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Biomedical subjects

M E Norre

Publications and source records attributed to M E Norre.

7 recordsLinked to original sources

Posturography measuring instability in vestibular dysfunction in the elderly.

Balance dysfunction may be a cause of falling in the elderly. Disturbance of the vestibular system may have a repercussion upon balance performance, causing instability. Unilateral vestibular hypofunction (UVH) and its disturbing influence upon the vestibulospinal reflex (VSR), measured by the postural sway, has been studied. This influence is dependent on the interfering action of central adaptive and compensatory mechanisms. This central compensation may be different for vestibulo-ocular reflex (VOR) and the VSR. This comparative study shows that the elaboration of compensation in elderly people is less efficacious at the VSR level than at the VOR level. The influence of visual fixation is also stressed by comparing the posturographic recordings made with eyes open and eyes closed.

Accidental Falls↗

Caloric vertical nystagmus: the vertical semicircular canal in caloric testing.

Vertical nystagmus elicited by caloric testing does not necessarily mean there is central pathology. In a patient with confirmed peripheral vestibular disease, caloric stimulation produced an intense vertical nystagmus, which showed all the features of a caloric nystagmus. The patient had bilateral mastoid cavities, allowing easy stimulation of the posterior semicircular canal, using air. At the same time, a unilateral horizontal semicircular canal functional loss was observed, raising the possibility of dissociated canal dysfunction.

Adult↗

The importance of rotatory proofs in the evaluation of a dizzy patient.

In order to obtain an adequate functional evaluation of the vestibular system, we have to take into account the results of as well the caloric as the rotary tests. The discordance obtained in some cases, where a complete bilateral caloric areflexia is present whereas a conserved reactivity is confirmed by the rotationstimulus, argues against the merely application of the caloric stimulus. The opposite data obtained by both tests provide us information necessary to a good understanding of the functional state of our dizzy patient. Those cases where an unilateral hypo- or areflexia is detected by the calorics, may prove to be either "compensated" or not at the rotary stimulus. This functional datum is very important, as it informs us about the "Regulations-funktion", the central vestibular processing. Even in some cases only the rotary proof may indicate a dysequillibrium, which constitutes an objectivation of the dizzy state of our patient. The caloric DP, though it is a similar dysequilibrium, cannot substitute the rotary DP, this imbalance being of the same nature but not identical. We confirm and illustrate these argumentations by the statements in a series of 513 patients examined by a complex rotatory stimulationscheme.

Eye Movements↗