Physical Therapy

Background Manual therapy of the cervical spine has occasionally been associated with serious adverse events involving compromise of the craniocervical arteries. Ultrasound studies have shown certain neck positions can alter craniocervical arterial blood flow velocities, however, findings are conflicting. Knowledge about the effects of neck position on blood flow may assist clinicians avoid potentially hazardous practices.

Objective To examine the effects of selected manual therapeutic interventions on blood flow in the craniocervical arteries and blood supply to the brain using magnetic resonance angiography (MRA)

Design The study was an experimental observational MRI study.

Method Healthy adult participants were imaged using MRA in the following neck positions: neutral, rotation, rotation/distraction (similar to a Cyriax manipulation), C1-C2 rotation (similar to a Maitland or osteopathic manipulation), and distraction.

Results Twenty healthy participants with a mean age of 33 years were imaged using 3T MRA. All participants had normal vascular anatomy. Average inflow to the brain in neutral was 6.98 ml/s and was not significantly changed by any of the test positions. There was no significant difference in flow in any of the four arteries in any position from neutral, despite large individual variations.

Limitations Only healthy asymptomatic individuals were investigated and a short section of the arteries only were imaged.

Conclusions Blood flow to the brain does not appear to be compromised by positions commonly utilised in manual therapy. Positions using end-range neck rotation and distraction do not appear to be more hazardous to cerebral circulation than more segmentally localised techniques

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