Doktoravhandlinger ved NTNU

Härtill 3 uppsatser Auditoriet, Nevrosenter Øst, St.Olavs Hospital, Trondheim Background and objectives Stress is in several studies mentioned as the most frequent trigger of headache. Nevertheless, the exact mechanisms by which stress induces headache is poorly understood and relatively few studies with rigorous scientific methods mimicking real life settings have been performed. In the present study an experimental model was used to study muscular, cardiovascular and biochemical responses to cognitive low-grade stress and investigate relationships between these responses and pain in the head and shoulder/neck areas. Methods This thesis is based on data recorded during and after a stress test in healthy controls and patients with migraine or tension-type headache (TTH). The stress test consisted of a two-choice reaction time test designed to imitate real-life working conditions in a stressful office environment. The stress test lasted for 60 minutes and was followed by 30 minutes of relaxation. We recorded pain and surface electromyographic (EMG) activity in the trapezius, splenius, temporalis and frontalis muscles, in addition to blood pressure (BP), heart rate (HR), skin blood flow (BF) in the fingers as well as noradrenaline, adrenaline and cortisol levels in blood sampled before and after the stress test. Results The main findings were higher pain responses in the temporalis and frontalis areas (with similar trends for trapezius and splenius) and more potentiation of pain during the test when comparing TTH patients with controls. Migraine patients developed more pain in the splenius and temporalis areas than controls. TTH patients had a more generalised pain increase in all areas, while pain increase was more regional (more pain in the neck/shoulder compared to the head) in migraine. TTH patients had delayed pain recovery in all areas compared to controls, while migraine had delayed pain recovery in the trapezius and temporalis areas. The temporalis EMG response was increased in migraineurs compared to controls, but there were no other differences in EMG responses between the diagnostic groups, and EMG responses were not correlated with pain responses. TTH patients had delayed EMG recovery in the trapezius compared to controls and migraineurs. Cardiovascular responses to cognitive stress in migraine patients did not differ from those in control subjects. In TTH patients, a lack of HR-adaptation during stress was found and a trend towards a delayed sys