Myofascial disorders in the trochlear region in unilateral migraine: A possible initiating or perpetuating factor

OBJECTIVE: Some patients with trochlear disorders have been found to suffer from concurrent migraine. However, a trochlear examination is not systematically done in patients with migraine. Moreover, a search for myofascial trigger points in the superior oblique muscle has never been reported in these patients. METHODS: The trochlear region was examined in 20 participants with strictly unilateral migraine without side-shift and in 20 controls. Referred pain elicited by different maneuvers during manual palpation (ie, maintained pressure, active muscle contraction, and stretching of the superior oblique muscle) was assessed with a visual analog scale. All participants were headache free on the day of evaluation. RESULTS: Sixteen participants with migraine (80%) perceived referred pain on examination of the trochlear area. It was described as a tightening sensation in the retro-orbital region, sometimes extending to the supraorbital region and the homolateral forehead. In 15 participants with migraine, both the active contraction and the stretching of the muscle increased the referred pain, which was consistent with definite myofascial trigger points. All the definite trigger points were ipsilateral to the side of the headache. Conversely, only 5 controls (20%) had referred pain. None of them had definite myofascial trigger points because muscle stretching did not increase the intensity of pain. The intensity of referred pain at each stage of the trochlear examination was greater in subjects with migraine than in controls (P<0.001). CONCLUSION: Patients with unilateral migraine commonly perceive referred pain from the trochlear area that probably comes from the myofascial trigger points. Myofascial disorders in the trochlear region might contribute to the perpetuation of concomitant migraine.