Cranial nerves Flashcards

Question 1

Q

CN 1

name
origin
exit
modality
sensory
symp
para
how to test

Answer

A

name - olfactory
origin- cerebrum
exit- cribiform plate
modality- sensory
sensory - smell
symp-x
para-x
how to test smell test, have you noticed any change to your sense of smell?

Question 2

Q

CN II

name
origin
exit
modality
sensory
symp
para
how to test

Answer

A

name - optic nerve
origin- cerebrum
exit- optic canal
modality- sensory
sensory- special sensation of sight
symp- x
para- x
how to test- specific testing of the optic nerve involves visual acuity assessment, color perception, visual fields assessment, and pupillary light reflexes assessment, accommodation assessment and funduscopic examination

Question 3

Q

CN III

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - oculomotor
origin - edinger westphal nucleus- cerebral peduncles brainstem
exit- superior orbital fissure
modality- motor
sensory-x
symp- superior tarsal muscle (helps to raise the eyelid)
para- Supplies the sphincter pupillae and the ciliary muscles of the eye
somatic- msot of the extra-ocular muscles (levator palpebrae superioris, superior rectus, inferior rectus, medial rectus and inferior oblique)
how to test- don’t move head, follow H pattern with just eyes. ask if they experience diplopia
lesion- ptosis (droppy eyelid), down and out (unopposed action of lateral rectus and superior oblique, miosis

Question 4

Q

CN IV

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - trochlear nerve
origin- posterior midbrain (only posterior), longest intracranial length
exit- superior orbital fissure
modality- motor
sensoryx
sympx
parax
somatic- innervates contralateral superior oblique, uses trochlea sling to depress and intort (internally rotate)
how to test - follow H motion
lesion- vertical diplopia (excentuated by looking in and down), may develop head tilt

Question 5

Q

CN Vi

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name- opthalmic division of trigeminal
origin- pons
exit- superior orbital fissure
modality- general somatic sensation
sensory- general somatic sensation via 3 branches (frontal nerve lacrimal nerve nasociliary nerve) to skin and mucous membranes of the frontonasal prominence (e.g., cornea, frontal forehead, upper eyelid and conjuctiva)
symp- yes but ?
para- yes but ?
somatic- x
how to test- corneal reflex and touch fore head
lesion- loss of sensation to area

Question 6

Q

CN Vii

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name- maxillary division of the trigeminal nerve
origin- pons
exit- foramen rotundum
modality- sensory
sensory- general somatic sensation to structrues of maxillary prominence (mid 1/3 of face)
symp- x
para- Lacrimal gland + Mucous glands of the nasal mucosa
somatic- x
how to test - cotton bud to area
lesion- loss of sensation (hyperalgia- hypersensitivty to pain + non-pain stimulus)

Question 7

Q

CN Viii

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - mandibular division of the trigmeinal nerve
origin- pons
exit- forman ovale
modality- general somatic sensation + somatic
sensory- general somatic to skin of inferior 1/3 face and anterior 2/3 of tongue (lingual nerve)
symp- submandibular and sublingual glands
para
somatic- nerves to muscles of mastication, tensor tympani, tensor veli palatini, ant digatric, omohyoid
how to test- pin prick sensation test, weakness of muscles of mastication
lesion

Question 8

Q

CN VI

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name- Abducens
origin- pontine medullary junction
exit- superior orbital fissure
modality- somatic motor
sensory- x
symp- x
para-x
somatic- innervated superior rectus to abduct the eyeballs
how to test- H movement
lesion- eyeball faces inwards as there is no opposition to medial rectus

Question 9

Q

CN VII

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - facial nerve
origin- pontine medullary junction
exit- internal acoustic meatus
modality- general sensation + somatic motor + sympathetic + parasympathetic
associated with second pharyngeal arch
sensory- general sensation to small area around the concha of the external ear + taste sensation to the anterior 2/3 of the tongue via the chorda tympani
para- submandibular and sublingual salivary glands.,nasal, palatine and pharyngeal mucous glands, lacrimal glands
somatic- muscles of facial expression, posterior belly of the digastric, stylohyoid and stapedius muscles
how to test- facial movements, taste and hyperacusus
lesion-
Intracranial lesion
- facial weakness
- Chorda tympani – reduced salivation and loss of taste on the ipsilateral 2/3 of the tongue.

Nerve to stapedius – ipsilateral hyperacusis (hypersensitive to sound).

Greater petrosal nerve – ipsilateral reduced lacrimal fluid production.

extracranial lesion
- just motor weakness

Question 10

Q

CN VIII

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - vestibulocochlear
origin- pontine medullary junction
exit- internal acoustic meatus
modality- sensory
sensory- special sensory for hearing and balance
symp- x
para- x
somatic-x
how to test - hearing test, nystagmus
lesion- vertigo and deafness

Question 11

Q

CN IX

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - glossopharyngeal nerve
origin- medulla oblongata
exit- jugular foramen
Derivatives of the 3rd pharyngeal arch
modality- general somatic sensation + special sensory+ para+ motor
sensory - general sensation to the oropharynx, carotid body and sinus, posterior 1/3 of the tongue, middle ear cavity and Eustachian tube. + special sensation of taste to posterior 1/3
symp- x
para- parotid gland
somatic- stylopharyngeus muscle of the pharynx
how to test - tested alongside CNX. get patient to say “ah” and evaluate the uvula
lesion- assess whether uvula curls away from paretic side

Question 12

Q

CN X

name
origin
exit
pharyngeal arch
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - vagus nerve
origin- medulla oblangata
exit- jugular foramen
pharyngeal arch- phayrngeal arches 4 and 6
modality- general somatic, special sense
sensory - skin of the EAM and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera. taste sensation to the root of the tongue and epiglottis.
symp- x
para- smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm
somatic- motor innervation to the majority of the muscles of the pharynx, soft palate and larynx
how to test - ask patient to say “ahh”, sensation of palpitations?
lesion- uvula curls towards unaffected side

Question 13

Q

CN XI

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - spinal accessory nerve
origin- medulla oblanagata
exit- jugular foramen
modality- motor somatic
sensory - x
symp- x
para- x
somatic- sternocleidomastoid and trapezius
how to test - sternocleidomastoid, the patient is asked to turn the head against resistance supplied by the examiner’s hand while the examiner palpates the active muscle (opposite the turned head).

For the upper trapezius, the patient is asked to elevate the shoulders against resistance supplied by the examiner.

lesion- muscle wasting

Question 14

Q

CN XII

name
origin
exit
modality
sensory
symp
para
somatic
how to test
lesion

Answer

A

name - hypoglossal nerve
origin- medulla oblanagata (anterior to olive)
exit- hypoglossal canal
modality- somatic
sensory -x
symp- x
para-x
somatic- all of the extrinsic or intrinsic muscles of the tongue except palatoglossus
how to test - ask the patient to extend the tongue and inspecting it for atrophy, fasciculations, and weakness
lesion-(deviation is toward the side of a lesion)

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Cranial nerves Flashcards

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