Investigation of fasciculus uncinatus anatomy with diffusion tensor imaging and fibrile dissection methods

Fasciculus uncinatus is a white matter structure which is connecting lobus temporalis with lobus frontalis. Fasciculus uncinatus shows lateralization consistent with cerebral hemisphere lateralization in healthy subjects. The deterioration of lateralization is observed in pathological conditions such as schizophrenia, epilepsy and antisocial personality disorder. The detection of lateralization in cadaver and in DTI images of healthy individuals is important for normal-abnormal criteria. The aim of our study, is to investigate the methodological criteria of the lateralization and to define the normal fasciculus uncinatus anatomy in detail to constitute the basis for clinical studies in this area. Fasciculus uncinatus dissection was performed by using the Klingler fibrillary dissection method of 8 cadaver brains obtained from Ege University Anatomy Department. On the other hand, fibril tractography was performed with DTI Studio program on diffuse brain MR from 10 healthy subjects. Anatomical differences between the right and left brain hemispheres were examined. Fasciculus uncinatus thickness analysis showed that except for one case, the fasciculus uncinatus thicknesses of the left hemispheres were greater than the fasciculus uncinatus thicknesses of the right hemispheres (p=0,03). In fasciculus uncinatus fractional anisotropy (FA) analysis, except for one case, fasciculus uncinatus FA values of left hemispheres were found to be higher than fasciculus uncinatus FA values of right hemispheres (p=0,009). The data of our study revealed that fasciculus uncinatus shows left lateralization. In our study, we believe that the evaluation of the fasciculus uncinatus anatomy improves the reliability of the data obtained by diffusion tensor imaging, extraction of the tractography map, and the combination of modified Klingler dissection methods. Key words: Fiber dissection, Diffusion tensor imaging, Cerebral lateralization, Fasciculus uncinatus