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EEG before and after total corpus callosotomy for pharmacoresistant infantile spasms: Fast oscillations and slow‐wave connectivity in hypsarrhythmia
Author(s) -
Baba Shiro,
Vakorin Vasily A.,
Doesburg Sam M.,
Nagamori Chizuko,
Cortez Miguel A.,
Honda Ryoko,
Ono Tomonori,
Toda Keisuke,
Nishimoto Hanako,
Ebihara Toshihiro,
Sakai Kana,
Ochi Ayako,
Snead O. Carter,
Baba Hiroshi,
Otsubo Hiroshi
Publication year - 2019
Publication title -
epilepsia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.687
H-Index - 191
eISSN - 1528-1167
pISSN - 0013-9580
DOI - 10.1111/epi.16295
Subject(s) - hypsarrhythmia , corpus callosotomy , epileptic spasms , ictal , epilepsy , electroencephalography , group b , medicine , pediatrics , psychology , anesthesia , epilepsy surgery , surgery , psychiatry
Objective We analyzed the features of fast oscillations ( FO s) and connectivity in hypsarrhythmia to identify biomarkers for predicting seizure outcomes after total corpus callosotomy ( TCC ) in children with pharmacoresistant infantile spasms ( IS ). We hypothesize that the power of FO s and connectivity of slow waves in hypsarrhythmia would indicate the prognosis of IS . Method We retrospectively identified 42 children with pharmacoresistant IS who underwent TCC from 2009 to 2014 at Nagasaki Medical Center. We collected preoperative hypsarrhythmia for 200 seconds from each child. Children were categorized into three groups with interictal epileptic discharges on EEG at 6 months after TCC : group A, no epileptic discharge; group B, lateralized epileptic discharges; and group C; bilateral epileptic discharges. We analyzed spectral power and phase synchronization in preoperative hypsarrhythmia among the three groups. Results We found 10 children in group A, 10 children in group B, and 22 children in group C. All group A and 1 in group B achieved seizure freedom after TCC . Six (67%) of 9 group B children who underwent further surgeries achieved seizure freedom. Ten (45%) of group C children had seizure reduction >50% after TCC , and 13 (87%) of 15 children who underwent further surgeries had residual seizures. The clinical profiles of the three groups did not differ significantly. The power of FO s (≥45 Hz) in hypsarrhythmia was significantly stronger in group C at the midline and temporal regions than in groups B and A ( P = .014). The connectivity of theta (4‐9 Hz) and FO s (29‐70 Hz) tended to increase in group C, compared with the increased connectivity of 1‐2 Hz in group A ( P = .08). Significance The increased power and connectivity of FO s in hypsarrhythmia may correlate with pharmacoresistant and surgically resistant seizures in IS . The existence and connectivity of FO s are associated with unilateral/bilateral cortical epileptogenicity in hypsarrhythmia. Prominent slow waves and connectivity without FO s might correlate with seizure freedom after TCC . Modulation of the callosal system with subcortical/cortical epileptic discharges might play a role in generating hypsarrhythmia and IS .