Neurophysiological study of secondary synchronous occipito-frontopolar spikes in childhood

M. Ueno et al., Neurophysiological study of secondary synchronous occipito-frontopolar spikes in childhood, CLIN NEU, 112(11), 2001, pp. 2106-2112
Citations number
Categorie Soggetti
Neurosciences & Behavoir
Journal title
ISSN journal
1388-2457 → ACNP
Year of publication
2106 - 2112
SICI code
Objectives: We conducted this latency study to clarify the neurophysiologic al mechanism underlying the synchronous appearance of independent occipital and frontopolar spike discharges in childhood epilepsies. Methods: The subjects were 13 children with localization-related epilepsies (LRE) who showed apparently synchronous occipital and frontopolar EEG spik e discharges. There was idiopathic LRE in 7 children, symptomatic LRE in 4, and cryptogenic LRE and a history of cryptogenic West syndrome in one pati ent each. Patient ages at the time of the study ranged from 4 years 3 month s to 14 years 0 month with a mean of 9 years 4 months. The EEGs were digiti zed at 1024 samples/s. The latency was measured between the peak of the occ ipital and frontopolar spike discharges. The conduction velocity was calcul ated by dividing the distance between the occipital and frontopolar electro des by the latencies. Results: We studied 19 EEGs including 6 serial EEGs recorded longitudinally in 5 patients. The number of occipito-frontal spike discharges available f or the study ranged from 12 to 70 with an average of 36 +/- 17 in each EEG record. Occipital spikes always preceded the frontopolar spikes by 11.1-31. 6 ms (average 19.3 +/-5.4 ms). The estimated conduction velocity ranged fro m 6.7 to 19.2 m/s with a mean of 12.2 +/-3.7 m/s. Conclusions: The synchronizing spike phenomenon we showed in this study was in the posterior to anterior direction (intrahemispheric synchrony) in con trast to that of secondary bilateral interhemispheric synchrony through the corpus callosum. It is suggested that the long occipito-frontal associatio n fibers play a role in synchronizing both spike discharges. This secondary occipito-frontopolar synchrony should be one of the developmental EEG phen omena related to the maturation of brain, and contribute to the multiplicat ion or diffusion of the preexisting localized spike discharges often seen i n pediatric LRE regardless of etiology. (C) 2001 Elsevier Science Ireland L td. All rights reserved.