Chapter contents Overview Somatic motor component Origin, central course Intracranial course Final innervation Visceral motor component Origin and course Final innervation

Cranial Nerve III - Oculomotor Nerve Page 16 of 16 Clinical correlation - Argyll-Robertson pupil Argyll-Robertson pupil is caused by damage to cells in the pretectal region of the midbrain. As a result of this damage, signals carried by CN II from the retina are not relayed via the pretectal nucleus on the affected side to the Edinger-Westphal nuclei. This results in a loss of both the direct and consensual pupillary light reflex when light is shined in the eye on the affected side. Because the accommodation reflex pathway is distinct from the pupillary light reflex pathway the accommodation reflex is unaffected. Figure 3-16. Argyll-Robertson pupil.

Last revised: March 22, 1998