[Vertebral-basilar artery insufficiency nystagmus (author's transl)]

The vertebral-basilar artery insufficiency nystagmus is the nystagmus induced by torsion and extension of the neck, continued for more than three minutes, after nystagmus of other origin has been excluded. It stands particularly in opposition with the nystagmus of cervical origin, which is proprioceptive. On the contrary, vertebral-basilar artery insufficiency nystagmus is of vascular origin. It enables the detection of an infra-clinical vertebral-basilar insufficiency. It deserves to be elicited before subjecting patients to any operation requiring prolonged cervical rotation.