Topiramate-Associated Movement Disorder: Case Series and Literature Review.

Abstract

Topiramate (TPM) is a fructose derivative, which was originally developed as an antiepileptic. In this context, movement disorders (MDs) are possible adverse events secondary to TPM. Two patients (cases 1 and 2) developed myoclonus, and the other 2 had restless leg syndrome (RLS, cases 3 and 4). The mean age of the individuals (3 female patients) was 45.75 ± 21.28 years. All the individuals had a negative family history for movement and psychiatry disorders. Topiramate was started at 25 mg with a gradual increase of 25 mg every week. The mean time of onset and recovery of the MD were 1.37 ± 1.10 and 1.02 ± 0.77 months, respectively. The mean TPM dose was 87.5 ± 47.87 mg. Individual 1 presented with upper and lower limb jerks; individual 2 only with upper limb involvement. Individuals 3 and 4 experienced insomnia and nocturnal leg discomfort during inactivity with an urge to move the legs, which they denied having previously; the RLS symptoms occurred within approximately 1 to 3 hours of TPM evening dose. On neurological examination, no tremor or bradykinesia was observed; deep tendon reflexes, sensory examination, and strength were normal and preserved. Laboratory tests, neuroimaging, and electromyography were within normal. Topiramate was discontinued in all of the subjects. Full recovery was obtained in all cases. To the authors' knowledge, there are 6 cases of myoclonus, 5 RLS, 2 dystonia, 1 dyskinesia, and 1 periodic limb MD. The best management is probably the discontinuation of TPM, but in RLS patients, the addition of a dopaminergic agonist can be beneficial.