Slide 1

Gross Anatomy: Cranial Nerve Review Ref: Table 8.5 (pages 848-849) in Drake et al. Slide 2 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 Slide 3 Physiological H Slide 4 Look straight ahead. Look right. A 30-year-old male presents with the chief complaint of double vision. Physical exam reveals: Slide 5 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? Slide 6 54-year-old male presents with the chief complaint of diplopia. Testing of extraocular movements reveals: Shouldnt see white on this test Slide 7 R L Where is the lesion? Slide 8 Slide 9 Slide 10 Compressive v. Ischemic Where is the lesion? Slide 11 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? Slide 12 * 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? * Slide 13 Cranial Nerve V Trigeminal Innervates what muscles? What is the circuit for the jaw jerk reflex? Slide 14 Whats the diagnosis? What nerve/ganglion/branches are involved? A. B. C. Slide 15 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 Slide 16 Smile. Where is the lesion? Slide 17 A 38-year-old female presents with painful blisters as shown in the figure. What nerve/ganglion/branches are involved? Slide 18 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 (Bells 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, dont have dry eyes. Chorda tympani is intact, dont have loss of taste Patient #4: A 40-year-old female with a fractured mandibular ramus and a lacerated lingual nerve. Slide 19 Cranial Nerve VII - Facial Nerve Facial Nerve Lesions Slide 20 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) Slide 21 Cranial Nerve IX - Glossopharyngeal Nerve Slide 22 Cranial Nerve X Vagus Nerve Slide 23 Cranial Nerve XI Spinal Accessory Nerve Muscles: Testing: Slide 24 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? Slide 25 Stick out your tongue. Where is the lesion? Slide 26 Cranial Nerve Reflexes Jaw Jerk Corneal Reflex Tearing Gag Cough In by: Out by: