Abnormalities in diffusion tensor imaging of the uncinate fasciculus relate to reduced memory in temporal lobe epilepsy.
OBJECTIVE
To use Diffusion Tensor Imaging (DTI) to explore structural integrity and connectivity of the uncinate fasciculus (UF) in patients with temporal lobe epilepsy (TLE) and its relationship to memory performance.


METHODS
DTI and UF reconstruction were performed in 28 patients with TLE (18 left, 10 right) and 10 normal controls. Differences between left and right UF fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and correlations between DTI measures and memory scores in the TLE groups were computed.


RESULTS
In controls, FA was higher in the left than right UF (p < 0.01). In left TLE, FA values were lower and ADC values higher than controls in the left UF and ADC values were higher in the right UF (all p < 0.05). In right TLE, ADCs were higher in the left and right UF compared to controls, and FA was reduced in the left UF (all p < 0.05). In left TLE, ADCs in the left UF were negatively correlated with Auditory Immediate (p < 0.05) and Delayed Memory (p < 0.01). Visual Delayed Memory was positively correlated with reduced FA in the ROI of the right UF and increased radial diffusivities (p < 0.05). No significant correlations were found in right TLE. Thus, DTI values correlated with memory scores in the expected direction in patients with left TLE.


CONCLUSIONS
Abnormal diffusion measures in the UF ipsilateral to the epileptogenic zone suggest that integrity of the UF is related to memory performance in patients with left TLE. Larger sample sizes are needed to evaluate structure-function correlations further.
Diehl
Beate
B
Neurological Institute, Epilepsy Center, The Cleveland Clinic Foundation, Cleveland, Ohio, USA. diehlbeate@yahoo.com
Busch
Robyn M
RM
Duncan
John S
JS
Piao
Zhe
Z
Tkach
Jean
J
Lüders
Hans O
HO
D000328:Adult; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging; D004833:Epilepsy, Temporal Lobe / Q000150:complications / Q000473:pathology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D012598:Sclerosis / Q000473:pathology; D013702:Temporal Lobe / Q000033:anatomy & histology*