title: Infantile spasms: ictal phenomena.
abstract: Ictal phenomena were studied during three separate six-hour video/polygraphic recording sessions in 10 patients with infantile spasms; 1,079 spasms occurred. Frequency during wakefulness (7.7 spasms/hour) was greater than that during sleep (2.5 spasms/hour); 46.6% of spasms occurred in clusters. Spasms were composed of one or more of three phases: a myoclonic contraction, a tonic contraction, and/or an arrest of activity. The most common types were myoclonic-tonic (40.3%) and myoclonic alone (36.3%). When classified by postural motor phenomena, 41.6% were "flexor", 16.3% "extensor", 39.0% "mixed", and 3.1% "arrest" alone. Electrographic monitoring revealed that myoclonic contractions were associated with an initial paroxysmal event. Tonic contractions and arrests were usually associated with suppression of electroencephalographic activity with or without rhythmic activity. Knowledge of these clinical and electrographic features is important for diagnosis and evaluation of proposed treatments.
mesh_terms: D002540:Cerebral Cortex / Q000503:physiopathology; D002675:Child, Preschool; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008991:Monitoring, Physiologic; D012894:Sleep Stages / Q000502:physiology; D013036:Spasms, Infantile / Q000503:physiopathology*