OBJECTIVE: To assess the efficacy and tolerability of topiramate for prophylaxis 
of migraine and cluster headache via a retrospective chart analysis.
BACKGROUND: Topiramate has multiple mechanisms of action that could potentially 
contribute to migraine prophylaxis. We conducted a retrospective chart review to 
assess the efficacy of topiramate as add-on therapy in patients with transformed 
migraine or cluster headache, and as first-line therapy in patients with 
episodic migraine.
METHODS: Patients diagnosed with transformed migraine, episodic migraine, or 
cluster headache, who received topiramate either as add-on therapy or 
monotherapy were selected via retrospective chart review. Patients had begun 
topiramate therapy at 25 mg/day for the first week and increased their dosage by 
25 mg/week to a maximum of 200 mg/day. Topiramate was used as add-on therapy for 
patients with transformed migraine and cluster headache, and as a first-line 
monotherapy in patients with episodic migraine who had no previous prophylactic 
therapy. The outcome parameters examined included a mean 28-day migraine 
frequency, migraine severity, number of headache days/month, number of abortive 
medication tablets/month, patient global evaluation, and the MIDAS scale.
RESULTS: One hundred seventy-eight patients (transformed migraine: n = 96; 
episodic migraine: n = 70; and cluster headache: n = 12) were included in the 
retrospective analysis. The mean dose of topiramate for all patients was 87.5 
mg/day. For patients with transformed migraine, mean migraine frequency 
decreased from 6.3/28 days to 3.7 (P = 0.005). Mean severity decreased from 7.1 
to 3.8 on a 10-point scale, with 10 representing the most severe pain (P = 
0.003). The mean number of headache days/month decreased from 22.1 to 9.6 (P = 
0.001), and the mean number of abortive medication tablets decreased from 
28.7/month to 10.6 (P = 0.001). Patient global evaluation indicated substantial 
or moderate improvement in 53% of patients with transformed migraine who used 
topiramate as add-on therapy. Mean MIDAS scale values decreased from 90.2 to 
24.9 (P< 0.0001). The 70 episodic migraine patients who were administered 
topiramate as first-line therapy exhibited a decrease in mean migraine frequency 
(5.8/28 days to 1.9, P = 0.001), while mean migraine severity decreased from 8.1 
to 2.0 (P = 0.003). Sixty-one percent of patients reported marked improvement. 
Nine of the 12 cluster headache patients exhibited substantial or moderate 
improvement in symptoms, whereas three had no improvement. The most common 
adverse effects were paresthesias (12%), cognitive effects (11%), and dizziness 
(6%). Eight patients discontinued topiramate due to adverse effects; cognitive 
effects were the most common reason. No patient discontinued topiramate 
treatment due to lack of efficacy. Twelve percent of patients lost more than 5 
lbs during treatment (a range of 5-120 lbs).
CONCLUSION: For both patients with transformed migraine (add-on therapy) and 
patients with episodic migraine (first-line monotherapy), topiramate yielded 
significant reductions in migraine frequency, migraine severity, number of 
headache days/month, and use of abortive medications. Topiramate also appears to 
be well tolerated and useful in the adjunctive treatment of cluster headache. 
Prospective double-blind, placebo-controlled trials will be required to confirm 
our results.