Cranial Nerve Screen Flashcards
What is CNII?
Optic
What is the Function of the Optic Nerve?
Special sensation: vision
What do you test for CNII Optic?
Visual Acuity and Visual Fields
How do you perform a Visual Acuity test for CNII Optic?
Read snellen eye chart 14 inches away with one eye covered. Repeat with other eye.
What do you do before performing any Cranial Nerve Test?
Explain the purpose of the test to the patient.
How do you perform a Visual Fields test for CNII - Optic?
patient looks straight ahead, with one eye covered, focusing on examiners face.
Examiner moves one to two wiggling fingers from above patients head toward center of eye, followed by lateral, inferior, and medial. Patient indicates when sees finger movement.
What is a normal response for CNII Optic Visual Acuity test?
Able to read items from chart.
What is a normal response CNII Optic Visual Fields test?
should detect finger movment in all four visual fields (Superior Lateral and Medial, Inferior Lateral and Medial)
What is CNIII, IV, and VI?
Oculomotor, Trochlear, and Abducens
What is the function of CNIII Oculomotor, CNIV Trochelar, and CNVI Abducens?
Motor: Extraocular muscles (EOM)
What do you test for CNIII Oculomotor, CNIV Trochlear, and CNVI Abducens?
Pupillary Reflex, Ptosis (eye drooping) and Visual Tracking / Smooth Pursuit?
How do you perform a CNIII Oculomotor, CNIV Troclear, and CNVI Abducens Pupillary Reflex test?
swing flashlight from periphery toward midline of 1 of patient’s eyes, avoid shining light in other eye.
What is the normal response for a CNIII Oculomotor, CNIV Trochelar, CNVI Abducens Pupillary Reflex test?
Immediate and simultaneous constriction of both stimulated and unstimulated pupils.
How do you perform a CNIII Oculomotor, CNIV Trochlear, and CNVI Abducens Ptosis (eye drooping test) and Visual Tracking/Smooth Pursuit test?
FIRST observe patient’s eyes - at rest neither eye should deviate from midline horizontal position and eyelids should not be drooping.
NEXT ask patient to cover one eye and follow your finger without moving their head while your finger makes a large “H” pattern. Repeat with other eye.
What is the normal response for a CNIII Oculomotor, CNIV Trochlear, and CNVI Abducens Ptosis (eye drooping) and Visual Tracking/Smooth Pursuit test?
Patient should be able to track your finger in all directions, with both eyes moving equally.
What is CNV?
Trigeminal
What is the function of CNV Trigeminal?
Sensation: Face
Motor: Muscles of Mastication
What do you test for CNV Trigeminal
Sensory and Motor
How do you perform a CNV Trigeminal Sensory test?
Assess sensation of upper, middle, and lower face using a safety pin (sharp/dull).
What is the normal response for a CNV Trigeminal Sensory test?
Should sense sharp/dull in all 3 regions of face: V1, V2, and V3. Record whether sensation is normal, impaired, or absent for each division and side.
How do you perform a CNV Trigeminal Motor test?
Assess muscles of mastication (masseter, temporalis) by palpating muscles as you ask patient to clinch teeth repeatedly.
What is the normal response for CNV Trigeminal motor test?
Should palpate strong contraction with equal muscle bulk.
What is CNVII?
Facial
What is the function of CNVII Facial?
Motor: Muscles of Facial Expression
How do you perform a CNVII Facial test?
On command, the patient should be able to
1) raise eyebrows
2) wrinkle forehead
3) drown
4) close eyes tightly
5) smile
6) pucker/whistle
What is the normal response for CNV Trigeminal test?
Observe for equal response of all muscle actions bilaterally.
What is nerve CNVIII?
Vestibulo-Cochlear
What is the function of CNVIII Vestibulo-Cochlear?
Special Sensations: Hearing and Balance (Vestibular)
What are you testing for CNVII Vestibular-Cochlear?
Vestibular Division
What test do you perform to test the Vestibular Division of CNVIII Vestibular-Cochlear?
Head Thrust Test
What does the Head Thrust Test assess and what is it responsible for? What will a patient report?
Assesses vestibulo-ocular reflex (VOR)
VOR is responsible for maintaining eye position during head motion.
When the VOR is damaged or absent, patients will report that their vision is blurred during head movement (oscillopsia).
How do you perform a CNVIII Vestibular-Cochlear Vestibular Division Head Thrust Test?
- Have patient sit with eyes open and focus on your nose.
- Next grasp the patients head between your hands and flex the chin to 30 deg.
- Quickly and unpredictably apply a small amplitude (10-20deg) retation of the head (the thrust) to the left or right.
What is a normal response for the CNVIII Vestibular-Cochlear Vestibular Division Head Thrust Test?
Eyes maintained target
What i an abnormal response for the CNVIII Vestibular-Cochlear Vestibular Division Head Thrust Test?
Patient’s eyes do not stay fixed on the target and correcting motion (termed a saccade) is made to bring the eyes back to target at the end of the head’s movement.
What is CNXI?
Accessory
What is the function of CNXI Accessory?
Motor: to trapezius and SCM
How do you perform a test for CNXI Accessory?
With patient seated, perform MMT of upper trapezius.
For left SCM, examiner has patient turn head to left as far as possible and then applies resistance to turn head to right. Test repeated for right SCM.
What is a normal response for CNXI Accessory test?
Tolerates maximal resistance.
What is CNXII?
Hypoglossal
What is the function of CNXII Hypoglossal?
Motor: Tongue muscles
How do you perform a test for CNXII Hypoglossal?
Tell patient to stick out tongue as far as possible, and then tell them to move tongue from side-to-side. Push against tongue with tongue blade to assess strength.
What is a normal response for CNXII Hypoglossal?
Equal and symmetrical tongue movement and strength
