Cranial Nerve Disorders

Question 1

what cranial nerves have special senses?

Answer 1

> olfaction
vision
taste
hearing

Question 2

what controls the muscles of mastication?

Answer 2

trigeminal nerve (V)

Question 3

what controls the muscles of the larynx and pharynx?

Answer 3

vagus (X)

Question 4

what cranial nerves have parasympathetic innervation?

Answer 4

> oculomotor (pupil constriction)
Facial nerve
glossopharyngeal (parotid)
vagus (thoracic and abdomen organs)

Question 5

what does the facial nerve supply with parasympathetic innervation?

Answer 5

> lacrimation

> salivation: submandibular and sublingual glands

Question 6

why would you only do the corneal test if the facial nerve is working?

Answer 6

it is an uncomfortable test and if the facial nerve is not working the patient cannot blink (showing the reflex is working). it will not tell you anything about the trigeminal nerve

Question 7

how would you test vestibular function?

Answer 7

> dix-hallpike manoeuvre

> untenbergers test

Question 8

in the pupillary light reaction what is the afferent component?

Answer 8

II: optic nerve

Question 9

what is the efferent component in the pupillary light reaction?

Answer 9

III oculomotor nerve

Question 10

what is the afferent component of the corneal reflex?

Answer 10

trigeminal V

Question 11

what is the efferent component of the corneal reflex?

Answer 11

VII facial nerve

Question 12

in the jaw jerk reflex in the trigeminal nerve the efferent or afferent component?

Answer 12

both!

Question 13

what is the afferent component of the gag reflex?

Answer 13

glossopharyngeal nerve IX

Question 14

what is the efferent component of the gag reflex?

Answer 14

vagus nerve X

Question 15

where do the oculomotor and trochlear nuclei lie?

Answer 15

in the mid brain

Question 16

where do the trigemina, abducent and facial nerve lie?

Answer 16

in the pons

Question 17

where does the vestibulocochlear nerve lie?

Answer 17

at the pontomedullary junction

Question 18

what nerves lie in the medulla?

Answer 18

> glossopharyngeal
vagus
accessory
hypoglossal

Question 19

what does an unusual combination of cranial nerve signs suggest?

Answer 19

there is chronic or malignant meningitis

Question 20

what do pure motor signs suggest?

Answer 20

myasthenia gravis

Question 21

what can damage cranial nerves within the brain?

Answer 21

> ischaemia

> tumour

Question 22

what can damage cranial nerves when crossing the subarachnoid space?

Answer 22

meningitis

Question 23

where can cranial nerves be damaged?

Answer 23

> within the brain
crossing the subarachnoid space
outside the skull

Question 24

what happens to the optic nerve in optic neuritis?

Answer 24

there is demyelination

Question 25

describe the symptoms and signs seen in optic neuritis

Answer 25

``` > monocular visual loos > pain on eye movement > reduced visual acuity > reduced colour vision > swollen optic disc ```

Question 26

what condition is optic neuritis associated with?

Answer 26

multiple sclerosis

Question 27

what happens if there is loss of parasympathetic input to the eye (complete third nerve palsy)?

Answer 27

there is a fixed dilated pupil

Question 28

does the pupil dilate or constrict with the sympathetic system?

Answer 28

it dilates

Question 29

what can cause dilated pupils?

Answer 29

``` > youth > dim lighting > anxiety > mydriatic eye drops > amphetamine > third nerve palsy > brain death ```

Question 30

what can cause constricted pupils?

Answer 30

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

Question 31

what is horners syndrome?

Answer 31

damage to the sympathetic chain causing ptosis and hydrosis

Question 32

name some eye movement disorders

Answer 32

``` > isolated third nerve palsy > isolated fourth nerve palsy > isolated sixth nerve palsy > combination of above pasly's > supranuclear gaze palsy > nystagmus ```

Question 33

describe microvascular third nerve palsy

Answer 33

caused by diabetes and hypertension. it is painless and the pupil is spared

Question 34

describe compressive third nerve palsy

Answer 34

caused by posterior communicating artery aneurysm and raised ICP. this is painful and the pupil is affected.

Question 35

what can cause isolated 6th nerve palsy?

Answer 35

> idiopathic > diabetes > meningitis > raised ICP

Question 36

what can cause nystagmus?

Answer 36

``` > congenital > peripheral vestibular problem > central vestibular/brainstem disease > cerebellar disease > toxins ```

Question 37

describe the attacks in trigeminal neuralgia

Answer 37

they are paroxysmal attacks of lancinating pain

Question 38

what causes trigeminal neuralgia?

Answer 38

vascular loop compression of the 5th nerve in the posterior fossa

Question 39

how is trigeminal neuralgia treated?

Answer 39

with carbamazepine

Question 40

is bells palsy upper or lower motor neuron?

Answer 40

lower motor neuron

Question 41

describe bells palsy facial weakness

Answer 41

> unilateral face weakness | > eye closure often affected, risk of corneal damage

Question 42

what can bells palsy be preceded by?

Answer 42

pain behind the ear

Question 43

what is bells palsy treated with?

Answer 43

steriods

Question 44

how is the forehead affected in an upper motor neuron condition?

Answer 44

it can still move at both sides as it bilaterally innervated

Question 45

how is the forehead affected in a lower motor neuron condition

Answer 45

half of it is affected and paralysed

Question 46

describe vestibular neuronitis

Answer 46

> sudden onset > disabling vertigo > vomiting > gradual recovery

Question 47

what is dysarthria?

Answer 47

disordered articulation, slurring of speech

Question 48

what is dysphagia?

Answer 48

difficulty swallowing

Question 49

in what condition can both dysarthria and dysphagia occur?

Answer 49

in bulbar and pseudobulbar palsy

Question 50

is bulbar palsy upper or lower motor neuron?

Answer 50

lower

Question 51

is pseudobulbar palsy upper or lower motor neuron?

Answer 51

upper

Question 52

what signs and symptoms are seen in pseudobulbar palsy?

Answer 52

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

Question 53

describe the lesion in bulbar palsy

Answer 53

> bilateral lower motor neuron affect IX-XII

Question 54

what signs and symptoms are seen in bulbar palsy?

Answer 54

``` > wasted fasciculating tongue > dysarthria > dysphonia > dysphagia > BEWARE OF FEEDING THESE PATIENTS ```