Relationship between vertebral artery blood flow in different head positions and vertigo.

Objective: To identify the vertebral artery blood flow in different head positions in patients with positional vertigo with no specific diagnosis.

Methods: Patients with history of vestibular symptoms associated with changes in head position were enrolled into the study. Healthy volunteers were evaluated as control group. Doppler ultrasonography examination of the cervical segment of the vertebral arteries was performed under three different head positions: (i) supine position, (ii) head hyperextended and rotated to the right side and (iii) head hyperextended and rotated to the left side.

Results: In the study group, right and left vertebral artery blood flow was significantly lower in the ipsilateral hyperextended position compared to standard supine position (respectively p = .014; p = .001), but did not differ significantly when compared between the standard supine and contralateral hyperextended positions (respectively = .959; p = .669). In the control group, left and right vertebral artery blood flow did not differ significantly when the head was hyperextended to the right or left sides compared to standard supine position (p > .05).

Conclusions: Our data demonstrated that the etiology of vestibular complaints in patients with undiagnosed positional vertigo might be related to impairment in vertebral artery blood flow according to head positions.