Quantitative magnetic resonance imaging (MRI) by way of T2 mapping may improve the identification of myofascial trigger points in the upper trapezius muscles linked to migraine headache, according to a study published in The Journal of Headache and Pain.
The investigators of this study sought to explore a high-resolution MRI approach as a means to objectively and quantitatively assess the upper trapezius muscle to identify myofascial trigger points involved in migraine headache.
The study sample included 10 right-handed patients (9 women and 1 man) with a clinical diagnosis of migraine headache and a history of unilateral or bilateral myofascial trigger points. All participants underwent manual palpation of the upper trapezius muscles, and capsules were used to mark the skin adjacent to the palpated myofascial trigger points. The investigators then performed an MRI of the neck and shoulder, during the same appointment using a 3 T whole-body scanner. A T2-prepared, 3D turbo spin echo sequence from the MRI scans was used to generate T2 maps that followed the manual placement of regions of interest; from these, T2 values were measured at the area where signal alterations attributed to myofascial trigger points were identified. The investigators further used MRI to evaluate any T2 hyperintensities detected in the regions of interest.
T2 values were obtained for 20 total measurements of the trapezius muscles. An average T2 value of 27.7±1.4 ms was calculated for the right-sided muscle and 28.7±1.0 ms was calculated for the left-sided muscle. No statistically significant difference between the right and left sides was observed (P =.1055). Concerning the signal alterations attributed to myofascial trigger points, a total of 9 T2 values were obtained for all but 2 patients, with an average T2 value of 32.3±2.5 ms for the right side and 33.0±1.5 ms for the left side. Again, no significant difference was observed between the right and left sides (P =.0781).
When comparing the ipsilateral T2 values of the trapezius muscles with those extracted from signal alterations attributed to myofascial trigger points, the investigators found a statistically significant difference for both sides (P =.0039) in which the mean T2 values were higher for signal alterations. Only 4 patients reported T2 hyperintensities for the right side, and 2 patients reported them for the left side.
Limitations to the study included the small cohort size made up of predominantly women and a lack of a control group without migraine headache. The investigators only focused on the myofascial trigger points on the side with most intense referred cranial pain. Furthermore, 3 signal alterations were not associated with the myofascial trigger point markers identified through manual palpation, and 1 trigger point derived from manual palpation did not correlate with the T2 maps.
The investigators suggest that high-resolution MRI allows for the improved identification and quantification of myofascial trigger points (even in terms of T2 mapping without signal alterations) compared with the current gold-standard method of physical examination of the neck and shoulder. This approach may guide more targeted and objectively verifiable therapeutic interventions in treating migraine headache.
This study was sponsored by the European Research Council and the German Joint Federal Committee. One author acknowledges receiving support from Philips Healthcare.
Sollmann N, Mathonia N, Weidlich D, et al. Quantitative magnetic resonance imaging of the upper trapezius muscles – assessment of myofascial trigger points in patients with migraine. J Headache Pain. 2019;20(1):8.