[Pupillometry in Menière's disease].

The autonomic dysfunction is one of the etiopathogenetic hypothesis of Ménière's disease. We have already described the presence of an anomalous pupillary contraction, induced by methacholine, during the attack stage of Ménière's disease, without cardio-vascular reflexes involving. We have now employed, in a larger number of cases, a new digital equipment with infrared lighting system, built by us. The pupillary area was measured in darkness by a personal computer in basal condition (time 0) and 10, 20, 30, 45, 60 minutes after methacholine instillation. We have observed 16 cases of Ménière's disease (during attack stage and free stage), 23 cases of other vertiginous disorders (during attack stage and free strage), 10 normal subjects (5 cases of these also during a caloric test). The pupillary contraction was always highest at 30 minutes after methacholine administration. Normal subjects didn't show anisocoria and the contraction was weak and symmetric. Caloric test modified only a little the pupillary response. We observed the same results in other vertiginous disorders. During free stage of Ménière's disease there was little basal anisocoria but the contraction was normal and symmetric. During attack stage of Ménière's disease the contraction was much more evident and higher on the affected side. Ménière's disease crisis is characterized by cholinergic pupillary hyperreactivity, that is not caused by labyrinthic reflexes. We suppose this autonomic dysfunction of central origin.