Vestibular disorders in primary thrombocytosis.

OBJECTIVE

Balance disturbances are some of the most common symptoms among the clinical manifestations of chronic myeloproliferative disorders (MPDs) with a high platelet count, such as essential thrombocythaemia (ET) and polycythaemia vera (PV). In this study, we evaluated the vestibulo-oculomotor and vestibulospinal reflexes in a group of patients suffering from these diseases.

DESIGN

Evaluation of balance disturbances.

SETTING

Department of Neurosciences, ENT Unit, University of Pisa, Italy.

METHOD: In this study, we evaluated 43 patients suffering from ET and PV who underwent otoneurologic examination, based on a study of the vestibulo-oculomotor and vestibulospinal reflexes.

RESULTS

There was exclusive central vestibular involvement in 26 cases (60.4%), peripheral and central signs were associated in 8 cases (18.6%), and the involvement was purely peripheral in 1 patient. In six patients (14%), the otoneurologic examination revealed no alterations.

CONCLUSIONS

The high percentage of balance disorders in cases of ET and PV probably depends upon disorders of the microcirculation due to platelet dysfunction. We also postulate a full explanation of the involvement of the central vestibular system on the basis of a greater availability of central activated serotonin acting as neuromediator.