[A new positioning maneuver for treating a subtype of postural unsteadiness - based on a modified model of the utricular macula].

Objectives: A new method for the treatment of a subtype of postural unsteadiness frequently seen in the medical office is proposed. Ten years of successful practical application and continuous refining of this new treatment lead to the definition of symptom-criteria, which are useful to distinguish patients, who get benefit by this new procedure and to a modified model of the utricular macula.

Materials and Methods: In a retrospective collection, the data of 15 patients with postural unsteadiness (mean duration of symptoms 61.7 months) successfully treated with the new maneuver are reported. Before treatment, all patients showed normal results in testing the caloric responses of the labyrinth, normal neurological investigation and no signs for cervical vertigo. Before and after treatment the DHI-score (Dizziness Handicap Index) was achieved by using the German version of the DHI-questionnaire. In all groups before and after treatment balance testing was performed using a posturography platform.

Results: Application of the new treatment lead to a significant improvement of the DHI-scores and of the posturographic results (significant reduction of body sway).

Discussion: The patients, who were successfully treated by the new maneuver have had presented the same symptoms like patients with a proven utricular dysfunction. This leads to a slightly modified model of the utricular macula. Beyond correctly positioned otoconia in the utricular macula and free otoconia in the endolymphatic utricular space, a third fraction of dysfunctional partially detached otoconia is postulated (causing the unsteadiness). Based on this theory, the single hair-cell with its accompanied otoconium might be the smallest receptor-unit of the macula-organ. This smallest receptor-unit might represent a biological mass-spring-system. According to technical mass-spring-systems used as accelerometers, the different sizes of the otoconia for a distinct direction of acceleration are necessary for covering different frequency-bands. Finally, a many years successfully tested modified variation of the new maneuver for treatment in the medical office and for self-treatment is proposed.