Isolated environmental tilt associated with lateral medullary compression by dolichoectasia of the vertebral artery. Is there a cause and effect relationship?

An elderly woman with the persistent isolated symptom of monocular and binocular tilting of environmental objects, was found on magnetic resonance imaging to have compression of the lateral medulla by an ectatic vertebral artery. The double Maddox rod test showed no relative torsion of either globe although 5 degrees of right excyclotorsion and left incyclotorsion (rightward ocular counter-rolling) was detected on testing with monocular viewing. There was no accompanying hyperdeviation, nystagmus or other neurologic signs. Symmetrical tilting of each globe associated with head tilt and skew deviation (the ocular tilt reflex) may be caused by lesions involving otolith connections. Isolated environmental tilt may herald the onset of lateral medullary infarction (Wallenberg's syndrome), or may be associated with vertebro-basilar insufficiency. Could compression of otolith connections in the medulla cause persistent ocular counter-rolling without accompanying neurologic signs?