Does mobilization of the upper cervical spine affect pain sensitivity and autonomic nervous system function in patients with cervico-craniofacial pain?: A randomized-controlled trial.

OBJECTIVES The aims were to investigate the effects of anterior-posterior upper cervical mobilization (APUCM) on pain modulation in craniofacial and cervical regions and its influence on the sympathetic nervous system. METHODS Thirty-two patients with cervico-craniofacial pain of myofascial origin were randomly allocated into experimental or placebo groups. Each patient received 3 treatments. Outcome measures included bilateral pressure pain thresholds assessed at craniofacial and cervical points preintervention, after the second intervention and after the final treatment. Pain intensity and sympathetic nervous system variables (skin conductance, breathing rate, heart rate, and skin temperature) were assessed before and immediately after each intervention. RESULTS The pressure pain thresholds in the craniofacial and cervical regions significantly increased (P<0.001) and pain intensity significantly decreased (P<0.001) in the treatment group compared with placebo. APUCM also produced a sympathoexcitatory response demonstrated by a significant increase in skin conductance, breathing rate, and heart rate (P<0.001), but not in skin temperature (P=0.071), after application of the technique compared with placebo. DISCUSSION This study provided preliminary evidence of a short-term hypoalgesic effect of APUCM on craniofacial and cervical regions of patients with cervico-craniofacial pain of myofascial origin, suggesting that APUCM may cause an immediate nociceptive modulation in the trigeminocervical complex. We also observed a sympathoexcitatory response, which could be related to the hypoalgesic effect induced by the technique, but this aspect should be confirmed in future studies.