CN 5 Examinations Flashcards
CN 5 exam overview
-observation of tone/strength of muscles of mastication
-corneal blink
-general facial sensation (light touch/sharp)
-generation sensation to ant 2/3 of tongue
Jaw jerk reflex
Exam process-motor
Masseter/temporalis
- fingers on anterior aspect of jaw and have patient clench
- same with temporalis and have clench jaw
CN 5 motor ROM
- Passive ROM -open/close-lat dev
2. Active ROM
Corneal blink reflex tests what CN?
Afferent: CN5
Efferent: CN7
Testing general facial sensation order
CN 5- 1 bilateral soft, continue with 2, 3
Then move to sharp
CN 5 exam that tests motor and sensory
Jaw jerk reflex
What does the jaw jerk reflex test?
Afferent and efferent limbs of CN 5 mediated through mesencephalic nucleus
What are the MC causes of CN 5 sensory dysfunction
TRAUMA
- dental/surgicla procedures
- dental anesthetic injections
- facial features
Trigeminal neuralgia aka? Aka?
Tic douloreux
Fothergill’s neuralgia
S/s of trigeminal neuralgia/tic douloureux, fothergills neuralgia
Student fleeting/excruciating attack of unilateral face pain
-“trigger zone” provokes pain as well as talking, chewing, brushing teeth, cold, wind on face
What is usually involved in TN?
V2/3
Cause of TN?
Idiopathic
No clinical motor or sensory deficit
How may M/F present with TN?
M: unshaven over trigger zone
F: no make-up over trigger zone
What is the MC disorder in CN5 sensory function?
TN
Occurs in MS patients MC. TN especially suggestive of MS if bilateral
Herpes Zoster of CN5
Shingles
s/s of herpes zoster
Follows dermatomes MC affects CN 5-1 Pain and vesicles over forehead, eyelid and cornea -keratitis -corneal ulceration/scaring -blindness sometimes
Neuroparalytic keratitis
Inflammation of the core an due to interruption of CN V-1
-decreased sensativity to cornea making it MC for injury/infection/ulceration/decreased vision/blindness
Numb cheek syndrome
Lesion of infraorbital nerve
MC due to perineural spread of tumor
Numb chin syndrome
Lesion of mental nerve
MC due to neoplastic process
Motor exam for CN 7 facial movements
Smile Frown Clench eyes tight Puff cheeks/resist Look up/wrinkle forehead
Corneal blink reflex
Patient should blink bilaterally when eye touched with cotton swab
What does corneal blink reflex test
Afferent: CN 5
Efferent CN 7
MC disorder of CN 7
Bell’s palsy
Cause of Bell’s palsy
Idiopathic
Thought viral, inflammatory though
Hyperacusis
Increased hearing
Stapedius innervated by CN7 that causes dampending now not working to dampen so LOUD
S/s of hyperacusis
Retro auricular pain
S/s of Bell’s palsy
Unilateral facial weakness
Hyperacusis
Dry eye (parasympathetic function not working
Loss of taste on ipsilateral half of tongue
Incomplete eye closure and decreased tearing: corneal ulceration
Most people with Bell’s palsy recover within
3 weeks
