Intracranial intradural variations of nerve roots.

BACKGROUND

The aim of this paper was to point out the intradural cranial nerve roots variations in their localization and number to establish the incidence and clinical importance of the cranial nerve root variations.

METHODS

The anatomical study was performed on 120 sides in 60 cadavers. There were 51 male cadavers with the mean age 43.3 and 9 female cadavers with the mean age of 39.5 years.

RESULTS

Abducens nerve variations were observed in 48 cases (80 %). They were more frequently on the left side, in 25 cases (41.66 %). Duplicated abducens nerve was observed in 25 cases (41.66 %). Double and triple abducens nerve variations were also observed.

CONCLUSIONS

Cranial nerve variations are rare, but variations of abducens nerve and atypical exit of the hypoglossal nerve from the fossa cranium posterior is not a rare variation. Knowledge of this variation may be important to various fields of medicine (Tab. 3, Fig. 8, Ref. 34).