Patients with episodic migraine show increased T2 values of the trapezius muscles - an investigation by quantitative high-resolution magnetic resonance imaging

Abstract

Background: Neck pain is frequent in patients with migraine. Likewise, evidence for inflammatory processes in the trapezius muscles is accumulating. However, non-invasive and objectively assessable correlates are missing in vivo.

Methods: Twenty-one subjects with episodic migraine (mean age: 24.6 ± 3.1 years, 18 females) and 22 controls (mean age: 23.0 ± 2.2 years, 17 females) without any history of headache prospectively underwent physical examination and quantitative magnetic resonance imaging of the trapezius muscles. A T2-prepared turbo spin-echo sequence was acquired for manual segmentation of the trapezius muscles and extraction of mean T2 values.

Results: There were no statistically significant differences regarding age, sex, body mass index, or number of myofascial trigger points (mTrPs) between groups. All patients with migraine presented with mTrPs in the trapezius muscles. T2 of the entire trapezius muscles was significantly higher in the migraine group when compared to controls (31.1 ± 0.8 ms vs. 30.1 ± 1.1 ms; p = 0.002).

Conclusions: Elevated T2 values of the trapezius muscles may indicate subtle inflammatory processes within musculature among patients with migraine because T2 increase is likely to stem from edematous changes. Future work may validate this finding in larger cohorts, but muscle T2 might have potential to develop into a viable in vivo biomarker for muscular affection in migraine.

Keywords: Magnetic resonance imaging; T2 mapping; migraine; myofascial trigger points; trapezius muscle; trigemino-cervical complex.

Figure 1.

Segmentation of the trapezius muscle. T2-weighted raw data (with the weakest T2-weighting, in arbitrary units [a.u.]) for an exemplary case. On the raw data, the masks obtained from segmentation of the trapezius muscle on the left side are indicated by an overlay in a representative axial slice.

Figure 2.

T2 values of the trapezius muscles. This graph illustrates the T2 values derived from segmentations of the entire trapezius muscles of both sides in subjects with migraine as well as controls. The circles and squares indicate individual T2 values (in ms), horizontal lines represent the mean and standard deviation (SD). The difference in T2 values between groups was statistically significant (p = 0.002).