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Flashcards in carvenous sinus - auditory - facial lesions Deck (59):
1

cavernous sinus is composed by

1. superior ophthalmic vein
2. sphenoparietal sinus

2

cavernous sinus - collection of venous sinuses from

1. either side of pituitary
2. eye
3. superficial cortex

3

cavernous sinus --> drained to

internal jugular vein

4

....passes through cavernous sinus

- CN III, CN IV, CN V1, CN VI
- occasionaly V2
- postganglionic sympathetic pupillary fibers
- carvenous portion of internal carotid artery

5

cavernous sinus syndrome present with

1. variable ophthalmoplegia
2. decreased corneal sensation
3. Horner syndrome
4. decreased maxillary sensation (occasionally)

6

cavernous sinus syndrome - most susceptible nerve to injury that pass through it

CN VI

7

cavernous sinus syndrome is secondary to

1. pituitary tumor mass effect
2. carotid - cavernous fistula
3. cavernous sinus thrombosis related to infection

8

sinus medial and below carvnous sinus

sphenoid sinus

9

cavernous sinus - distribution of nerves and arteries through it

Internal carotid - III
VI IV
(left) V1
V2

10

it seperatess right from left cavernous sinus

hypophysis

11

structures that passes though subarachnoid space above the cavernous sinus

INTERNAL CAROTID and anterior cerebral artery
(anterior cerebral is above)

12

ear is divided to

outer ear
middle ear
inner ear

13

visible portion of ear

outer ear (pinna)

14

outer ear consists of

pinna (λοβός)
auditory canal
eardrum

15

outer ear - function

transfers sound waves via vibration of eardrum

16

middle ear - structure

air filled space with three bones called the ossicles (malleus, incus, stapes)

17

three ossicles

1. malleus
2. incus
3. stapes

18

middle ear - function

ossicles (malleus, incus, stapes) conduct and amplify sound from eardrum to inner eye

19

middle ear is filled with

air

20

inner fluid is filled with

Fluid-filled cochlea

21

inner fluid - shaped

snail

22

inner fluid contains

basilar membrane

23

basilar membrane - function

vibrates 2ry to sound waves

24

vibration from basilar membrane to auditory nerve

vibration transduced via specialized hair cells to auditory nerve

25

auditory signal - auditory nerve - next step?

brainstem

26

auditory signal - pathway

sound --> sound waves into auditory canal --> vibration of eardrum --> ossicles conduct and amplify sound to inner ear --> basilar membrane vibration --> vibration transduced via specialized hair cells --> auditory nerve signaling --> brain stem

27

tonotopy?

each frequency leads to vibration at specific location

28

tonotopy - distribution?

low frequency heard at apex near helicotrema (wide and flexible)
high frequnecy heard at base of cochlear (thin and rigid)

29

types of hearing loss

1. conductive
2. sensorineural
3. noise-induced

30

conductive hearing loss - Rinne test

abnormal (bone>air) negative

31

conductive hearing loss - Weber test

localizes to affected air

32

sensorineural hearing loss - Rinne test

normal (air>bone) positive

33

sensorineural hearing loss - Weber test

localized to unaffected air

34

noise-induced hearing loss - mechanism

1. hearing loss due to damage sterociliated cells in organ of Corti
2. hearing loss due to sudden extremely loud noises --> tympanic membrane rupture

35

hearing loss due to damage sterociliated cells in organ of Corti - characteristic

loss of high frequency hearing first

36

cholosteatoma?

overgrowth of desquamated keratin debris within middle ear space

37

cholosteatoma - composed by

desquamated keratin debris

38

colosteatoma - complication and mechanism

may erode ossicles and mastoid air cells, retraction or ruptures of tympanic membrane --> conductive hearing loss

39

colosteatoma - otorrhoea characteristic

foul-smelling

40

facial nerve lesion - types (according area)

1. upper motor neuron (UMN) lesion
2. lower motor neuron (LMN) lesion

41

UMN facial nerve lesion - area

lesion of motor cortex or connection between cortex and facial nerve nucleus in pons

42

UMN facial nerve lesion - appearance

contralateral paralysis of lower face
forehead spared due to bilateral UMN innervation

43

LMN facial nerve lesion - area of lesion and appearance

- ipsilateral paralysis of upper and lower face
hyperacusis
- loss of taste sensation to antrior tongue

44

facial UMN lesion is AKA

central facial palsy

45

facial LMN lesion is AKA

facial nerve palsy

46

facial nerve palsy?

destruction of facial nucleus or CN VII anywhere along its course

47

peripheral ipsilateral facial paralysis - clinical characteristics

absent forehead creases and drooping smile with inability to close eye on involved side

48

facial nerve palsy - treatment

corticosteroids
acyclovir
Most patients have gradual recovery of function

49

MCC of facial nerve palsy (and frequency)

Bell palsy (idiopathic) (70%)

50

causes of facial nerve palsy

1. Bell palsy (idiopathic)
2. Lyme diseae
3. HSV
4. sarcoidosis
5. tumors
7. diabetes
8. HZV (Ramsey Hunt syndrome)

51

three ossicles

1. malleus
2. incus
3. stapes

52

mastication muscles - number

4

53

mastication muscles - innervation

V3 (mandibular)

54

mastication muscles - names

1. masseter
2. temporalis
3. medial pterygoid
4. lateral pterygoid

55

mastication muscle - function

- 3 muscles close jaw (masseter, temporalis, medial pterygoid)
- 1 muscle open the jaw (lateral pterygoid)

56

Ramsay Hnat syndrome is caused by

HZV

57

Trigeminal nerve divisions

V1: ophthalmic
V2: maxillary
V3: mandibular

58

cavernous sinus syndrome is secondary to (and symptoms)

1. pituitary tumor mass effect
2. carotid - cavernous fistula
3. cavernous sinus thrombosis related to infection
symptoms: 1. variable ophthalmoplegia
`2. decreased corneal sensation
3. Horner syndrome
4. decreased maxillary sensation (occasionally)

59

Hyperacusis

increased sensitivity to certain frequency and volume ranges of sound