Environmental tilt illusion as the only symptom of a thalamic astrocytoma

Academic Article


  • A 14-year-old girl experienced two episodes of environmental tilt illusion. During both episodes, which lasted less than 1 minute, she perceived all objects within view as rotated 45 degrees clockwise. There were no auras, accompanying symptoms, or sequelae. Neuro-ophthalmic examination findings were normal except for a right relative afferent pupil defect (RAPD). Imaging disclosed a cystic mass in the left posterior thalamus with compression of the brachium of the left superior colliculus. Stereotactic biopsy revealed a pilocytic astrocytoma. This is the first case documenting environmental tilt illusion as an isolated symptom of a thalamic lesion. Disruption of vestibular connections between the posterior thalamus and the posterior parietal cortex may be the cause of this visual perceptive disorder.
  • Published In

    Digital Object Identifier (doi)

    Author List

  • Aldridge AJ; Kline LB; Girkin CA
  • Start Page

  • 145
  • End Page

  • 147
  • Volume

  • 23
  • Issue

  • 2