Medication-overuse headache (MOH) is defined by the International Classification of Headache Disorders as a headache in patients with a pre-existing primary headache disorder that occurs on ≥15 days per month for >3 months, and is caused by overuse of medication intended for acute or symptomatic headache treatment. The prevalence of MOH in the general population is around 1%, but the condition is much more common in people with headache, in particular chronic migraine. The phenotype of the headache in MOH depends on the initial primary headache and the type of overused acute medication. In this Review, we will discuss the epidemiology, risk factors, pathophysiology, prevention and treatment of MOH. Treatment of MOH is performed in three steps: educating patients about the relationship between frequent intake of acute headache medication and MOH with the aim to reduce intake of acute medication; initiation of migraine prevention (such as topiramate or onabotulinumtoxin A in migraine) in patients who fail step 1; detoxification on an outpatient basis or in a day hospital or inpatient setting, depending on severity and comorbidities. The success rate of treatment is around 50-70%, although patients whose MOH is associated with opioid overuse have higher relapse rates. In all patients with MOH, relapse rates can be reduced by patient education and care in the follow-up period.
In collaboration with some of the leading headache centres in Germany, Switzerland and Austria, we have established new guidelines for the treatment of migraine attacks and the prevention of migraine. A thorough literature research of the last 10 years has been the basis of the current recommendations. At the beginning, we present therapeutic novelties, followed by a summary of all recommendations. After an introduction, we cover topics like drug therapy and practical experience, non-effective medication, migraine prevention, interventional methods, non-medicational and psychological methods for prevention and therapies without proof of efficacy.
BackgroundIn Friedreich's ataxia (FA) the genetically decreased expression of the mitochondrial protein frataxin leads to disturbance of the mitochondrial iron metabolism. Within the cerebellum the dentate nuclei (DN) are primarily affected. Histopathological studies show atrophy and accumulation of mitochondrial iron in DN. Dentate iron content has been suggested as a biomarker to measure the effects of siderophores/antioxidant treatment of FA. We assessed the iron content and the volume of DN in FA patients and controls based on ultra-high-field MRI (7 Tesla) images.MethodsFourteen FA patients (mean age 38.1 yrs) and 14 age- and gender-matched controls participated. Multi-echo gradient echo and susceptibility weighted imaging (SWI) sequences were acquired on a 7 T whole-body scanner. For comparison SWI images were acquired on a 1.5 T MR scanner. Volumes of the DN and cerebellum were assessed at 7 and 1.5 T, respectively. Parametric maps of T2 and T2* sequences were created and proton transverse relaxation rates were estimated as a measure of iron content.ResultsIn FA, the DN and the cerebellum were significantly smaller compared to controls. However, proton transverse relaxation rates of the DN were not significantly different between both groups.ConclusionsApplying in vivo MRI methods we could demonstrate significant atrophy of the DN in the presence of normal iron content. The findings suggest that relaxation rates are not reliable biomarkers in clinical trials evaluating the potential effect of FA therapy.
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