disorders of cranial nerves

Question 1

what are some functions of cranial nerves?

Answer 1

“special” senses
ordinary sensation
control of muscle activity
autonomic functions

Question 2

what are the “special” senses

Answer 2

olfaction (I)
vision (II)
taste (VII IX X)
hearing (VIII)

Question 3

what nerves control “ordinary” sensation?

Answer 3

mainly trigeminal

the ear from the facial and glossopharyngeal nerves

Question 4

what nerves control the eye muscles?

Answer 4

oculomotor
trochlear (SO)
abducens (LR)

Question 5

what nerve controls the muscles of mastication?

Answer 5

trigeminal

Question 6

what nerve controls the muscles of facial expression?

Answer 6

facial nerve

Question 7

what nerve controls the muscles of the larynx and pharynx?

Answer 7

mainly vagus

Question 8

what nerve controls the SCM and trapezius muscles?

Answer 8

accessory

Question 9

what branch of the nervous system does autonomic function fall under (for cranial nerves)

Answer 9

parasympathetic

Question 10

what is responsible for pupillary constriction

Answer 10

oculumotor nerve

Question 11

what is responsible for lacrimation?

Answer 11

facial nerve

Question 12

what is responsible for innervating the submandibular and sublingual glands?

Answer 12

facial nerve

Question 13

what is responsible for innervating the parotid gland?

Answer 13

glossopharyngeal nerve

Question 14

how do we test the function of the olfactory nerve?

Answer 14

smell - unilateral or bilateral loss

Question 15

how do we test thefunction of the optic nerve?

Answer 15

visual acuity
visual fields
pupillary reactions
fundoscopy
colour vision

Question 16

how do we test the cranial nerves that innervate the muscles of the eye?

Answer 16

any evidence of ptosis
pupil of equal size
pupillary reactions
eye movements - vertical and horizontal

Question 17

how do we test the function of the trigeminal nerve?

Answer 17

sensation in the opthalmic, maxillary and mandibular divisions
power in muscles of mastication
corneal reflex
jar jerk

Question 18

how do we test the function of the facial nerve?

Answer 18

muscles of facial expression
corneal reflex
taste

Question 19

how do we test the function of the vestibulocochlear nerve?

Answer 19

Rinne and Weber’s tests for hearing

vestibular function using dix hallpike maneuver and utenbergers test

Question 20

how do we test the function of the glossopharyngeal and vagus nerves?

Answer 20

movement of palate
gag reflex
quality of speech
quality of cough

Question 21

how do we test the function of the accessory nerve?

Answer 21

head turning and shoulder shrugging

Question 22

how do we test the function of the hypoglossal nerve?

Answer 22

appearance, movement and power of tongue

Question 23

what cranial nerves are involved in the pupillary light reaction?

Answer 23

afferent - II

efferent - III

Question 24

what cranial nerves are involved in the corneal reflex?

Answer 24

afferent - V

efferent - VII

Question 25

what cranial nerves are involved in the jaw jerk reflex?

Answer 25

afferent and efferent - V

Question 26

what cranial nerves are involved in the gag reflex?

Answer 26

afferent - IX | efferent - X

Question 27

where are the nuclei of cranial nerves III and IV?

Answer 27

midbrain

Question 28

where are the nuclei of cranial nerves V,. VI and VII located?

Answer 28

pons

Question 29

what is the nucleus for cranial nerve VIII located?

Answer 29

pontomedullary junction

Question 30

where are the nuclei for cranial nerves IX, X, XI and XII located?

Answer 30

medulla

Question 31

where would the lesion be if the signs were bilateral and affecting cranial nerve III?

Answer 31

midbrain

Question 32

where would the lesion be if the signs were a combination of cranial nerves III, IV and VI?

Answer 32

superior orbital fissure

Question 33

where would the lesion be if the signs were a combination of cranial nerves VI and VII?

Answer 33

pons

Question 34

where would the lesion be if the signs were a combination of cranial nerves V and VIII?

Answer 34

cerebellopontine angle

Question 35

what would an unusual combination of cranial nerve signs possibly suggest?

Answer 35

chronic or malignant meningitis

Question 36

what would PURE motor signs relating to cranial nerve possibly suggest?

Answer 36

myasthenia gravis

Question 37

where can cranial nerves be damaged?

Answer 37

within the brain crossing the sub arachnoid space outside of the skull

Question 38

what is the pathology of optic neuritis?

Answer 38

demyelination within the optic nerve

Question 39

what are some signs of optic neuritis?

Answer 39

``` monocular visual loss pain on eye movement reduced visual acuity reduced colour vision optic disc may be swollen ```

Question 40

what branch of the nervous system controls constriction of the pupil?

Answer 40

parasympathetic

Question 41

what does a loss of parasympathetic input to the eye result in?

Answer 41

fixed, dilated pupil

Question 42

what are some causes of dilated pupils?

Answer 42

``` dim lighting youth anxiety/excitement mydriatic eye drops amphetamine or cocaine OD third nerve palsy brain death ```

Question 43

what are some causes of small (constricted pupils)

Answer 43

``` old age bright light miotic eye drops opiate overdose horners syndrome ```

Question 44

what are some eye movement disorders related to cranial nerves?

Answer 44

``` isolated third nerve palsy isolated fourth nerve palsy isolated sixth nerve palsy combination of the above nystagmus supranuclear gaze palsy ```

Question 45

what are the 2 different kinds of isolated third nerve palsy?

Answer 45

microvascular | compressive

Question 46

what are some causes of microvascular third nerve palsy?

Answer 46

diabetes | hypertension

Question 47

what are some characteristics of microvascular third nerve palsy?

Answer 47

painless, pupil spared`

Question 48

what are some causes of compressive isolated third nerve palsy?

Answer 48

posterior communicating artery aneurysm | raised ICP

Question 49

what are some characteristics of compressive third nerve palsy?

Answer 49

painful | pupil affected

Question 50

what are some causes of isolated sixth nerve palsy?

Answer 50

idiopathic diabetes meningitis raised ICP

Question 51

what can cause nystagmus?

Answer 51

central vestibular/brainstem disease cerebellar disease toxins (medication and alcohol)

Question 52

what is trigeminal neuralgia?

Answer 52

paroxysmal attacks of lancinating pain

Question 53

what is trigeminal neuralgia caused by?

Answer 53

compression of the fifth cranial nerve in the posterior fossa

Question 54

how is trigeminal neuralgia treated medically

Answer 54

carbamazepine

Question 55

what are some features of vestibular neuronitis?

Answer 55

sudden onset disabling vertigo vomiting gradual recovery

Question 56

what is dysarthria?

Answer 56

disordered articulation, slurring of speech

Question 57

what is dysphagia?

Answer 57

difficulty swallowing

Question 58

what is the difference between bulbar and pseudobulbar palsy?

Answer 58

bulbar palsy is LMN | pseudo is UMN

Question 59

what is the pathology of pseudobulbar palsy?

Answer 59

bilateral UMN lesions

Question 60

what are some signs of pseudobulbar palsy?

Answer 60

``` dysarthria dysphonia dysphagia spastic, immobile tongue brisk jaw jerk brisk gag reflex ```

Question 61

what is the pathology of bulbar palsy?

Answer 61

bilateral LMN lesions affecting CN IX - XII

Question 62

what can cause bulbar palsy?

Answer 62

``` MND polio tumours vascular lesions of the medulla syphilis ```

Question 63

what are some signs of bulbar palsy?

Answer 63

wasted, fasciculating tongue dysarthria dysphonia dysphagia

Question 64

what should you beware of doing to bulbar palsy patients?

Answer 64

feeding them