INTRODUCTION
Activation of the anterior cingulate cortex (ACC) is related to chronic pain. Contact with nature could decrease ACC activation. Our objective was to assess the efficacy of horticulture therapy on the variation of the ACC activation in individuals with chronic low back pain.
METHODS
We conducted a randomized controlled cross-over 3 weeks duration pilot study. All participants had two sessions of 90-min of horticulture and two sessions of 90-min of handiwork per week. The sequence order of the activities (handiwork and horticulture) was randomized. Each participant had three brain MRI: before, after the first and second activity. The primary outcome was the variation in ACC perfusion in ml/100g/min using arterial spin labelling MRI. The secondary outcomes were the variation in the rumination and the catastrophizing scores.
RESULTS
Sixteen participants were included: 14 women (87.5%), LBP intensity (NRS) 45.1 (27.2)/100, activity limitation (RMDQ) 9.3 (4.1)/24. The variation to baseline in ACC perfusion was -0.1 (10.7) CI 95% [-5.6, 5.8] ml (blood)/100g (tissue)/min after handiwork and -0.1 (8.7) [CI 95%, -4.7, 4.6] after HT and did not differ between the 2 activities (p=0.907). The variations in the rumination [-0.1 (10.7) after handiwork and -0.1 (8.7) after HT] and the catastrophizing score [-0.5 (4.4) after handiwork and -0.3 (2.8) after HT] did not differ between activities (p=0.988 and 0.216, respectively). Several reasons may explain our results: limited exposure to the interventions, small sample size and/or population’s profile (moderately affected by pain).
DISCUSSION
The current study showed no significant variation in ACC blood perfusion after horticulture therapy. Both handiwork and horticulture activities showed negligible effect on ACC blood perfusion.