Clinical observation of the effect of prophylaxis on allodynia in patients with migraine

OBJECTIVE: The clinical characteristics of migraine with and without allodynia were compared to evaluate the risk factors of cutaneous allodynia in migraine. The effects of prophylactic therapy on allodynia in patients with migraine were assessed based on the change in pain threshold after therapy. PATIENTS AND METHODS: A total of 71 patients with migraine admitted to the Department of Neurology of Shandong Provincial Hospital were recruited in this study. The included patients were aged 18–70 years and did not present positive symptoms according to the nervous system examination. The variation in cutaneous allodynia was assessed for the role of classic prophylactic therapy in migraine-related allodynia, also termed as central sensitization (CS). Patients with migraine were randomized into two groups (topiramate and flunarizine groups), and the effect of drugs was evaluated by the change in cutaneous pain threshold between the two groups. Fifty-five patients were tested for pain threshold due to instrument failure. Pressure allodynia was measured with a force gage, and pricking was measured with Electronic von Frey Anesthesiometer. The pain threshold was measured every 3 months for 6 months. The variations in pain threshold after treatment were compared using t-test and χ(2) test. RESULTS: Allodynia was seen in 70.4% of the patients; of these, 76.3% were females. Female gender, duration of illness, and frequency of migraine attacks per month were significantly associated with allodynia. The rate of allodynia and frequency of headache declined significantly, the number of patients with allodynia was reduced, and the pain threshold improved dramatically after treatment. The composite adverse events were low after treatment with topiramate and flunarizine. CONCLUSION: Allodynia was observed, especially in females who experienced frequent migraine attacks for a prolonged period. Gender, duration of illness, and number of migraine attacks per month were the major predictors of allodynia. Topiramate and flunarizine administered orally for a short duration can effectively improve the pain threshold and CS of patients with migraine, and efficiently relieve allodynia.