Diffusion tensor analysis of temporal and extra-temporal lobe tracts in temporal lobe epilepsy

Govindan, Rajkumar Munian; Makki, Malek I.; Sundaram, Senthil K.; Juhász, Csaba; Chugani, Harry T.

doi:10.1016/j.eplepsyres.2008.03.011

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Volume 80, Issue 1 , Pages 30-41, July 2008

Diffusion tensor analysis of temporal and extra-temporal lobe tracts in temporal lobe epilepsy

Rajkumar Munian Govindan
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
Malek I. Makki
- Department of Radiology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
Senthil K. Sundaram
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
Csaba Juhász
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
Harry T. Chugani
- Carman and Ann Adams Department of Pediatrics, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Department of Neurology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Department of Radiology, Children's Hospital of Michigan, Detroit Medical Center, Wayne State University, Detroit, MI, United States
- Corresponding author at: Division of Pediatric Neurology/PET Center, Children's Hospital of Michigan, 3901 Beaubien Boulevard, Detroit, MI 48201, United States. Tel.: +1 313 993 2605; fax: +1 313 993 3845.

Received 30 July 2007; received in revised form 7 February 2008; accepted 5 March 2008.

Summary

Objective

To determine whether the major temporal lobe white matter tracts in patients with temporal lobe epilepsy manifest abnormal water diffusion properties.

Methods

Diffusion tensor MRI measurements were obtained from tractography for uncinate, arcuate, inferior longitudinal fasciculi and corticospinal tract in 13 children with left temporal lobe epilepsy and normal conventional MRI, and the data were compared to measurements in 12 age-matched normal volunteers. The relationship between tensor parameters and duration of epilepsy was also determined.

Results

All four tracts in the affected left hemisphere showed lower mean anisotropy, planar and linear indices, but higher spherical index in patients versus controls. Diffusion changes in the left uncinate and arcuate fasciculus correlated significantly with duration of epilepsy. Arcuate fasciculus showed a reversal of the normal left–right asymmetry. Various diffusion abnormalities were also seen in the four tracts studied in the right hemisphere.

Conclusion

Our findings indicate abnormal water diffusion in temporal lobe and extra-temporal lobe tracts with robust changes in the direction perpendicular to the axons. Diffusion abnormalities associated with duration of epilepsy suggest progressive changes in ipsilateral uncinate and arcuate fasciculus due to chronic seizure activity. Finally, our results in arcuate fasciculus are consistent with language reorganization to the contralateral right hemisphere.

Keywords: Temporal lobe epilepsy, Diffusion tensor imaging, Tractography