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An Analysis of the “Carry-over Effect” Following Successful Short-term Treatment of Transformed Migraine With Divalproex Sodium


Address all correspondence to Dr. John F. Rothrock, University of South Alabama, Department of Neurology, MCSB 1155, 2451 Fillingim Street, Mobile, AL 36617.


Objective.– To determine whether successful short-term prophylactic treatment of transformed migraine may be followed by a continued respite from headaches once the treatment has been discontinued (“carry-over effect”).

Background.– The optimal duration of prophylactic treatment for pervasive headache and for migraine, in particular, is unknown.

Methods.– We prospectively evaluated a series of patients with transformed migraine, all of whom were managed according to a uniform treatment protocol involving prophylactic therapy with divalproex sodium for a period not exceeding 12 weeks. All patients reporting a positive treatment response were followed for at least 2 months after the discontinuation of divalproex sodium, and the incidence of the carry-over effect in that group was assessed.

Results.– A short-term carry-over effect occurred in 12 (60%) of 20 patients, but more sustained relief occurred in only 8 (40%).

Conclusions.– The successful short-term treatment of transformed migraine with divalproex sodium will often produce a short-term carry-over effect, but this response will be sustained only in a minority of patients.

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