Crainial Nerves

Question 1

Olfactory Nerve

Answer 1

Provides sense of smell (usually not tested)

Question 2

Optic Nerve

Answer 2

Vision. (test should be completed one eye at a time). Ask PT if there is any blurring of vision, loss of vision, spots in the visual field, or peripheral vision loss (tunnel vision)

More detailed testing can be done by standing straight in front of the PT and asking him to cover one eye and look straight at you. Slowly bring your fingertip in turn from above, below, to the right, and to the left direction of gaze until the PT can see it.

Compare with the earliest that you can see it with the equivalent eye. If a deficit is present, roughly map out the positions of the blind spots by passing the fingertip across the visual field.

Question 3

Oculomotor, Trochlear, Abducens Nerves

Answer 3

All three of these nerves control eye movements.

All three nerves can be tested by having the Pt eyes follow the examiner’s fingers in all four directions (quadrants) and then in towards the tip of the nose (giving a cross-eye look).

Oculomotor nerve can further be tested by shining a light into one eye at a time checking for equal and bilateral pupil constriction.

Question 4

Trigeminal Nerve

Answer 4

Governs the sensation of the forehead, face, clenching of the jaw. It also supplies the muscles of the ear (tensor tympani) necessary for normal hearing.

Tested by lightly stroking the forehead, face, and jaw on each side with a finger or wisp of cotton wool.

Question 5

Facial Nerve

Answer 5

Face muscles. It stimulates the scalp, forehead, eyelids, muscles of facial expression, cheeks, and jaw. It is tested by having the PT:

Smile
Show his teeth
Whistle
Wrinkle his forehead
Close eyes tightly

The tow sides should preform symmetrically. Symmetry of the nasolabial folds (lines from nose to outside corners of the mouth) should be observed.

Question 6

Acoustic Nerve

Answer 6

Controls hearing and balance.

Test by whispering to PT, rubbing fingers together next to PT’s ears, or putting a tuning fork near the PT’s ears.

Compare this against the other ear.

Question 7

Glossopharyngeal Nerve

Answer 7

Sensation form the upper mouth and throat area. Supplies the sensory component of the gag reflex and constriction of the pharyngeal wall when saying “ahh.”

Tested by touching the back of the PT’s throat with a tongue depressor. This should cause a gagging response.

This nerve is normally not tested.

Question 8

Vagus Nerve

Answer 8

Has many functions, including control of the roof of the mouth and vocal cords.

The examiner can test this nerve by having the PT say “aah” while watching for the palate to rise.

Note the tone of the voice; hoarseness may also indicate vagus nerve involvement.

Question 9

Spinal Accessory Nerve

Answer 9

Controls the turning of the head from side to side and shoulder shrug against resistance.

Test this nerve by having the PT turn his head from side to side. Resistance is provided by placing one hand against the side of the PT’s head.

The examiner should note that an injury to the nerve on one side will cause an inability to turn the head to the opposite side or weakness/absence of the shoulder shrug on the affected side.

Question 10

Hypoglossal Nerve

Answer 10

Governs the muscle activity of the tongue. An injury to one of the hyposglossal nerves causes the tongue to twist to that side when stuck out of the mouth