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Biomedical subjects

M E Norré

Publications and source records attributed to M E Norré.

At least 19 recordsLinked to original sources
PubMed1996

Head stabilization in peripheral vestibular syndromes.

In classical posturography the standing position has been evaluated by recording the postural sway on a force-plate and measuring some parameters such as surface and velocity (Platform or P-recording). The postural sway not only results in forces exerted on the support surface by the feet, but the head also participates in the movements of this postural sway. For recording of the head movements (H-recording), a lightbulb is placed on top of the head and the described light-path is recorded by a TV camera. Such an H-recording can be achieved simultaneously with the platform-recording. A comparative study indicates that, for some patients differences could be found between H- and P-recordings, for others not. The H-recording, in fact, gives information about the stabilization of the head, compared with the stability on the platform (P-recording). The importance of the information furnished by the double recording in Static Posturography type IV (SPGIV) can be deduced from the number of patients showing one or more differences between the types of recording. Nearly 70% showed a difference in at least one test. In fact, 55% showed it in two or more tests. In half of the tests, considered separately, a difference was noted. The differences observed provide complementary information in this combined recording. If the H-recording were to be used as a separate technique, it has to be born in mind that the results are certainly not always the same as when using P-recording, as in classical posturography.

Adolescent↗
PubMed1995

Head extension effect in static posturography.

The effect of head extension on the standing position has been studied by analysis of recordings made by static posturography type III (SPGIII), a set of six test of posturography for sensory interaction. The head extension effect in posturography was evaluated by comparing the results of testing with head extension on a stable platform and on foam rubber to testing with a normal head position. In normal subjects head extension increased the postural sway, but there was no more effect on foam rubber than on the stable platform. For patients with peripheral vestibular disorders the head extension effect on the measured postural sway was evaluated by the difference from the normal condition. This difference could be positive, zero, or negative on the stable platform as well as on foam rubber. In both patients and normal subjects, foam rubber had no more effect than the stable platform. The several types of results could be seen in each category of peripheral vestibular disorders. Only minor nuances could be observed: positive differences were more pronounced in benign paroxysmal positional vertigo, whereas negative ones were more obvious in unilateral vestibular deficits. These findings, moreover, deny that head extension in SPGIII should be considered a condition revealing vestibular dysfunction, as has been supposed. As head extension has an influence on the neck proprioceptor as well as on the position of the otoliths, its effect is ambiguous, which makes the interpretation rather difficult. A neck proprioceptive as well as an otolithic explanation appears to have some clinical support.

Head↗
PubMed1995

Posturography: head stabilisation compared with platform recording. Application in vestibular disorders.

Posturography with simultaneous recording of the head movements (H-recording) and of the pressure of the feet on the platform (P-recording) has been applied in patients with peripheral vestibular disorders. For the whole testing (four tests with visual and proprioceptive interaction) 40% showed an identical degree of abnormality for the measurements of surface in P- and H-recording. In a large majority of the patients, showing a difference between H- and P-recording, this difference indicated a lower degree for the H-recording. Concerning the four tests separately, the differences for eyes closed tests were more frequently positive (larger surface for head movements) than for eyes open tests. Also on foam rubber there was more difference than on stable platform. Especially the test with eyes closed on foam rubber showed more differences. These data show that in a minority of patients the comparison of H-recording and P-recording affords complementary information showing in these cases some independence of head stabilisation and foot-stabilisation. Head-recording can be used as a posturographic technique but one has to keep in mind the possible differences with platform-recording.

Functional Laterality↗
PubMed1995

Reliability of examination data in the diagnosis of benign paroxysmal positional vertigo.

A practical clinical view of the reliability of the data obtained in the several steps of the examination procedure is discussed to obtain an objective basis for the selection of patients with provoked vertigo (benign paroxysmal positioning vertigo [BPPV]) in view of treatment of this type of vertigo by rehabilitation therapy. Clinical experience supports the concept that the diagnosis has to be based not only upon a typical history, but also upon the presence of a reproducible vertigo and paroxysmal positional nystagmus (ppn). Such a ppn can be reproduced not only as a "classic" nystagmus by the Dix-Hallpike maneuver, but also as a positional nystagmus and vertigo during electronystagmographic recording in the position tests and in the vestibular habituation training (VHT)-test battery (a battery of 19 maneuvers applied for defining the adequate exercises in the rehabilitation treatment of BPPV). The ppn is not a constant reproductible sign in every patient, and in some, only one of these tests confirms the BPPV. This experience is confirmed by the analysis of the reviewed data in 95 patients, which showed that one third of the patients described their vertigo in a rather atypical way, whereas further testing revealed a BPPV. In this way any absolute reliability of history has to be denied. In fact, only the finding of a ppn is conclusive for confirming BPPV. However, as in former experiences, here too, the presence of such a ppn appeared not to be a constant datum, so that in some patients more than one examination was necessary to come to a reliable diagnosis. Patients in whom only vertigo could be reproduced, never confirmed by nystagmus, were excluded as an atypical ppv group.

Adolescent↗
PubMed1994

Relevance of function tests in the diagnosis of vestibular disorders.

The diagnostic value or relevance of a vestibular function test is dependent on the whole clinical and functional context of each particular case. It is not the ability to show 'abnormality' in a high number of patients complaining of whatever kind of vertigo, that indicates the relevance of a function test. Neither is relevance of a test based upon the possibility that this test can re-categorize some patients in the same way as has been done by other tests. Each test evaluates some particular functional aspect and this is very different from one test to another. A test is more relevant, i.e. indicates more abnormality when the type of vertigo caused by the dysfunction is also considered. These statements are confirmed by experience in peripheral vestibular disorders, especially benign paroxysmal positional vertigo (BPPV). A paroxysmal positional nystagmus (ppn) (nystagmus and vertigo elicited by movements and manoeuvres) is linked to the problem of provoked vertigo and gives a confirmation of this vertigo by reproducing it in some manoeuvres. Some inconstancy in the reproduction of this ppn may cause difficulties in diagnosis. Caloric tests are the clue for diagnosis of sudden unilateral loss (so-called neuronitis), whereas they give only complementary information for patients with BPPV. Posturography adds information in all categories concerning the standing position and can be interesting in the scope of rehabilitation treatment. The findings of a retrospective study in patients with BPPV (n = 95), compared with patients with Ménière's disease (n = 89) and others with sudden unilateral loss syndrome (n = 48), illustrate these concepts.

Audiometry↗
PubMed1994

Sensory interaction posturography in patients with peripheral vestibular disorders.

The results of posturography, using all sensory inputs, are compared with recordings when one or more of the sensory inputs are altered by the test conditions. This gives an idea of the sensory interaction in central compensation in the vestibulospinal reflex. Positive and negative effects could be observed in patients with peripheral vestibular disorders.

Female↗
PubMed1994

Diagnostic problems in patients with benign paroxysmal positional vertigo.

The steps of the examination procedure applied for a correct diagnosis of benign paroxysmal positional vertigo (BPPV) are reviewed. A precise diagnosis is important in view of treatment of this type of vertigo by rehabilitation therapy. Clinical experience supports the concept that the diagnosis has to be based not only on a typical history, but also on the presence of a reproducible vertigo and paroxysmal positioning nystagmus. In the procedure applied in the department, this nystagmus can be reproduced by the Dix-Hallpike maneuver under Frenzel's glasses, during electronystagmography (ENG) recording in the position tests, or it can be present in the vestibular habituation training test battery (a battery of 19 maneuvers applied for defining the adequate exercises in the rehabilitation treatment for BPPV). Analysis of the reviewed data in 95 patients showed that one third of the patients described the vertigo in a rather atypical way, while the further testing revealed a typical BPPV. This experience denies any absolute reliability to only history. In fact, only the finding of such a paroxysmal positioning nystagmus is conclusive for confirming BPPV. However, also the presence of such a nystagmus appeared not to be a constant datum, so that in some patients more than one examination was necessary to come to a reliable diagnosis. It is obvious that, for detecting a paroxysmal positioning nystagmus, ENG is less reliable than the Dix-Hallpike maneuver under Frenzel's glasses.

Adult↗
PubMed1994

Can posturography contribute to the diagnosis of vertigo in patients where other tests fail to do so?

In this study, patients showing abnormal posturographic results in a test-configuration upon examination of the visuo-proprioceptive-vestibular interaction (Static Posturography type III, SPGIII) are reviewed. Group I (n = 81) comprised patients for whom no clear diagnosis could be obtained (neither central nor peripheral) and with rather atypical complaints. Group II (n = 77) comprised patients in whom a well-defined peripheral disorder could be found (typical provoked vertigo as BPPV (n = 30) and Meniere's disease (n = 30)). Group I consisted of s subgroup Ia, including patients with a complete negative classical examination (n = 32), a subgroup Ib with patients showing minor central signs (n = 28), and subgroup Ic comprising patients with slight peripheral indications (n = 21). The findings in SPGIII were compared between these two groups and are discussed in the light of earlier experience with such data in typical peripheral vestibular disorders. Similar sensory interaction patterns were found in both groups, with only small differences between them, suggesting that in some of these cases, especially in subgroups Ia and Ic, vestibular disturbance might be present, which would not have been sufficiently and clearly revealed by the classical tests. Especially the negative effects, i.e. when the withdrawal of a sensory input improved stability instead of aggravating it, which is the opposite to what should be expected, suggest that the other sensory inputs, vision and proprioception, play a role in the definition of the posturographic results in typical vestibular disorders as well as in diagnosis.

Adult↗
PubMed1994

Vestibular patients examined by posturography: sensory interaction testing.

Posturography (PG) examines the influence of vestibular disturbance on standing balance via the vestibulospinal reflex. Testing under several conditions, in which the sensory input by vision and proprioception is impeded from contributing in a normal way, evaluates the "sensory interaction." In a number of patients with known peripheral vestibular disorders, PG showed normal results, which indicate that, for these patients, the possible influence of the vestibular dysfunction has been cancelled at the central level (compensation). In the others, influence was seen in several degrees. The sensory interaction indicated that this group can be subdivided according to the sensory input that had the most influence in the balance performance in standing. The sensory contribution of vision and proprioception was mostly positive (i.e., enhancing the vestibular compensation). In some cases, there was a negative effect, indicating that the sensory input considered had a disturbing influence. No pattern of results could typify the several groups of peripheral vestibular disturbances. Posturography provides complementary information to the classically obtained diagnoses. The data of posturographic examination can provide useful information about the problem of falling in the elderly and give suggestions for adequate rehabilitation exercises.

Caloric Tests↗
PubMed1993

Sensory interaction testing in platform posturography.

Mostly techniques measuring the vestibulo-ocular reflex (VOR) have been used for the evaluation of patients with dizziness problems. Some investigators, however, have also tried to take into account the vestibulospinal reflex (VSR). So recording techniques for the Romberg-test have been proposed and called posturography (PG). By interfering with the visual and proprioceptive sensory inputs during this PG-testing one tries to find out how 'sensory interaction' is organized in the balance performance of the patient examined. To interfere with vision, closure of the eyes has been commonly used and to interfere with proprioception, the patient can be put on foam-rubber, which makes the contribution of the foot-ankle proprioception less adequate. These interferences are applied once separately and once combined. The degree of 'abnormality' is assessed by a score-system for parameters surface (S) and velocity (V), which measure the postural sway. A comparison of tests with and without influence on the sensory inputs gives an idea of the sensory interaction. Patients with peripheral vestibular disorders were examined: patients with BPPV, with spontaneous vertigo attacks and with a sudden vestibular deficit. When applying this evaluation technique different formulae or patterns can be found. Firstly complete normal evaluation, which means that there is no influence of the vestibular disturbance upon the PG results. Secondly a normal balance when using all available sensory information, but disturbed balance as soon as one of the sensory inputs is influenced by the test conditions. Thirdly striking destabilization when closing the eyes. Fourthly striking destabilization when misleading the ankle and foot proprioceptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Sensory interaction posturography in patients with benign paroxysmal positional vertigo.

BPPV (benign paroxysmal positional vertigo) is a very common peripheral vestibular disturbance. The dysfunction becomes manifest mainly by vertigo and typical nystagmus. However, the vestibulospinal reflex (VSR) can also be disturbed. This can be shown by the SPGIII (static posturography type III), which is a platform technique evaluating 'sensory interaction' in a way comparable to that of the Equi-test. Half the patients with BPPV show disturbed posturographic results. By interfering with the sensory input of vision and/or proprioception, the separate contribution of each input can be evaluated. Different 'formulae' are seen, from complete normal results, through 'overall' formulae, i.e. an undifferentiated influence in all test-conditions, to specific formulae, where we find 'eye-closure' and 'head retroflexed'-effect and so-called 'vestibular formulae'. These formulae are an expression of the different degrees of compensation achieved by the centres and especially of the 'substituting' compensation by vision and proprioception. These results confirm that posturography does not provide a typical results-pattern, thus the type of peripheral vestibular disorder cannot be diagnosed by it alone. The results give functional information on how the standing position is achieved in these patients with a disturbed VSR-input. The several formulae prove that indeed different compensatory patterns are possible, as has been shown by experiments on vestibular compensation.

Adolescent↗
PubMed1992

Contribution of a posturographic six-test set to the evaluation of patients with peripheral vestibular disorders.

A posturographic six-test set was developed in order to investigate the contribution of each sensory input in the balance performance of patients with peripheral vestibular disturbances. In test 1 (t1) the three sensory inputs are contributing to balance. In (t2), the contribution of vision is excluded by closing the eyes; in (t3) the neck proprioceptor is influenced by extreme retroflexion of the head, and in (t4) the input of the foot-ankle proprioceptor is altered by standing on foam rubber. The first two conditions are combined with the third one in (t5-t6). This test procedure compares the results obtained when the input of one (or two) sensors is impeded or altered with the results when the same sensors are uninfluenced. This comparison allows us to evaluate the individual contribution of the sensory inputs involved in the process of balance, especially in the compensation process in patients with benign paroxysmal positioning vertigo (BPPV) and with Ménière's disease. This comparative evaluation shows several "formulae." So can formulae with positive tests for head in retroflexion condition be more frequently met in the BPPV-group, whereas influence of visual exclusion is more frequently seen in the Ménière group.

Adult↗
PubMed1990

Posture in otoneurology. Volume I.

In this study, posture is studied in the context of neuro-otological problems. In the several chapters, postural elements, postural influence upon balance aspects as well as postural components of the balance function in normal and pathological conditions are emphasized. Two main applications are put forward: rehabilitation by postural treatment techniques (REHAB) and examination techniques for the vestibulospinal aspects (posturography--PG). I. Balance function Balance is provided by automatic reflexes for stabilization of the visual field (vestibulo-ocular reflex--VOR) and for a correct posture, erect standing (vestibulo-spinal reflex--VSR) and head position (vestibulo-collic reflex--VCR). The fundamental characteristics of these reflexes are described, especially of those related to posture. The reflexes are elaborated on the basis of sensory inputs that inform about changed relations to space and environment, provided by visual, vestibular and proprioceptive systems. The sensory signals are further processed by the centers to adequate reflexes and to some extent to a conscious awareness. II. Dysfunction and adaptation Dysfunction in the balance mechanisms leads to erroneous reflexes, but most importantly to frightening sensations of vertigo. The peripheral disturbances produce a sensory mismatch which is the primum movens of vertigo. Built-in adaptive mechanisms cope with this disturbance and restore global balance function. The mechanisms involved have been studied as vestibular compensation and habituation, VOR-reflex plasticity and sensory "substitutive" compensation. The mechanisms are set into action by the dysfunctional situation and constitute an error-controlled process. Emphasis is laid upon the items related to rehabilitation treatment and posturography. A survey of clinical entities of vestibular peripheral dysfunction is included. III. Examination techniques The logical approach to the patient with vertigo consists in an analysis of the complaints pattern, correlation of it with the dysfunctional state revealed by clinical observation, and functional tests of balance. Correct interpretation of the test results is a pre-requisite. Postural aspects of these examination techniques, especially posturography, are put into evidence in this review. The strategy used in the department is sketched. IV. Contribution of the examination techniques: functional evaluation results The several data obtained by each examination technique are discussed within the scope of the experiences in the department. Data from the literature and from personal experience, especially interpreted in the context of rehabilitation and posturography, are analysed. V. Reh

Adaptation, Physiological↗
PubMed1989

Vestibular habituation training for positional vertigo in elderly patients.

Positional vertigo can be successfully treated by exercises (Vestibular Habituation Training, VHT) in elderly patients as well as in younger ones. Provided the patients have been correctly selected, this type of treatment is the only way for an adequate treatment of such a type of vertigo. Application of VHT has to be recommended also in elderly people, as the results obtained are as favourable as those in younger people. Only a slower evolution is observed, which can be correlated with a more restricted activity pattern in the elderly.

Adult↗
PubMed1989

Vestibulospinal findings in two syndromes with spontaneous vertigo attacks.

The influence of vestibular dysfunction upon the vestibulospinal reflex (VSR) in two common peripheral syndromes was investigated by two types of posturographic examination: "static" posturography, recording and analyzing the postural sway in stance, and "kinetic" posturography, recording the stepping in place test. The influence of the dysfunction was examined outside the attacks, ie, between attacks and not during or immediately after an attack, in patients with Meniere's disease and in others with a sudden vestibular loss syndrome, "neuronitis." However, in both syndromes the influence of the dysfunction was obvious only in some patients; this indicates that central adaptation intervened in the other patients. In this way, central compensation related to the VSR was assessed and compared with compensation for the vestibulo-ocular reflex assessed by the rotation tests. Discordance was shown in a number of cases, ie, a number of cases showed compensation for one reflex, but not for the other. Comparison of the results of both posturographic methods also showed discordance. Normal performance in the walking test could not always be correlated with normal performance in the standing test and vice versa.

Humans↗
PubMed1989

Vestibular habituation training: exercise treatment for vertigo based upon the habituation effect.

Vestibular habituation training is an exercise treatment for positional vertigo based on the assumption that such a type of vertigo can be cured by habituation effect. The latter is produced by repeating the situation eliciting vertigo. In this way the mechanisms of adaptation and compensation are stimulated, processes of which have been considered "error controlled." Clinical experience with the vestibular habituation training test battery (consisting of 19 maneuvers) showed that in each particular patient only a limited number of responses were positive in various combinations. Selecting the exercises is then a logical consequence. Followup showed a progressive reduction of the positive cases, as well as the number of positive maneuvers. This is in accordance with the development of compensation as it has been observed in experimental conditions and with the decline of progressive responses observed in habituation experiments.

Exercise↗