This document provides information on examining the 12 cranial nerves. It describes the pathway of smell for the olfactory nerve and how to test for smell. It discusses examining the optic nerve by testing visual acuity, color vision, visual fields, and the fundus. The document outlines how to test the oculomotor, trochlear, and abducent nerves by examining eye movements. It also describes examining the trigeminal, facial, vestibulocochlear, glossopharyngeal, vagus, spinal accessory, and hypoglossal nerves by testing motor function, reflexes, and sensory abilities.

1. neurology
cranial nerves examination
Dr mohamed rizk khodair
lecturer of neurology
October 6 university
Mohamedrizk.med@edu.edu.eg
‫والجراحة‬ ‫الطب‬ ‫كلية‬

2. Cranial nerves

3. Pathway of smell
From the receptors in the olfactory mucosa , the fibers of olfactory nerve pierce the cribriform plate of the
ethmoid bona and run in the olfactory groove to relay in the olfactory bulb , a new set of fibers travels in
olfactory tract to terminate in the olfactory sensory area in the uncus of the temporal lobe of both sides

4. 1- Olfactory nerve examination
Familiar substance (mint - coffee ) .
Non irritant .
Each nostril alone .
Close the eye

5. Lesion in olfactory :
Anosmia: unilateral traumatic , inflammatory , neoplastic : foster Kennedy syndrome ( ipsilateral optic
atrophy due to direct pressure on optic nerve, contralateral papilledema due to increase ICT,
ipsilateral anosmia may occur due to pressure on the olfactory.
NB : Unilateral lesion of uncus doesn’t cause anosmia as the sense of smell is bilaterally represented .
Bilateral : ENT , hysterical , hereditary
Parosmia :( perverted sense of smell ) ‫متغيرة‬ ‫الراويح‬ ‫يشم‬ common in hepatitis and pregnancy
Olfactory hallucination : perception of smell usually unpleasant in absence of stimulus , due to
central olfactory affections ( temporal lobe epilepsy)

6. 2-optic nerve

7. How to examine
• Visual acuity
• Color vision
• Visual field
• Fundus examination

8. Visual acuity
• Snellen chart .
• Counting finger 6 m to 30 cm
• Hand movement
• Perception of light

9. Color vision (ishihara color plates)

10. Field of vision
Confrontation test

11. Cranial Nerves: Optic
Pupil, acuity, Field, Fundi
By Confrontation test
→ Uniocular vision
→ Binocular vision

12. Ocular motility

13. Cranial Nerves: Conjugate Eye Movements

14. Oculomotor nerve palsy

15. Trochlear nerve palsy

16. Abducent nerve palsy

17. Partial or complete
ptosis

18. Pupil :
Size , shape , symmetry
Response to direct or indirect light reflex (ll,lll)
Accommodation reaction (ll,lll)
Ciliospinal reflex
Normal comment : Round regular reactive .
Causes of miosis : Horner syndrome (congenital or acquired ), pontine lesion, opiate toxicity
Causes of mydriasis : diminution of vision , drug , compression of 3rd CN

19. Each eye separate
Both eyes together
Spontaneous or with fixation
Horizontal or vertical or rotatory
Unilateral or bilateral
If it has rapid and slow phase ( direction of nystagmus is that of rapid phase)
Nystagmus

20. Trigeminal nerve
sensory
Pain , touch ,
Both side of the face
Ophthalmic , maxillary , mandibular
branches
The inner & outer part of the face

21. Motor examination of 5th Nerve :
Inspection : temporalis and masseter
palpation : temporalis , masseter
pterygoid : with and without resistance
unilateral : jaw is deviated to diseased side
bilateral : inability to open mouth
Reflexes :
Superficial reflexes : corneal & conjunctival reflexes (5&7)
Pathological reflexes : Jaw reflexes (5th&5th) normally : absent or minimally
exaggerated : bilateral UMNL above
pons

22. Cranial Nerves: Trigeminal: reflexes

23. Facial nerve :
How to examine
Muscle power
Frontalis , orbicularis oculi
Orbicularis oris , buccinators , retractor anguli
Reflexes :
Corneal reflex (5th& 7th)
Glabellar reflex (7th&7th)
Taste sensation

24. Facial nerve :
Upper half of face
Inspection : 1) lack of forehead corrugations
2) dribbling of tears
Palpitation :
Inability of elevate eyebrows properly
Eye can be easily opened by examiner
Glabber reflex
Normally : blinking bilateral (bilateral
contraction of orbicularis oculi ) blinking stops
after 2-3 contraction ( due to habituation )
Abnormally : lost in LMNL , exaggerated in
UMNL , persistent in parkinsonism
Lower half of face
Inspection : obliterated nasolabial fold
Deviation of the mouth to the healthy side
Dribbling of saliva , dropping of angle of mouth
Palpitation : inability to blow the check , inability to
whistle , inability to show teeth properly

25. Vestibulocochlear CN :
Cochlear : test for acuity of hearing
Rinne’s test : using vibrating tunining fork on mastoid process
Weber test : place tuning fork in the middle of head .

26. 9th , 10th , 11th (cranial accessory)
CNS :
• Inspection : base of uvula , soft palate
• Palpation : use torch and tongue depressor and say ah and see the uvula
• Reflexes :
• palatal reflex (5th& 10th ) : normally stimulation of soft palate leads to its elevation .
• pharyngeal ( gag ) reflex(9th& 10th): normally stimulation of posterior pharyngeal wall lead to local
contraction and gag reflex
Exaggerated : in pseudobulbar palsy
Lost : in true bulbar palsy

27. Spinal accessory :
Inspection : shoulder , head
Palpation :
trapezius : ask patient to turn head rt and left , tested by asked patient to turn his chin against
resistant
Unilateral lesion : head is tilted to disease side
Sternomastoid : inspect shoulder depression , tested by elevation of shoulder against resistance

28. Inspection : tongue fasciculation ,tongue corrugation , wasting , abnormal movement
Palpitation : without resistant & with resistant
Hypoglossal Nerve