Topiramate: a case series study in migraine prophylaxis.

We reviewed the electronic records of 74 migraine patients treated with topiramate for more than 6 weeks. Twenty-four patients had episodic migraine and 50 had chronic (transformed) migraine. Most (81%) started treatment at 25 mg per day and reached a dose of 100 mg twice a day (mean dose on the last follow-up visit was 208 mg). The mean headache frequency decreased from 20.6 days to 13.6 days per month (P<0.0001) for all headaches (9.9-5.1 (P<0.0001) and 25.7-17.7 (P<0.001) for episodic migraine and chronic migraine, respectively). The percentage of patients whose headache frequency was reduced by > or =50% was 44.6% for all patients; 58.3 for episodic migraine and 38.0 for chronic migraine. For all patients mean headache severity (10-point scale) was reduced from 6.2 to 4.8 (P<0.0001). Patients on monotherapy (20%) and polytherapy (80%) had similar reductions in headache frequency. Adverse events were usually mild to moderate and were seen in 58.1% (paresthesias in 25%, cognitive difficulties 14.9%). Mean weight loss was 3.1 +/- 4 kg (3.8% of total body weight).