Imaging evaluation of cranial nerves 3, 4, and 6.

Neuropathies of the oculomotor, trochlear, and abducens nerves may present with isolated or complex neurologic findings. An understanding of the anatomy of these cranial nerves as they traverse the brainstem, basilar cisterns, and cavernous sinus on their way to the orbit can assist in localizing the suggested site of pathology and help to focus imaging protocols. Differential diagnostic possibilities for specific anatomic locations are reviewed.