A Rare Sonographic Case of Caudal Duplication Versus Polymelia

Caudal duplication is a rare condition that results in varying degrees of duplication of organs within the gastrointestinal, genitourinary, reproductive, spinal, and vertebral systems. Polymelia is a rare congenital defect that presents as supernumerary limbs. This case report describes a fetus with characteristics of both conditions but does not present with the classic scenario of either condition.

The supernumerary rubber hand illusion revisited: perceived duplication of limbs and visuotactile events

A controversial and unresolved issue in cognitive neuroscience is whether humans can experience supernumerary limbs as part of their own body. Some previous experiments have claimed that it is possible to elicit supernumerary hand illusions based on modified versions of the rubber hand illusion. However, other studies have provided conflicting results that suggest that only one rubber hand can be perceived as one’s own. To address this issue, we developed a supernumerary hand illusion paradigm that allowed us to disambiguate ownership of individual rubber hands from simultaneous ownership of two fake hands. In our setup, the participant’s real right hand was hidden under a platform, while two identical right rubber hands were placed in parallel on top of the platform in direct view of the participant. We applied synchronous strokes to both rubber hands and the real hand (SS), synchronous strokes to one rubber hand and the real hand and asynchronous strokes to the other model hand (AS and SA) or asynchronous strokes to both fake hands in relation to the real hand (AA). Our results demonstrate that a genuine illusion of owning two rubber hands can be elicited and that such a supernumerary hand illusion can be isolated from the sense of ownership of a single rubber hand both in terms of questionnaire ratings and threat-evoked skin conductance responses (SCRs). These findings advance our knowledge about the dynamic flexibility and fundamental constraints of body representation and emphasize the importance of correlated afferent signals for causal inference in body ownership.

Heteropagus Twins with Hepatobiliary and Gastrointestinal Connectedness and Complex Cardiac Malformation in Autosite

Introduction: Heteropagus twins are a set of conjoined twins with one being grossly abnormal, the ‘parasite’, and the other being relatively normal, the ‘autosite’. Case Report: A pair of heteropagus twins were initially identified on prenatal ultrasound and subsequently confirmed using prenatal MRI at 25 weeks gestational age. Prenatal imaging identified supernumerary limbs, accessory small bowel loops in the parasitic twin, a hypoplastic left heart in the right hemithorax of the autosite, and a shared liver and bowel between the two. Delivery occurred at 38 + 5 weeks gestation via C-section with an APGAR score of 9/9 for the autosite at both 1 and 5 minutes. MRI confirmed an interconnected autosite-parasite liver that was herniating into the left hemithorax as well as continuous autosite-parasite bowel loops. The patient underwent surgical management including resection of the parasitic twin and repair of the congenital heart defect and is now thriving. Discussion: Heteropagus twins include a spectrum of clinical entities from nonconjoined twins to intact conjoined twins. The predominant theory regarding etiology is an incomplete cleavage of a monozygotic embryo at approximately 2 weeks gestation. Following differentiation, ischemia-induced atrophy leads to the embryonic death of the parasite and hemodynamic changes in the autosite to support parasite tissues. The use of antenatal and postnatal imaging is crucial in establishing the diagnosis, management plan, and longterm prognosis secondary to the congenital cardiac malformations and degree of interconnectedness. Conclusion: This is the first reported case of heteropagus twins with co-existing hepatobiliary and gastrointestinal continuity.

Pygomelia and True Hermaphroditism in a Nine Week Old Large White Piglet Case Report

A nine weeks old female Large White piglet which was presented to the Veterinary Teaching Hospital, Federal University of Agriculture, Abeokuta, with a complaint of extra limbs was diagnosed with pygomelia and concurrent true hermaphroditism based on gross morphologic features, radiography, exploratory laparotomy and histopathology of the malformed organs. The piglet had two well-developed extra hind limbs consisting of the femur, tibia, fibula and the phalanges. Radiographically, the accessory limbs were attached to the ischium through a rudimentary pelvic bone. The supernumerary limbs were smaller than the normal appendages, but contained equal digits. The anal orifice was observed cranial to the right supernumerary limb. Caudal to the left supernumerary limb a rudimentary penis was observed. Two oval shaped fibrous masses were palpated in the inguinal canal of the piglet. In addition, there was a transparent tubular tract measuring 24 cm in length which contained serous fluid. The right kidney was rudimentary measuring 2.10 cm, while the left kidney appeared hypertrophied measuring 6.10 cm. The histology of the left kidney showed dysplastic areas of undifferentiated mesenchymal stroma in the cortex and medulla with the presence of groups of immature glomeruli in the cortex. The tubules in the medulla were scanty in number and had atypical epithelium. The adrenal glands had normal architecture with ectopic adrenal tissue in the adrenal capsule, while the ovaries and uterus were normal. It was concluded that the complex anomalies in the piglet might be as a result of a complex mode of inheritance.

Pins & Needles: Towards Limb Disownership in Augmented Reality

ABSTRACTThe seemingly stable construct of our bodily self depends on the continued, successful integration of multisensory feedback about our body, rather than its purely physical composition. Accordingly, pathological disruption of such neural processing is linked to striking alterations of the bodily self, ranging from limb misidentification to disownership, and even the desire to amputate a healthy limb. While previous embodiment research has relied on experimental setups using supernumerary limbs in variants of the Rubber Hand Illusion, we here used Augmented Reality to directly manipulate the feeling of ownership for one’s own, biological limb. Using a Head-Mounted Display, participants received visual feedback about their own arm, from an embodied first-person perspective. In a series of three studies, in independent cohorts, we altered embodiment by providing visuotactile feedback that could be synchronous (control condition) or asynchronous (400ms delay, Real Hand Illusion). During the illusion, participants reported a significant decrease in ownership of their own limb, along with a lowered sense of agency. Supporting the right-parietal body network, we found an increased illusion strength for the left upper limb as well as a modulation of the feeling of ownership during anodal transcranial direct current stimulation. Extending previous research, these findings demonstrate that a controlled, visuotactile conflict about one’s own limb can be used to directly and systematically modulate ownership – without a proxy. This not only corroborates the malleability of body representation but questions its permanence. These findings warrant further exploration of combined VR and neuromodulation therapies for disorders of the bodily self.

Towards a Soft Robotic 3rd Arm for Activities of Daily Living

Limb sensorimotor function plays an important role in activities of daily living (ADLs) and quality of life. Spinal cord dysfunctions, such as cervical spondylotic myelopathy (CSM), often affect limb function and limit independence. In this paper, we apply technologies from the emerging field of soft robotics to develop Soft Robotic 3rd Arms (SR3As) that branch out of the body — thus providing an artificial limb that enables effective execution of ADLs for CSM patients and the like. Soft robotics is a fairly recent addition to the field of robotics. Differing from traditional, “hard”, robotics, soft robotics are made of flexible materials such as silicone rather than stiff materials such as metals. One such soft robotic actuator is the fiber-reinforced actuator (FRA). Fabricated utilizing a combination of silicone bladder(s) and inextensible materials, these actuators are able to perform one of various motions through changes of pressure [1]. Supernumerary limbs (3rd arms), in contrast, are extra robotic limbs that can function cooperatively or independently of the user’s own limbs. These differ from exoskeletal robotics, as they are not fixated to the user’s limb to augment strength, but rather are placed elsewhere on the body to assist in tasks that would otherwise require multiple people. Examples of such devices include MIT/Boeing’s supernumerary arms to assist in the assembly of aircraft fuselage [2] or the supernumerary hand Softhand [3]. Combining these two concepts, an articulate SR3A was created (Fig. 1). By replacing traditional actuators with soft actuators, the limb is not only lighter, but it also better replicates the equivalent human limb. In addition to these benefits, the SR3A would also need to be less expensive to fabricate and actuate than an arm using rigid body components. This paper presents the design of a proof-of-concept prototype of a SR3A utilizing soft robotic actuators that could be used to assist individuals with hand impairments perform ADLs.

First Report of Polymelia in Shakini Breed Chicken from Nepal

Polymelia is a congenital anomaly (birth defect condition) which is associated with extra limbs or supernumerary limbs in human and animals. Congenital anomalies are associated with genetic factors (transgenes, chromosomes), environmental agents (infection, toxins, teratogens, fertilization techniques, management) or a combination of factors (Keeler et al., 1981; Newman et al., 1999). In supernumerary ectopic limb (SEC) anomaly, accessory limbs are attached to the various body regions (Fourie, 1990; Hiraga et al., 1989). These accessory limbs are usually smaller than the normal limbs and have stiff joints and sparse muscles with innervations (Pohlmeyer, 1974).Polymelia is reported from human, cattle, deer, dolphin, frog, cat, dog and poultry but is extremely rare in swine (Hiraga & Demis, 1993; Ramdan et al., 1998; Talamillo et al., 2005). Polymelia in birds is very rare. Only a few cases of polymelia in chicken are recorded from different parts of the world. A Nera black chicken (Gallus domesticus) with polymelia and rudimentary wing was reported from Nigeria in 2008 (Odunayo et al., 2013). A chicken with polymelia was reported from Kitam village, Sikkim, India in 2012(10 News WTSP Tampa Bay). In Egypt amputation of polymelia in a layer chicken was done in 2014 (Abu-Seida, 2014).For the first time polymelia in shakini breed chicken (Gallus domesticus) is recorded in Nepal. There is no previous report on such deformity in domesticated fowl in Nepal. The chicken with polymelia is ten days old and is detected in the author’s neighborhood in Pokhara valley, midwestern region of Nepal during the month of December, 2014. Physical examination of the chicken revealed well developed extra limbs consisting of the femur, tibiofibula and the phalanges which are attached to the upper region of the coccygeal area of the chicken. The limbs are smaller than the normal limbs with equal digits but are non-functional. The chicken looks normal and seems to have no problem with the supernumery limbs so far.J. Nat. Hist. Mus. Vol. 28, 2014: 175-177