Complex periodic limb movements during sleep or partial epileptic seizures?

A 69-year-old woman had insomnia, restless legs syndrome, and violent movements during sleep; she had had a generalized seizure several years previously. She underwent 4 days of video-EEG investigation for these movements (table, and figure e-1 on the Neurology(R) Web site at Neurology.org). There was no epileptic activity, but repetitive, stereotyped movements (88 movements/hour; movement duration: 2.5 seconds) occurred only during sleep, which were typical of periodic leg movements but associated with atypical, polyphasic hand cycling/rubbing movements (see video). This complex motor pattern might be confused with a focal epileptic seizure.