Premium
Cranial nerves 3,4 and 6: from brainstem to orbit
Author(s) -
KAWASAKI A
Publication year - 2012
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2012.1662.x
Subject(s) - anatomy , midbrain , oculomotor nerve , abducens nerve , trochlear nerve , pons , medicine , brainstem , cranial nerves , medial longitudinal fasciculus , orbit (dynamics) , oculomotor nucleus , palsy , clivus , extraocular muscles , skull , central nervous system , pathology , alternative medicine , aerospace engineering , psychiatry , engineering , endocrinology
Purpose To review the pertinent anatomy of the ocular motor cranial nerves in correlation with their clinical presentation Methods didactic lecture and cass Results The nucleus of the oculomotor nerve (CN3) is composed of several subnuclei. The central caudal subnucleus innervates the levator palpebrae bilaterally. Fibers from the superior rectus subnucleus decussate and innervate the SR muscle of the contralateral eye. Axonal fascicles from each subnucleus remain topographically arranged as they traverse the midbrain. Autonomic fibers (pupil and accommodation) orient dorsomedially in the peripheral nerve as it exits the peduncles of the ventral midbrain. The clinical presentation of a nuclear, fascicular and peripheral lesion of CN3 are distinctive and localizing. The trochlear nerve (CN4) is the smallest cranial nerve yet has the longest pathway. It is susceptible during closed head injury. The abducens nerve (CN6) exits the ventral pons and ascends the clivus to reach the cavernous sinus. It is prone to injury with changes in intracranial pressure. Lesions of the clivus can also cause bilateral abducens palsy. Conclusion Understanding the anatomic pathway of the ocular motor nerves can help focus the etiology and location of the lesion.Commercial interest