Prediction of Migraine Prevention Efficacy Based on Individual's Pain Modulation

Prediction of Migraine Prevention Efficacy: Individualization of Treatment by Coupling Drug's Mode of Action With Patient's Mechanism of Pain Modulation

A major reason for the substantial underuse of pharmacological prevention of migraine is its inadequate efficacy, since only ~50% of patients respond to a specific agent. There is currently no evidence-based way to identify the patients that will respond to a specific preventive treatment. Amitriptyline is one of the commonest agents used for migraine prevention, strengthening patient's pain inhibitory capacity. Individual tailoring of analgesics according to pain inhibitory capacity has been shown effective by our group for painful diabetic neuropathy patients. Specifically, patients with reduced pain inhibition capacity gained more from a drug that augment pain inhibition as compared to those with efficient inhibitory capacity. The investigators now propose to assess migraineurs for their pain inhibition capacity, and examine whether, along similar reasoning, those with reduced inhibitory capacity are the ones more likely to respond to amitriptyline. Psychophysical and neurophysiological dimensions of pain inhibitory modulation will be assessed in migraineurs, who will, subsequently, receive either amitriptyline or placebo for 8 weeks, in a randomized two arms parallel double blind design, and followed up for attacks reduction. The investigators expect to identify the best predictors for efficacy of migraine prevention by the study drug. This approach will promote individualization of migraine therapy.

migraine, Amitriptyline, pain modulation, pain psychophysics, pain neurophysiology, preventive treatment

predictive value of the pre-treatment pain measures parameter(s) for benefit from amitriptyline treatment

ANCOVA will be utilized, based on factors treatment (amitriptyline or placebo), conditioned pain modulation capabilities (responder or non-responder), their interaction, a number of covariates, to predict reduction attacks.

The scores for Spielberger's anxiety state and trait questionnaire, and for pain catastrophising questionnaire will be used.

Inclusion Criteria: age >18 premenopausal meeting the international headache society criteria for migraine having >4 attacks or days of migraine/month Exclusion Criteria: baseline month diary indicating lower frequency of migraine chronic migraine (>15 days of headache per month) use of migraine preventive treatment during previous 3 month language barrier or cognitive dysfunction