Physical exam: Cranial nerves and motor system exam

Question 1

Cranial nerves and motor system exam: Learning objectives

Answer 1

1. Review the 3 important principles:
   a) Is the mental status intact?
   b) Are the right- and left-sided findings symmetric?
   c) Is the lesion in the central or the peripheral nervous system?
2. Identify and test the 12 cranial nerves
3. Master testing of the motor system: Muscle strength, movement, bulk, tone, and cerebellar function
4. Learn to grade muscle strength
5. Assess cerebellar function: Point to point movements like finger to nose, heel to shin, gait

Question 2

Common concerns for CN and motor system exam

Answer 2

1. Cough
2. Dizziness or vertigo
3. Generalized, proximal, or distal weakness
4. Numbness, abnormal or loss of sensation
5. Loss of consciousness, fainting, or syncope
6. Seizures
7. Tremors
8. Involuntary movements

Question 3

CN I

Answer 3

• Have you noticed any changes in your sense of smell?

* Can you please tell me what do you smell? Coffee, alcohol?

Question 4

CN I

Answer 4

a) Have you noticed any changes in your sense of smell?

b) Can you please tell me what do you smell? Coffee, alcohol?

Question 5

CN II

Answer 5

a) Do you wear glasses or contact lenses?
b) Visual acuity using smellen chart placed at about 35 cm distance: Can you please read the lowest line you can? (Make sure to do one eye at a time)
c) Visual fields: Can you please cover your right eye with your right arm? Look straight at me and let me know when you see my finger moving.
d) Pupillary reflex: I am going to shine light in your eyes, please look straight to the wall, each eye. Direct and consensual
e) Now, I would like to do a fundoscopic exam.

Question 6

CN III, IV, VI Ocular

Answer 6

a) By inspection, both eyes appear symmetrical. There is no deviation, nystagmus, head tilting, ptosis.
b) Can you please follow this pen without moving your head? Let me know if you see things double or blurred
c) Normal extra-ocular muscle movements, no nystagmus or double vision were noted.

Question 7

CN V: Vagus

Answer 7

Motor:

a. By inspection: no atrophy of the temporal or masseter area
b. Can you please clench, feel the temporalis and masseter
c. Can you open your mouth against my hand?
d. Can you please move your jaw to one side and do not let me move it

Sensory:

a. This is a piece of cotton, and this is how it feels, I am going to touch your face, and whenever you feel it, please tell me. Can you close your eyes please?
b. Touch the face in symmetrical areas; cover the ophthalmic, maxillary, and mandibular areas. Does it feel the same?
c. Facial sensation of the trigeminal nerve is intact and equal on both sides

Reflexes:
a. I would normally do Corneal reflex (You have to mention it to get the point)

Taste:
a. Have you noticed any changes in the taste

Question 8

CN VII: Facial

Answer 8

Motor:
a. Face is symmetrical, no deviation of the angle of the mouth, normal nasolabial folds, no drooling

b. Can you please copy me:
i. Raise your eye brows, can you frown (wrinkle your forehead) please?
ii. Can you close your eyes, and do not let me open them?
iii. Can you blow your cheeks? Whistle?
iv. Can you show me your teeth? And smile?

c. If there is a mouth angle deviation Deviates opposite to the side of the lesion)

d. UMNL vs. LMNL:
i. UMNL: intact upper face muscles (the nucleus receives double-sided innervation)
ii. LMNL (Bell’s palsy) -> ptosis; all face muscles are affected

Sensory:

a. Mr/Ms. _____have you noticed any changes in taste? (Outer 2/3 of the tongue)
b. Mr/Ms. _____have you noticed any changes in your hearing?

Reflexes:

a. Jaw reflex
b. Corneal reflex (afferent: CN V, efferent: CN VII)

Question 9

CN VIII: Acustic

Answer 9

Now, I am going to assess your hearing. I am going to whisper a number into one of your ears and I want you to repeat it.
a. Whisper ABC while rubbing fingers in front of the other ear OR by rubbing your fingers
b. Because the hearing is normal, I am going to skip Weber and Rinne tests
i. Rinne: place the tuning fork in front of ear, then on the mastoid process
ii. Weber: place the tuning fork on the forehead
(Note: Air conduction is better than bone conduction. No lateralization. This is Normal)

Question 10

CN IX, X: Glossopharyngeal and Vagus

Answer 10

a. Patient voice is normal, no hoarseness
b. Can you swallow a sip of water please? Normal swallowing
c. Can you open your mouth please? Soft palate is symmetrical, uvula is central
a. Uvula deviates to the opposite side of the lesion
d. To check the reflexes: I need to do the gag reflex

Question 11

CN XI: Spinal accessory

Answer 11

a. Can you please shrug your shoulders and do not let me push them down?
b. Turn your head to the right, and to the left. I am going to resist you.

Question 12

CN XII: Hypoglossal

Answer 12

a. Can you please open your mouth? Can you stick your tongue out?
i. Tongue is central, no deviation. No fasciculation or atrophy of tongue.
ii. If there is a lesion, the tongue deviates towards the lesion side
b. Can you please move it to the right and to the left? Can you stick it against your cheeks and do not let me move it? “Normal movements of the tongue is noted”

Question 13

Cerebellar signs

Answer 13

• Gait test: Ataxia
• Romberg: Ataxia fue to neuropathy (INCREASES w/ eyes closes). Cerebellar ataxia (ALWAYS ON).
• Nystagmus
• Finger to finger
• Finger to nose test
• Heel to shin