Directional preponderance, 1942-1974. A review.

The subject reviewed is the phenomenon of Directional Preponderance (DP), a term first proposed in 1942 by Fitzgerald & Hallpike for an abnormality in the pattern of the caloric responses found to occur in association with a variety of unilateral lesions, both central and peripheral, of the vestibular system. On the basis of observations carried out upon a series of human subjects, Fitzgerald, Hallpike & Cawthorne (1942) argued that the DP towards the unaffected labyrinth which follows unilateral labyrinthectomy is subserved in part by a unilateral loss of utricular function--a utricular paresis. Support for the utricular paresis hypothesis, as developed in the course of subsequent studies by Hallpike and his co-workers is thought to be provided by a substantial body of evidence, both clinical and experimental, which has since become available. This is reviewed.