Antidepressant-associated myoclonic status in a patient with symptomatic generalized epilepsy: does risk occur with therapeutic doses?

The clinical and EEG data of a 49-year-old man with myoclonic and generalized tonic-clonic seizures resulting from early childhood encephalitis are described. He experienced no tonic-clonic seizure for 10 years before brief exposure first to 60 mg/day duloxetine and then to 20mg/day paroxetine for depressive symptoms. These drugs were separately prescribed at a 9-month interval, and after beginning each drug, the patient experienced tonic-clonic seizures of worsening intensity and myoclonus of increasing frequency. Clinical features correlated with subcontinuous, generalized spike-wave discharges on the EEG. Discontinuation of antidepressant treatment resulted in rapid disappearance of clinical and electrophysiological manifestations of myoclonic status. We suggest care must be taken when using serotonin-noradrenaline reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs), as these drugs pose the risk of complications in the specific population of people with myoclonic seizures.