The dynamic illegible E (DIE) test: a simple technique for assessing the ability of the vestibulo-ocular reflex to overcome vestibular pathology.

Vestibulo-ocular reflex (VOR) compensation, shown by the Dynamic Illegible E test (DIE test), for vestibular damage (as shown by caloric reduction) did not coincide consistently with time from initial onset of vestibular disease. We theorize that the reason for this is the variable efficiency of different compensatory mechanisms used by individuals in overcoming vestibular pathology. Methods of compensation are discussed in detail. The DIE test measures the efficiency of the VOR by comparing visual acuity with head still and head moving. While many patients compensated satisfactorily for vestibular injury to the point where they were able to function adequately, other patients appeared not to compensate. There was no obvious prior indication of which patients would compensate well. There was a suggestion that younger patients did better, but neither duration of symptoms nor severity of pathology appeared to be factors in the ability to compensate. Although younger patients may fare better as a group, there are no predictive criteria for the amount or rate of recovery which an individual patient with vestibular pathology will make.