Nocturnal paroxysmal arousals with motor behaviors during sleep: frontal lobe epilepsy or parasomnia?

Abstract

Nocturnal paroxysmal arousals with motor behaviors have been described in a few individuals, and their possible epileptic origin as nocturnal frontal lobe seizures has been suggested. However, the clinical and polysomnographic differentiation from parasomnias and physiologic movements during sleep have not been clarified yet. In this study, we evaluated a group of patients with nocturnal motor behaviors and tried to characterize paroxysmal arousals. Thirty-four participants (mean [+/-SD] age 22.7 [+/-12.9] years) noting nocturnal motor agitation or behaviors and 12 healthy controls (mean age 24.1 [+/-3.1] years) underwent nocturnal polysomnography with video-tape recording and motor behaviors analysis. Arousals with motor attacks were classified as minimal, minor, or major depending on semiology, complexity, and duration of behaviors. All patients showed several minimal (e.g., scratching or rubbing the nose and the head) and minor (e.g., pelvic thrusting or swinging with dystonic component) attacks, and 53% also had major episodes (e.g., sudden elevation of the head and trunk from the bed with complex behaviors) occurring mainly in non-rapid eye movement sleep. In all the patients, motor attacks were characterized by stereotypy, sudden onset, short duration, and repetitiveness. In 80%, epileptiform abnormalities were found. All control subjects showed motor events, but they were fewer, slower, nonstereotyped, and semiologically different from the patients'. No significant difference in conventional sleep parameters between the two groups were found. Paroxysmal arousals with motor behaviors probably represent a particular form of nocturnal frontal lobe epilepsy rather than an unusual parasomnia. The semiologic characteristics of these type of arousals are difficult to recognize and differentiate from physiologic movements or parasomnias without video-polygraphic analysis.