THE CALORIC EYE TRACKING PATTERN TEST (CETP-TEST)

Abstract

During the examination of patients who complain of vertigo or who have equilibrium disorders, it is often difficult to determine the etiology of the disorder, that is to determine whether it is dependent on a peripheral or central vestibular disorder. In an attempt to determine the etiology in these cases, we devised a new method, the caloric eye tracking pattern test (CETP-Test).Twelve normal subjects and 95 patients were tested. The latter group included 17 with per-pheral disorders such as Meniere's disease, benign paroxysmal positional nystagmus, and others, and 78 with central disorders such as vertebral basilar artery insufficiency, Wernicke's encephalopathy, and others. The cases of central disorders were limited to those patients whose eye tracking pattern, before the caloric stimulation was normal.In normal subjects and in patients with peripheral disorders, as is well known caloric nystagmus had no influence on the eye-tracking pattern. In contrast, in patients with central vestibular disorders, caloric nystagmus evoked superimposed abnormalities or saccades on the eye tracking pattern, in spite of the fact that eye tracking pattern before the caloric stimulation was normal.It is obvious that in normal subjects and in patients with vestibular periphral disorders, there are no oculomotor disorders. The efore even if vestibular asymmetry is revealed by the caloric test, neither superimposed nystagmus nor saccades is evoked. In some cases of central disorder of the oculomotor system is slight, the eye tracking pattern is normal. It seems however that once the vestibulais asymmetry is shown by the caloric test, the latent saccadic movements are evoked. In regard to, a vascular lesion, since the disorder is reversible, the caloric eye tracking pattern will be also reversible during recovery. With an irreversible organic disorder, of course, the caloric eye tracking pattern remains constant These results allow us to make the differential diagnosis between peripheral and central disorders.