Ictal Pattern of EEG and Muscular Activation in Symptomatic Infantile Spasms: A Videopolygraphic and Computer Analysis

• Published in: Epilepsia (Copenhagen) Vol. 43; no. 12; pp. 1559 - 1563
• Main Authors: Bisulli, Francesca, Volpi, Lilia, Meletti, Stefano, Rubboli, Guido, Franzoni, Emilio, Moscano, Milena, D'Orsi, Giuseppe, Tassinari, Carlo Alberto
• Format: Journal Article
• Language: English
• Published: Boston, MA, USA Blackwell Science Inc 01.12.2002; Blackwell
• Subjects: Backaverage; Biological and medical sciences; Brain Damage, Chronic - congenital; Brain Damage, Chronic - diagnosis; Brain Damage, Chronic - physiopathology; Cerebral Cortex - abnormalities; Cerebral Cortex - physiopathology; Child, Preschool; Computerized analysis; Dominance, Cerebral - physiology; Electroencephalography; Electromyography; Female; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Infant; Isometric Contraction - physiology; Medical sciences; Muscle, Skeletal - innervation; Muscular pattern; Nervous system (semeiology, syndromes); Neurology; Recruitment, Neurophysiological - physiology; Signal Processing, Computer-Assisted; Spasms, Infantile - diagnosis; Spasms, Infantile - physiopathology; Symptomatic infantile spasms; Video‐polygraphic recording; Human; Nervous system diseases; Epilepsy; Exploration; Electroencephalography; Striated muscle; Video recording; Crisis; Polygraphy; Electrodiagnosis; West syndrome; Central nervous system disease; Computerized processing; Video-polygraphic recording-Muscular pattern-Symptomatic infantile spasms-Computerized analysis-Backaverage; Child
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1046/j.1528-1157.2002.15302.x

Purpose: To investigate ictal muscular phenomena characterizing symptomatic infantile spasms (ISs) and their relation to ictal EEG. Methods: Four children with severe encephalopathy, neurologic impairment, and refractory ISs related to different dysplastic lesions, underwent videopolygraphic recordings collecting surface electromyogram (EMG) activity from several cranial and limb muscles to evaluate the pattern of muscular recruitment, duration, and side‐to‐side asymmetry of ISs. Acquired data were stored for off‐line analysis by a computerized polygraphic system. Results: Spasms were characterized by a complex pattern of muscular activation. A constant or rostrocaudal propagation pattern was lacking in all patients. Intervals between the onset of EMG activity in different muscles in each spasm were very long: ≤100–200 ms. Two patients, with hemispheric cortical dysplasia and agenesis of the corpus callosum, had asymmetric and asynchronous spasms in which the EMG onset of the muscles contralateral to the affected hemisphere constantly anticipated that of the ipsilateral ones. Backaveraging of EEG activity disclosed a high‐amplitude EEG complex on the same side as the dysplastic lesion, preceding or succeeding the contralateral muscle activity onset. In the other two patients with diffuse cortical dysplasia, no EEG transient was related to EMG activity onset. Conclusions: Despite clinical similarity between spasms in the same patient, our data demonstrate the complexity and heterogeneity of these motor phenomena. Our findings cannot be explained simply in terms of cortical or reticular generators like other motor phenomena such as cortical myoclonus or startle reflex.