Vestibular and cerebellar disease Flashcards Preview

Neurology > Vestibular and cerebellar disease > Flashcards

Flashcards in Vestibular and cerebellar disease Deck (46):
1

Classic signs - ataxia

- overstep
- cross over legs

2

2 types of ataxia with alcohol

- APPENDICULAR: jerky, uncoordinated limbs mvt, as though each mm were working independently from others
- TRUNCAL: postural instability, gait instability - disorderly wide-based gait with inconsistent foot positioning

3

Define ataxia

neurological sign consisting of gross incoordination of muscle movements. It is an aspecific clinical manifestation

4

What to look at when observing ataxia. How to differentiate from MSK problems

- limbs, head and how trunk moves during locomotion
- becomes better coordinated when running (MSK problems get worse with running

5

3 types of ataxia

sensory, vestibular and cerebellar

6

Define hypometria

shorter protraction phase of gait

7

Define hypermetria

longer protraction phase of gait

8

Define dysmetria - 3

ability to control teh distance, power and speed of an action in impaired. combination of hypo- and hypermetria

9

Neurolocalisation - sensory ataxia

General proprioceptive pathways:
- peripheral nn
- dorsal root
- SC
- brainstem
- forebrain

10

CS - sensory ataxia

- abnormal postural reactions
- limb paresis

11

Neurolocalisation - vestibular ataxia

Vestibular apparatus:
- vestibular nuclei (central)
- vestibular portion of CN 8
- vestibular receptors (peripheral_

12

T/F vestibular system is a unilateral system

True - the RHS controls the RHS and vice versa

13

CS - sciatica

arched back as this provides greatest pressure relief on nn root.

14

How does the vestibular system affect the extensors?

Causes excitation/ tone to extensors --> head tilt and limp limbs if not working properly

15

CS - vestibular ataxia

- head tilt
- leaning, falling or rolling to one side
- abnormal nystagmus (slow side always to side with lesion)
- positional strabismus
- normal (peripheral) or abnormal (central) postural reactions

16

Is prognosis of a vestibular problem affected by localisation (i.e. central/ peripheral)?

No

17

T/F: nervous system copes better with acute than chronic changes

False - oppositve

18

Why might you get reduced ear movement with vestibular disease?

lesion may spread and affect facial nerve --> paresis/ paralysis due to close proximity

19

CS - Cerebellar ataxia

- wide based stance
- intention tremors of head
- loss of balance and truncal sway
- delayed onset and dysmetric hopping
- ipsilateral menace deficits with normal vision
- no limb paresis OR conscious proprioception deficits
- pendular nystagmus

20

How do forebrain and cerebellum interact?

Forebrain - initiates movement
Cerebellum - coordinates movement

21

How are the 3 types of ataxia differentiated (sensory, vestibular, cerebellar)?

CS

22

Outline the neuro exam in terms of observation and hands-on examination parts

OBSERVATION:
mental status and behaviour
posture
gait
identification of abnormal voluntary movements
HANDS-ON EXAMINATION
postural reaction testing
cranial nerves assessment
spinal reflexes, mm tone and size
sensory evaluation

23

2 components of inner ear

semicircular canals and cochlea (hearing)

24

What part of the vestibular system detects head motion and angular acceleration?

semicircular canals

25

What part of the vestibular system detects head position and gravity?

saccule and utricle

26

Which nn does bulla disease affect?

facial and vestibulocochlear nn and SNS trunk (--> Horner's)

27

Where do vestibular nuclei receive input from? 3

* semicircular canals
* saccule and utricle
* visual/ proprioceptive and tactile inputs
- cerebellum: primarily inhibitory
- spinal cord
- potine reticular formation
- contra-lateral vestibular nuclei

28

With the occulovestibular reflex, turning the head causes what?

Increased firing on the side where the head is turning to and decreased firing on the side the head is turning away from.

29

Where do vestibular nuclei communicate with?

* forebrain, perceived orientation
* SC and cerebellum
* oculomotor system, eye movements

30

Outline head tilting

- rotation of median plane of head
- one ear lower than other
- often indicates a vestibular disorder (i.e. a disorder of the balancing system)

31

Outline head turning

- where the median plane of the head remains perpendicular to the ground, i.e. nose turned to one side
- may indicate a forebrain disorder

32

Describe pendular nystagmus

- siamese, birman, himalayan (melanin disorder and more fibres cross over)
- congenital abnormality (larger # fibres cross chiasma)
- cerebellar disorders and visual deficits
- jerk nystagmus: horizontal, vertical and rotary

33

Name different types of nystagmus

- physiological
- pendular
- searching
- jerk (horizontal, vertical, rotary)

34

Name the 5 features of Horner's syndrome (SA)

= loss of sympathetic innervation to eye:
- enopthalmos
- TE protrusion
- ptosis
- miosis
- (congested BVs)

35

Features of Horner's syndrome in horses

- ptosis - examine eyelashes closely
- miosis
- enophthalmus
- prominent TE
- conjunctival and nasal hyperaemia
- sweating

36

Name 4 important CS to determine whether a vestibular lesion is central or peripheral

* conscious proprioceptive deficit
* consciousness
- cranial nerve deficits
- vertical nystagmus (will often improve with time)

37

Outline difference in CS between central and peripheral nystagmus

CENTRAL: possible conscious proprioceptive deficit, consciousness (normal, obtunded, stupor, coma), cranial nerves (5-8 may be affected), vertical nystagmus (yes)
PERIPHERAL: no conscious proprioceptive deficit, consciousness (alert, disorientation possible), cranial nerve deficits (8 only), no vertical nystagmus

38

What is the first Q that should be asked when examining a pupil for a peripheral vestibular proble?

Ototoxic drugs

39

What is a myringotomy?

sx procedure, penetration of TM, remove fluid from middle ear, relatively safe, very diagnostically helpful

40

CS - bilateral vestibular problem

- no nystagmus
- no occulovestibular response
* head swaying from left to right

41

3 parts - cerebellum

- vestibulo-cerebellum (central)
- spino-cerebellum (central)
- cerebro-cerebellum (peripheral)

42

3 functions - cerebellum

- maintain equilibrium
- regulate mm tone (--> preserves mm position at rest and mvt)
- coordinate mvt

43

If the head tilt is away from the sign of the proprioceptive deficit, what should you consider?

paradoxical vestibular problem (head tilt usually towards lesion but may be away from it and thus also away from the proprioceptive deficit)

44

Name different regions of the cerebellum 5

- rostral lobe
- caudal lobe
- flocculonodular lobe
- caudal cerebellar peduncle
- cerebella nuclei fragment

45

CS - cerebellar syndrome

- spastic, dys- or hyper-metric ataxia (goose-stepping)
- intention tremor
- ipsilateral menace deficit + normal vision
- broad-based stance
- postural reactions delayed with exaggerated responses
- menace deficit (ipsilateral) with normal vision
+/- anisocoria (pupil dilate contralateral to side of lesion)
+/- opisthotonus (rare)
+/- vestibular signs

46

Define opisthotonus

tetanic spasm in which the body is bent back and stiffened, head will be in an extended position