White fiber dissection of brain; the internal capsule: a cadaveric study.

AIM This study was done to study the three dimensional anatomy of internal capsule's white fibers completely by cadaveric dissection and its relation to basal ganglia and other related anatomical structures. MATERIAL AND METHODS Eight formalin fixed cerebral hemispheres were dissected for internal capsule under operating microscope. Klingler's technique of fiber dissection was adopted. The internal capsule was dissected from superiolateral inferior and medial surface of cerebral hemisphere. During and after dissection its relation with basal ganglia and other related structures were studied. RESULTS The internal capsule was demonstrated by dissecting fibers of all its parts. Fibers that forms the internal capsule originate from different parts of cerebral cortex and pass through corona radiata that lies in lateral periventricular area and lateral to the caudate nucleus above the upper border of lentiform nucleus. The internal capsule is situated medial to lentiform nucleus and lateral to caudate nucleus and thalamus. Caudally it continues in the midbrain as cerebral peduncle. It has an anterior limb, genu, posterior limb, retrolentiform and sublentiform part. The relation of different parts of internal capsule with surrounding structures were also shown. CONCLUSION Knowledge of the microsurgical anatomy of the internal capsule and other white fibers tracts is essential for neurosurgeons and other neuroscientists.