Ipsilateral and contralateral MRI volumetric abnormalities in chronic unilateral temporal lobe epilepsy and their clinical correlates.
OBJECTIVE
To assess the presence, extent, and clinical correlates of quantitative MR volumetric abnormalities in ipsilateral and contralateral hippocampus, and temporal and extratemporal lobe regions in unilateral temporal lobe epilepsy (TLE).


METHODS
In total, 34 subjects with unilateral left (n = 15) or right (n = 19) TLE were compared with 65 healthy controls. Regions of interest included the ipsilateral and contralateral hippocampus as well as temporal, frontal, parietal, and occipital lobe gray and white matter. Clinical markers of neurodevelopmental insult (initial precipitating insult, early age of recurrent seizures) and chronicity of epilepsy (epilepsy duration, estimated number of lifetime generalized seizures) were related to magnetic resonance (MR) volume abnormalities.


RESULTS
Quantitative MR abnormalities extend beyond the ipsilateral hippocampus and temporal lobe with extratemporal (frontal and parietal lobe) reductions in cerebral white matter, especially ipsilateral but also contralateral to the side of seizure onset. Volumetric abnormalities in ipsilateral hippocampus and bilateral cerebral white matter are associated with factors related to both the onset and the chronicity of the patients' epilepsy.


CONCLUSIONS
These cross-sectional findings support the view that volumetric abnormalities in chronic TLE are associated with a combination of neurodevelopmental and progressive effects, characterized by a prominent disruption in ipsilateral hippocampus and neural connectivity (i.e., white matter volume loss) that extends beyond the temporal lobe, affecting both ipsilateral and contralateral hemispheres.
Seidenberg
Michael
M
Rosalind Franklin University of Medicine and Science, North Chicago, Illinois 60064, USA. Michael.Seidenberg@rosalindfranklin.edu
Kelly
Kiesa Getz
KG
Parrish
Joy
J
Geary
Elizabeth
E
Dow
Christian
C
Rutecki
Paul
P
Hermann
Bruce
B
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001284:Atrophy; D015415:Biomarkers; D002540:Cerebral Cortex / Q000473:pathology*; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D003936:Diagnosis, Computer-Assisted / Q000706:statistics & numerical data; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012720:Severity of Illness Index; D013702:Temporal Lobe / Q000473:pathology*
D015415:Biomarkers