Cranial nerves

PPT on cranial nerves function, situation and test of cranial nerves.

1. CRANIAL NERVES Dr. Bhawna MPT (Pediatrics)

2. Equipment Needed: Cotton ball, safety pin, snellen chart Tongue blade Tuning fork Reflex hammer pen light pencil and paper sweet/sour substances Familiar aromatic substance (coffee, vanilla)

3. To learn how to examine the functions of the 12 pairs of cranial nerves. To understand the functions of the 12 pairs of cranial nerves . 12 pairs of cranial nerve supply muscles of eyeball, face, palate, pharynx, larynx, tongue and two large muscle of neck. Control special senses like smell, sight, hearing, taste and touch.

4. Olfactory Optic Forebrain Oculomotor Trochlear Midbrain Trigeminal Abducent Pones Facial Vestibulocochlear Glossopharyngeal Vagus Medulla Accessory Hypoglossal

5. CN I: Olfactory Sensory: smell Apply simple odors to one nostril at a time Do not test unless history indicates.

6. CN II: Optic Sensory :- vision Function :- sight Test :- visual activity. Check visual field.

7. CN III: Oculomotor Motor nerve Supply five Extrinsic muscles of the eyeball except for superior oblique and lateral rectus muscle. Superior rectus – looking up and out. Inferior rectus – looking down and out. Inferior oblique – looking up and in. Medial rectus – medial movement. Levator palpebrae superioris – extraocular muscle.

8. CN IV: Trochlear Motor nerve. Supply Superior oblique muscle – looking down and in.

9. CN V: Trigeminal Mixed nerve. Sensory : face , teeth and tongue. Motor : muscle of mastication. Tactile and pain sensation on entire face. Test – 1) corneal reflex; sense of touch, pain, and temperature; clench teeth; move mandible side to side. 2) Sneeze reflex. 3) Jaw jerk reflex.

10. CN VI: Abducens Motor nerve Supply :- Lateral Rectus Muscle – lateral movement.

11. CN VII: Facial Sensory supply :- Taste to anterior 2/3 of tongue Motor supply :- Ability to frown Smile , show teeth Puff out checks whistle , close eyes

12. Motor supply :- muscles of facial expression Secretion of saliva Tears .

13. Test :- Observe patient as he talks and smile. Eye closer Asymmetrical elevation of one corner of mouth. Nasolabial fold. Forehead wrinkles( frontalis ) Tight closer of eye ( orbicularis oculi) Whistling ( buccinator ) Pursuing the mouth (orbicularis oris )

14. Taste :- tested by using sugar and tartaric acid.

15. CN VIII:Vestibulocochlear Sensory supply: Hearing, balance and posture. Rinne’s test: on mastoid process Weber’s test: on center of forehead or vertex. Rhomberg test

16. CN IX: Glossopharyngeal Sensory: - Taste, secretion of saliva. Motor: - Able to swallow - Gag reflex ( ) Gag reflex (afferent IX, efferent X)

17. CN X: Vagus Sensory listen to person talk (hoarseness) Motor ask person to say “ah” (soft palate contract and uvula stays midline) senses aortic blood pressure 􀂄 slows heart rate 􀂄 stimulates digestive organs 􀂄 taste [Gag reflex (afferent IX, efferent X)]

18. CN XI: Spinal Accessary Motor: Turn head side to side shrug shoulders with resistance

19. 1. Sternocleidomastoid Press a hand against the patient's jaw and have the patient Rotate the head against resistance. Pressing against the right. Compare power and muscle bulk on each side. 2. Trapezius Have the patient shrug shoulders against resistance and assess Weakness and compare power on each side.

20. Sternocleidomastoid Trapezius muscle

21. CN XII: Hypoglossal Motor: protrude tongue move tongue from side to side with resistance