HEALTH ASSESSMENT - Cranial Nerves & Reflexes

Cranial Nerves

Cranial Nerve		Major Function
I. Olfactory	sensory	smell
II. Optic	sensory	vision
III. Oculomotor	motor	eyelid and eyeball movement
IV. Trochlear	motor	innervates superior oblique
		turns eye downward and laterally
V. Trigeminal	motor	chewing
	sensory	face & mouth touch & pain
VI. Abducens	motor	turns eye laterally
VII. Facial	motor	controls most facial expressions
		secretion of tears & saliva
	sensory	taste
VIII. Vestibulocochlear(auditory)	sensory	hearing
		equillibrium sensation
IX. Glossopharyngeal	motor	swallowing
	sensory	senses carotid blood pressure & taste buds
X. Vagus	sensory	senses aortic blood pressure
		slows heart rate
	motor	stimulates digestive organs
		taste
XI. Accessory	motor	controls trapezius & sternocleidomastoid
XII. Hypoglossal	motor	controls tongue movements

Cranial Nerve I—Olfactory

Ask client to close eyes and identify different mild aromas, such as coffee and vanilla.

Cranial Nerve II—Optic

Ask the client to read Snellen’s chart; check visual fields by confrontation, and conduct an ophthalmoscopicexamination.

Cranial Nerve III—Oculomotor

Assess six ocular movements and pupil reaction.

Cranial Nerve IV—Trochlear

Assess six ocular movements.

Cranial Nerve V—Trigeminal

While client looks upward, lightly touch the lateral sclera of the eye to elicit the blink reflex. To test light sensation, have the client close eyes, and wipe a wisp of cotton over client’s forehead and paranasal sinuses. To test deep sensation, use alternating blunt and sharp ends of a safety pin over same area.

Cranial Nerve VI—Abducens

Assess directions of gaze.

Cranial Nerve VII—Facial

Ask the client to smile, raise the eyebrows, frown, puff out cheeks, and close eyes tightly. Ask the client to identify various tastes placed on the tip and sides of tongue—sugar, salt—and to identify areas of taste.

Cranial Nerve VIII—Auditory

Assess the client’s ability to hear the spoken word and the vibrations of a tuning fork.

Cranial Nerve IX—Glossopharyngeal

Apply tastes on the posterior tongue for identification. Ask the client to move tongue from side to side and up and down.

Cranial Nerve X—Vagus

Assessed with CN IX; assess the client’s speech for hoarseness.

Cranial Nerve XI—Accessory

Ask the client to shrug shoulders against resistance from your hands and to turn head to the side against resistance from your hand. Repeat for the other side.

Cranial Nerve XII—Hypoglossal

Ask the client to protrude tongue at midline, then move it side to side.

Reflexes

Scale for Grading Reflex Response

Grade
0	No reflex response
+1	Minimal activity (hypoactive)
+2	Normal response
+3	More active than normal
+4	Maximal activity (hyperactive)

Biceps Reflex

• Partially flex the client’s arm at the elbow, and rest the forearm over the thighs, placing the palm of the hand down.

• Place the thumb of your nondominant hand horizontally over the biceps tendon.

• Deliver a blow (slight downward thrust) with the percussion hammer to your thumb.

• Observe the normal slight flexion of the elbow, and feel the biceps’s contraction through your thumb.

Triceps Reflex

• Flex the client’s arm at the elbow, and support it in the palm of your nondominant hand.

• Palpate the triceps tendon about 2–5 cm (1–2 inches) above the elbow.

• Deliver a blow with the percussion hammer directly to the tendon

• Observe for the normal slight extension of the elbow.

Brachioradialis Reflex

• Rest the client’s arm in a relaxed position on your forearm or on the client’s own leg.

• Deliver a blow with the percussion hammer directly on the radius 2–5 cm (1–2 inches) above the wrist or the styloid process, the bony prominence on the thumb side of the wrist.

• Observe the normal flexion and supination of the forearm. The fingers of the hand might also extend slightly.

Patellar Reflex

• Ask the client to sit on the edge of the examining table so that legs hang freely.

• Locate the patellar tendon directly below the patella.

• Deliver a blow with the percussion hammer directly to the tendon.

• Observe the normal extension or kicking out of the leg as the quadriceps muscle contracts

• If no response occurs, and you suspect the client is not relaxed, ask the client to interlock fingers and pull.

Achilles Reflex

• With the client in the same position as for the patellar reflex test, slightly dorsiflex the client’s ankle by supporting the foot lightly in your hand.

• Deliver a blow with the percussion hammer directly to the Achilles tendon just above the heel.

• Observe and feel the normal plantar flexion (downward jerk) of the foot.

Plantar (Babinski’s) Reflex

• Use a moderately sharp object, such as the handle of the percussion hammer, a key, or the dull end of a pin or applicator stick.

• Stroke the lateral border of the sole of the client’s foot, starting at the heel, continuing to the ball of the foot, and then proceeding across the ball of the foot toward the big toe.

• Observe the response. Normally, all five toes bend downward; this reaction is negative Babinski’s. In an abnormal Babinski response, the toes spread outward and the big toe moves upward.