The seventh cranial nerve is routinely tested in the unconscious ICU patient as the motor component of the corneal reflex. In the conscious patient, one may also test facial nerve function by asking the patient to perform a standard series of grimaces. The usual series involves asking the patient to raise their eyebrows, close their eyes very tightly, puff out their cheeks, make a cheesy grin, and protrude their lower lip in a pout. The seventh nerve was one among about four cranial nerves asked about in Question 21.2 from the first paper of 2014 (other involved were CN IX, CN XII, CN VII, CN VI).
Obvious features
Subtle features
Unilateral lesion:
Bilateral lesions are freakishly rare in isolation
Obviously, the facial nerve forms the efferent component of the corneal reflex, and a bilateral absence of the corneal reflex is to be expected in the context of braindeath.
The LITFL summary of cranial nerve lesions is without peer in terms of useful information density.
Walker, H. Kenneth, W. Dallas Hall, and J. Willis Hurst. "Clinical methods." 3rd edition.(1990).Chapter 62. Cranial Nerve VII: The Facial Nerve and Taste - by Kenneth Walker