Short-term evolution of heart rate variability following occipito-mastoid suture normalization in healthy subjects

Abstract

Background
 Occipito-mastoid structure normalization (OMSN) is an osteopathy manipulative treatment aiming at reducing tensions around the jugular foramen, where cranial nerves IX, X and XI come out of the skull. Tensions in this area may induce compressions of those nerves, which might imply symptoms related to those nerves dysfunctions (e.g., dysphagia, gastrointestinal issues, cardiac issues, upper body muscle pain, fatigue). Vagus nerve X is the main parasympathetic nerves of this area. Heart rate variability (HRV) is a surrogate for vagal modulation, and purpose of this study was to observe how HRV variables evolved before and after an OMSN.
 Methods
 Pre- and post- intervention HRV was analyzed in two randomly distributed groups of 15 participants. One received the OMSN and the other a SHAM technique. HRV was collected supine 5 min before and 5 min after a10-minute application of either OMSN or SHAM. HRV was analyzed on the last 4 minutes of the 5 minutes sample in time- and frequency-domain.
 Results
 HR significantly decreased in both groups (change in mean (CIM) -2.6 (4.3), and -2.3 (2.1) bpm, for NSOM and SHAM, respectively) but without difference between groups (p = 0.245). Vagally-related HRV variable root mean square of successive differences (RMSSD) increased in both groups, but in a significantly higher proportion in OMSN group (CIM 8.1 ±6.4 and 2.8 ±6.2 ms, p = 0.030 for NSOM and SHAM, respectively). No differences between groups were observed on frequency-domain analysis.
 Conclusion
 Compared to a SHAM technique, OMSN had a significant effect on HRV vagally-related metric RMSSD. This effect was measured in the very short term and thus, OMSN may be used to imply a short-term influence on parasympathetic ANS modulations. Further research are needed to investigate medium and long-term influences of this manipulation.