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Temporal lobe epilepsy and focal cortical dysplasia in children: A tip to find the abnormality
Author(s) -
Bartolini Luca,
Whitehead Matthew T.,
Ho ChengYing,
Sepeta Leigh N.,
Oluigbo Chima O.,
Havens Kathryn,
Freilich Emily R.,
Schreiber John M.,
Gaillard William D.
Publication year - 2017
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.13615
Subject(s) - cortical dysplasia , temporal lobe , epilepsy , magnetic resonance imaging , medicine , hippocampal sclerosis , abnormality , epilepsy surgery , white matter , dysplasia , pathology , radiology , psychiatry
Summary Objective To demonstrate an association between magnetic resonance imaging ( MRI ) findings and pathologic characteristics in children who had surgery for medically refractory epilepsy due to focal cortical dysplasia ( FCD ). Methods We retrospectively studied 110 children who had epilepsy surgery. Twenty‐seven patients with FCD were included. Thirteen had temporal lobe epilepsy ( TLE ) and 14 had extra‐temporal lobe epilepsy ( ETLE ). Three patients had associated mesial temporal sclerosis. Preoperative 3T MRI s interleaved with nine controls were blindly re‐reviewed and categorized according to signal alteration. Pathologic specimens were classified according to the 2011 International League Against Epilepsy ( ILAE ) classification and compared to MRI studies. Results Rates of pathology subtypes differed between TLE and ETLE (χ 2 (3) = 8.57, p = 0.04). FCD type I was more frequent in TLE , whereas FCD type II was more frequent in ETLE . In the TLE group, nine patients had temporal tip abnormalities. They all exhibited gray–white matter blurring with decreased myelination and white matter hyperintense signal. Blurring involved the whole temporal tip, not just the area of dysplasia. These patients were less likely to demonstrate cortical thickening compared to those without temporal tip findings (χ 2 (1) = 9.55, p = 0.002). Three of them had FCD Ib, three had FCD II a, two had FCD III a, and one had FCD II b; MRI features could not entirely distinguish between FCD subtypes. TLE patients showed more pronounced findings than ETLE on MRI (χ 2 (1) = 11.95, p = 0.003, odds ratio [ OR ] 18.00). In all cases of FCD , isolated blurring was more likely to be associated with FCD II , whereas blurring with decreased myelination was seen with FCD I (χ 2 (6) = 13.07, p = 0.042). Significance Our study described associations between MRI characteristics and pathology in children with FCD and offered a detailed analysis of temporal lobe tip abnormalities and FCD subtypes in children with TLE . These findings may contribute to the presurgical evaluation of patients with refractory epilepsy.