Four roots of abducent nerve at its exit from the pontomedullary sulcus: endoscopic case study In the

The abducent nerve occupies a strategic position at the middle third of the clivus. With the recent advances in the field of imaging techniques and endoscopic skull base surgery it is important to understand the neurovascular relationships and variations in its course. Very limited literature is available on the cisternal course of abducent nerve as studied by an endoscope. A few studies have described the course of abducent nerve endoscopically through an endonasal approach. In this study we attempted to explore its cisternal course endoscopically through a retrosigmoid approach to the cerebello-pontine angle with emphasis on its neurovascular relationship. Duplication and triplication of the abducent nerve have been reported by some authors, but four roots of abducent nerve have not been reported. In the present study, in one of the cadavers it was found that on the left side the abducent nerve emerged as four roots from the pontomedullary sulcus.