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.