantly lower in the intervention group on 3 of 6 subscales, i.e., quality (− 14.2 (95%CI -27.0;-1.3)), availability (− 15,9 (− 29.1;-2.6)) and information provision (− 15.2 (− 29.1;-1.4)). Patients in the intervention group visited the GP practice and the emergency department more often ((RR 1.3 (1.0;1.7) and 1.70 (1.0;2.8)), respectively). Conclusions: In conclusion, the GRIP intervention, which was designed to involve the primary care team during and after cancer treatment, increased the number of primary healthcare contacts. However, it did not improve patient satisfaction with care and it increased emergency department visits. As the high uptake of the intervention suggests a need of patients, future research should focus on optimizing the design and implementation of the intervention. Trial registration: GRIP is retrospectively (21/06/2016) registered in the ‘Netherlands Trial Register’ (NTR5909)

    Effects of a time out consultation with the general practitioner on cancer treatment decision-making: a randomised controlled trial: Time out with the general practitioner and cancer treatment decision

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    Objective: Improving shared decision-making (SDM) enables more tailored cancer treatment decisions. We evaluated a Time Out consultation (TOC) with the general practitioner (GP), between cancer diagnosis and treatment decision, which aims at supporting SDM and improving continuity of primary care. This study aims to evaluate the effects of a TOC on perceived SDM, information provision and self-efficacy. Methods: This randomised controlled trial included newly diagnosed patients with curable cancer (breast, lung, colorectal, gynaecologic and melanoma) from four Dutch hospitals. Primary outcome is perceived SDM and secondary outcomes are information provision and self-efficacy. Results: One hundred fifty-four patients (control n = 77, intervention n = 77) – female: 75%, mean age: 61 (SD ± 11.9). In the intervention group, 80.5% (n = 62) had a TOC, of which 82.3% (n = 51) took place after treatment decision. Perceived SDM was lower in the intervention group (−8.9 [95% CI: 0.6–17.1]). Among those with a TOC before treatment decision (n = 11), perceived SDM was comparable to the control group (66.5 ± 27.2 vs. 67.9 ± 26.1). Conclusion: Even though patients are motivated to have a TOC, implementing a TOC between diagnosis and treatment decision is challenging. Effects of a timely TOC could not be established. Non-timely TOC decreased perceived SDM. Planning of the TOC should be optimised, and future research should establish if adequately timed TOC results in improved SDM in cancer patients

    Temporal evolution of event-related desynchronization in acute stroke: A pilot study

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    Objective\ud Assessment of event-related desynchronization (ERD) may assist in predicting recovery from stroke and rehabilitation, for instance in BCI applications. Here, we explore the temporal evolution of ERD during stroke recovery.\ud \ud Methods\ud Ten stroke patients and eleven healthy controls were recruited to participate in a hand movement task while EEG was being recorded. Four measurements were conducted in eight patients within four months. We quantified changes of ERD using a modulation strength measure, Sm, which represents an area and amplitude of ERD.\ud \ud Results\ud 7/8 patients showed good recovery. Absence-or-reduction of ipsilesional modulation was initially found in stroke patients but not in the healthy controls. In the patient group, two evolutions were found in 6/8 patients: a significant increase in ipsilesional Sm; and a decreasing trend in contralesional Sm. In the only non-recovery patient, absence of ipsilesional modulation was observed, while his contralesional Sm increased with time after stroke.\ud \ud Conclusion\ud The two evolutions presumably reflect the reorganization of brain networks and functional recovery after acute stroke. The significant increase of ipsilesional Sm in patients with a good recovery suggests an important role of this hemisphere during recov

    Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead

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    Objective: Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study is to assess the performances of a new eight channel steering-DBS lead and compare this with a conventional cylindrical contact (CC) lead. Approach: The two leads were evaluated in a finite element electric field model combined with multicompartment neuron and axon models, representing the internal capsule (IC) fibers and subthalamic nucleus (STN) cells. We defined the optimal stimulation setting as the configuration that activated the highest percentage of STN cells, without activating any IC fibers. With this criterion, we compared monopolar stimulation using a single contact of the steering-DBS lead and CC lead, on three locations and four orientations of the lead. In addition, we performed a current steering test case by dividing the current over two contacts with the steering-DBS lead in its worst-case orientation. Main Results: In most cases, the steering-DBS lead is able to stimulate a significantly higher percentage of STN cells compared to the CC lead using single contact stimulation or using a two contact current steering protocol when there is approximately a 1 mm displacement of the CC lead. The results also show that correct placement and orientation of the lead in the target remains an important aspect in achieving the optimal stimulation outcome. Significance Currently, clinical trials are set up in Europe with a similar design as the steering-DBS lead. Our results illustrate the importance of the orientation of the new steering-DBS lead in avoiding side effects induced by stimulation of IC fibers. Therefore, in clinical trials sufficient attention should be paid to implanting the steering DBS-lead in the most effective orientation
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