Cranial Nerves Flashcards
How do you test a patients mental state?
New memory
Recent memory
Remote memory
Orientation
An example of how you would test a patients new memory?
Give 3 new words, ask them to repeat the words and then return to these later, asking the patient to repeat them to you.
An example of how you would test a patients recent memory?
Ask them a recent relevant question. i.e. what was the weather like this morning? What did you have for breakfast?
An example of how you would test a patients remote memory?
Ask questions, i.e. who is the king? who is the prime minister? who do I work for?
An example of how you would test a patients orientation?
Time - which day is it and what time of day is it?
Place - where are you?
Person - who is this?
What is the name of the first cranial nerve?
CN I - Olfactory
Is cranial nerve I, Olfactory nerve, sensory or motor?
Sensory
How do we test the cranial nerve I (olfactory)?
Sense of smell
Test each nostril with a strong smell
What is a loss of smell also known as?
Anosmia
What is the name of the second cranial nerve?
CN II - Optic Nerve
Is cranial nerve I, optic nerve, sensory or motor?
Sensory
Which 3 tests do we use to test cranial nerve II (Optic nerve)?
Visual Acuity
Visual Fields
Fundoscopy
How would you test a patients visual acuity for cranial nerve II (Optic nerve)?
Like a sight test, patient should wear glasses if they need to
Cover one eye, read something around 6 ft away.
Cover other eye and do the same
If a smellen chart is available use that.
How would you test a patients visual fields for cranial nerve II (Optic nerve)?
Stand 1m from pt with arms outstretched. Instruct pt not to move eyes or head
Wiggle fingers in periphery of vision (compare to your own peripheral vision)
Patient to tell you which finger(s) are wiggling
Stand 1m from pt. Pt covers right eye, you cover left eye.
Bring finger from outside of line of vision to periphery of vision and pt tells you when they can see it (compared to your vision)
Test 4 positions on each eye
What is fundoscopy?
The assessment of the fundus using an ophthalmoscope
How would you test cranial nerve II (Optic nerve) using fundocsopy?
Dim the lights
Ask the patient to fixate on a distant targer
Approach the patient from the side
Examine the optic nerve and surrounding retina
What can be seen in this picture?
Fundus
More specifically the left fundus
When observing a patients fundus what are you observing for / or lack thereof?
Shine light into the eye, look for a red reflex - an absence of red reflex = cataracts
Examine the eye for:
Lens for opacities - cataracts may cause and prevent full examination of the fundus
Disc - this is found by following a large retinal vein back towards the disc as all veins radiate from the disc
Look for the disc which is yellowish orange to creamy pink oval or round in structure
The optic disc normally measures 1.5mm
The ophthalmoscope magnifies the normal retina about 15 times
Optic disc is the nose side of the face
Retinal arteries, light red and smaller
Retinal veins, dark red and larger than arteries
Which 3 cranial nerves do we test together?
CN III Oculomotor
CN IV Trochlear
CN VI Abducens
Is cranial nerve III, Oculomotor nerve, sensory or motor?
Motor
Is cranial nerve IV, trochlear nerve, sensory or motor?
Motor
Is cranial nerve VI, abducens nerve, sensory or motor?
Motor
When testing cranial nerves III, IV and VI (III Oculomotor, IV Trochlear, VI Abducens) what are we first observing the eyes for?
Ptosis - dropping of the eyelid/eyelids
Palpebral fissures - gap between upper eyelid and lower eyelid. A slight difference may be noted in 1/3rd of the population
When testing cranial nerve III (oculomotor), what should you test the pupils for?
Constriction of the pupils
Check for consensual reflex - when both pupils constrict, even though light has only been shone in one eye
Which cranial nerves would you perform the + test for?
cranial nerves III, IV and VI (III Oculomotor, IV Trochlear, VI Abducens)
How do you perform the + test?
Ensure patient keeps their head still
Ask patient to follow an object with their eyes as you draw a + with your finger
Up and down test superior and inferior rectus
Left and right tests medial and lateral rectus
How do you perform a H test?
Draw a H with your finger, ask patient to follow along with eyes, pause slightly at end of each horizontal plane and check for nystagmus - test horizontal and vertical gaze
Superior oblique pulls eye down and out
Inferior oblique pulls eye up and out
Which cranial nerves are you testing when performing a H+ test?
cranial nerves III, IV and VI (III Oculomotor, IV Trochlear, VI Abducens)
How would you test for Diplopia and convergence?
Move your finger towards pt’s nose. Ask pt to follow it with their eye.
Eyes should both fix on finger all the way to nose (convergance)
There should be no double vision (diplopia) until at least the finger is very near to the nose
What is diplopia?
Double vision / seeing double
What is convergance?
Convergence describes the way our eyes move together and point inward when we look at near objects
Convergance Insufficiency is present if the eyes do not point together inward as one looks at objects close-up
Under which cranial nerves do we test for diplopia and convergence?
cranial nerves III, IV and VI (III Oculomotor, IV Trochlear, VI Abducens)
What is the name of the fifth cranial nerve?
CN V - Trigeminal
Is cranial nerve V, trigeminal nerve, sensory or motor?
Both
Which branch of the trigeminal nerve covers V1?
Ophthalmic nerve
Which branch of the trigeminal nerve covers V2?
Maxillary nerve
Which branch of the trigeminal nerve covers V3?
Mandibular nerve
In which 3 ways do we test the cranial nerve V (Trigeminal nerve)?
Sensation
Muscles of mastication
Jaw jerk
How do we test sensation in cranial nerve V (Trigeminal nerve)?
Test generally by comparing sensation to touch
Can also test pain and temperature
How do we test muscles of mastication in cranial nerve V (Trigeminal nerve)?
Clench teeth and palpate masseter and temporalis muscles
How do we test cranial nerve V (Trigeminal nerve) using a jaw jerk?
muscle stretch reflex that is elicited by a brisk tap with a reflex hammer on the front of the chin while the mouth is slightly opened and the jaw is relaxed.
What is the seventh cranial nerve?
CN VII - Facial nerve
Is cranial nerve VII, Facial nerve, sensory or motor?
Both
How do we test the motor input of a patients CN VII (facial nerve)?
Ask the patient to…
- Pretend to blow a trumpet
- Show their teeth/smile
- Frown
- Whistle
- Close their eyes and don’t let you open them
Of which of the cranial nerves does dysfunction result in Bell’s palsy?
cranial nerve VII (facial nerve)
How do we test the sensory input of a patients CN VII (facial nerve)?
Salty or sweet drink (difficult in practice)
What is the eight cranial nerve?
CN VIII - Vestibulocochlear
Is cranial nerve VIII, vestibulocochlear nerve, sensory or motor?
Sensory
Which 3 exams do we use to test cranial nerve VIII (vestibulocochlear)?
Auriscopic Exam
Auditory Acuity
Weber’s and Rinnes Tests
When testing cranial nerve VIII (Vestibulocochlear), what are you examining when performing an auriscopic exam?
Inspection of the patient’s ear canal and tympanic membrane
What can be seen in this picture?
Healthy tympanic membrane
When testing cranial nerve VIII (Vestibulocochlear), how do you use an Auriscope?
- Use the largest speculum that will fit the canal
- Straighten the ear canal by holding the ear firmly, gently pull it upward, backward and slightly away from the head
- Hold the auriscope horizontally, right hand right ear & vice versa
- Place your little finger against the pt’s cheek
- Insert the speculum, directing it downwards and forwards
What do you look for when using an Auriscope when testing cranial nerve VIII (Vestibulocochlear)?
- Wax ~ can vary in colour & consistency
- Yellow & flaky to brown & sticky or dark & hard
- Look for the cone of light as a landmark
- Look above the cone of light for the malleus, (short process and handle) and around the margin of the TM
- Look for the drum, noting its colour
- Silvery/pearly grey/off white & shiny is normal
- Pink & inflamed/infected & dull is abnormal
- An abnormal eardrum may bulge
- Old wax is black
- A black hole is a perforation of the eardrum
What can be observed in the following photos?
Infected / inflamed tympanic membrane
How would you test for auditory acuity when testing cranial nerve VIII (Vestibulocochlear)?
Stand behind the patient
Ask the patient to cover one ear and whisper a number or word of at least two syllables
Ask the patient to repeat what they heard
Repeat for the other ear using a different word
How would you perform a Weber’s test when testing cranial nerve VIII (Vestibulocochlear)?
Tests for lateralization
* Apply the vibrating tuning fork to the centre of
the forehead or on top of the head
* Ask the patient where they hear it, on one side or both sides
* Patients will hear the sound in the midline or equally in both ears
* Hearing more predominantly in one ear points to either conductive or sensorineural loss
What test is being performed here? And which cranial nerve is it testing?
Weber’s test
Cranial nerve VIII - Vestibulocochlear
How would you perform a Rinne’s test when testing cranial nerve VIII (Vestibulocochlear)?
Compares air conduction and bone conduction
Strike the tuning fork (512Hertz) so it vibrates lightly
Hold the fork against the mastoid process
When the pt can’t hear the sound anymore put the fork by the ear. In a normal finding the pt will be able to hear the sound again
Abnormal finding indicates conductive hearing loss
What test is being performed here? And which cranial nerve is it testing?
Rinne’s test
Cranial nerve VIII - Vestibulocochlear
What is the ninth cranial nerve?
CN IX - Glossopharyngeal nerve
Is cranial nerve IX, Glossopharyngeal nerve, sensory or motor?
Both
How do you test cranial nerve IX (Glossopharyngeal)?
Ask the patient to swallow
What is the tenth cranial nerve?
CN X - Vagus nerve
Is cranial nerve X, vagus nerve, sensory or motor?
Both
How do you test cranial nerve X (Vagus nerve)?
Check palate and uvula rise - say ‘AH’
Uvula should rise centrally - if it rises to one side it will deviate to the good side
What is the eleventh cranial nerve?
Cranial nerve XI - Accessory
Is cranial nerve XI, accessory nerve, sensory or motor?
Motor
How do you test cranial nerve XI (Accessory nerve)?
Sternocleidomastoid muscles and trapezius muscles against resistance
What is the twelfth cranial nerve?
CN XII - Hypoglossal
Is cranial nerve XII, Hypoglossal nerve, sensory or motor?
Both
How do you test cranial nerve XII (hypoglossal nerve)?
Ask the patient to protrude the tongue
Tongue should come out in the midline, if it deviated, it will do so to the bad side
Ask the patient to push the tongue into each cheek against resistance
