Download Gross Anatomy: Cranial Nerve Review Ref: Table 8.5 (pages 848

Gross Anatomy:
Cranial Nerve Review
Ref: Table 8.5 (pages 848-849) in Drake et al.
Cranial Nerves III, IV and VI
CN III innervates: MR, SR, IR, IO, levator palpebrae superioris, sphincter pupillae, cilliary mm.
CN IV innervates: Superior oblique
CN VI innervates: lateral rectus
Physiological “H”
A 30-year-old male presents with the chief complaint of “double
vision”. Physical exam reveals:
Look straight ahead.
Look right.
An 8-year-old girl
presents as shown.
Cranial nerve testing
reveals?
Test CN XI
SCM may be paralyzed on left
side
If she holds head like this to see
better, problem lies with CN IV
- trochlear, which innervated
Superior Oblique; her right eye
is extorted
If it was torticullis, it would be
on the left side, because it is
shortening of the muscle
What is your DDx?
54-year-old male presents with the chief complaint of diplopia.
Testing of extraocular movements reveals:
Where is the lesion?
R
L
Where is the lesion?
Where is the lesion?
Where is the lesion?
Compressive v. Ischemic
A 37-year-old female presents with
the chief complaint of difficulty
walking. History reveals that she
is a heavy crack user and
supports her habit through
prostitution. Physical exam
reveals a gait ataxia; patellar
reflex is 1 / 4 bilaterally.
Examination of the eye provides
the results to the right:
What are your observations?
What is the most likely diagnosis?
Cranial Nerve V – Trigeminal
What nerve provides sensory
innervation at the:
•
forehead: ophthalmic V1
•
tip of nose: ophthalmic V1
•
upper vs. lower eyelid:
ophthalmic vs maxillary
•
upper vs. lower lip: maxillary
vs mandibular
•
tip of chin:
What nerve innervates the skin here?
*
*
Cranial Nerve V – Trigeminal
Innervates what muscles?
What is the circuit for the jaw jerk reflex?
What’s the diagnosis?
What nerve/ganglion/branches are involved?
B.
A.
C.
Cranial Nerve VII - Facial Nerve
How would you test the function of
CN VII?
Sensory: Taste?
Motor: Smile, wrinkle forehead
(mm. of facial expression)
Buccinator – keeps food
from collecting between
teeth and oral vestibule
Smile.
Where is the lesion?
A 38-year-old female
presents with
painful blisters as
shown in the
figure.
What
nerve/ganglion/branches
are involved?
Compare and contrast the expected physical exam findings
[related to CN VII] in following 4 patients:
Patient #1: A 23-year-old female with a vestibular schwannoma (a tumor of
CN VIII). (at the internal auditory meatus; everything that nerve does) Difficulty with facial
expression (Bell’s Palsy), loss of taste, dry eye, dry mouth,
Patient #2: A 10-year-old male with chronic otitis media that has eroded the
facial canal. Lesion is after the greater petrosal nerve; innervation to lacrimal gland is intact
as well as….
Patient #3: A 20-year-old male with a fractured mastoid.
Greater petrosal nerve is intact, don’t have dry eyes. Chorda tympani is intact, don’t have loss of
taste
Patient #4: A 40-year-old female with a fractured mandibular ramus and a
lacerated lingual nerve.
Cranial Nerve
VII Lesions
- Facial Nerve
Facial Nerve
A 59-year-old female presents with the chief complaints of
hoarseness, difficulty swallowing and dry mouth. Physical
examination reveals:
• Paralyzed vocal fold, on the right
• Weak gag and cough reflexes
• Weakness shrugging shoulder, on the right
• Weakness turning head to left against resistance
• Decreased taste sensation on the right
Where is the lesion?
(i.e. identify one location where an injury/lesion could cause all of the above
findings)
Cranial Nerve IX Glossopharyngeal Nerve
Cranial Nerve X –
Vagus Nerve
Cranial Nerve XI –
Spinal Accessory Nerve
Muscles:
Testing:
Cranial Nerve XII – Hypoglossal Nerve
Muscles:
Testing:
Injury to the hypoglossal nerve as it crosses the
internal carotid artery would result in paralysis of what other
muscles?
Stick out your tongue. Where is the lesion?
Cranial Nerve Reflexes
In by:
• Jaw Jerk
• Corneal Reflex
• Tearing
• Gag
• Cough
Out by: