Object segmentation in cluttered environment based on gaze tracing and gaze blinking

People with disabilities, such as patients with motor paralysis conditions, lack independence and cannot move most parts of their bodies except for their eyes. Supportive robot technology is highly beneficial in supporting these types of patients. We propose a gaze-informed location-based (or gaze-based) object segmentation, which is a core module of successful patient-robot interaction in an object-search task (i.e., a situation when a robot has to search for and deliver a target object to the patient). We have introduced the concepts of gaze tracing (GT) and gaze blinking (GB), which are integrated into our proposed object segmentation technique, to yield the benefit of an accurate visual segmentation of unknown objects in a complex scene. Gaze tracing information can be used as a clue as to where the target object is located in a scene. Then, gaze blinking can be used to confirm the position of the target object. The effectiveness of our proposed method has been demonstrated using a humanoid robot in experiments with different types of highly cluttered scenes. Based on the limited gaze guidance from the user, we achieved an 85% F-score of unknown object segmentation in an unknown environment.

Post COVID-19 Guillain Barre Syndrome in Immunocompromised Children - A report of two cases and review of literature

IntroductionSevere acute respiratory syndrome Coronavirus 2 (SARS-CoV 2) is a novel coronavirus that caused an outbreak since 31 December 2019. Although the most commonly noted symptoms were fever and respiratory illness, a wide variety of other symptoms have also been seen. There has been increasing number of cases of neurological manifestations of Covid –19. Further, there has been growing association between Covid-19 and Guillain Barre Syndrome (GBS).Case presentationIn this report, we present two cases of acute lymphoblastic leukemia affected by Covid-19 who after recovery from Covid-19 developed symptoms of GBS. They presented with complaints of bilaterally symmetrical ascending motor paralysis and were diagnosed with Guillain Barre Syndrome by electrophysiological tests and were started on intravenous immunoglobins for five days @ 0.4mg/kg/day after which the condition of both children gradually improved.ConclusionThis case report adds to the emerging evidence that suggests the association of GBS post Covid infections. COVID-19 can result in several autoimmune neurological phenomena including GBS. In the setting of the pandemic, COVID-19 as an underlying trigger should be considered in all immunologic phenomena. This applies to all patients, including children.

Contralateral and Ipsilateral Interactions in the Somatosensory Pathway in Healthy Humans

Hyper-adaptability, the ability to adapt to changes in the internal environment caused by neurological disorders, is necessary to recover from various disabilities, such as motor paralysis and sensory impairment. In the recovery from motor paralysis, the pre-existing neural pathway of the ipsilateral descending pathway, which is normally suppressed and preserved in the course of development, is activated to contribute to the motor control of the paretic limb. Conversely, in sensory pathways, it remains unclear whether there are compensatory pathways which are beneficial for the recovery of sensory impairment due to damaged unilateral somatosensory pathways, such as thalamic hemorrhage. Here, we investigated the interaction between the left and right somatosensory pathways in healthy humans using paired median nerve somatosensory evoked potentials (SEPs). Paired median nerve SEPs were recorded at CP3 and CP4 with a reference of Fz in the International 10–20 System. The paired median nerve stimulation with different interstimulus intervals (ISIs; 1, 2, 3, 5, 10, 20, 40, 60, and 100 ms) was performed to test the influence of the first stimulus (to the right median nerve) on the P14, P14/N20, and N20/P25 components induced by the second stimulus (left side). Results showed that the first stimulation had no effect on SEP amplitudes (P14, P14/N20, and N20/P25) evoked by the second stimulation in all ISI conditions, suggesting that there might not be a neural connectivity formed by a small number of synapses in the left–right interaction of the somatosensory pathway. Additionally, the somatosensory pathway may be less diverse in healthy participants.

Improved assessment of overall health in variably aged murine models of Multiple Sclerosis with a novel frailty index tool

The experimental autoimmune encephalomyelitis (EAE) model is the most commonly used animal model of Multiple Sclerosis (MS). However, phenotypic characterization of mice based on the traditional 5-point clinical paralysis scale does not fully capture disease progression. The frailty index (FI) conceptualizes frailty as the accumulation of health deficits and it is widely used to assess overall health in aging humans and pre-clinical models. Here we adapted an established mouse FI tool for use in EAE mice and determined whether this could evaluate general signs of health in variably aged female EAE mice. The EAE-Clinical FI included 34 items related to clinical signs and deficits characteristic of aging and MS. This tool clearly showed more detailed EAE progression and severity at all ages, highlighting changes in systems other than motor paralysis measured with the traditional 5-point paralysis scale. When we induced disease at 3- and 6-months-of-age, mice showed typical EAE clinical manifestations with peak disease severity between 17-19 days post-induction and mean frailty scores of 0.36 ± 0.04 (3-month-old) and 0.43 ± 0.05 (6-month-old). By contrast, disease severity peaked after 14 days in 12-month-old mice. They showed atypical signs including wobbling, early belly drag, and splayed hindlegs that were better captured with the EAE-Clinical FI. Peak frailty scores also were higher than those of younger animals (0.54 ± 0.04). As MS most often develops in young to middle-aged people, this new tool may have significant value for use in EAE animal studies as first step towards translation to people with MS.

Common ocular motor paralysis in a tabetic anatomical examination. A. Papadaki. (Neurological Review, 1904)

Musculi externi eyes are rarely (39: 100) paralyzed in the prodromal period of the tabes. Paralysis is mild and transient at first, but returns severe and prolonged. In this case, all, or almost all, of the motor of the eye is affected, which deviates outward, and ptosis sets in. Temporary paralysis, according to some, are considered to be a consequence of peripheral neuritis, and long-term paralysis is a consequence of damage to the centers of the medulla oblongata. Adamkievitz considered the cause of transient diplopia to be a short-term rush of blood to the nerve trunks and nuclei, and Gweicher - sclerosis of the arteries and ischemia of the motor centers. Dejerine, in a case of isolated paralysis, of a tabetik's eyelid lifter, after opening, found a deep degeneration of his nerve filament, while the trunk of nervi oculomotorii turned out to be unchanged. Because of this, he considers the disease to be peripheral nervo-tabes.

The effect of slaughtering skills on the welfare of cattle during stunning with a captive bolt

The performance of stunning in various abattoirs can differ. The aim of the study was to compare the stunning of cattle with a captive bolt in two abattoirs. We monitored the slaughtering skills by measuring the deviation of the location of the stunning shot hole on the skull from the ideal point and further by measuring the angle of inclination of the stunning shot on the skull from the ideal perpendicular angle. We observed the impact of different slaughter skills on the quality of stunning of animals based on the occurrence of failure to achieve motor paralysis after a stun shot. The failure to collapse occurred significantly more frequently (P < 0.05) in abattoir A than in abattoir B. In both abattoirs there was a higher (P < 0.05) number of bulls failing to collapse than in females (cows and heifers). However, the effect of slaughter skills on the occurrence of signs associated with insufficient stunning was not found. The signs occurred in abattoir A and abattoir B to the same extent. In bulls, the number of animals with signs was higher (P < 0.05) than in females in both abattoirs. The results show that insufficient proficiency of skills in stunning cattle with a captive bolt leads to a higher number of animals failing to collapse after a stun shot. The effect of slaughter skills on the occurrence of signs in bulls and females was not proven; however, in bulls a higher incidence of signs was demonstrated than in females.

Astrocyte deletion of α2-Na/K ATPase triggers episodic motor paralysis in mice via a metabolic pathway

Familial hemiplegic migraine is an episodic neurological disorder characterized by transient sensory and motor symptoms and signs. Mutations of the ion pump α2-Na/K ATPase cause familial hemiplegic migraine, but the mechanisms by which α2-Na/K ATPase mutations lead to the migraine phenotype remain incompletely understood. Here, we show that mice in which α2-Na/K ATPase is conditionally deleted in astrocytes display episodic paralysis. Functional neuroimaging reveals that conditional α2-Na/K ATPase knockout triggers spontaneous cortical spreading depression events that are associated with EEG low voltage activity events, which correlate with transient motor impairment in these mice. Transcriptomic and metabolomic analyses show that α2-Na/K ATPase loss alters metabolic gene expression with consequent serine and glycine elevation in the brain. A serine- and glycine-free diet rescues the transient motor impairment in conditional α2-Na/K ATPase knockout mice. Together, our findings define a metabolic mechanism regulated by astrocytic α2-Na/K ATPase that triggers episodic motor paralysis in mice.

A Review on the Pathophysiology and Management of Anterior Spinal Artery Syndrome

As an uncommon cause of spinal cord infarction, anterior spinal cord syndrome can manifest with motor paralysis, loss of pain, and temperature sensation distal to the site of the lesion. The main pathogenesis of this syndrome is the disruption of blood flow in the anterior spinal artery. Mortality and morbidity differ with the etiology of the syndrome. So knowing the etiology of blood flow disruption is essential for patient management. This review article highlights the important clinical manifestation of Anterior spinal artery syndrome. Also describes etiology, pathogenesis, diagnosis, prognosis, possible management, and complications.