Isolated paroxysmal arousals as focal epilepsy.

Paroxysmal motor phenomena and arousals during sleep are frequent. The differential diagnoses between benign hypnic transient events, epileptic and non-epileptic seizures represent a common clinical problem. Video-EEG monitoring during sleep, recording several episodes in the same patient, is essential in order to characterize these phenomena. It offers the possibility to compare electro-clinical data, to demonstrate the eventual stereotyped pattern of motor phenomena and their progression in time, and to study EEG-polygraphic correlates. The recently described double split-screen synchronized display (DSSSD) technique represents a useful tool for comparing particular clinical patterns of epileptic seizures when dealing with complex, hypermotor phenomena observed in frontal lobe epilepsy. We reviewed the data of 24 patients admitted during a two-year period (2002-2003) to our epilepsy sleep unit for isolated paroxysmal sleep motor events. Four patients presented with very brief paroxysmal arousals without daytime fits. Three of our patients presented isolated paroxysmal arousals, whereas in one, the events were associated with hypermotor seizures. We present a simplified variant of the DSSSD method (modified DSSSD) that can be used to study episodes of paroxysmal arousals in order to confirm their stereotyped motor pattern. The clinical aspects and the EEG-polygraphy patterns were informative, with the absence of asymmetrical tonic or dystonic posturing of the limbs. Scalp EEG alone does not usually provide much information in patients with isolated paroxysmal arousals. Coupled to the modified DSSSD technique, it may allow confirmation of the diagnosis of frontal epilepsy, as was the case in our four patients. [Published with video sequences].