Biomedical subjects

G Rode

Publications and source records attributed to G Rode.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Validity of the breast imaging reporting and data system BI-RADS(TM) for clinical mammography in men].

AIM: The implementation of diagnostic standards enhances quality assurance. The American College of Radiology's Breast Imaging-Reporting and Data System (BI-RADS(TM)) is intended to standardize terminology in the mammography report, the assessment of the findings, and the recommendation af action to be taken. The purpose of this study was to assess the value of the standardized system for clinically apparent male breast tumors. Do the special male anatomy and physiology limit the applicability of an evaluation system designed for female screening mammograms? METHODS: 4 investigators with different degrees of experience retrospectively evaluated 160 male mammograms. Our study was based on the 36 cases which could be correlated to histopathological findings: gynecomastia in the majority of cases, but also 4 invasive ductal carcinoma, 1 leiomyosarcoma and 1 ductal carcinoma in situ. RESULTS: Assessment of the mammograms by BI-RADS(TM) (3(rd) Edition 1998) correctly placed all cases of malignancy into categories 4 and 5 without respect to the investigators's level of experience. CONCLUSION: Therefore, we conclude that the BI-RADS(TM)-classification can successfully be used to classify male mammograms with a high positive predictive value for malignancy. Knowledge of gender-specific imaging characteristics increases the specificity at a constant high level of sensitivity.

Aged↗

PubMed2001

[Otolith manifestations in Wallenberg syndrome].

Central vestibular pathways issuing from the otolith may be involved in Wallenberg syndrome, resulting in specific symptoms. These "otolith" symptoms are less well known than vestibular symptoms issuing from the canal. We report 15 patients with Wallenberg syndrome who had one or more clinical signs suggestive of otolith pathway involvement. Clinical examination looked for: Eleven patients presented ipsilesional skew deviation; ipsilesional tilt of subjective visual vertical was found in 8 patients; a room tilt illusion was described in 4 patients in either the frontal or the sagittal plane: 9 patients presented axial lateropulsion toward the lesioned side; 8 patients presented ipsilesional ocular lateropulsion, 6 of them in association with axial lateropulsion. Finally, 3 patients presented positional nystagmus evoked by head tilt in the roll or the pitch plane. Pathophysiology of these symptoms and evidence for an otolith pathway involvement are discussed.

Adult↗

PubMed2001

[Role of rehabilitation in hemineglect syndromes].

Unilateral neglect syndrome compromises functional outcome of left hemiparetic patients. Treatment of this syndrome is a challenge in motor rehabilitation in order to reduce the incapacity and improve the prognosis. In this study, we present a review of the literature focusing on the different rehabilitation techniques proposed and their theoretical basis: improvement of the ability to maintain attention, improvement of spatial selective attention by implicit or explicit cueing, reduction of rightward orienting bias by sensory manipulations. Recently, we reported the improvement of symptoms of unilateral neglect syndrome after a prism adaptation to a rightward optical deviation. Unlike previous physiological manipulations used to improve neglect, this improvement lasted for at least two hours after prism removal. These results are most promising for rehabilitation programs. They may be linked to a stimulation of a short-term plasticity of brain functions and underline the interest of action in rehabilitation of neglect.

Adaptation, Physiological↗

PubMed2001

[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↗

PubMed2000

Cognitive bias induced by visuo-motor adaptation to prisms: a simulation of unilateral neglect in normal individuals?

Unilateral neglect has been recently shown to be improved following a short period of adaptation to wedge prisms. The present study investigates whether visuo-motor adaptation can generate a bias in normals on line bisection tasks classically used to assess unilateral neglect. Our results show that adaptation to left-deviating prisms induces a stronger rightward bias for the perceptual than the motor line bisection task. This bias is in the same direction as the one observed in unilateral neglect. No significant effect is produced by adaptation to right-deviating prisms. Our data confirm that the plasticity of inter-sensory and sensori-motor coordinations affects higher levels of space representation. These asymmetric results may reflect the inherent bias of the brain's structural organisation and provide an empirical explanation for the left-sided predominance of unilateral neglect.

Adaptation, Physiological↗

PubMed2000

An 'automatic pilot' for the hand in human posterior parietal cortex: toward reinterpreting optic ataxia.

We designed a protocol distinguishing between automatic and intentional motor reactions to changes in target location triggered at movement onset. In response to target jumps, but not to a similar change cued by a color switch, normal subjects often could not avoid automatically correcting fast aiming movements. This suggests that an 'automatic pilot' relying on spatial vision drives fast corrective arm movements that can escape intentional control. In a patient with a bilateral posterior parietal cortex (PPC) lesion, motor corrections could only be slow and deliberate. We propose that 'on-line' control is the most specific function of the PPC and that optic ataxia could result from a disruption of automatic hand guidance.

Adult↗

PubMed1999

Regression of vasomotor disorders under intrathecal baclofen in a case of spastic paraplegia.

Continuous intrathecal baclofen infusion via a subcutaneously implanted programmable pump has been used in the treatment of severe spasticity. Improvement classically concerns the neurological (hypertonia, spasms, hyperreflexia), urological (bladder function) and other clinically relevant outcomes, such as functional status of daily living. This short note reports on another effect of intrathecal baclofen on vasomotor disorders and cyanosis in the lower limbs, described in a patient with spastic paraplegia.

Adult↗

PubMed1998

Prism adaptation to a rightward optical deviation rehabilitates left hemispatial neglect.

A large proportion of right-hemisphere stroke patients show hemispatial neglect-a neurological deficit of perception, attention, representation, and/or performing actions within their left-sided space, inducing many functional debilitating effects on everyday life, and responsible for poor functional recovery and ability to benefit from treatment. The frequent parietal locus of the lesion producing neglect reflects the impairment of coordinate transformation used by the nervous system to represent extrapersonal space. Given that adaptation to a visual distortion can provide an efficient way to stimulate neural structures responsible for the transformation of sensorimotor coordinates, the aim of our study was to investigate the effect of prism adaptation on various neglect symptoms, including the pathological shift of the subjective midline to the right. All patients exposed to the optical shift of the visual field to the right were improved on their manual body-midline demonstration and on classical neuropsychological tests. Unlike other physiological manipulations used to improve neglect, this improvement lasted for at least two hours after prism removal and thus could be useful in rehabilitation programmes. The positive effect found for both sensorimotor and more cognitive spatial functions suggests that they share or depend on a common level of space representation linked to multisensory integration.

Adaptation, Ocular↗

PubMed1998

Improvement of the motor deficit of neglect patients through vestibular stimulation: evidence for a motor neglect component.

The effect of vestibular stimulation on motor performance has been studied comparatively in 2 groups of hemiplegic patients, one including 9 right brain-damaged patients (RBD) with neglect, the other 9 left brain-damaged patients (LBD) without neglect. In the RBD group, a transient but significant improvement of motor performance was observed following stimulation, although motor scores remained unchanged in two cases. Moreover, a temporary remission of personal neglect and anosognosia was obtained in 8 out of 9 patients. In contrast to the RBD group, the motor performance of the LBD group was not improved through vestibular stimulation, although a moderate improvement of force was noticed in one ambidextrous patient who had shown transient signs of neglect at the acute stage. These results suggest the participation of a motor neglect component in the motor deficit of neglect patients. The motor neglect component may be considered as one of the many manifestations of the neglect syndrome and, as such, can be improved by the sensory manipulations which presumably restore a conscious representation of the left side of space.

Adult↗

PubMed1998

Postural asymmetry reduction by vestibular caloric stimulation in left hemiparetic patients.

The purpose of this study was to investigate the effects of caloric vestibular stimulation on the postural sway characteristics of hemiparetic patients. Two groups of 15 hemiparetic patients each (right and left) were compared to a group of 15 control subjects. Hemiplegic patients were selected for the study if they showed ability to stand without external support for at least 30 seconds. Posturographic evaluation was performed on a statokinesimetric platform just before and after a cold contralesional ear irrigation (20 degrees C) during 60 seconds. Two quantitative parameters were analysed: the antero-posterior difference and the lateral difference, reflecting the asymmetry of standing in the antero-posterior and frontal planes, respectively. The results of the 3 groups studied were compared with a Student's t-test. Before stimulation, as previously reported, left hemiparetic patients showed a predominant lateral displacement of the centre of pressure toward the side of the lesion, as compared to right hemiparetic patients. After vestibular stimulation, the lateral displacement was reduced in both patient groups, predominantly in the left hemiparetic group. After vestibular stimulation, the lateral displacement thus was not different in both patient groups and in the control group. Antero-posterior differences were not significantly different in the patient groups and in the control group before stimulation and were not affected by vestibular stimulation. The suggestion is made that greatest postural imbalance produced by right brain damage could reflect a persistent distorsion of a "spatial postural representation". Vestibular stimulation may restore symmetrical activity in the cerebral structures involved in the generation of this "spatial postural representation".

Adult↗

PubMed1997

Predominance of postural imbalance in left hemiparetic patients.

Postural sway characteristics in a group of 15 left hemiparetic patients were compared with those in a group of 15 right hemiparetic patients using a statokinesimetric platform. The results in the two patient groups were also compared with those derived from a group of 15 age-matched healthy control subjects. Three postural sway parameters were used: the total sway area, the anteroposterior sway and the lateral sway. Hemiparetic patients showed a larger sway area and a lateral displacement of the center of pressure toward the side of the lesion compared to normal subjects. Furthermore, left hemiparetic patients showed greater sway area and lateral displacement compared to right hemiparetic patients. We suggest that the predominance of postural imbalance in left hemiparetic patients could be due to a displacement of postural reference toward the lesion's side.

Adult↗

PubMed1996

Inverse relationship between sensation of effort and muscular force during recovery from pure motor hemiplegia: a single-case study.

A 39-year-old patient with a right pure motor hemiplegia, who complained of a striking sensation of effort when he performed a movement, was regularly examined during 4 months. The effort sensation and the force recovery have been measured during the execution of upper limb movements: shoulder antepulsion up to horizontal, supined elbow flexion up to horizontal and full hand digital grip. The subject was asked to realize a movement with the paretic arm and to concentrate on the felt effort; then he had to perform the same movement against a resistance with the healthy arm, until the perceived heaviness matched the effort sensation felt on the other side. Recovery of force and evolution of effort sensation did not follow linear trends over time. The curves displayed significant steps and plateaus, which were mainly observed for the proximal movements. The steps tended to be clustered within a few days, consistent with crucial periods in the restoration process. Within these, significant reduction of the effort sensation and increase of the force were together observed. These critical moments of the motor recovery could be analyzed as the result of an improvement of the neural traffic in the internal capsule and an activation of specific structures involved in the representation of the force and effort.

Adult↗

PubMed1995

Implicit processing of somaesthetic information: a dissociation between where and how?

We present the case of a patient with a lesion of the thalamus who was completely anaesthetized on his right side. He was unable to detect and describe a tactile stimulus applied to his affected right arm, but could direct his normal left hand toward the specific right hand site where the stimulus had been applied when so instructed ('blind touch'). Strikingly, this pointing ability disappeared when the patient had to indicate on a picture of an arm where the stimulus was applied, and when he had to name the stimulus location during his pointing. Similar results were also obtained for localizing the unfelt fingertip ('blind proprioception'). Neuropsychological case studies have demonstrated that brain lesions can produce reciprocal dissociations between object identification (what is the object) and object-oriented action (how to direct a movement to the object). Along these lines, it is suggested that our patient exhibited a dissociation between a 'where' system and a 'how' system for tactile and proprioceptive stimuli.

Cerebral Hemorrhage↗

PubMed1995

[Disulfiram (Esperal) toxicity. Apropos of 3 original cases].

Prescribed since 1948 to control chronic alcoholism, disulfiram may cause severe toxicity as report in three cases of acute motive axonal polyneuritis. Disulfiram toxicity may present different clinical aspects: 1) Cytolytic hepatitis with fatal evolution in 30% of cases (fulminant hepatitis), and full recovery for the other 70%. The onset of the symptoms usually occurs as early as 15 days to a maximum of 6 months (most within 2 months) after initiation of treatment. 2) Severe optic neuritis with full recovery in 2 months. 3) Peripheral neuropathy usually dose dependent, with different clinical presentations: polyneuritis with sensory, motor, or both deficits, and few cases of tetraplegia. 4) Encephalopathy frequently associated with one of the precedent symptoms, having a favorable outcome (probably resulting in inhibition of dopamine-beta-hydroxylase by disulfiram). The mechanism of toxicity (direct or idiosyncractic) remain unclear. Disulfiram has been used safely in millions of people since 1948, and we have only few cases reports of severe toxicity. From a practical point of view, treated patients should benefit by a neurological examination once a month, ophtalmological examination every 2 months, and hepatic enzymes monitored twice a month during the 2 first months. This is the price to prevent and to detect side effects of disulfiram therapy.

Adult↗

PubMed1995

[Neglect of the representational space: demonstration by mental evocation of the map of France].

Neglect of the representational space has been shown in 8 patients asked to evoke mentally the map of France and to name as many towns as possible successively on each side of a vertical axis splitting the map in two equivalent halves. They had first to imagine the map with an axis in the south-north direction and then with an axis in the reverse direction (north-south). The results were similar to those reported by Bisiach and Luzzatti (1979). They reflect a disturbance of the mechanisms involved in conscious representation of space. In addition we report on the effects of vestibular stimulation on the reversibility of representational neglect in 3 patients. These preliminary results provide support for the idea that vestibular stimulation would play centrally by restoring the symmetry of the internal representation of egocentric space.

Analysis of Variance↗

PubMed1994

Temporary remission of representational hemineglect through vestibular stimulation.

This study was aimed at finding whether vestibular stimulation could reduce neglect of representational space, in the same way it reduces other manifestations of the neglect syndrome. Representational neglect was shown in 8 patients asked to evoke mentally the map of France and to name as many towns as possible successively on each side of a vertical axis splitting the map in two equivalent halves. Performances appeared much poorer on the left than on the right side. Immediately after a cold left ear irrigation, the left side scores improved in all patients, although the right scores remained unchanged. The results are discussed within the framework of the representational theory of neglect. It is proposed that mental representation of space would result from dynamic and distributed neural mechanisms.

Attention↗

PubMed1993

Echocontrast agent enhanced color flow imaging of the breast.

An ultrasound contrast agent which survives transit through the pulmonary circulation after injection into a peripheral vein can also be used for the demonstration of flow characteristics in the peripheral organs. Such a substance (SH U 508 A, Schering AG, Berlin) was tested in the Gynecological Department of the University of Marburg for its suitability for enhancing color-coded Doppler signals in mammary diagnosis in a group of ten women with breast tumors. The observations made are compared with the histologically confirmed diagnoses. The very distinct enhancement of the color-coded Doppler signals allows reliable demonstration of the vascularization characteristics, not only of the malignant, but also of all benign solid tumors examined. Color signals were even recorded from normal mammary tissue, which means that the demonstration of perfusion can no longer be used on its own as a diagnostic criterion. Observation of the characteristics of the blood supply to a tumor might, on the other hand, be an advantage, not only in respect of tumor typing, but also as regards the prognosis of a tumor. In this connection, the registration of the arrival, retention and wash-out phases specific to a contrast agent appears to furnish particularly interesting information about the growth dynamics of a tumor.

Journal Article↗

PubMed1992

Partial remission of hemiplegia and somatoparaphrenia through vestibular stimulation in a case of unilateral neglect.

In a case of long lasting severe neglect resulting from a large right parieto-temporo-occipital infarct, vestibular stimulation produced a temporary reduction of the motor deficit and disappearance of the somatoparaphrenic delusion, in addition to the already reported improvement of extrapersonal and personal neglect and anosognosia. These data open new perspectives in the understanding of the neglect syndrome and of functional involvement of the parietal lobe in space representation.

Aged↗