Look at the huge placebo effect on migraine!
One has to doubt everything when it comes
to migraine.

1: Headache. 2007 Feb;47(2):170-80.

Comment in:
   Nat Clin Pract Neurol. 2007 Aug;3(8):434-5.

Efficacy and safety of topiramate for the treatment of chronic
migraine: a
randomized, double-blind, placebo-controlled trial.

Silberstein SD, Lipton RB, Dodick DW, Freitag FG, Ramadan N, Mathew N,
Brandes JL, Bigal M, Saper J, Ascher S, Jordan DM, Greenberg SJ,
Hulihan J; Topiramate
Chronic Migraine Study Group.

Jefferson Headache Center, Philadelphia, PA 19107, USA.

OBJECTIVE: To evaluate the efficacy and safety of topiramate (100 mg/
day)
compared with placebo for the treatment of chronic migraine. METHODS:
This was a randomized, placebo-controlled, parallel-group, multicenter
study consisting of 16 weeks of double-blind treatment. Subjects aged
18 to 65 years with 15 or more headache days per month, at least half
of which were migraine/migrainous headaches, were randomized 1:1 to
either topiramate 100 mg/day or placebo. An initial dose of topiramate
25 mg/day (or placebo) was titrated upward in weekly increments of 25
mg/day to a maximum of 100 mg/day (or to the maximum tolerated dose).
Concomitant preventive migraine treatment was not allowed, and acute
headache medication use was not to exceed 4 days per week during the
double-blind
maintenance period. The primary efficacy endpoint was the change from
baseline in the mean monthly number of migraine/migrainous days; the
change in the mean monthly number of migraine days also was analyzed.
A fixed sequence approach (ie, gatekeeper approach) using analysis of
covariance was used to analyze theefficacy endpoints. Assessments of
safety and tolerability included physical and
neurologic examinations, clinical laboratory parameters, and
spontaneous reports of clinical adverse events.

RESULTS:
The intent-to-treat population included 306 (topiramate, n = 153;
placebo,
n = 153) of 328 randomized subjects who provided
at least 1 efficacy assessment; 55.8% of the topiramate group and
55.2% on
placebo were trial completers. The mean final topiramate maintenance
dose was 86.0 mg/day. The mean duration of therapy was 91.7 days for
the topiramate group and 90.6 days for the placebo group. Topiramate
treatment resulted in a statistically significant mean reduction of
migraine/migrainous headache days (topiramate -6.4 vs placebo -4.7,
P= .010) and migraine headache days relative to baseline (topiramate
-5.6 vs placebo -4.1,
P= .032). Treatment-emergent adverse events occurred in 132 (82.5%)
and 113 (70.2%) of topiramate-treated and placebo-treated subjects,
respectively, and were generally of mild or moderate
severity. Most commonly reported adverse events in the topiramate
group were paresthesia (n = 46, 28.8%), upper respiratory tract
infection (n = 22, 13.8%), and fatigue (n = 19, 11.9%). The most
common adverse events in the placebo group were upper respiratory
tract infection (n = 20, 12.4%), fatigue (n = 16, 9.9%),and nausea (n
= 13, 8.1%). Discontinuations due to adverse events occurred in 18
(10.9%) topiramate subjects and 10 (6.1%) placebo subjects. There were
no serious adverse events or deaths.

CONCLUSIONS:
Topiramate treatment at daily doses of
approximately 100 mg resulted in statistically significant
improvements compared with placebo in mean monthly migraine/migrainous
and migraine headache days.Topiramate is safe and generally well
tolerated in this group of subjects with chronic migraine, a
burdensome condition with important unmet treatment needs.Safety and
tolerability of topiramate were consistent with experience in previous
clinical trials involving the drug.

PMID: 17300356 [PubMed - indexed for MEDLINE]

Related Links

   Topiramate reduces headache days in chronic migraine: a
randomized, double-blind,
placebo-controlled study. [Cephalalgia. 2007]
PMID:17441971

   Topiramate for migraine prevention: a randomized controlled trial.
[JAMA. 2004]
PMID:14982912

   Topiramate for migraine prevention in children: a randomized,
double-blind,
placebo-controlled trial. [Headache. 2005]
PMID:16324162

   Efficacy and tolerability of topiramate 200 mg/d in the prevention
of migraine with/without aura in adults: a randomized, placebo-
controlled, double-blind, 12-week pilot study. [Clin Ther. 2006]
PMID:16990078

   Topiramate in migraine prevention: results of a large controlled
trial. [Arch
Neurol. 2004]
PMID:15096395