Agarwal N, Ahmed AK, Wiggins RH, McCulley TJ, Kontzialis M, Macedo LL, Choudhri AF, Ditta LC, Ishii M, Gallia GL, Aygun N, Blitz AM. Segmental Imaging of the Trochlear Nerve: Anatomic and Pathologic Considerations.
J Neuroophthalmol 2021;
41:e7-e15. [PMID:
33136684 DOI:
10.1097/wno.0000000000001125]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND
The trochlear nerve (the fourth cranial nerve) is the only cranial nerve that arises from the dorsal aspect of the midbrain. The nerve has a lengthy course making it highly susceptible to injury. It is also the smallest cranial nerve and is often difficult to identify on neuroimaging.
EVIDENCE ACQUISITION
High-resolution 3-dimensional skull base MRI allows for submillimeter isotropic acquisition and is optimal for cranial nerve evaluation. In this text, the detailed anatomy of the fourth cranial nerve applicable to imaging will be reviewed.
RESULTS
Detailed anatomic knowledge of each segment of the trochlear nerve is necessary in patients with trochlear nerve palsy. A systematic approach to identification and assessment of each trochlear nerve segment is essential. Pathologic cases are provided for each segment.
CONCLUSIONS
A segmental approach to high-resolution 3-dimensional MRI for the study of the trochlear nerve is suggested.
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