Disorders of Special Sensory Function: The Cranial Nerves Flashcards
(84 cards)
1
Q
CN 1?
A
olfactory N
2
Q
CN 2?
A
optic N
3
Q
CN 3?
A
occulomotor N
4
Q
CN4?
A
trochlear N
5
Q
CN 5?
A
trigeminal N
6
Q
CN 6?
A
abducens N
7
Q
CN 7?
A
facial N
8
Q
CN 8?
A
vestibulocochlear N
9
Q
CN 9?
A
glossopharyngeal N
10
Q
CN 10?
A
vagus N?
11
Q
CN 11?
A
accessory N
12
Q
CN 12?
A
hypoglossal
13
Q
what are 4 different functions of cranial nerves?
A
“Special” senses
“Ordinary” sensation
Control of muscle activity
Autonomic functions
14
Q
which cranial nerves supply special senses?
A
Olfaction (I)
Vision (II) (seeing)
Taste (VII, IX and X)
Hearing - and balance (VIII)
15
Q
which cranial nerve is in control of olfaction?
A
CN 1
16
Q
which cranial nerve is in control of vision?
A
CN 2
17
Q
which cranial nerves are in control of taste?
A
VII, IX and X
18
Q
which cranial nerves are in control of hearing and balance?
A
VIII
19
Q
which cranial nerves are in control of ordinary sensation?
A
Mainly the Vth (trigeminal nerve)
The ear from the VIIth (facial) and IXth (glossopharyneal) nerves
20
Q
what are the eye muscles innervated by?
A
III (oculomotor), IV (trochlear) and VI (abducence) (LR6,SO4, rest 3)
21
Q
what pneumonic is a reminder of innervation of eye muscles?
A
(LR6,SO4, rest 3)
22
Q
what are the muscles of mastication innervated by?
A
V (trigeminal)
23
Q
what are the muscles of facial expression innervated by?
A
VII (facial)
24
Q
what are the muscles of larynx and pharynx innervated by?
A
mainly X (vagus)
25
what are the muscles of sternomastoid and trapezius muscle innervated by?
XI (accessory)
26
what is the autonomic function of occulomotor (CN III)?
Pupillary constriction
27
what is the autonomic function of facial (CN VII)?
Lacrimation – VII (facial)
Salivation – submandibular and sublingual glands – VII (facial)
28
what is the autonomic function of glossopharyngeal (CN IX)?
Salivation – parotid gland
29
what is the autonomic function of vagal (CN X)?
Vagal (X) input to organs in thorax and abdomen
30
what is tested for in affected olfactory (CN I)?
smell – unilateral or bilateral loss
use of a smell kit
31
what is tested for in affected optic (CN II)?
visual acuity
visual fields
pupillary reactions
fundoscopy
colour vision
32
what is tested for in affected III, IV and VI – oculomotor, trochlear and abducence?
any evidence of ptosis?
pupil of equal size?
pupillary reactions
eye movements – vertical and horizontal
33
what is tested for in affected trigeminal N?
sensation in the ophthalmic, maxillary and mandibular divisions
{light touch/pin prick}
power in the muscles of mastication (clench teeth and open mouth - feel for muscle bulk either side)
corneal reflex
jaw jerk
34
how do you test corneal reflex?
tiny piece cotton wool touch cornea - patient experiences blinking sensation
35
how do you test for jaw jerk?
light tap on jaw on finger
36
what is tested for in affected facial N?
Muscles of facial expression
run through cartoon, ask patient to do each one looking at symmetry and assymmetry
Corneal reflex
efferent pathway of corneal reflex
Taste
loss of sense of taste
37
what is tested for in affected vestibulocochlear N?
Hearing using Rinne’s and Weber’s tests
Vestibular function using Dix-Hallpike manoevre and Untenberger’s test
38
what is tested for in affected IX (glossopharyngeal) and X (vagal)?
movement of the palate
gag reflex
quality of speech
quality of cough
39
what is tested for in affected IX XI – Accessory nerve?
Head turning and shoulder shrugging
sternomastoid and trapezius function
40
what is tested for in affected XII – Hypoglossal nerve?
Appearance, movement and power of tongue
41
what cranial nerves are responsible for Pupillary light reaction?
afferent – II ; efferent – III
42
what cranial nerves are responsible for Corneal reflex?
afferent – V ; efferent – VII
43
what cranial nerves are responsible for jaw jerk?
afferent and efferent – V
44
what cranial nerves are responsible for gag reflex?
afferent – IX ; efferent - X
45
what is the location of III and IV (Oculomotor and Trochlear) nuclei ?
MID-BRAIN
46
what is the location of V, VI AND VII (Trigeminal, Abducent and Facial) nuclei?
PONS
47
what is the location of VIII (Vestibulocochlear) nuclei?
PONTOMEDULLARY
48
what is the location of IX, X XI and XII (Glossopharyngeal, Vagus, Accessory and Hypoglossal) nuclei?
MEDULLA
49
where would the lesion be affecting the occulomotor N?
midbrain
50
where would the lesion be affecting the III +IV+VI?
superior orbital fissure
51
where would the lesion be affecting the VI +VII?
pons
52
where would the lesion be affecting the CN V + VIII?
cerebellopontine angle
53
what would an example be of an unusual combination of CN disfunction?
chronic or malignant meningitis
54
what is a pure motor sign affecting neuromuscular junction (causing weakness)?
myasthenia gravis
55
Not all cranial nerve signs imply a cranial nerve lesion, give examples?
eye movement disorders, facial weakness, difficulty swallowing after a stroke
double vision in myasthenia or thyroid eye disease
56
how can cranial nerves be damaged within the brain?
ischaemia, tumour
57
how can cranial nerves be damaged crossing sub arachnoid space?
meningitis
58
how can cranial nerves be damaged outside skull?
base of skull tumours arising in nasopharynx
59
what is optic neuritis?
demyelination within the optic nerve
60
what are symptoms of optic neuritis?
monocular visual loss
pain on eye movement
reduced visual acuity
reduced colour vision
optic disc may be swollen
61
what condition is optic neuritis often associated with?
multiple sclerosis
62
what are parasympathetic pupillary responses?
constriction of the pupil
63
what does loss of parasympathetic input of pupil result in?
loss of parasympathetic input results in a fixed, dilated pupil
e.g. complete third nerve palsy
64
what does loss of sympathetic input of pupil result in
damage anywhere within the sympathetic pathway can lead to a constricted pupil
65
what is the sympathetic pupillary response?
pupillary dilatation
66
what are causes of dilated pupils?
Youth
Dim lighting
Anxiety, excitement
“Mydriatic” eye drops
Amphetamine, cocaine overdose
Third nerve palsy
Brain death
67
what are causes of small pupils?
Old age
Bright light
“Miotic” eye drops
Opiate overdose
Horner’s Syndrome
68
give examples of eye movement disorders?
Isolated third nerve palsy
Isolated fourth nerve palsy
Isolated sixth nerve palsy
Combination of the above
Supranuclear gaze palsy (not cranial nerve issue)
Nystagmus
69
what is microvacular third nerve palsy?
diabetes, hypertension
Painless, pupil spared
70
what is compressive third nerve palsy?
posterior communicating
artery aneurysm, raised ICP
Painful, pupil affected
71
what is Isolated sixth nerve palsy?
Numerous causes including
idiopathic
diabetes
meningitis
raised intracranial pressure
72
what is nystagmus?
Congenital
Serious visual impairment
Peripheral vestibular problem
Central vestibular / brainstem disease
Cerebellar disease
Toxins (medication and alcohol) (most common)
73
what is trigeminal neuralgia?
Paroxysmal attacks of lancinating pain
Triggers
Middle age and older
Caused by vascular loop
Compression fifth nerve in the posterior fossa
74
what are treatment options of trigeminal neuralgia?
Treated medically with carbamazepine (not well tolerated in older patients)
Surgical options if medication resistant
75
what is bells palsy?
Unilateral facial weakness
Lower motor neurone type
Often preceded by pain behind ear
Eye closure affected
Risk of corneal damage
76
how is bells palsy treated?
Treated with steroids
Usually good recovery
77
what causes upper motor neuronal facial paralysis?
stroke/tumour
78
what causes lower motor neuronal facial paralysis?
Bell’s Palsy, Lyme, sarcoid
79
what is vestibular neuronitis?
Sudden onset
Disabling vertigo
Vomiting
Gradual recovery
Cause uncertain ? viral
80
what is dysarthria?
disordered articulation, slurring of speech
81
what is dysphagia?
difficulty swallowing
82
what occurs in bulbar- and pseudobulbar palsy?
dysarthria and dysphagia
83
what causes bulbar palsy?
lower motor neurone
84
what causes Pseudobulbar palsy?
upper motor neurone
