Objectives: To investigate whether the positional release technique (PRT) affects central sensitization in patients with chronic tension-type headache (TTH).

Design: Randomized controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis.

Setting: Two university neurology clinics.

Participants: Patients (N=32) with TTH and myofascial trigger points (MTrP) in their cervical muscles.

Interventions: Patients in the PRT group received 10 treatment sessions for each of their MTrPs over the course of 5 weeks. All participants could use ibuprofen 200 mg for their headaches during the study.

Main outcome measures: The primary outcome measure was brain metabolite profile. The secondary outcome measures were headache frequency and intensity, McGill score, and pressure pain threshold (PPT), which were evaluated in each participant during 5 weeks with proton magnetic resonance spectroscopy, patients' self-reports, the McGill Pain Questionnaire, and a pressure algometer.

Results: Analysis of the data from 26 patients showed that headache frequency (P=.001), headache intensity (P=.002), McGill score (P=.003), and local PPT (P=.003) changed significantly after PRT. The myo-inositol/creatine concentration ratio in the somatosensory cortex (P=.041) decreased significantly in the control group. Furthermore, there were significant differences between groups in headache frequency (P<.001), headache intensity (P<.001), McGill score (P<.001), local PPT (P=.004), distal PPT (P=.041), and glutamate-glutamine/creatine concentration ratio in the thalamus (P=.014).

Conclusions: These findings indicate that PRT did not affect central sensitization in patients with TTH despite the improvement in clinical symptoms.