Serial postoperative awake and sleep EEG and long-term seizure outcome after anterior temporal lobectomy for hippocampal sclerosis.
OBJECTIVE
To test if postoperative prolonged awake and sleep EEG monitoring predict long-term seizure outcome in patients operated for drug-resistant temporal lobe epilepsy due to hippocampal sclerosis (TLE-HS).


METHODS
This longitudinal study includes 107 patients with MTLE-HS who underwent anterior temporal lobectomy (ATL), were followed for at least 5 years (mean 8.3, range 5-12), had postoperative EEG after 2 months and at least one prolonged video-EEG monitoring during both wakefulness and sleep after 12 and 24 months. At each follow-up visit, the presence of interictal epileptiform discharges (IED) was determined, and seizure outcome was evaluated.


RESULTS
Sixty-six patients (62%) remained free from auras and seizures throughout the follow-up period. Twenty-six (24%), 22 (21%), and 16 (16%) patients had IED at the 2-month, 12-month, and 24-month follow-up, respectively. The presence of IED at each time point was found to be associated with seizure or aura recurrence. Sleep recording contributed to the identification of patients with IED, as half of patients with IED displayed anomalies in sleep EEG only. In multivariate analysis, the presence of IED 2 months after surgery was found to be associated with seizure or aura recurrence independent of pre-operative factors consistently reported as outcome predictors in the literature.


CONCLUSIONS
The presence of IED in serial postoperative EEG including sleep recording may predict long-term seizure outcome after ATL for TLE-HS. Serial postoperative EEGs may contribute to outcome prediction and help making decision about medication withdrawal in patients operated for TLE-HS.
IRCCS "NEUROMED", Pozzilli (IS), Italy. Electronic address: gdigennaro@neuromed.it.
Giancarlo
G
Di Gennaro
Department of Neurology and Psychiatry, "Sapienza University of Rome", Italy.
Sara
S
Casciato
IRCCS "NEUROMED", Pozzilli (IS), Italy.
Alfredo
A
D'Aniello
IRCCS "NEUROMED", Pozzilli (IS), Italy.
Marco
M
De Risi
IRCCS "NEUROMED", Pozzilli (IS), Italy.
Pier Paolo
PP
Quarato
IRCCS "NEUROMED", Pozzilli (IS), Italy.
Addolorata
A
Mascia
IRCCS "NEUROMED", Pozzilli (IS), Italy.
Liliana G
LG
Grammaldo
'Neurone' Foundation for Research in Neuropsychobiology and Clinical Neurosciences, Rome, Italy.
Giulio N
GN
Meldolesi
IRCCS "NEUROMED", Pozzilli (IS), Italy; Department of Neurosurgery, "Sapienza University of Rome", Italy.
Vincenzo
V
Esposito
Mental Health Unit, Centre of Epidemiology, Surveillance and Health Promotion, Italian National Institute of Health, Rome, Italy.
Angelo
A
Picardi
D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy; D002648:Child; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000209:etiology / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011184:Postoperative Period; D011379:Prognosis; D012189:Retrospective Studies; D012598:Sclerosis / Q000150:complications / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D012640:Seizures / Q000209:etiology / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D012890:Sleep / Q000502:physiology*; D016896:Treatment Outcome; D014851:Wakefulness / Q000502:physiology*; D055815:Young Adult
Epilepsy surgery; Outcome; Postoperative EEG; Temporal lobe epilepsy with hippocampal sclerosis