Acquired pendular continuous eye movement was observed in a 43-year-old male with vertebral basilar aneurysm. He complained of gait disturbance, numbness on extremities and vertical oscillopsia. Vertical pendular eye movements with frqeuencies ranging from 3to 4 Hz and amplitudes between 5 and 15 degrees with eye's open in the dark were recorded. This patient demonstrated impaired smooth pursuit eye movement and optokinetic nystagmus in the horizontal and vertical axis.The saccade velocity was reduced markedly.
The vertebral-basilar aneurysm of 12 mm in a diameter was confirmed by CT and VAG at the level of the pons.
Eight years after the onset of the initial symptoms, adduction disturbance in both eyes were developed and bilateral MLF syndrome revealed. At the time, vertical pendular eye movements were completely disappeared. From the findings of neurotological examinations, mechanism of vertical pendular eye movement was discussed.
