Clinical and imaging features of the room tilt illusion.

Room tilt illusion (RTI) is a transient disorder of the environmental visuo-spatial perception consisting of paroxysmal tilts of the visual scene. It is attributed to an erroneous cortical mismatch of the visual and vestibular three-dimensional coordinate maps. Thirteen subjects were included in this retrospective case series. Clinical presentation was 180º rotation of the visual scene following the coronal plane in seven patients. The most common cause for RTI in our series was posterior circulation ischaemia (five cases). Cases of endolymphatic sac tumour, critical illness neuropathy, acute traumatic myelopathy and multiple system atrophy causing RTI are reported for the first time. No case of supratentorial focal lesion was found. In order to describe the clinical and imaging features of RTI, 135 cases previously reported in the literature were reviewed along with our series. There was a male predominance (60.2 %). Mean age was 51.2 ± 20.3 years. The most common location of the injury was the central nervous system (CNS) (61.4 %). Supratentorial and infratentorial structures accounted for the same frequency of lesions. The most common aetiology was cerebral ischaemia (infarction or transient ischaemic episode; 27.7 %). These patients were significantly older and their lesions commonly involved posterior fossa structures when compared to patients with non-vascular disorders. In summary, RTI is a manifestation of several CNS and vestibular disorders, and rarely of peripheral nervous system disorders, triggered by disruption of vestibular and sensory perception or integration. Cerebral ischaemic disorders are the most common aetiology for this rare syndrome.