TY - JOUR
T1 - Initial delta and delayed theta/alpha pattern in the temporal region on ictal EEG suggests purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy
AU - Itabashi, Izumi
AU - Jin, Kazutaka
AU - Sato, Shiho
AU - Suzuki, Hiroyoshi
AU - Iwasaki, Masaki
AU - Kitazawa, Yu
AU - Kakisaka, Yosuke
AU - Nakasato, Nobukazu
N1 - Funding Information:
The authors thank all EEG technologists of the epilepsy monitoring units at Tohoku University Hospital. This work was supported by Grants-in-Aid for Scientific Research (No. JP16H05435 and No. JP16K09708) from the Japan Society for the Promotion of Science.
Publisher Copyright:
© 2021 International Federation of Clinical Neurophysiology
PY - 2021/3
Y1 - 2021/3
N2 - Objective: To determine whether the ictal scalp EEG findings suggest purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy (mTLE) associated with hippocampal sclerosis (HS). Methods: Twenty-three patients with mTLE with pathologically confirmed HS were divided into 12 with epileptogenicity only in the hippocampus (HS only group) and 11 with epileptogenicity in both the hippocampus and temporal neocortex or other locations (HS plus group), based on the combination of surgical procedures, postoperative outcome, and pathological findings. Sixteen underwent selective amygdalohippocampectomy (SelAH) and 7 received anterior temporal lobectomy. Ictal scalp EEG findings of 79 focal impaired awareness seizures were compared between the HS only and HS plus groups. We focused on the 1–4 Hz rhythmic delta activity at ictal onset followed by 5–9 Hz rhythmic theta/alpha activity 10–30 s after the onset in the temporal region. Results: The initial delta and delayed theta/alpha (ID-DT) pattern was observed in 8 of 12 patients in the HS only group, but in none of 11 patients in the HS plus group (p < 0.01). Conclusions: ID-DT pattern on ictal EEG suggests purely hippocampal epileptogenicity in mTLE with HS. Significance: Patients with the ID-DT pattern are likely to become seizure-free after SelAH.
AB - Objective: To determine whether the ictal scalp EEG findings suggest purely hippocampal epileptogenicity in patients with mesial temporal lobe epilepsy (mTLE) associated with hippocampal sclerosis (HS). Methods: Twenty-three patients with mTLE with pathologically confirmed HS were divided into 12 with epileptogenicity only in the hippocampus (HS only group) and 11 with epileptogenicity in both the hippocampus and temporal neocortex or other locations (HS plus group), based on the combination of surgical procedures, postoperative outcome, and pathological findings. Sixteen underwent selective amygdalohippocampectomy (SelAH) and 7 received anterior temporal lobectomy. Ictal scalp EEG findings of 79 focal impaired awareness seizures were compared between the HS only and HS plus groups. We focused on the 1–4 Hz rhythmic delta activity at ictal onset followed by 5–9 Hz rhythmic theta/alpha activity 10–30 s after the onset in the temporal region. Results: The initial delta and delayed theta/alpha (ID-DT) pattern was observed in 8 of 12 patients in the HS only group, but in none of 11 patients in the HS plus group (p < 0.01). Conclusions: ID-DT pattern on ictal EEG suggests purely hippocampal epileptogenicity in mTLE with HS. Significance: Patients with the ID-DT pattern are likely to become seizure-free after SelAH.
KW - Anterior temporal lobectomy
KW - Hippocampal sclerosis
KW - Ictal EEG
KW - Mesial temporal lobe epilepsy
KW - Selective amygdalohippocampectomy
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U2 - 10.1016/j.clinph.2020.11.041
DO - 10.1016/j.clinph.2020.11.041
M3 - Article
C2 - 33561726
AN - SCOPUS:85100567069
VL - 132
SP - 737
EP - 743
JO - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
JF - Electroencephalography and Clinical Neurophysiology - Electromyography and Motor Control
SN - 1388-2457
IS - 3
ER -