Allodynia in migraine: clinical observation and role of prophylactic therapy.

OBJECTIVES: There is no study on the role of prophylactic therapy on allodynia in patients with migraine. We report the predictors of allodynia in migraine and the effect of divalproate or amitriptyline in alleviating allodynia.

METHODS: Four hundred forty-eight consecutive patients with migraine diagnosed as per International Headache Society criteria were prospectively included. The presence of allodynia, its type and severity, and details of headache were enquired. Two hundred twenty-seven migraineurs were randomly allocated to amitriptyline (25 to 50 mg/d) or divalproate (500 to 750 mg/d). The improvement in allodynia and headache severity was recorded at 3 and 6 months. The side effects of the drugs were noted.

RESULTS: The median age of the patients was 32 years (range, 10 to 62 y) and 77.6% were females. 71.4% patients had allodynia; static mechanical in 90%, dynamic in 89.1%, and thermal in 17%. The allodynia was related to the duration of illness, frequency, severity of migraine, and female gender. Both divalproate and amitriptyline significantly reduced the frequency and severity of allodynia at 3 and 6 months compared with baseline though there was no group difference. The composite side effects were similar but valproate was discontinued in 5 patients because of polycystic ovary.

CONCLUSIONS: 71.4% migraineurs had allodynia that was related to the duration, severity, frequency of migraine, and female gender. Divalproate and amitriptyline were equally effective in relieving allodynia.