Corneal reflexes, facial sensation, and jaw movements
Swallowing and rise of the palate, gag reflex Voice and speech Shoulder and neck movements Tongue symmetry and position
Cranial Nerve I—Olfactory. Test the sense ofsmell by presenting the patient with familiar and nonirritating odors. First be sure that each nasal passage is open by compressing one side of the nose and asking the patient to sniff through the other. The patient should then close both eyes. Occlude one nostril and test smell in the other with such substances as cloves, coffee, soap, or vanilla. Ask if the patient smells anything and, if so, what. Test the other side. A person should normally perceive odor on each side, and can often identify it.
Cranial Nerve II—Optic. Test visual acuity (see pp. 144-145).
Inspect the optic fundi with your ophthalmoscope, paying special attention to the optic discs (see pp. 151-155).
Screen the visual fields by confrontation (see pp. 145-146). Occasionally—in a stroke patient, for example—screening indicates a visual field defect, such as a homonymous hemianopsia, that you cannot confirm by testing one eye at a time. This screening observation, nevertheless, is significant.
Loss of smell has many causes, including nasal disease, head trauma, smoking, aging, and the use of cocaine. It may be congenital.
Optic atrophy, papilledema
These findings suggest visual extinction, a subtle impairment detectable only when testing both eyes simultaneously. It suggests a lesion in the parietal cortex.
Cranial Nerves II and HI—Optic and Oculomotor. Inspect the size and shape of the pupils, and compare one side with the other. Test the pupillary reactions to light, if these are abnormal, examine the near response also (see p. 149).
Cranial Nerves III, IV, and VI—Oculomotor, Trochlear, and Abducens. Test the extraocular movements in the six cardinal directions of gaze, and look for loss of conjugate movements in any of the six directions. Check convergence of the eyes. Identify any nystagmus, noting the direction of gaze in which it appears, the plane in which movements occur (horizontal, vertical, rotary, or mixed), and the direction of the quick and slow components (see pp. 149-151).
Look for ptosis (drooping of the upper eyelids). A slight difference in the width of the palpebral fissures may be noted in about one third of all normal people.
Cranial Nerve V—Trigeminal
Motor. While palpating the temporal and masseter muscles in turn, ask the patient to clench his or her teeth. Note the strength of muscle contraction.
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