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Biomedical subjects

J M Beis

Publications and source records attributed to J M Beis.

15 recordsLinked to original sources

Mirror asomatognosia in right lesions stroke victims.

The objectives of this prospective study were: to search for mirror-induced disorders of the body image in right hemisphere stroke victims using a description task of the contralateral upper limb, to analyze their clinical features, and to discuss possible mechanisms. Sixteen consecutive patients with documented unilateral right hemisphere stroke were examined for asomatognosia at the acute phase of stroke, then at least 2 months after stroke under three test conditions: without a mirror, with a conventional mirror, with an inverted mirror. Video recordings of the tests were analyzed to assess performance. The diagnosis of asomatognosia was retained if the subject reported at least one of three sensations: limb transformation, limb strangeness, and/or limb alienation. During the acute phase, 14/16 patients presented manifestations of asomatognosia. All of these spontaneous manifestations had disappeared 2 months later, but were reactivated in 12 patients when exposed to mirror images. The mirror tests revealed four situations: no disorder (n = 4), asomatognosia with both mirrors (n = 5), asomatognosia with the conventional or inverted mirrors (n = 1 and 5), and asomatognosia with the inverted mirror (n = 1). These manifestations were designated as mirror-asomatognosia, a disorder resulting from adaptations of the procedures leading to reorganization of the internal representations of the body image. These findings suggest there are several such internal representations of the body image and that direct body image and mirror body image would be two specific ones. These clinical manifestations and their evolution over time are an expression of the progressive nature of the underlying compensatory mechanisms made possible by brain plasticity.

Adult↗

Mirror images and unilateral spatial neglect.

Responding correctly to a mirror image requires the creation of a rather peculiar form of dual representation. Mirror agnosia and mirror ataxia, i.e. a deficit in reaching an object reflected in a mirror, have been reported to be associated with parietal lobe lesions. This prospective study was conducted to investigate the capacity of subjects with neglect to identify the mirror image nature of visual information. Four consecutive brain-damaged patients with neglect, selected on the basis of specific criteria, and four control subjects performed grasping and object displacement tests under two response conditions (normal mirror and inverted mirror). Video recordings of the tests were analyzed to assess performance using the following criteria: (i) direction of the arm movement during the initial phase of movement, (ii) number of corrections of the hand position before grasping. The control subjects successfully grasped the objects in both experimental conditions. The patients (1) neglected the contralesional space, grasping objects correctly in the ipsilesional space (normal mirror condition) and (2) neglected the ipsilesional space, grasping correctly objects in the contralesional space (inverted mirror). Controls used real object-centered correction clues to modify the position and direction of their hand movement. The patients only produced horizontal displacements of the upper limb in the "healthy" and neglected space. These results suggest that patients with neglect do not use the same clues and do not modify their procedures as they cannot recalibrate their spatial representations. These differences concerned non-mirror-image clues and directional and positional as well as attentional vectors. Theoretical and rehabilitative implications are discussed.

Adult↗

[Classification and mechanisms of body perceptions in the amputees].

OBJECTIVE: Amputees can experience several types of physical illusions and phantom limb phenomenon. The objective was to establish a synthetic classification of theses perceptions. METHOD: Prospective study in 75 amputees (group 1: amputation (n = 60), group 2: congenital defect). The subjects were asked first to report their perceptions spontaneously and then to detail the perception, if exist, of the missing limb: form recognition, posture, movement, reminiscence of a lost limb. RESULTS: Different types of perception were described besides the perception of the real state : normal, deformed or commemorative phantom limb and illusion of a normal body. DISCUSSION: Whatever the model (i.e.: neuro-matrix) which support the construction of the scheme and the body image, the representations related to identified perceptions, use various innate, autobiographic and identity frames of references as well as instantaneous peripheral information, treated by reorganized cerebral structures. Each type of perception is related to a particular representation pattern. CONCLUSION: This approach, in accordance with the literature, offers a better understanding of the differences between amelic and amputated subjects and of their perception of any prosthetic equipment.

Amputees↗

[Early surgery management of pelvic region pressure ulcers versus directed cicatrization in a population of spinal cord injured patients].

OBJECTIVE: To estimate the benefit brought by an early surgery management of pelvis region pressure ulcers compared to medical processing in a population of subjects spinal cord disabled. MATERIAL AND METHOD: The studied population consist of 53 patients (62 pressure ulcers) divided into two groups: the group 1 includes 30 patients (34 pressure ulcers) presenting pressure ulcers stage III or IV (NPUAP scale) with early surgery management, included consecutively during a period of 2 years; the group 2 includes 23 patients (28 escarres) included in a retrospective way, with medical processing by the same team of care. The criteria of judgment are the delay of healing and the delay of delivery of the station sat in the armchair. RESULTS: In the group 1, the average delay of healing is of 42 days and the average delay of delivery for the armchair of 39 days. In the group 2 healing can be obtained only in 13 cases and in an average delay of 180 days. Differences are significant (p < 0.05). DISCUSSION - CONCLUSION: The originality of this study results in the comparison of two processing within two groups of patients having close demographic characteristics. It clearly shows the interest of the early surgery of the pelvic pressure ulcers comparing to medical processing and illustrates the requirement for a close cooperation between teams specialized in plastic surgery and teams specialized physical medicine.

Adult↗

Vestibular caloric stimulation evokes phantom limb illusions in patients with paraplegia.

STUDY DESIGN: Prospective study. OBJECTIVES: To determine the mechanisms of body illusions in paraplegia patients as compared with the amputee phantom phenomena. METHODS: A vestibular caloric stimulation was performed in 10 consecutive patients with complete section of the spinal cord. Perception of body, before and after stimulation, was classed as illusion of a normal body (lower limbs with normal morphological, postural and kinetic characteristics perceived as before spinal injury), normal phantom (overly vivid perception of all or part of the lower limbs), deformed phantom (perception of all or part of the limbs below the injury level as abnormal in shape, posture, movement or even number), or painful phantom. RESULTS: After vestibular caloric stimulation, nine out of 10 patients stated their perception of body segments below the injury level had changed to normal phantoms or to deformed phantoms (morphological, postural or kinetic changes). Among the four patients who initially had painful limbs, two stated the stimulation greatly relieved their pain. CONCLUSION: The normal or deformed phantom evoked by vestibular stimulation would result from use of identity data or instantaneous data as is observed in amputees. Cerebral remapping following deafferentation could be the origin of the deformed phantoms. Illusions corresponding to phenomena perceived at the time of the accident corresponding to autobiographical engrammes do not appear to be evoked by vestibular stimulation, as is also the case in amputees.

Adult↗

[Georges Gilles of Tourette, pioneer of gait analysis in the nervous system diseases].

Georges Gilles de la Tourette's contribution to neurology goes beyond the description of the neurological disorder named after him. On December 28, 1885, he defended his doctoral thesis devoted to "gait in the diseases of the nervous system, studied by the method of imprints". In collaboration with Albert Londe, he worked for two years in Charcot's department on "a simple method applicable to both healthy and unhealthy patients", establishing the scientific and modern basis of functional exploration of human gait. The purpose was to "record the modifications of the gait and to fix them permanently, using suitable devises to guarantee not only rigorous comparison, but also to prevent observers, making use of the same method, from disputing or canceling the results completely independent of the experimenter himself". Georges Gilles de la Tourette defined the various characteristic parameters and provided the normal reference values in males and females, determining the physiological asymmetry of steps. He described spastic gait, shaking palsy, and locomotor ataxia. He distinguished between disorders of nervous control and related joint diseases. He also classified gait disorders occurring during hemiplegia. Modern development of kinetic, kinematic and biomechanical studies is a good illustration of the current relevancy of Gilles de la Tourette's contribution.

France↗

[Illusions of body normality in amputees and paraplegic patients].

Phantom limbs in amputees, or body illusion in hemiplegics, have been the subject of wide ranging descriptions. The detected abnormalities involve morphological, postural and/or kinetic features. The aim of this prospective study carried out in 25 amputees and 10 adult paraplegics was to describe the typology of these perceptions. Data were collected from free and semi-directive investigations before and after caloric vestibular stimulation. Amputees and paraplegics perceived normal, deformed and painful body phantom segments, reffered perceptions and "normal limbs" which took on the request posture considering the general body position (illusion of body normality). This perception corresponds to an image of the body, such as it should be and not such as it is. In amputees, the limb follows the movements of the prothesis. These perceptions conform quite well reality so that the loss of the paralyzed limb is not perceived as a missing limb. This illusion of body normality should be distinguished from the normal phantom limb, characterized by a stronger perception of the lost limb compared with the other. In both amputees and paraplegics, vestibular stimulation can generate or modify phantoms limbs or body illusion and can abolish painful phantom limbs. The neuromatrix, which rebuilds body representations, could get its information from reorganized cortical areas (instantaneous body image), autobiographical engrams (painful phantoms limbs), or innate engrams (identity body schema) that, via congruence mechanisms, could be identified as a somatic reference, particularly for motor programming. This interpretation is compatible with current knowledge and suggests how amputees can easily use a prothesis.

Adult↗

[Presenting a battery for assessing spatial neglect. Norms and effects of age, educational level, sex, hand and laterality].

The aim of this study was to build up a battery for assessing spatial neglect, then to analyse the norms and potential effects of age, education level, sex, hand used, and laterality. It was also to contribute evaluating the pseudoneglect phenomenon described by Heilman, which consists in a tendency of normal subjects to neglect the right peripersonal space. Tasks selected were presented to important groups of normal subjects, most often larger than 450. The battery comprised of a bell cancellation test, scene copy, clock drawing, two line bisection tasks, identification of overlapping figures, text reading, writing task, and the representational task of the France map. For each of them, different variables were selected, especially investigating the difference between performance in the right and the left hemispaces. This study allowed defining the threshold values (percentiles 5 and 95) for deciding of the pathological character of a patient performance. It also showed that the pseudoneglect phenomenon is more obvious in some tasks such as line bisection, and probably also in the representational task of the France map and writing. His importance and at times his side were influenced by the factors we studied, with between tasks differences, but also by the nature of the task to be performed, and especially his verbal component.

Adult↗

Buccal hemineglect.

OBJECTIVES: To determine whether the peripersonal and intrapersonal buccal space can be affected by a hemispheric stroke and to evaluate the clinical signs resulting from buccal neglect. METHODS: A prospective study comparing 2 groups of patients with hemiplegia, 1 with a right hemispheric lesion and the other with a left hemispheric lesion. Patients were selected consecutively on the basis of specific criteria at least 1 month after stroke. RESULTS: Buccal hemineglect was usually concomitant with other hemineglect phenomena resulting from lesions of the right hemisphere (10 of 12 in right lesions and 1 of 12 in left lesions). Clinical signs associated with this condition consisted of impaired swallowing (retention, defective insalivation, presence of food debris in the left hemibuccal space, loss of saliva from the left side of the mouth, and choking); loss of the ability to perceive salty, sweet, or acid tastes; and impaired buccal representation. These problems were usually incorrectly diagnosed initially. Outcome was usually favorable, but functional disorders persisted in some patients for more than 18 months. The underlying attention and representation mechanisms are discussed with reference to experimental lesions of the postarcuate (area 6) cortex in rhesus monkeys. The area around the mouth may be considered to be, as in monkeys, a peripersonal space, ie, probably of little functional importance. The lesion may involve area 6 or its projections to the thalamus or posterior parietal cortex. CONCLUSIONS: Buccal hemineglect, which is likely to cause social embarrassment, should be considered whenever the oral phase of swallowing is impaired in a context of neglect syndromes. Prophylactic measures and rehabilitation can reduce the impact and complications of the condition (food bolus).

Adult↗

Eye patching in unilateral spatial neglect: efficacy of two methods.

OBJECTIVES: To determine whether patches obscuring half the visual field affect eye movement in subjects with unilateral spatial neglect and whether there is consequent improvement in the subject's everyday life, and to interpret the potential changes observed with the aid of a theoretical model. DESIGN: Prospective and randomized study. SETTING: Rehabilitation medicine department in an urban general hospital. PATIENTS: Twenty-two subjects with left unilateral neglect. INTERVENTION: Two eye-patching procedures-right half-field patches (n = 7) and right mononuclar patch (n = 7)-and control group (n = 8). MAIN OUTCOME MEASURES: Functional tests (FIM) and analytical tests (measurement of right eye movements by photo-oculography) at admission and after 3 months. RESULTS: Results of the paired comparison tests showed (1) significant differences between the control group and the group with the half-eye patches for total FIM score (p = .01) and the displacements of the right eye in the left field (p = .02), and (2) no significant differences between the control group and the group with the right monocular patch. CONCLUSION: Patching the right half-field helped subjects initially regain voluntary control over the deficit. The actual interpretation is based on physiologic and psychophysiologic models.

Bandages↗

Event-related potentials in the segmental exclusion syndrome of the upper limb.

Upper limb segmental exclusion syndromes are frequent after traumatic or infectious affections. They can be defined as an insufficient utilization of a limb segment--fingers or hand--reversible on verbal exhortation and arising in subjects with no other neurologic or psychiatric disorder. Our hypothesis was that the segmental exclusion syndrome could be likened to a neglect behavior. To verify the validity of this hypothesis, we measured digital nerve short-latency SEP and SEP-P300 waves in response to odd-ball task target stimuli in healthy volunteers (n = 11) and patients with digit exclusion syndromes (n = 19). For N20 latency, there was no significant difference (Wilcoxon's test: p = 0.52) between normal and excluded digits. Stimulation of the excluded vs normal digit resulted in a significant lengthening in SEP-P300 latency (p = 0.0003). The implication of these results and means of extending our knowledge of the pathophysiology of exclusion syndromes are discussed.

Adolescent↗

Detection of visual field deficits and visual neglect with computerized light emitting diodes.

A computer test for visual field deficits and visual neglect was developed and evaluated by testing 63 patients with brain damage. This computer test controls the sequence of unilateral or bilateral lights series, and stores the responses. Test results are compared to clinical and ophthalmological tests and neuropsychological assessment. Visual field deficits were present in 17 patients on the computerized test, in 16 patients on ophthalmological test, and in 13 patients on clinical examination. Neglect was present in 12 patients on the computerized test, and in 10 patients on the neuropsychological assessment. Eighteen patients had mixed disorder (hemianopia and neglect). Results of the chi 2 statistic confirm the greatest correlation between the computerized test and the ophthalmological (phi = 0.93; p < 0.001) and neuropsychological (phi = 0.90; p < 0.001) tests. Correlation between the computerized test and the clinical examination was poorer (phi = 0.85; p < 0.001). The computerized test makes it possible to detect mixed disorder with the same tool, during the same examination.

Adolescent↗

Temporary phantom limbs evoked by vestibular caloric stimulation in amputees.

OBJECTIVE: Relationships between the vestibular system and the body schema have been suggested but never demonstrated in amputees. We studied the effects of vestibular stimulation on body representation in amputees focusing on the phantom limb phenomenon. METHOD: Prospective study in 31 amputated subjects of one or several limbs before the age of 16 years. The amputees underwent a caloric vestibular stimulation test, ipsilateral (n = 31) and contralateral (n = 8) to the side of amputation. Amputees were asked to report their perceptions spontaneously and to answer open questions. Four types of perceptions were analyzed: normal phantom, deformed phantom, painful phantom, and no phantom, before, during, and after the vestibular stimulation test. Data were compared between the two groups for pre- and post-test perceptions (chi2 test). RESULTS: Vestibular caloric stimulation provoked temporary perception of a normal phantom limb in 16 of 17 amputees who previously did not experience phantoms. For 12 of 12 amputees who currently experienced deformed or painful phantom limbs, caloric stimulation led to temporary replacement of the abnormal phantom with a non-painful normal phantom. CONCLUSIONS: The phenomena observed: 1) throw light on assumed mechanisms controlling construction of static and dynamic engrams used to produce the body schema; 2) complete the neuromatrix theory proposed to explain the phantom limb phenomenon; and 3) suggest that the vestibular system triggers the procedure of reconstruction of the global body schema.

Adult↗