The microsurgical anatomy of the abducens nerve in its intracranial course.

The microsurgical anatomy of the abducens nerve through its intracranial course was studied in 20 specimens obtained from 10 cadaver heads fixed in formalin. Another 20 specimens were used to study the pattern of branching of the nerve trunk. The following intracranial segments were studied: subarachnoid or intracisternal, petroclival, and intracavernous. Angulations, neurovascular relationships, and branching patterns of the nerve are described. The long intracranial course of the abducens nerve, its tortuosity, and its tight attachment to the skull base at the level of the petrous apex may influence its vulnerability in some pathological conditions.