Disorders of Cranial Nerves Flashcards
1
Q
What are each of the cranial nerves called?
A
2
Q
What is CN I called?
A
Olfactory nerve
3
Q
What is CN II called?
A
Optic nerve
4
Q
What is CN III called?
A
Oculomotor nerve
5
Q
What is CN IV called?
A
Trochlear nerve
6
Q
What is CN V called?
A
Trigeminal nerve
7
Q
What is CN VI called?
A
Abducens nerve
8
Q
What is CN VII called?
A
Facial nerve
9
Q
What is CN VIII called?
A
Vestibulocochlear nerve
10
Q
What is CN IX called?
A
Glossopharyngeal nerve
11
Q
What is CN X called?
A
Vagus nerve
12
Q
What is CN XI called?
A
Accessory nerve
13
Q
What is CN XII called?
A
Hypoglossal nerve
14
Q
What are different functions of cranial nerves?
A
- ‘Special’ senses
- ‘Ordinary’ sensation
- Control of muscle activity
- Autonomic functions
15
Q
What cranial nerves transmit the ‘special senses’?
A
- Olfaction (I)
- Vision (II)
- Taste (VII, IX and X)
- Hearing and balance (VIII)
16
Q
What cranial nerve is responsible for olfaction?
A
CN I
17
Q
What cranial nerve is responsible for vision?
A
CN II
18
Q
What cranial nerve is responsible for taste?
A
CN VII, IX and X
19
Q
What cranial nerve is responsible for hearing and balance?
A
CN VIII
20
Q
What cranial nerve controls the eye muscles?
A
CN III, IV and VI
21
Q
What cranial nerve controls the muscles of mastication?
A
CN V
22
Q
What cranial nerves control the muscles of facial expression?
A
VII
23
Q
What cranial nerves control the muscles of the pharynx?
A
Mainly X
24
Q
What cranial nerves controls the muscles of the pharynx?
A
Mainly CN X
25
What cranial nerve controls the sternomastoid?
CN XI
26
What cranial nerve controls the trapezius muscles?
CN XI
27
What cranial nerve controls pupil constriction?
CN III
28
What cranial nerve controls lacrimation?
CN VII
29
What cranial nerve controls salvation?
* Submandibular and sublingual glands VII
* Parotid gland IX
30
What does physical examination of CN I test?
* Smell, unilateral or bilateral loss
31
What does physical examination of CN II test?
* Visual acuity, visual fields, pupillary reactions, fundoscopy, colour vision
32
What does physical examination of CN III, IV and VI test?
* Evidence of ptosis (drooping of the upper eyelid), pupil of equal size, pupillary reactions, eye movements (horizontal and vertical)
33
What is ptosis?
Drooping of upper eyelid
34
What does physical examination of CN V test?
* Sensation in ophthalmic, maxillary and mandibular divisions, power in the muscles of mastication, corneal reflex, jaw jerk
35
What does physical examination of CN VI test
* Muscles of facial expression, corneal reflex, taste
36
What does physical exmination of CN VIII test?
* Hearing using Rinne’s and Weber’s tests, vestibular function using Dix-Hallpike manoeuvre and Untenberger’s test
37
What does physical examination of CN IX test?
* Movement of the palate, gag reflex, quality of speech, quality of cough
38
What does physical examination of CN XI test?
* Head turning and shoulder shrugging
39
What does physical examination of CN XII test?
* Appearance, movement and power of tongue
40
What are exampes of cranial nerve reflexes?
* Pupillary light reaction
* Afferent II
* Efferent III
* Corneal reflex
* Afferent V
* Efferent VII
* Jaw jerk
* Afferent and efferent V
* Gag reflex
* Afferent IX
* Efferent X
41
What cranial nerves are responsible for the pupillary light reaction reflex?
* Afferent II
* Efferent III
42
What cranial nerves are responsible for the corneal reflex?
* Afferent V
* Efferent VII
43
What cranial nerves are responsible for the jaw jerk reflex?
* Afferent and efferent V
44
What cranial nerves are responsible for the gag reflex?
* Afferent IX
* Efferent X
45
The nuclei of what cranial nerves are locacted in the mid-brain?
CN III and IV
46
The nuclei of what cranial nerves are locacted in the pons?
CN V, VI and VII
47
The nuclei of what cranial nerves are locacted in the pontomedullary junction?
CN VIII
48
The nuclei of what cranial nerves are locacted in the medulla?
49
A combination of cranial nerve signs can indicate where the problem is in the brain, what does bilateral III indicate?
Midbrain
50
A combination of cranial nerve signs can indicate where the problem is in the brain, what does III and IV and VI indicate?
Superior orbital fissure
51
A combination of cranial nerve signs can indicate where the problem is in the brain, what does VI and VII indicate?
Pons
52
A combination of cranial nerve signs can indicate where the problem is in the brain, what does V and VIII indicate?
Cerebellopontine angle
53
A combination of cranial nerve signs can indicate where the problem is in the brain, what does unusual combinations indicate?
Chronic or malignant meningitis
54
What do cranial nerve signs usually indicate?
Cranial nerve lesion
55
Not all cranial nerve signs imply a cranial nerve lesion, what are examples?
* Eye movement disorders, facial weakness, difficulty swallowing after stroke
* Double vision in myasthenia or thyroid eye disease
56
Where are the different locations that cranial nerves can be damaged?
* Within the brain
* Such as by ischaemia or tumour
* Crossing the subarachnoid space
* Such as by meningitis
* Outside the skull
* Such as by base of skull tumours arising in nasopharynx
57
What can cranial nerves be damaged by within the brain?
Ischaemia or tumour
58
What can cranial nerves be damaged by when crossing the subarachnoid space?
Meningitis
59
What can cranial nerves be damaged by outside the skull?
* Such as by base of skull tumours arising in nasopharynx
60
What is optic neuritis?
Inflammation of the optic nerve, demyelination within the optic nerve
61
What is the clinical presentation of optic neuritis?
* Monocular visual loss
* Pain on eye movement
* Reduced visual acuity
* Reduced colour vision
* Optic disc may be swollen
* Often associated with MS
62
What effect does parasympathetic innervation have on the pupil?
Constriction of pupil
63
What does loss of parasympathetic innervation to the pupil result in?
* Loss of parasympathetic input results in a fixed, dilated pupil
* Such as CN III palsy
64
What effect does sympathetic innervation have on the pupil?
Pipillary dilation
65
What can loss of sympathetic innervation on the pupil cause?
* Damage can lead to constricted pupil
66
What are some causes of dilated pupils?
* Young
* Dim lighting
* Anxiety, excitement
* “Mydriatic” eye crops
* Amphetamine, cocaine overdose
* CN III palsy
* Brain death
67
What are some causes of constricted pupils?
* Old age
* Bright light
* “Miotic” eye drops
* Opiate overdose
* Horner’s syndrome
68
What are some examples of eye movement disorders?
* Isolated CN III palsy
* Isolated CN IV palsy
* Isolated VI palsy
* Combination of the above
* Supranuclear gaze palsy]Nystagmus
69
What can isolated CN III nerve palsy be caused by?
* Microvascular
* Diabetes, hypertension
* Painless, pupil spared
* Compressive
* Posterior communicating artery aneurysm
* Raised ICP
* Painful, pupil affected
70
What can isolated CN VI nerve palsy be caused by?
* Idiopathic
* Diabetes
* Meningitis
* Raised ICP
71
What are some causes of nystagmus?
* Congenital
* Serious visual impairment
* Peripheral vestibular problem
* Central vestibular/brainstem disease
* Cerebellar disease
* Toxins (medication and alcohol)
72
What is nystagmus?
Vision condition in which the eyes make repetitive, uncontrolled movements
73
What is trigeminal neuralgia?
This is a chronic pain condition affecting CN V, where even mild stimulation of your face may trigger a jolt of excruciating pain
74
What is the clinical presentation of trigeminal neuralgia?
Paroxysmal attacks of lancinating pain
Middle age and older
Has triggers
75
What is trigeminal neuralgia caused by?
Caused by vascular loop:
* Compression of CN V in posterior fossa
76
What is the treatment of trigeminal neuralgia?
Treated medically with carbamazepine, surgical options if medication resistant
77
What is Bells's palsy?
Is idiopathic facial nerve palsy
78
What is the clinical presentation of Bell's palsy?
Unilateral facial weakness
Lower motor neuron type
Often preceded by pain behind ear
Eye closure affected
Risk of corneal damage
79
What is the treatment of Bell's palsy?
Treated with steroids, usually good recovery
80
Is Bell's palsy a UMN or LMN disease?
LMN
81
What is the difference between UMN and LMN paralysis?
Main difference is that in UMN there is hemiplegia (paralysis of one side of the body) of the contralateral mid and lower face, whereas LMN there is complete hemiplegia of the ipsilateral face
82
What is hemiplegia?
Paralysis of one side of the body
83
What is vestibular neuronitis?
Inflammation of the vestibular nerve (branch of CN VIII)
84
What is the clinical presentation of vestibular neuronitis?
Characterised by sudden severe attack of vertigo
Vomiting
Gradual recovery
85
What is vestibular neuronitis characterised by?
Sudden severe attack of vertigo
86
What is dysarthria?
Disordered articulation, slurring of speech
87
What is dysphagia?
Difficulty swallowing
88
In what disease does dysarthria and dysphagia occur?
Both occur in bulbar and pseudobulbar palsy:
* Bulbar is lower motor neuron
* Pseudobulbar is upper motor neuron
89
Is bulbar palsy UMN or LMN?
LMN
90
Is peudobulbar palsy UMN or LMN?
UMN
91
What is pseudobulbar palsy?
Caused by bilateral UMN lesions such as in vascular lesions of both internal capsules or MND
92
What is the clinical presentation of pseudobulbar palsy?
* Dysarthria
* Dysphonia (involuntary spasms in the muscles of the larynx causing the voice to break having a strained sound)
* Dysphagia
* Spastic, immobile tongue
* Brisk jaw jerk
* Brisk gag reflex
93
What is dysphonia?
Involuntary splasms in the muscles of the larynx causing the voice to break having a strained sound
94
What is bulbar palsy?
Caused by LMN lesions affecting CN IX to XII, such as:
* MND
* Polio
* Tumours
* Vascular lesions of the medulla
* Syphilis
95
What are causes of Bulbar palsy?
Caused by LMN lesions affecting CN IX to XII, such as:
* MND
* Polio
* Tumours
* Vascular lesions of the medulla
* Syphilis
96
What is the clinical presentation of Bulbar palsy?
* Wasted, fasciculation tongue
* Dysarthria
* Dysphonia
* Dysphagia
