Acute withdrawal of headache medication in chronic migraine patients with medication overuse may lead to a dramatic reduction in headache frequency and severity. However, the brain networks... Show moreAcute withdrawal of headache medication in chronic migraine patients with medication overuse may lead to a dramatic reduction in headache frequency and severity. However, the brain networks underlying chronic migraine and a favorable response to acute withdrawal are still poorly understood. The goal of the present study was to characterize the pattern of intrinsic magnetic resonance imaging (MRI) functional connectivity (FC) specific to chronic migraine and to identify changes in FC that characterize subjects with CM reverting to less frequent headaches. Subjects with chronic migraine (N = 99) underwent a resting-state functional MRI scan before and after three months of medication withdrawal therapy. In addition, we included four control groups who were scanned once: healthy participants (N = 27), patients with episodic migraine (N = 25), patients with chronic back pain (N = 22), and patients with clinical depression (N = 17). Using dual regression analysis, we compared whole-brain voxel-level functional connectivity with ten well-known resting-state networks between chronic migraine and control groups, and between responders to treatment (≥50 % reduction in monthly headache days) and non-responders (<50 % reduction), before and after treatment. Subjects with chronic migraine showed differences in FC with a number of RS-networks, most of which involved the visual cortex, compared with healthy controls. A comparison with patients with episodic migraine, chronic pain and depression showed differences in the same direction, suggesting that altered patterns of functional connectivity in chronic migraine patients could to some extent be explained by shared symptomatology with other pain, depression, or migraine conditions. A comparison between responders and non-responders indicated that effective withdrawal reduced FC with the visual cortex for responders. Interestingly, responders already differed in functional connectivity of the visual cortex at baseline compared with non-responders. Altogether, we show that chronic migraine and successful medication withdrawal therapy are linked to changes in the functional connectivity of the visual cortex. These neuroimaging findings provide new insights into the pathways underlying migraine chronification and its reversibility. Show less
Chronic migraine is a highly disabling and difficult to treat form of migraine. In this thesis, various clinical aspects and the management of chronic migraine are investigated, in order to enhance... Show moreChronic migraine is a highly disabling and difficult to treat form of migraine. In this thesis, various clinical aspects and the management of chronic migraine are investigated, in order to enhance prevention and treatment of chronic migraine. Important risk factors for chronic migraine are depression, anxiety, cutaneous allodynia and especially overuse of acute anti-headache medication. The studies in this thesis conform that withdrawal of the overused medication results into a meaningful improvement in many patients. A double-blind randomised controlled trial did not show any additional benefit of treatment with Botulinum toxin A adjacent to acute withdrawal. Another double-blind randomised controlled trial did suggest effectiveness of a behavioural intervention during acute withdrawal on the reduction of medication intake during and shortly after withdrawal. Cutaneous allodynia (the perception of pain upon a non-painful stimuli) is a clinical marker of central sensitisation, an important mechanism in the pathophysiology of chronic migraine. The presence of cutaneous allodynia in general, and the extent of allodynia symptoms, appear to be a predictor for response to withdrawal therapy. Show less
