Neural Mechanisms of Qigong Sensory Training Massage for Children With Autism Spectrum Disorder: A Feasibility Study

Abstract

Objectives: Despite the enormous prevalence of autism spectrum disorder (ASD), its global impact has yet to be realized. Millions of families worldwide need effective treatments to help them get through everyday challenges like eating, sleeping, digestion, and social interaction. Qigong Sensory Training (QST) is a nonverbal, parent-delivered intervention recently shown to be effective at reducing these everyday challenges in children with ASD. This study tested the feasibility of a protocol for investigating QST's neural mechanism.

Methods: During a single visit, 20 children, 4- to 7-year-old, with ASD viewed images of emotional faces before and after receiving QST or watching a video (controls). Heart rate variability was recorded throughout the visit, and power in the high frequency band (0.15-0.4 Hz) was calculated to estimate parasympathetic tone in 5-s nonoverlapping windows. Cerebral oximetry of prefrontal cortex was recorded during rest and while viewing emotional faces.

Results: 95% completion rate and 7.6% missing data met a priori standards confirming protocol feasibility for future studies. Preliminary data suggest: (1) during the intervention, parasympathetic tone increased more in children receiving massage (M = 2.9, SD = 0.3) versus controls (M = 2.5, SD = 0.5); (2) while viewing emotional faces post-intervention, parasympathetic tone was more affected (reduced) in the massage group (p = 0.036); and (3) prefrontal cortex response to emotional faces was greater after massage compared to controls. These results did not reach statistical significance in this small study powered to test feasibility.

Discussion/conclusion: This study demonstrates solid protocol feasibility. If replicated in a larger sample, these findings would provide important clues to the neural mechanism of action underlying QST's efficacy for improving sensory, social, and communication difficulties in children with autism.

Keywords: Complementary and Alternative Medicine; Qigong Sensory Training; autism; autonomic nervous system; cerebral oximetry; heart rate variability; massage; nonclassical auditory pathway; parasympathetic tone; vagal tone.

Figure 1.

Nonclassical auditory and tactile neural pathways include limbic system (left) in contrast to classical paths to primary sensory cortex (gray arrow on right) (diagram adapted from Noise and Health, 2000, http://www.noiseandhealth.org/viewimage.asp?img=NoiseHealth_2000_2_7_49_31742_1.jpg).¹⁹

Figure 2.

Group mean parasympathetic tone (log10 of high frequency power) during QST massage (blue and gray) or while watching a video about QST massage (orange). The blue and orange groups were treated identically until the start of the intervention (0:00). About 7 min into the intervention, the groups began to diverge, with the measure of parasympathetic tone (HF power) decreasing for the video group and continuing to increase slightly for the massage group. The gray group includes the same children as the orange group, who received the massage at the end of the study visit. We evaluated the trajectory of change in heart rate variability, comparing the massage and video groups (blue and orange lines) using a random effects model with a quadratic term. The model suggested that the trajectories of the 2 groups were different, but the difference did not reach statistical significance at the 0.05 alpha level in this small study, powered for feasibility testing.

Figure 3.

Comparison of group means and standard errors (next to each endpoint) of CO and HRV measures before and after receiving QST massage (blue) or watching a video about QST massage (orange). The left column shows CO drifting downward (indicating less inhibitory activity) over time during rest, while HRV (high frequency power) increases slightly, indicating greater parasympathetic tone. These changes are seen equally for both groups and likely reflect gradual relaxation as they adapt to the study environment. In contrast, the right column, which shows the mean change from the preceding rest period to the period of viewing emotional faces (to control for drift), shows the groups diverging. While the video group mean reflected a pattern of relaxation (less inhibition, lower oxygen use) or remained the same (HRV), the massage group mean change showed increased CO (more inhibition, more processing) and lower parasympathetic tone while viewing emotional faces. Except for the change in HRV from rest to faces (bottom right, p = 0.036), none of the groups are statistically distinct in this small sample. However, patterns in mean changes may be useful for generating hypotheses to be tested in subsequent studies. CO, cerebral oximetry; HRV, heart rate variability; PFC, prefrontal cortex.