Absence Of Proprioception Research Articles

A Haptic Feedback System for Phase-Based Sensory Restoration in Above-Knee Prosthetic Leg Users.

Persons with amputations lack important senses from the amputated limb. With the absence of proprioception in the amputated leg, amputees have far more difficulty maintaining a natural gait with balance and stability. The biggest determinant of temporal limb behavior during locomotion is the phase in the gait cycle, which can be estimated using the center of pressure (COP) under the feet. We hypothesize that feedback from the COP of the prosthetic foot can help restore a more robust sense of phase in transfemoral (above-knee) amputees. This paper presents a device that provides vibrotactile feedback based on the COP from the prosthesis, providing proprioception and potentially an improved sense of phase to the user. Experiments showed that the haptic device significantly decreased variability of stride length, step width, and trunk sway in novice (able-bodied) users of a transfemoral prosthetic leg during treadmill locomotion (N=9), indicating improved gait stability.

Intervertebral Disc Extrusion between T8 and T9 in a Dachshund

Background: Intervertebral disc extrusion with consequent spinal compression or intervertebral disc disease (IVDD) is one of the most common causes of compressive myelopathy in dogs, and the thoracolumbar spine discs between T12 and L2 are most affected. Extrusions in cranial thoracic region are rare, and there is few cases in literature reporting this situations, this rarity is attributed to the presence of the intercapital ligament connecting the rib heads between T2 and T10, which strengthens this region both mechanically and anatomically. The aim of this article is report the clinical signs, diagnosis and treatment of a case of Type I Hansen IVDD between T8 and T9 in a Dachshund breed dog.Case: An 8-year-old Dachshund male dog was presented for investigation of pelvic limb incoordination and back pain, which started 10 days prior to the consultation. It had a history of a similar condition 3 months earlier that showed improvement after clinical treatment. On neurological examination was identified in both pelvic limbs proprioceptive ataxia, absence of proprioception, increased muscle tone, presence of interdigital reflex and increased patellar reflex. Cutaneous trunci reflex was absent below T11 on the left side, and pain was noted upon palpation of T7 through the T12 vertebrae. A grade II asymmetric thoracolumbar lesion with hyperesthesia was diagnosed. On suspicion of IVDD, cerebrospinal fluid (CSF) collection and CT scan analysis of the thoracolumbar region were performed. CT scan showed the presence of hyperattenuating and mineralized material, 1 cm long, on the floor of the spinal canal, mainly on the left side, occupying 80% of the diameter of the spinal canal between T8 and T9. The patient was then submitted to decompression surgery through hemilaminectomy and showed a good recovery. As the occurrence of disc extrusion in cranial thoracic region of chondrodystrophic breeds is rare, we report the clinical signs, diagnosis and treatment of a case of Type I Hansen intervertebral disc disease (IVDD) between T8 and T9 in a Dachshund breed dog.Discussion: All spinal discs can undergo a process of degeneration causing IVDD, in which the cervical and thoracolumbar regions are the most affected due to reasons not yet fully understood, however spinal cord compression between the T1 and T9 vertebrae is very rare, probably due to the strengthening provided by the intercapital ligament to the posterior annulus fibrosus. Disc extrusion in unusual locations in chondrodystrophic breeds is mainly reported as extrusion between vertebrae T1 and T2, and T9 and T10, with some cases was attributed to an anatomical abnormality of the intercapital ligament. The evaluation of intervertebral discs of the German shepherd breed dogs using MRI showed disc degeneration processes in thoracic vertebras. Disc extrusions often result in more severe clinical signs than protrusions, and occur acutely or subacutely, which was different from the case described here, maybe because the presence of the intercapital ligament permitted gradual extrusion allowing the spinal cord to adapt to the compression. Despite surgical access to this region being described as more complex due to the presence and proximity of the rib head to the vertebral body and the possibility of injuring the intercostal muscles causing pneumothorax, the hemilaminectomy and rib head excision at T9 could be performed without any complications. Thus, although unusual, the cranial thoracic region should not be overlooked as a possible site of occurrence of IVDD, since the diagnosis, treatment and prognosis are similar to those in patients with extrusions in the most common sites.Keywords: intervertebral disc degeneration, dogs, paresis, ataxia.

Desempenho sensório-motor na paresia aferente em paciente após acidente vascular encefálico crônico: relato de caso

Introdução: Lesões no giro cerebral pós-central podem causar o fenômeno de paresia aferente. Objetivo: Descrever o desempenho sensório-motor de uma paciente com paresia aferente pós-acidente vascular encefálico (AVE) crônico. Métodos: Paciente do sexo feminino, 39 anos, com diagnóstico de hemorragia subaracnoide aguda por rompimento de aneurisma em artéria cerebral média direita foi submetida a protocolo de desempenho físico de Fugl-Meyer, avaliação sensorial de Nottingham, teste dos sinos, testes de sequência motora e dez testes funcionais, sendo os dois últimos executados com e sem privação visual. Resultados: A paciente apresentou comprometimento motor leve, hipoestesia tátil e ausência de propriocepção em punho e mão, astereognosia e dificuldade na resolução de tarefas motoras durante a privação visual. Conclusão: A paciente com sequelas crônicas pós-AVE apresentou déficits sensoriais e lentidão ou incapacidade de realização das tarefas motoras manuais na ausência da orientação visual, caracterizando, assim, a paresia aferente.

Reliability and Validity of the Sensory Component of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI): A Systematic Review

Since 1982, the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) has been used to classify sensation of spinal cord injury (SCI) through pinprick and light touch scores. The absence of proprioception, pain, and temperature within this scale creates questions about its validity and accuracy. To assess whether the sensory component of the ISNCSCI represents a reliable and valid measure of classification of SCI. A systematic review of studies examining the reliability and validity of the sensory component of the ISNCSCI published between 1982 and February 2013 was conducted. The electronic databases MEDLINE via Ovid, CINAHL, PEDro, and Scopus were searched for relevant articles. A secondary search of reference lists was also completed. Chosen articles were assessed according to the Oxford Centre for Evidence-Based Medicine hierarchy of evidence and critically appraised using the McMasters Critical Review Form. A statistical analysis was conducted to investigate the variability of the results given by reliability studies. Twelve studies were identified: 9 reviewed reliability and 3 reviewed validity. All studies demonstrated low levels of evidence and moderate critical appraisal scores. The majority of the articles (~67%; 6/9) assessing the reliability suggested that training was positively associated with better posttest results. The results of the 3 studies that assessed the validity of the ISNCSCI scale were confounding. Due to the low to moderate quality of the current literature, the sensory component of the ISNCSCI requires further revision and investigation if it is to be a useful tool in clinical trials.

Role of proprioception and vision in handwriting

The objective of this study is to better understand the role of proprioception in handwriting and test earlier conclusions stating that the automated shaping of letters was not impaired by the removal of visual control in deafferentation. To this aim we compared the performance of the deafferented patient GL, who suffers from a complete loss of cutaneous and proprioceptive sensation, with that of eight healthy age- and sex-matched subjects. The word “Parallele”, written within a short sentence with and without visual control, was quantified using a digital writing tablet. Three of the 13 analyzed parameters were strikingly different in patient GL compared to healthy subjects, both with and without vision: increase of number of pen touches, increase in number of inversions in velocity, and decrease of mean stroke frequency. The changes in these three parameters indicate a strong impairment in automated behaviour in the absence of proprioception and touch. This impairment is also supported by the significantly longer movement duration, which is also significantly increased by the removal of visual control. The present study provides for the first time a quantification of handwriting in a completely deafferented patient and reveals the central role of proprioception for the storage, updating, and maintenance of skilled motor programs. The fact that the deficits are already present with visual feedback suggests that the role of vision in handwriting is only secondary.

Vestibular Syndrome Due to a Choroid Plexus Papilloma in a Ferret

A 6-year-old, castrated male ferret (Mustela putorius furo) was presented with progressive neurological signs consisting of a right-sided head tilt and ataxia. Neurological examination revealed hemiparesis and absence of proprioception on the right side, consistent with central vestibular syndrome. Measurement of blood glucose excluded hypoglycemia due to insulinoma. Contrast-enhanced computed tomography revealed the presence of an intracranial mass, consistent with either granuloma or neoplasia. Palliative treatment with prednisolone yielded no improvement. At postmortem examination, a final diagnosis of a choroid plexus papilloma originating from the fourth ventricle was made. This is the first report of such a tumor in a ferret.

Proprioception Contributes to the Sense of Agency during Visual Observation of Hand Movements: Evidence from Temporal Judgments of Action

The ability to recognize visually one's own movement is important for motor control and, through attribution of agency, for social interactions. Agency of actions may be decided by comparisons of visual feedback, efferent signals, and proprioceptive inputs. Because the ability to identify one's own visual feedback from passive movements is decreased relative to active movements, or in some cases is even absent, the role of proprioception in self-recognition has been questioned. Proprioception during passive and active movements may, however, differ, and so to address any role for proprioception in the sense of agency, the active movement condition must be examined. Here we tested a chronically deafferented man (I.W.) and an age-matched group of six healthy controls in a task requiring judgement of the timing of action. Subjects performed finger movements and watched a visual cursor that moved either synchronously or asynchronously with a random delay, and reported whether or not they felt they controlled the cursor. Movement accuracy was matched between groups. In the absence of proprioception, I.W. was less able than the control group to discriminate self- from computer-produced cursor movement based on the timing of movement. In a control visual discrimination task with concurrent similar finger movements but no agency detection, I.W. was unimpaired, suggesting that this effect was task specific. We conclude that proprioception does contribute to the visual identification of ownership during active movements and, thus, to the sense of agency.

Vision without Proprioception Modulates Cortico-spinal Excitability during Hand Motor Imagery

Several studies have shown a cortico-spinal facilitation during motor imagery. This facilitation effect is weaker when the actual hand posture is incompatible with the imagined movement. To determine whether the source of this interference effect arises from online proprioceptive information, we examined transcranial magnetic stimulation (TMS)-induced motor-evoked potentials during motor imagery in the deafferented subject G.L. The patient and 7 control subjects were asked to close their eyes and imagine joining the tips of the thumb and the little finger while maintaining a hand posture compatible or incompatible with the imagined movement. Contrary to control subjects' performance, G.L.'s results show that the facilitation observed during motor imagery was independent of the hand posture. To examine how vision of the hand interacts with the imagery process, G.L. and control subjects performed the same task with the eyes open. Like control subjects, when G.L. looked at her hand, a greater facilitation was observed when her hand posture was compatible with the imagined movement than when it was incompatible. These results suggest that in the absence of proprioception, vision may facilitate or inhibit motor representations and support the idea that limb position in the brain is organized around multisensory representations.

Internally driven control of reaching movements: A study on a proprioceptively deafferented subject

We investigated the possibility of controlling reaching movements on the sole basis of central mechanisms, i.e., without peripheral feedback on hand and target positions. A deafferented subject (GL) and control subjects reached with the unseen hand for a straight-ahead target that could be displaced laterally at movement onset. The shifted target was continuously or briefly lit, or not visible. In this latter condition, a beep from either side of subjects’ head single-handedly signaled the change in the movement goal, so that movements could only be controlled through an internal representation of the memorised target position. Compared to controls, GL showed quantitatively similar corrections (77% of the target displacement, on an average) and similar reaction times to the target shift (mean = 516 ms), regardless of target visual information. These results highlight a remarkable capacity for controlling reaching movements on the sole basis of internally driven processes. On the other hand, trajectories in double-step trials differed drastically between GL and controls. Controls’ trajectories were composed of two segments, the second of which brought the hand directly toward the displaced target. The patient produced three-segment, stair-like trajectories. The first and third segments were mainly in the sagittal plane and the second segment was a vector-image of the lateral target shift. A control experiment showed that GL's trajectories were not the result of a voluntary strategy used to adjust movement trajectory in the absence of peripheral information on hand position. We suggest that GL's trajectories reflect a deficit in interjoint coordination in the absence of proprioception.

Arm-trunk coordination in the absence of proprioception.

During trunk-assisted reaching to targets placed within arm's length, the influence of trunk motion on the hand trajectory is compensated for by changes in the arm configuration. The role of proprioception in this compensation was investigated by analyzing the movements of 2 deafferented and 12 healthy subjects. Subjects reached to remembered targets (placed approximately 80 degrees ipsilateral or approximately 45 degrees contralateral to the sagittal midline) with an active forward movement of the trunk produced by hip flexion. In 40% of randomly selected trials, trunk motion was mechanically blocked. No visual feedback was provided during the experiment. The hand trajectory and velocity profiles of healthy subjects remained invariant whether or not the trunk was blocked. The invariance was achieved by changes in arm interjoint coordination that, for reaches toward the ipsilateral target, started as early as 50 ms after the perturbation. Both deafferented subjects exhibited considerable, though incomplete, compensation for the effects of the perturbation. Compensation was more successful for reaches to the ipsilateral target. Both deafferented subjects showed invariance between conditions (unobstructed or blocked trunk motion) in their hand paths to the ipsilateral target, and one did to the contralateral target. For the other deafferented subject, hand paths in the two types of trials began to deviate after about 50% into the movement, because of excessive elbow extension. In movements to the ipsilateral target, when deafferented subjects compensated successfully, the changes in arm joint angles were initiated as early as 50 ms after the trunk perturbation, similar to healthy subjects. Although the deafferented subjects showed less than ideal compensatory control, they compensated to a remarkably large extent given their complete loss of proprioception. The presence of partial compensation in the absence of vision and proprioception points to the likelihood that not only proprioception but also vestibulospinal pathways help mediate this compensation.

The role of proprioception and attention in a visuomotor adaptation task.

The role of proprioception in the control and adaptation of visuomotor relationships is still unclear. We have studied a deafferented subject, IW, and control subjects in a task in which they used single joint elbow extension to move to a visual target, with visual feedback of the terminal position provided by a cursor displayed in the plane of their movements. We report the differences in movement accuracy between the deafferented subject and controls in the normal task and when challenged with a cognitive load, counting backwards. All subjects were less accurate when counting; this was a small effect for the controls (<10% change) but much greater for the deafferented subject (>60% change). We also examined changes in movement kinematics when the instructed amplitude was altered via a changed gain between final arm position and presentation of the feedback cursor. The deafferented subject maintained temporal movement parameters stable and altered amplitude by scaling force (i.e. changed peak velocity), whereas the controls scaled both movement velocity and duration. Finally, we compared the subjects' adaptation of movement amplitude after a period of exposure to the changed visuomotor gain. The deafferented subject was able to adapt, but his adaptation was severely impaired by the counting task. These results suggest that proprioception is not an absolute requirement for adaptation to occur. Instead, proprioception has a more subtle role to play in the adjustment to visuomotor perturbations. It has an important role in the control of reaching movements, while in the absence of proprioception, attention appears necessary to monitor movements.

Feedback control during mastication of solid food textures—a clinical-experimental study

Statement of problem. On the basis of animal experiments, it has been hypothesized that the dynamics of food reduction are controlled by peripheral receptors. Studies on this subject in human beings are rare. Purpose. This study investigated the influence of periodontal and joint proprioceptors on mastication in human beings. Material and methods. Both jaw joints and the chewing-side teeth were consecutively anesthetized in a 6-person panel by chewing wine gum. The effects on the kinematics, chewing force, and electromyographic activity were measured. Results. The results substantiate a positive feedback of periodontal receptors for chewing force control. A substantial influence of joint receptors on movement control could not be found. Conclusion. Despite the absence of proprioception in both jaw joints and the periodontal receptors in the chewing side, the characteristics of the measured kinematic and dynamic values remained essentially unchanged. (J Prosthet Dent 1998;80:330-6.)

The relative contribution of retinal and extraretinal signals in determining the accuracy of reaching movements in normal subjects and a deafferented patient.

This experiment investigated the relative extent to which different signals from the visuo-oculomotor system are used to improve accuracy of arm movements. Different visuo-oculomotor conditions were used to produce various retinal and extraretinal signals leading to a similar target amplitude: (a) fixating a central target while pointing to a peripheral visual target, (b) tracking a target through smooth pursuit movement and then pointing to the target when its excursion ceased, and (c) pointing to a target reached previously by a saccadic eye movement. The experiment was performed with a deafferented subject and control subjects. For the deafferented patient, the absence of proprioception prevented any comparison between internal representations of target and limb (through proprioception) positions during the arm movement. The deafferented patient's endpoint therefore provided a good estimate of the accuracy of the target coordinates used by the arm motor system. The deafferented subject showed relatively good accuracy by producing a saccade prior to the pointing, but large overshooting in the fixation condition and undershooting in the pursuit condition. The results suggest that the deafferented subject does use oculomotor signals to program arm movement and that signals associated with fast movements of the eyes are better for pointing accuracy than slow ramp movements. The inaccuracy of the deafferented subject when no eye movement is allowed (the condition in which the controls were the most accurate) suggests that, in this condition, a proprioceptive map is involved in which both the target and the arm are represented.

Position proprioception in a microcomputer-controlled prosthesis.

Powered upper-extremity multifunctional prostheses have been in existence for several decades. However, the acceptance rate by amputees of these devices is extremely poor. An examination of the reasons for the poor level of acceptance has revealed that a major problem is the absence of proprioception of the position of the prosthesis. This makes its operation very difficult and usually results in it being rejected by amputees. A control technique termed extended physiological proprioception was introduced some years ago to provide amputees with proprioception of the position in space of their prostheses. This paper deals with a new realisation of a prosthesis with extended physiological proprioception. The system is under the control of a microcomputer and electrical actuators are used throughout. In the case of the above-elbow prosthesis chosen for this study, the input signals are obtained from a shoulder goniometer on the amputated side. Function is broadened by giving the amputee a repertoire of input/output relationships from which to choose depending on the task being performed.

Bruxism in children with brain damage.

Ninety-one children with brain damage were examined with regard to the degree of dental wear in relation to the degree and symptom of brain damage. Abnormal wear was found in a statistically established greater frequency in the group of children most severely mentally retarded, while it was not found in children of normal intelligence. Of the children with most severe mental retardation, 8 were at a 6-month level of development and all of these had abnormal wear. The others had reached the one-year-old stage, at which it is likely that normal protective reflexes or the ability to sense pain in the parodontium begin to develop. Of 7 children with severe cerebral palsy, 4 showed abnormal wear and also belonged to the most severely mentally retarded group. The investigation shows that abnormal dental wear is more closely related to a low level of mental development than to the degree of severity of cerebral palsy. The absence of proprioception in the parodontium is discussed as a possible cause of bruxism.