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The point about the effect of supranuclear lesions (ones damaging the corticobulbar pathway) on the function of the facial and hypoglossal nerves is an extremely important one. To be certain you are on it read pages 482 - 4 in Blumenfeld and check out Figure 12.13.

The terse comment at the bottom of the box, "but the sternocleidomastoid is special" refers to the unusual action of this muscle. Generally we recognize that each hemisphere is concerned with the opposite side of the body and - by extension - the opposite half of surrounding space. Thus, stimulation of the appropriate part of the right cerebral hemisphere will cause both the head and the eyes to turn to the left. But it is the right sternocleidomastoid muscle that helps turn the head to the left by pulling the mastoid process forward. So, most authors (Kandel, Blumenfeld (Pg 499) and Wilson-Pauwels et al - the yellow cranial nerve book folks) say that the corticobulbar input to the part of the accessory nucleus innervating the sternocleidomastoid muscle is uncrossed....ie the right hemisphere controls the right sternocleidomastoid muscle.