Disorders of Cranial Nerves Flashcards Preview

Systems: Neurology AB > Disorders of Cranial Nerves > Flashcards

Flashcards in Disorders of Cranial Nerves Deck (93)
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1
Q

Name the 12 cranial nerves in order.

A
I Olfactory
II Optic
III Oculomotor
IV Trochlear
V Trigeminal
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
2
Q

What are the 4 classifications of functions that cranial nerves have?

A
  • Special senses
  • Ordinary sensation
  • Control of muscle activity
  • Autonomic functions
3
Q

What cranial nerves are involved in the special senses?

A

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

4
Q

Ordinary sensation is mainly by which cranial nerve?

A

V

5
Q

What cranial nerves are responsible for ordinary sensation of the ear?

A

VII and IX

6
Q

What cranial nerves are involved in control of muscle activity?

A
III
IV
V
VI
VII
X
XI
7
Q

Which cranial nerves control the ocular muscles?

A

III
IV
VI

8
Q

Which cranial nerve controls the muscles of mastication?

A

V

9
Q

Which cranial nerve controls the muscles of facial expression?

A

VII

10
Q

Which cranial nerve controls the muscles of the larynx and pharynx?

A

Mainly X

11
Q

Which cranial nerve controls the sternocleidomastoid and trapezius muscles?

A

XI

12
Q

What cranial nerves have parasympathetic components?

A

III
VII
IX
X

13
Q

Which cranial nerves is responsible for pupillary constriction?

A

III

14
Q

Which cranial nerve is responsible for lacrimation?

A

VII

15
Q

Which cranial nerve is responsible for salivation by the submandibular and sublingual glands?

A

VII

16
Q

Which cranial nerve is responsible for salivation by the parotid gland?

A

IX

17
Q

Which cranial nerve is responsible for input to organs in the thorax and abdomen?

A

X

18
Q

I

What do we test?

A

Loss of smell

-Unilateral or bilateral

19
Q

II

What do we test?

A
  • Visual acuity
  • Visual fields
  • Pupillary reactions
  • Fundoscopy
  • Colour vision
20
Q

III, IV, VI

What do we test?

A
  • Any evidence of ptosis?
  • Pupil of equal size?
  • Pupillary reactions
  • Eye movements – vertical and horizontal
21
Q

V

What do we test?

A
  • Sensation in the ophthalmic, maxillary and mandibular divisions
  • Power in the muscles of mastication
  • Corneal reflex
  • Jaw jerk
22
Q

VII

What do we test?

A
  • Muscles of facial expression
  • Corneal reflex
  • Taste
23
Q

VIII

What do we test?

A
  • Hearing using Rinne’s and Weber’s tests

- Vestibular function using Dix-Hallpike manoevre and Untenberger’s test

24
Q

IX, X

What do we test?

A
  • Movement of the palate
  • Gag reflex
  • Quality of speech
  • Quality of cough
25
Q

XI

What do we test?

A

Head turning and shoulder shrugging

26
Q

XII

What do we test?

A

Appearance, movement and power of tongue

27
Q

Which cranial nerve is responsible for the afferent pupillary light reaction?

A

II

28
Q

Which cranial nerve is responsible for the efferent pupillary light reaction?

A

III

29
Q

Which cranial nerve is responsible for the afferent corneal reflex?

A

V

30
Q

Which cranial nerve is responsible for the efferent corneal reflex?

A

VII

31
Q

Which cranial nerve is responsible for the afferent jaw jerk?

A

V

32
Q

Which cranial nerve is responsible for the efferent jaw jerk?

A

V

33
Q

Which cranial nerve is responsible for the afferent gag reflex?

A

IX

34
Q

Which cranial nerve is responsible for the efferent gag reflex?

A

X

35
Q

Where does the III nuclei lie?

A

Mid-brain

36
Q

Where does the V nuclei lie?

A

Pons

37
Q

Where does the X nuclei lie?

A

Medulla

38
Q

Where does the IV nuclei lie?

A

Mid-brain

39
Q

Where does the XII nuclei lie?

A

Medulla

40
Q

Where does the VI nuclei lie?

A

Pons

41
Q

Where does the IX nuclei lie?

A

Medulla

42
Q

Where does the XI nuclei lie?

A

Medulla

43
Q

Where does the VII nuclei lie?

A

Pons

44
Q

Where does the VIII nuclei lie?

A

Pontomedullary junction

45
Q

What may an unusual combination of cranial nerve signs suggest?

A

Chronic or malignant meningitis

46
Q

What may pure motor cranial nerve signs suggest?

A

Myasthenia gravis

47
Q

Where may there be a problem if there is bilateral III signs?

A

Midbrain

48
Q

Where may there be a problem if there are III, IV and VI signs?

A

Superior orbital fissure

49
Q

Where may there be a problem if there is VI and VII signs?

A

Pons

50
Q

Where may there be a problem if there is V and VIII signs?

A

Cerebellopontine angle

51
Q

When may eye movement disorder, facial weakness and difficulty swallowing occur other than in cranial nerve lesions?

A

After stroke

52
Q

When may double vision occur other than in cranial nerve lesions?

A

Myasthenia or thyroid eye disease

53
Q

How can cranial nerves be damaged within the brain?

A
  • Ischaemia

- Tumour

54
Q

How can cranial nerves be damaged crossing the sub-arachnoid space?

A

Meningitis

55
Q

How can cranial nerves be damaged outside the skull?

A

-Skull tumours

56
Q

What is optic neuritis?

A

Demyelination within the optic nerve

57
Q

What are the signs and symptoms of optic neuritis?

A
  • Monocular visual loss
  • Pain on eye movement
  • Reduced visual acuity
  • Reduced colour vision
  • Optic disc may be swollen
58
Q

What is optic neuritis often associated with?

A

MS

59
Q

What does parasympathetic innervation of the pupil result in?

A

Constriction

60
Q

What does sympathetic innervation of the pupil result in?

A

Dilatation

61
Q

What can lead to a constricted pupil?

A

Loss of parasympathetic input

62
Q

What can lead to a fixed, dilated pupil?

A

Damage anywhere within the sympathetic pathway can lead to a constricted pupil

63
Q

What are some causes of dilated pupils?

A
  • Youth
  • Dim lighting
  • Anxiety, excitement
  • “Mydriatic” eye drops
  • Amphetamine, cocaine overdose
  • Third nerve palsy
  • Brain death
64
Q

What are some causes of constricted pupils?

A
  • Old age
  • Bright light
  • “Miotic” eye drops
  • Opiate overdose
  • Horner’s Syndrome
65
Q

Give examples of eye movement disorders.

A
  • Isolated third nerve palsy
  • Isolated fourth nerve palsy
  • Isolated sixth nerve palsy
  • Combination of the above
  • Supranuclear gaze palsy
  • Nystagmus
66
Q

What are some microvascular causes of isolated third nerve palsy?

A
  • Diabetes

- Hypertension

67
Q

How does a third nerve palsy present if it is microvascular in origin?

A

Painless, pupil spared

68
Q

How does a third nerve palsy present if it is compressive in origin?

A

Painful, pupil affected

69
Q

What are some compressive causes of isolated third nerve palsy?

A
  • Posterior communicating artery aneurysm

- Raised ICP

70
Q

What can cause isolated sixth nerve palsy?

A
  • Idiopathic
  • Diabetes
  • Meningitis
  • Raised intracranial pressure
71
Q

What can cause nystagmus?

A
  • Congenital
  • Serious visual impairment
  • Peripheral vestibular problem
  • Central vestibular / brainstem disease
  • Cerebellar disease
  • Toxins (medication and alcohol)
72
Q

What is trigeminal neuralgia?

A

Paroxysmal attacks of lancinating pain that has triggers

73
Q

What causes trigeminal neuralgia?

A

Vasuclar loop (compression of fifth nerve in the posterior fossa)

74
Q

How is trigeminal neuralgia treated?

A
  • Treated medically with carbamazepine

- Surgical options if medication resistant

75
Q

Who does trigeminal neuralgia affect?

A

Middle age and older

76
Q

What is Bell’s palsy?

A

Idiopathic facial nerve palsy

-Unilateral facial weakness

77
Q

What is Bell’s palsy often preceded by?

A

Pain behind the ear

78
Q

How is Bell’s palsy treated?

A

Treated with steroids and usually good recovery

79
Q

Why is there risk of corneal damage in Bell’s palsy?

A

Eye closure is affected

80
Q

Give 2 UMN causes of facial paralysis.

A
  • Stroke

- Tumour

81
Q

Give 3 LMN causes of facial paralysis.

A
  • Bell’s palsy
  • Lyme
  • Sarcoid
82
Q

How does vestibular neuronitis present?

A
  • Sudden onset
  • Disabling vertigo
  • Vomiting
  • Gradual recovery
83
Q

What is the cause of vestibular neuronitis?

A

Cause uncertain but possibly viral

84
Q

Dysarthria

A

-Disordered articulation, slurring of speech

85
Q

Dysphagia

A

Difficulty swallowing

86
Q

What is the pathology of pseudobulbar palsy?

A

Bilateral UMN lesions

87
Q

What is the pathology of bulbar palsy?

A

Bilateral LMN lesions affecting IX - XII

88
Q

What can occur in both bulbar and pseudobulbar palsy?

A

Dysarthria and dysphagia

89
Q

How does pseudobular palsy present?

A
  • Dysarthria
  • Dysphonia
  • Dysphagia
  • Spastic, immobile tongue
  • Brisk jaw jerk
  • Brisk gag reflex
90
Q

Give an example of a cause of pseudobulbar palsy.

A

Bilateral UMN lesions e.g. in vascular lesions of both internal capsules, MND

91
Q

Give examples of causes of bulbar palsy

A
  • MND
  • Polio
  • Tumours
  • Vascular lesions of the medulla
  • Syphilis
92
Q

How does bulbar palsy present?

A
  • Wasted, fasciculating tongue
  • Dysarthria
  • Dysphonia
  • Dysphagia
93
Q

What should you beware of doing in bulbar palsy patients?

A

Feeding patients