"Worldwide, headache affects approximately 50% of adults each year. Approximately 11% of cases meet the criteria for migraine," Prof Paolo Martelletti (Rome, Italy) said today, speaking at the Congress of the European Pain Federation EFIC in Florence. "In Europe and America, we estimate the prevalence of migraine to be 6 to 8% in men and 15 to 18% in women."

According to WHO data, migraine is more prevalent than other common disorders such as diabetes and asthma, and is in fact the third most common condition in the world. "Migraine was also ranked seventh highest among specific causes of disability globally," Prof Martelletti explained. "Out of all headache disorders, chronic migraine patients suffer from the highest number of headaches per month - at least 15 days of headache, eight of which are with migraine."

While migraine patients are all too familiar with the intense pain caused by the neurological condition, those who have not experienced a severe headache or migraine may not be able to appreciate the wider, unseen impact that the problem can have, Prof Martelletti explained. "The disruptive nature of regular attacks can affect those around them and can prove detrimental to many aspects of everyday life, bringing about high levels of stress and often depression." The scientific literature indicates a strong association between primary headaches and psychiatric disorders, including increased suicide risk. "However, the evidence of a possible link between chronic migraine and psychiatric disorder is not a recent finding", Prof Martelletti said. "Back in 1895, Living already described the occurrence of depressed mood, irritability, and anxiety in patients with chronic headache."

Heavy burden of disease, high rate of co-morbidities

People with chronic migraine report more co-morbidities than episodic migraine sufferers. "As many of these diseases - like obesity, high blood pressure, and anxiety disorders - have high prevalence rates in the general population, it's possible that your patients with chronic migraine may be visiting your office to discuss these disorders and not their migraines", Prof Martelletti said. "Identifying patients with these conditions who also suffer from migraines may help in determining an adequate treatment plan."

Moreover, persistent chronic migraines cause a higher rate of headache-related disability, higher direct and indirect costs, and more frequent utilization of health services than episodic headache conditions. Migraine patients are all too familiar with unemployment, loss of work or school days and missing out on family occasions as well as many other social aspects of life.

An accurate diagnosis of chronic migraine is crucial, according to Prof Martelletti: "Understanding the current medical and emotional state of the patient - as well as having a thorough understanding of patient's current medication use - is of paramount importance to designing effective therapy."

There are two types of medication treatment options that can help patients manage their headaches and migraines. Acute medications are taken as needed to stop the pain once the headache or migraine has begun. Preventive medications help stop headaches or migraines from occurring.

Medication overuse: when painkillers cause pain

A particular problem with respect to migraine treatment is the high frequency of medication overuse, as Prof Martelletti explained: "Between 50 and 80% of chronic migraine patients seen in headache clinics overuse acute medications. Although these drugs provide relief from the pain and other symptoms associated with migraine, overuse can actually make headaches worse. In addition, medication overuse can influence the onset of comorbidities such as psychiatric and cardiovascular disorders or gastrointestinal complications."

Medication overuse is defined as regular use of combination analgesics, ergotamines, triptans or opioids on ten or more days per month, for more than three months; or regular use of simple analgesics or any combination of these drugs on more than 15 days per month for more than three months without overuse of any single class alone. "An attempt should be made to limit the use of acute medication to treatment of no more than two or three headaches per week, and with no more than two doses per headache", said Prof Martelletti, outlining the therapeutic approach. "Medication overuse should be treated by withdrawing acute medications, and with the use of preventives."

A number of studies presented at the EFIC Congress in Florence explored questions relating to medication overuse and detoxification. The COMOESTAS study (EFIC Abstract Allena et al), for example, which involved eight headache centres in seven countries, indicates a very good prognosis for detoxified patients, with a higher rate of responders among migraineurs than among sufferers from other headache disorders.

New therapies: botulinum toxin has preventive effect

Experts agree that there is a huge unmet need in the management of headache disorders. "We welcome all new research and the development of new therapies which can bring relief to our patients," according to Prof Martelletti. "As hardly any preventive therapy has been shown to be effective for chronic migraine, the positive effects of botulinum toxin type A, or Botox, with 155 units injected into 31 sites in appropriate muscles of the head, the face and the neck, are very promising."

The PREEMPT (Phase III REsearch Evaluating Migraine Prophylaxis Therapy) programme, which led to the licensing of the substance, evaluated the safety profile and efficacy of botulinum toxin as a prophylactic headache treatment in chronic migraine patients. "The trial showed that treatment with this substance reduces the frequency of headache and migraine, and so can bring important benefits for patients", Prof Martelletti said. "In clinical practice, as long as we manage our patients' expectations and help them set realistic goals, Botox injections provide a valuable, evidence-based approach to the treatment of chronic migraine. Regular treatments with Botox provide an effective approach to the long-term management of chronic migraine and may have a disease-modifying effect in some cases where the chronic condition, though not entirely cured, may revert to its episodic form."

The potential for botulinum toxin in migraine prophylaxis is also revealed by a British study presented at the EFIC Congress in Florence (EFIC Abstract Carganillo et al), which demonstrated a reduction in the frequency and severity of headaches in refractory chronic migraine patients consistent with the PREEMPT trial.