Effect of valproic acid on withdrawal therapy in patients with overuse of chronic daily headache medications

Treatment of medication-overuse headache: A systematic review

INTRODUCTION

The objective of this review is to provide an evidence-based discussion of different treatment strategies for medication-overuse headache (MOH).

METHOD

We searched PubMed for articles discussing the treatment and prognosis of MOH published between 2004 and August 2014. Titles, abstract and articles were reviewed systematically. The level of evidence provided by each study of the included articles was determined according to the American Academy of Neurology Clinical practice guideline manual. We discuss the level of evidence to support the early discontinuation/withdrawal of overused medications, the level of evidence to support the use of preventive treatment, the short- and long-term prognosis, and the outcome according to the class of drug overused in patients diagnosed with MOH.

RESULTS

The initial search resulted in 1313 articles; 68 articles met our inclusion criteria and were discussed. The level of evidence to support early discontinuation of overused medications alone is low due to the absence of controlled studies. Adding preventive medication to early discontinuation led to a better outcome than early discontinuation alone. For patients with chronic migraine (CM) and medication overuse (MO), there are large randomized control trials supporting the use of onabotulinumtoxinA and topiramate without early discontinuation of overuse; however, the evidence is limited since data were obtained from post hoc analysis.

CONCLUSION

Considering current available evidence and the systemic toxicity of overusing acute headache medication, we suggest discontinuation of the overused medication with the addition of preventive medication. Appropriately sized, randomized controlled trials evaluating the safety and long-term efficacy of preventive medication plus early discontinuation of overuse vs preventive medication alone vs early discontinuation of overuse alone are needed.

The importance of toxoplasma gondii infection in diseases presenting with headaches. Headaches and aseptic meningitis may be manifestations of the Jarisch-Herxheimer reaction

Worldwide, approximately 2 billion people are chronically infected with T. gondii with largely unknown consequences. This review presents clinical symptoms, differential diagnosis, triggering factors, treatment, and pathomechanisms responsible for idiopathic intracranial hypertension, pseudotumor cerebri, and aseptic meningitis. Literature cited in this work illustrates that immune state and other biologic mediator imbalances due to various endogenous and exogenous triggering factors may markedly affect latent central nervous system T. gondii infection/inflammation intensity, and cause reactivation of cerebral toxoplasmosis (CT). Irregularities in pro- and anti-inflammatory processes may markedly disturb the host and/or T. gondii defense mechanisms important for immune control of the parasite thereby manifesting as a wide range of neurologic symptoms and signs observed in some patients with migraine, epilepsy, celiac disease, Henoch-Schönlein purpura, and other brain disorders. This is consistent with reactivation of CT in mice after treatment with dexamethasone associated with depression of type T(H)1 immune response, and development of CT after administration of etanercept or other bioproducts. It seems that various types of headaches, epilepsy, aseptic meningitis, systemic adverse reactions to drugs or other substances represent the Jarisch-Herxheimer reaction due to apoptosis of T. gondii tachyzoites. Also development of some brain tumors, such as ependymoma and glioma may be associated with a chronic course of CT. Thus, all these patients should be tested for T. gondii infection.

Headache attributed to a substance or its withdrawal

Medication overuse, and subsequent medication overuse headache (MOH), is a growing and still underestimated problem worldwide. A significant number of recent epidemiological studies suggest that up to 4% of the general population in Europe, North America, and Asia overuse analgesics and other drugs for the treatment of pain conditions such as migraine. These studies also provide convincing evidence that about 1% of the general population suffers from MOH. The condition can be caused by almost all antiheadache drugs, including analgesics, ergots, triptans, and combined preparations. The clinical symptoms of MOH are heterogeneous and may vary from just an increase in headache attack frequency to a constant holocranial pain over years. The International Headache Society (IHS) defined MOH in its first classification in 1988 but modified the diagnostic criteria in its second classification in 2004 to facilitate diagnosis and the conduct of clinical trials. The underlying pathophysiology of MOH is not well understood. The only therapy is withdrawal from the overused substances. The only strategy to reduce the prevalence of MOH is to prevent the development of MOH in the first place by clear restriction of monthly doses of antiheadache drugs and constant education of both patients and physicians prescribing or recommending antiheadache drugs.

Hemicrania continua evolving from cluster headache responsive to valproic acid

Hemicrania continua (HC) is a rare type of primary headache characterized by a prompt and enduring response to indomethacin. We describe a patient who suffered from cluster headache evolving into ipsilateral HC, who does not tolerate a long-term indomethacin therapy. The case was complex in terms of diagnosis, associated comorbidity, and choice of treatment; after several trials with different therapeutic regimens, we started the patient on a therapy with valproic acid and obtained an improvement of her HC.