Topiramate-induced periodic limb movement disorder in a patient affected by focal epilepsy

Periodic limb movement disorder (PLMD) is characterized by pathological periodic limb movements during sleep, insomnia and/or diurnal sleepiness, and the absence of another primary sleep disorder. We report a patient with complex partial seizures who developed PLMD while taking topiramate (TPM). He had no evidence of metabolic and/or other conditions inducing PLMD. He also had fragmented sleep and disruptive PLMS on polysomnography, and PLMS subsided with change of antiepileptic drug. Topiramate may modulate the dopaminergic pathway by inhibition of glutamate release, thereby inducing PLMD as observed in our patient. Although a single case does not allow any generalization, PLMD should be considered in patients complaining of insomnia and treated with TPM.