Nortriptyline-Induced Room Tilt Illusion.

Room tilt illusion (RTI) is a rare and transient perceptual disturbance in which an individual perceives their surroundings as having been rotated or tilted, usually at 90 or 180 degrees. Primarily linked with vestibular disorders and neurological lesions, this report details the only reported occurrence of the RTI phenomena in nortriptyline use for treatment-refractory depression. The patient developed RTI six days after starting the medication and the disturbance resolved after medication cessation. Although the mechanism behind such a phenomenon with medication use has not been elucidated, its etiology may rest on the effect of tricyclic antidepressants on the vestibulo-thalamo-cortical system and visual-vestibular integration. Clinicians should be aware of the potential for such a medication-induced perceptual disturbance, especially in the workup for more serious etiologies in elderly patients with co-morbidities.