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Flashcards in Cerebellar Impairments Deck (30)
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1
Q

List some of the roles the cerebellum has

A
  1. Coordination
  2. Balance
  3. Muscle tone
  4. VOR suppression
  5. Motor Control
  6. Motor learning
2
Q

List the functional lobes of the cerebellum as well as their role/what they communicate with

A
  1. Cerebrocerebellum
    • cerebellum ⇔ cortex
    • distal extremities
  2. Spinocerebellum
    • cerebellum ⇔ spinal cord
    • Trunk, EOMs, proximal muscles
  3. Vestibulocerebellum
    • cerebellum ⇔ vestibular apparatus and system
    • VOR, equilibrium/balance
3
Q

List major brainstem nuclei that communicate with the cerebellum

A
  1. Vestibular Nuclei
  2. Deep Pontine nuclei
  3. Red nuclei
  4. Superior and Inferior Olivary Nuclei
  5. Reticular Formation
4
Q

what are the major afferents and efferents to the vestibulocerebellum?

A
  1. Afferents:
    • Vestibular primary afferents
    • Vestibular nuclei
    • Visual areas
  2. Efferents:
    • M/L vestibular nuclei
5
Q

List the roles in movement that the vestibulocerebellum has

A
  1. VOR
  2. Gaze and eye movements
  3. Posture and balance
6
Q

List clinical signs that can indicate damage to the vestibulocerebellum

A
  1. Nystagmus
  2. Impaired VOR
  3. Imbalance
7
Q

what are the major afferents and efferents to the spinocerebellum?

A
  1. Afferents
    • Vestibular and reticular nuclei
    • DSCT and VSCT
    • cerebrum
  2. Efferents
    • Vestibular and reticular nuclei
    • Cerebrum
    • red nuclei
8
Q

List the roles in movement that the spinocerebellum has

A
  1. Gaze and eye movements
  2. Postural tone
  3. Balance
  4. Locomotion
  5. Limb movements
  6. Coordinate agonist-antagonist muscle pairs
9
Q

List clinical signs that can indicate damage to the spinocerebellum

A
  1. Oculomotor deficits
  2. Hypotonia
  3. Imbalance
  4. Falls
  5. Gait ataxia
  6. Tremor
  7. Lack of check
  8. Dysdiadochokinesia
  9. Dysmetria
10
Q

List the major afferents and efferents to the cerebrocerebellum

A
  1. Afferents
    • cerebrum (wide range of areas)
  2. Efferents
    • cerebrum
    • red nucleus
11
Q

List the roles in movement that the cerebrocerebellum has

A
  1. Complex, multijoint voluntary limb movements
  2. Visually guided movements
  3. Motor planning
  4. Sensoriomotor error assessment
12
Q

List clinical signs that can indicate damage to the cerebrocerebellum

A
  1. Dysdiadochokinesia
  2. Dysmetria
  3. Dyssynergia
  4. Decomposition
13
Q

List broad clinical manifestations of cerebellar lesions

A
  1. Ataxia
  2. Dysmetria
  3. Dyssnergia
  4. Dysdiadochokinesia
  5. Hypotonia
  6. Cerebellar tremor
  7. Imbalance
  8. Oculomotor deficits
  9. Speech deficits
  10. Impaired MC
14
Q

Define ataxia

A
  1. Generally uncoordinated or disordered movement
  2. worsens with movement of multiple joints together or by moving quickly
15
Q

what are the 3 types of ataxia?

A
  1. Truncal
  2. Appendicular (limb)
  3. Gait
16
Q

Describe truncal ataxia

A
  1. Oscillations in sitting and standing
    • tends to be more pronounced in sitting
  2. Falling/LOB often occurs towards side of lesion
17
Q

Describe appendicular (limb) ataxia

A
  1. Tends to be more noticeable in arms and hands
  2. Associated with tremors
18
Q

Describe gait ataxia

A
  1. “Drunken ataxia”
    • lack consistency in timing, length and direction of steps typical of healthy adults
    • widened BOS
    • arms up in low, medium or high guard position
    • increased variability in both timing of and movement excursion
  2. influenced by multitude of cerebellar impairments
  3. leads to sig balance difficulties
  4. falls common
    • backwards and/or to side of lesion
19
Q

Define dysmetria

describe its mechanism

A

inability to properly scale movement distance

mechanism → inability to account for interaction torques → impaired ability to predict and account for dynamics of limbs as they interact

20
Q

examination for dysmetria

A
  1. Finger-to-nose, finger-to-finger
  2. Heel-to-shin, ankle circles/alphabet
21
Q

What is dyssnergia?

A
  1. Impairment of multi-joint movements leading to decompensation of movement
    • Loss of proper sequencing, movement becomes fragmented
    • Commonly compensated w/massed patterns of movements
    • Closely associated w/dysmetria
22
Q

what is asynergia?

A

complete loss of ability to associate movements for complex movements

23
Q

What is dysdiadochokinesia?

A
  1. deficit in coordination between agonist-antagonist muscle pairs elicted during voluntary rapid alternating movements
    • excessive slowness, inconsistency in range of RAMs (worsens as movement continues)
    • manifests as rigid movements, compensatory bradykinesia of limbs
    • can impact speech and swallow muscles - dysarthria and dyshagia
24
Q

What is hypotonia?

A
  1. In particular, decreased extensor tone necessary for holding body upright against gravity
    • can see effects in limbs, EOMS, speech muscles
    • typically more problematic in more severe cerebellar lesions or in the acute stages of cerebellar injury only
    • usually resolves w/time
25
Q

What is a cerebellar tremor?

A
  1. an oscillatory and predictable tremor that is due to insufficient ability to anticipate the effects of movements and excessive reliance on sensory feedback loops
    • typcially an action tremor
      • postural
      • intentional/kinetic
26
Q

What does imbalance from cerebellar lesion typically look like?

A
  1. increased postural sway
  2. impaired postural responses to perturbations
  3. titubation → abnormal oscillation of head/neck
  4. disequilibrium
  5. midline disorientation → lateral pulsion towards side of lesion
27
Q

What types of occulomotor deficits may be observed with cerebellar lesions? (include general regions impacted)

A
  1. Spinocerebellar
    • impaired smooth pursuit
    • impaired saccades
  2. Vestibulocerebellar
    • Nystagmus may be present (most common = gaze-evoked)
    • Loss of VOR suppression
28
Q

What types of speech deficits may be present after a cerebellar lesion?

A
  1. Ataxic dysarthria:
    • impaired articulation
    • impaired prosody
    • slowed speech
    • volume variability
    • staccato voice
29
Q

How is motor control impacted by a cerebellar lesion?

A
  1. loss of real-time integration of feedback from peripheral systems
    • anticipated movement vs actual movment
  2. delayed or absent adjustments to inaccurate motor programs
30
Q

How is motor learning impaired following a cerebellar lesion?

A
  1. impaired ability to store adapted movement patterns after repeated exposure
  2. Impaired automatic processes involved w/rapidly adjusting movements for new, predictable demands
    • becomes inefficient and difficult, high cog load

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