[Room tilt illusion: Report of two cases and terminological review]

The room tilt illusion is a transient misperception of the visual image as tilted on its side or even upside down; in this case it has been termed acute upside down reversal of vision. We report on two cases of room tilt illusion as manifestation of VIII nerve neuritis (herpes-zoster infection) and cerebellar hemorrhage. Room tilt illusion has been reported in association with vertebrobasilar stroke, migraine, multiple sclerosis, epilepsy and labyrinthine disorders. The pathophysiology of this rare visual illusion has been related to a lesion of the visual or vestibulo-otolith pathways. In animals the neurones of the parieto-insular vestibular cortex areas are multisensory. So, they can respond to somatosensory, optokinetic and visual stimuli. In humans the knowledge about vestibular cortex function and localization is less precise than in animals. However, we propose a disorder of multisensorial vestibular cortex, resulting from a lession of vestibular pathways or association cortex, as mechanism of this phenomenon.