Chronic migraine and chronic daily headache in the Asia-Pacific region: a systematic review.

BACKGROUND: Data on the prevalence and characteristics of chronic migraine (CM) and chronic daily headache (CDH) in the Asia-Pacific region are limited. METHODS: We performed a systematic review on this topic, searching for studies published from 1996 to 2012 that reported the prevalence (population-based studies) or frequency (clinic studies) of CM or CDH. We calculated 95% confidence intervals for the prevalence in population studies. Results were qualitatively described. RESULTS: Seven population studies and 19 hospital clinic studies from Asia were included. The CDH prevalence in population studies was 1.0-3.9% (median 2.9%). Only two studies from Taiwan reported the population prevalence of CM (1.0% and 1.7%). In addition, we derived a prevalence of 0.6% from a Malaysian study. Eleven clinic studies reported a CM frequency of 4.7-82% (median 52%) as a subset of CDH; classification of medication overuse varied. CM was associated with substantial disability. CONCLUSIONS: The prevalence of CM and CDH in Asia appears lower than the global average, but applying the above prevalence estimates to the Asia-Pacific population would suggest that CM alone affects between 23 and 65 million individuals in the region.

Anticonvulsants in migraine.

Migraine is a common, disabling disorder that often requires preventive treatment. The decision to treat migraine preventively generally is based on disability, problems with acute medicines, patient preference, risk of acute medication overuse, special circumstances, and concern that high migraine attack frequency may be a risk factor for chronic daily headache. Migraine and epilepsy are comorbid episodic central nervous system disorders that can have stereotyped symptoms with negative and positive phenomena. Controlled trials have demonstrated the efficacy of anticonvulsants in migraine prevention. Valproic acid, topiramate and, to a lesser extent, gabapentin, have demonstrated efficacy in randomized, placebo-controlled trials. Lamotrigine may be effective at controlling migraine aura, but has not demonstrated effectiveness at controlling migraine headache. Anticonvulsants are a useful option for the preventive treatment of migraine.

Hemicrania continua with aura.

Hemicrania continua is a primary headache disorder that is characterized by a continuous unilateral headache of moderate severity, exacerbations of severe pain and complete responsiveness to indomethacin. We report four patients with a unique variant of hemicrania continua: visual auras that precede or accompany the pain exacerbations.

Hemiplegic cluster.

We report four cases of a new variant of cluster headache associated with hemiparesis. Clinical similarities with hemiplegic migraine suggest that hemiplegic cluster, too, may be a channelopathy. One of our patients had a family history suggestive of an autosomal dominant inheritance.

Should butalbital-containing analgesics be banned? Yes.

In the United States analgesic-overuse headache is often caused by butalbital-containing analgesics. These agents can cause physical and psychological dependency, and dangerous withdrawal syndromes. Butalbital-containing analgesics have already been banned in several European countries. They are proven effective in tension-type headache, but not in migraine; there are many alternative treatments for migraine and tension-type headache. In the 20 years since analgesic overuse headache was widely recognized, butalbital overuse has remained distressingly common. It is time to ban these agents.