Bilateral duplication of the abducens nerve - case study.

Area of Science:

• Neuroanatomy
• Human Anatomy
• Surgical Anatomy

Background:

• The abducens nerve (cranial nerve VI) has a lengthy intracranial course and intricate anatomical relationships.
• Knowledge of abducens nerve anatomy is vital for understanding the causes and symptoms of abducens nerve palsy.
• While typically a single nerve trunk, variations like duplication can occur.

Observation:

• A detailed anatomical description of bilateral abducens nerve duplication is presented in one cadaver.
• The nerve exhibited an atypical course within the cavernous sinus but a normal distribution to the lateral rectus muscle bilaterally.
• Specific variations in dural penetration and fusion points were noted on the right and left sides.

Findings:

• Bilateral duplication of the abducens nerve was observed, with unique pathways in the subarachnoid space, dura mater, and cavernous sinus.
• On the right, both trunks fused before dural penetration; on the left, they penetrated separately before fusing.
• The nerve trunks showed complex branching and reunification within the cavernous sinus before a typical orbital course.

Implications:

• Abducens nerve duplication is a significant anatomical variation that requires consideration in neurosurgical and diagnostic procedures.
• Awareness of this variation is essential for accurate interpretation of imaging and during interventions in the petroclival region and cavernous sinus.
• This finding contributes to the understanding of cranial nerve variations and their potential clinical relevance.