Immediate autonomic nervous system activity in skin microcirculation during osteopathic cranial vault hold intervention

Abstract Effects of osteopathy in the cranial field (OCF) frequently involve changes in skin blood flow (SBF) and autonomic nervous system (ANS) functioning. ANS related frequency markers fell short to adequately explain physiological reactions in general as well as during OCF. An intermediate (IM) frequency band generated by a brainstem pacemaker expanded ANS research in SBF. Studying IM frequencies during OCF may provide new insights on treatment relevant ANS responses. Data from forehead SBF measurements in twenty-five healthy participants were recorded in a blocked design before, during, and following an osteopathic cranial vault hold (CVH) intervention. Analyses included momentary frequencies of highest amplitude (MFHA) from wavelet time-frequency distributions and amplitudes in low (0.05 – 0.12 Hz), intermediate (0.12 – 0.18 Hz), and high (0.18 – 0.4 Hz) frequency bands. During CVH, LF averaged interval durations significantly increased, while IM and HF band durations decreased. Amplitudes significantly increased in LF, IM and HF bands. A cluster analysis found individual response patterns where 77% of the participants exhibited a highly stable, slowed LF oscillation (0.07 Hz) while another group remained in an IM dominated mode. Further explorative analyses suggested that the increase of LF activity duration during CVH may be related to higher self-regulation ability. Rhythmic patterns due to sensory input reduction and CVH in SBF matched previous findings on a central pacemaker induced ‘0.15 Hz rhythm’/IM activity, which may explain physiological reactions during CVH. These findings suggest further investigations of the role of OCF interventions in ANS mediated disorders.