Taylor's focal cortical dysplasia increases the risk of sleep-related epilepsy.
OBJECTIVE
To analyze the topography of the epileptogenic zone (EZ) and the etiologic substrate as risk factors for sleep-related focal epilepsy.


METHODS
Three hundred three patients (172 males and 131 females, mean age at surgery 25.6 +/- 13.1 years), who were seizure-free after resective surgery for drug-resistant focal epilepsy, were retrospectively reviewed. Statistical analysis was conducted to evaluate the risk of presenting sleep-related epilepsy (SRE) against topography of resection (assumed to correspond or to include the EZ) and results of histology.


RESULTS
Thirty-nine patients (12.8%) presented with an SRE. At bivariate analysis, a higher frequency of SRE was associated with a frontal lobe EZ (p = 1.94 x 10(-9)) and Taylor's FCD (TFCD, p = 2.20 x 10(-16)), whereas architectural FCD (p = 0.00977), ganglioglioma (p = 0.02508), and mesial temporal sclerosis (p = 2.47 x 10(-5)) were correlated with a reduced frequency of SRE. Multivariate analysis demonstrated that the only variable significantly associated with SRE was the presence of a TFCD, which increased 14-fold the risk of SRE [p = 1.66 x 10(-10); risk ratio (RR) = 14.44].


CONCLUSIONS
In this study, we have demonstrated a significant and strong association between SRE and TFCD in a select population of patients with drug-resistant focal epilepsy submitted to surgical resection of the EZ. Although our results cannot be applied to the entire spectrum of SRE, the presence of TFCD as the underlying etiology should be considered when evaluating patients with SRE, because surgery can provide excellent results on seizures in these cases.
Nobili
Lino
L
Claudio Munari Epilepsy Surgery Center, Sleep Medicine Center, Ospedale Niguarda Ca' Granda, Piazza Ospedale Maggiore, 320162 Milan, Italy. lino.nobili@ospedaleniguarda.it
Cardinale
Francesco
F
Magliola
Umberto
U
Cicolin
Alessandro
A
Didato
Giuseppe
G
Bramerio
Manuela
M
Fuschillo
Dalila
D
Spreafico
Roberto
R
Mai
Roberto
R
Sartori
Ivana
I
Francione
Stefano
S
Lo Russo
Giorgio
G
Castana
Laura
L
Tassi
Laura
L
Cossu
Massimo
M
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000473:pathology* / Q000601:surgery; D015897:Comorbidity; D018572:Disease-Free Survival; D004351:Drug Resistance; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data; D004828:Epilepsies, Partial / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D054220:Malformations of Cortical Development / Q000453:epidemiology* / Q000473:pathology*; D015999:Multivariate Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012598:Sclerosis / Q000473:pathology; D020178:Sleep Disorders, Circadian Rhythm / Q000453:epidemiology* / Q000473:pathology