Topographical Pressure Pain Sensitivity Maps of the Temporalis Muscle in People with Frequent Episodic and Chronic Tension-Type Headache.

BACKGROUND

Previous pilot studies suggest the presence of heterogeneous sensitivity to pressure in primary headaches without considering the frequency of headache episodes.

OBJECTIVE

To investigate the differences in topographical pressure pain sensitivity maps in the temporalis muscle between individuals with frequent episodic (FETTH) and chronic (CTTH) tension-type headache by controlling the presence of anxiety and depression.

METHODS

oPressure pain thresholds (PPTs) were assessed bilaterally from 9 points distributed over the temporalis muscle (3 points in the anterior portion, 3 in the middle portion, and the remaining 3 in the posterior portion of the muscle belly) in 113 patients with FETTH and 91 with CTTH in a blinded design. Topographical pressure pain sensitivity maps based on interpolation of the PPTs were constructed. Clinical features of headache were collected in a 4-week headache diary. Anxiety and depression (Hospital Anxiety and Depression Scale) were also assessed.

RESULTS

The multilevel analysis of covariance found significant difference in PPT levels between points (F = 47.649; P < 0.001), but not between groups (F = 0.801; P = 0.602) or sides (F = 0.331; P = 0.565). No significant effect of gender (F = 0.785; P = 0.667), depression (F = 0.515; P = 0.846), or anxiety (F = 0.639; P = 0.745) was observed. Post hoc comparisons revealed: (1) no differences between FETTH and CTTH; (2) no side-to-side differences; and (3) anterior-to-posterior gradient with the most sensitive points located in the anterior column, followed by those located in the central column and the posterior column of the muscle (all, P < 0.001).

CONCLUSIONS

This study confirmed an anterior-to-posterior gradient of sensitivity to pressure in both groups, with the highest sensitivity at the anterior part of the muscle. Further, we found similar pressure pain sensitivity in the trigeminal area in people with FETTH or CTTH with no association with depressive or anxiety levels.