Cervical idiopathic dystonia (CID) is the most common kind of primary dystonia, but its pathogenesis remains still unclear. As in other movement disorders, the major challenge is to recognize the ...organic from the psychogenic phenotype. Our objective was to evaluate the reliability of blink reflex test (BRT) in detecting powerful differences in patients with diagnosis of CID or (clinically presumed) psychogenic dystonia (PD). Twelve subjects were enrolled (6 CID, 6 PD), and BRT was assessed in term of R1 and R2 latencies and habituation phenomenon (trains of 10 stimulus, 1 Hz of frequency, 200 ms of duration). Electrodes were placed over the orbicular inferior muscle (recording electrode) and lateral canthus (reference). CID patients showed both an enhanced latency of polysynaptic R2 responses and a lack of habituation compared with subjects diagnosed as PD ( t -test: p < 0.001). Our results support the hypothesis of a dysfunction of brainstem reflex circuits on the basis of CID. As in Parkinson Disease, one could speculate that this phenomenon relies on changes in the inhibitory drive from basal ganglia output structures, via tecto-reticular projections, to the superior colliculus.
Augmenting Recurrent Neural Networks Resilience by Dropout Bacciu, Davide; Crecchi, Francesco
IEEE transaction on neural networks and learning systems,
2020-Jan., 2020-01-00, 2020-1-00, 20200101, Letnik:
31, Številka:
1
Journal Article
This brief discusses the simple idea that dropout regularization can be used to efficiently induce resiliency to missing inputs at prediction time in a generic neural network. We show how the ...approach can be effective on tasks where imputation strategies often fail, namely, involving recurrent neural networks and scenarios where whole sequences of input observations are missing. The experimental analysis provides an assessment of the accuracy-resiliency tradeoff in multiple recurrent models, including reservoir computing methods, and comprising real-world ambient intelligence and biomedical time series.
The past decade has seen the emergence of rehabilitation treatments using virtual reality. One of the advantages in using this technology is the potential to create positive motivation, by means of ...engaging environments and tasks shaped in the form of serious games. The aim of this study is to determine the efficacy of immersive Virtual Environments and weaRable hAptic devices (VERA) for rehabilitation of upper limb in children with Cerebral Palsy (CP) and Developmental Dyspraxia (DD).
A two period cross-over design was adopted for determining the differences between the proposed therapy and a conventional treatment. Eight children were randomized into two groups: one group received the VERA treatment in the first period and the manual therapy in the second period, and viceversa for the other group. Children were assessed at the beginning and the end of each period through both the Nine Hole Peg Test (9-HPT, primary outcome) and Kinesiological Measurements obtained during the performing of similar tasks in a real setting scenario (secondary outcomes).
All subjects, not depending from which group they come from, significantly improved in both the performance of the 9-HPT and in the parameters of the kinesiological measurements (movement error and smoothness). No statistically significant differences have been found between the two groups.
These findings suggest that immersive VE and wearable haptic devices is a viable alternative to conventional therapy for improving upper extremity function in children with neuromotor impairments. Trial registration ClinicalTrials, NCT03353623. Registered 27 November 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03353623.
The past decade has seen the emergence of rehabilitation treatments using virtual reality (VR) environments although translation into clinical practice has been limited so far. In this paper, an ...immersive VR rehabilitation training system endowed with wearable haptics is proposed for children with neuromotor impairments: it aims to enhance involvement and engagement of patients, to provide congruent multi-sensory afferent feedback during motor exercises and to benefit from the flexibility of VR in adapting exercises to the patient's need. An experimental rehabilitation session conducted with children with cerebral palsy (CP) and developmental dyspraxia (DD) has been performed to evaluate the usability of the system and proof of concept trial of the proposed approach. We compared CP/DD performance with both typically developing children and adult control group. Results show the system was compliant with different levels of motor skills and allowed patients to complete the experimental rehabilitation session, with performance varying according to the expected motor abilities of different groups. Moreover, a kinematic assessmentbased on the presented system has been designed. Obtained results reflected different motor abilities of patients and participants, suggesting suitability of the proposed kinematic assessment as a motor function outcome.
Diplegic cerebral palsy (CP) is often associated with musculoskeletal disorders that contribute to worsen walking function. The standard care in these cases is single-event multilevel surgery (SEMLS) ...followed by rehabilitation. Our aim was to investigate whether a rehabilitation program starting even before SEML could add a benefit with respect to standard postoperative programs considered by previous research.
From 2 months before to 13 months after SEMLS (except for the first month after surgery), the participant underwent a motor training focused on ROM exercises with tactile and kinaesthetic feedback. Walking performance, walking capacity, and quality-of-life were assessed before and after SEMLS at different follow-up times.
Walking capacity improved 3 months after SEMLS (i.e., earlier than in current literature) and walking performance improved 12 months after SEMLS (instead of simply returning to baseline as previously reported), with a positive impact on quality-of-life.
This case suggests that a rehabilitation program starting even before SEMLS could add benefits over walking function and quality-of-life of children with diplegic CP compared to postoperative programs only.
Deep neural networks are vulnerable to adversarial examples, i.e., carefully-crafted inputs that mislead classification at test time. Recent defenses have been shown to improve adversarial robustness ...by detecting anomalous deviations from legitimate training samples at different layer representations - a behavior normally exhibited by adversarial attacks. Despite technical differences, all aforementioned methods share a common backbone structure that we formalize and highlight in this contribution, as it can help in identifying promising research directions and drawbacks of existing methods. The first main contribution of this work is the review of these detection methods in the form of a unifying framework designed to accommodate both existing defenses and newer ones to come. In terms of drawbacks, the overmentioned defenses require comparing input samples against an oversized number of reference prototypes, possibly at different representation layers, dramatically worsening the test-time efficiency. Besides, such defenses are typically based on ensembling classifiers with heuristic methods, rather than optimizing the whole architecture in an end-to-end manner to better perform detection. As a second main contribution of this work, we introduce FADER, a novel technique for speeding up detection-based methods. FADER overcome the issues above by employing RBF networks as detectors: by fixing the number of required prototypes, the runtime complexity of adversarial examples detectors can be controlled. Our experiments outline up to 73× prototypes reduction compared to analyzed detectors for MNIST dataset, up to 50× for CIFAR10 dataset, and up to 82× on ImageNet10 dataset respectively, without sacrificing classification accuracy on both clean and adversarial data.
Pointing in cervical dystonia patients Tramonti Fantozzi, Maria Paola; Benedetti, Roberta; Crecchi, Alessandra ...
Frontiers in systems neuroscience,
11/2023, Letnik:
17
Journal Article
Recenzirano
Odprti dostop
The normal hemispheric balance can be altered by the asymmetric sensorimotor signal elicited by Cervical Dystonia (CD), leading to motor and cognitive deficits.
Directional errors, peak velocities, ...movement and reaction times of pointing towards out-of-reach targets in the horizontal plane were analysed in 18 CD patients and in 11 aged-matched healthy controls.
CD patients displayed a larger scatter of individual trials around the average pointing direction (variable error) than normal subjects, whatever the arm used, and the target pointed. When pointing in the left hemispace, all subjects showed a left deviation (constant error) with respect to the target position, which was significantly larger in CD patients than controls, whatever the direction of the abnormal neck torsion could be. Reaction times were larger and peak velocities lower in CD patients than controls.
Deficits in the pointing precision of CD patients may arise from a disruption of motor commands related to the sensorimotor imbalance, from a subtle increase in shoulder rigidity or from a reduced agonists activation. Their larger left bias in pointing to left targets could be due to an increased right parietal dominance, independently upon the direction of head roll/jaw rotation which expands the left space representation and/or increases left spatial attention. These deficits may potentially extend to tracking and gazing objects in the left hemispace, leading to reduced skills in spatial-dependent motor and cognitive performance.
Significant results have been shown when an upper limb robot-assisted rehabilitation is delivered to stroke patients.
To evaluate the effects of upper limb robot-assisted rehabilitation on motor ...recovery in stroke patients who underwent a treatment based on a haptic device.
Thirty-nine stroke patients (twenty-three subacute and sixteen chronic) underwent rehabilitation training by using MOTORE/Armotion haptic system. Thirteen healthy subjects were recruited for comparison purpose.The following clinical outcome measures were used: Chedoke-McMaster Stroke Assessment, Modified Ashworth Scale (MAS), Fugl-Meyer Assessment (FM), Medical Research Council, Motricity Index (MI), Box and Block Test (B&B) and Modified Barthel Index (mBI).The following parameters were computed: mean speed, maximum speed, mean time, path length, normalized jerk, mean force, mean error, mean energy expenditure and active patient-robot interaction percentage.The assessments were carried-out before and after treatment.
Significant changes were observed in both groups in the FM, MI, B&B and mean speed. Significant changes were observed in mBI, mean time, mean force, mean energy expenditure and active patient-robot interaction percentage in subacute stroke patients. In chronic stroke patients significant changes were found on the MAS-elbow.
The haptic device used is at least as effective as an existing device used in similar studies.
Background. After the declaration of the pandemic status in several countries, the continuity of face-to-face visits in psychiatric facilities has been delayed or even interrupted to reduce viral ...spread. Little is known about the personality factors associated with medication beliefs and adherence amongst individuals with mental illness during the COVID-19 pandemic. This brief report describes a preliminary naturalistic longitudinal study that explored whether the Big Five personality traits prospectively moderate the effects of medication beliefs on changes in adherence during the pandemic for a group of outpatients with psychosis or bipolar disorder. Methods. Thirteen outpatients undergoing routine face-to-face follow-up assessments during the pandemic were included (41 observations overall) and completed the Revised Italian Version of the Ten-Item Personality Inventory, the Beliefs about Medicines Questionnaire, the Morisky Medication Adherence Scale—8-item and the Beck Depression Inventory—II. Results. Participants had stronger concerns about their psychiatric medications rather than beliefs about their necessity, and adherence to medications was generally low. Participants who had more necessity beliefs than concerns had better adherence to medications. People scoring higher in Conscientiousness and Neuroticism traits and more concerned about the medication side effects had poorer adherence. Conclusions. These preliminary data suggest the importance of a careful assessment of the adherence to medications amongst people with psychosis/bipolar disorder during the pandemic. Interventions aimed to improve adherence might focus on patients’ medication beliefs and their Conscientiousness and Neuroticism personality traits.
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