Objective: This case series is the first to describe divergence palsy as an adverse effect of antiepileptic drug use. Diplopia is a common adverse effect of antiepileptic drugs, but no explanatory motility deficit has ever been reported.
Methods: We present 2 patients, 1 on oxcarbazepine and 1 on divalproex, each with a normal examination result between spells and divergency palsy when symptomatic.
Results: Discontinuation of the antiepileptic medication led to resolution of the episodes in both cases. Rechallenge with the offending agent after washout in one patient resulted in recurrence of diplopia and divergence palsy, both resolving after subsequent withdrawal of the antiepileptic.
Conclusions: Antiepileptic drugs may cause divergence palsy.
*Department of Ophthalmology, Division of Neuro-Ophthalmology, Massachusetts Eye and Ear Infirmary; †Department of Neurology; and ‡Department of Surgery, Division of Ophthalmology, Beth Israel Deaconess Medical Center, Boston, MA.
Address correspondence and reprint requests to Marc Albert Bouffard, MD, 608 Massachusetts Ave. #1, Boston, MA 02118; E-mail: marc_bouffard@meei.harvard.edu
Conflicts of Interest and Source of Funding: The authors have no conflicts of interest to declare.
The authors alone are responsible for the content and writing of the paper.
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