- Title
- Comments in response to letter to the editor by Karl et al. Manual Therapy 2009;14(6):e17 (letter)
- Creator
- Thomas, Lucy C.; Rivett, Darren A.; Bolton, Philip S.
- Relation
- Manual Therapy Vol. 14, Issue 6, p. e18
- Publisher Link
- http://dx.doi.org/10.1016/j.math.2009.07.006
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2009
- Description
- Our choice of the duplex criteria of a greater than 50% increase or decrease in peak systolic (PS) velocity between the neutral head position and contralateral rotation position was based on Haynes (2000) study in which he suggests marked changes in PS velocity could be considered abnormal (his 2000 study reported decreases between 35% and 68%) and Freed's et al. (1998) suggestion that a greater than 50% change in PS velocity in the vertebral artery (VA) between neutral and contralateral head positions is indicative of stenosis. In our study the average PS values in the neutral head position for the left and right vertebral arteries were 33.6 and 35.16 cm/s respectively and we did not observe the high values which the authors suggested may have made a 50% change less significant. Our study had one subject with a decrease in duplex determined PS velocity to 18.65 cm/s (52%) but all other subjects showed increases on contralateral rotation ranging from 65% to 176% of the neutral head position value. We agree that an initial high PS value in the neutral head position may make a 50% change (reduction) on rotation less likely to compromise brain perfusion sufficient to impact on its function. This however, was not the case in our study.
- Subject
- peak systolic velocity; PS velocity; stenosis; neutral head positions; vertebral arteries
- Identifier
- http://hdl.handle.net/1959.13/807191
- Identifier
- uon:7328
- Identifier
- ISSN:1356-689X
- Language
- eng
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