Diffusion tensor tractography studies on mechanisms of recovery of injured fornix

The fornix, which connects the medial temporal lobe and the medial diencephalon, is involved in episodic memory as an important part of the Papez circuit. The mechanisms of recovery of an injured fornix revealed by diffusion tensor tractography in the five studies are summarized as follows: 1) recovery through the nerve tract from an injured fornical crus to the medial temporal lobe via the normal pathway of the fornical crus; 2) recovery through the nerve tract originating from an ipsi-lesional fornical body connected to the ipsi-lesional medial temporal lobe via the splenium of the corpus callosum; 3) recovery through the nerve tract from the ipsi-lesional fornical body extending to the contra-lesional medial temporal lobe via the splenium of the corpus callosum; 4) recovery through the nerve tract originating from the ipsi-lesional fornical column connected to the ipsi-lesional medial temporal lobe; and 5) recovery through the nerve tract originating from the contra-lesional fornical column connected to the ipsi-lesional medial temporal lobe via the contra-lesional medial temporal lobe and the splenium of the corpus callosum. These diffusion tensor tractography studies on mechanisms of recovery of injured fornical crus appeared to provide useful information for clinicians caring for patients with brain injury, however, studies on this topic are still in the beginning stages.