Neuro - Cerebellum Dysfunction - General

Front 1

Which cerebellum lobes are responsible for which functions?

Back 1

• Anterior lobe - posture and trunk movement
• Middle lobe - coordination
• Flocculonodular lobe - muscle tone and eye movement

Front 2

• What connects the cerebellum to the rest of the brain?
  
• What proportion of the brain's weight is the cerebellum?
• What proportion of the brain's neurons does the cerebellum contain?

Back 2

• Cerebellar peduncles
  
• 10%
• 50%

Front 3

The cerebellum promotes accuracy, synchrony, and coordination of what four movement types?

Back 3

• Postural responses
• Equilibrium responses
• Voluntary muscle actions
• Reflex muscle actions

Front 4

What are 5 possible results of Cb lesions?

Back 4

1. Ataxia
2. Clumsiness
3. Dyscoordination
4. Muscle tone abnormalities
5. Delayed (but not prevented) initiation of movement

Front 5

What findings will present with single-sided Cb pathology? Will these present bilaterally, contralaterally, or ipsilaterally?

Back 5

• B/L increased base of support
• Ambulation veers I/L upon "march in place"
• Inability to maintain single-leg stance I/L
• Intention tremor (beating, waggling tremor when nearing end points of UE movement) of I/L UE
• Dysmetria and DDK I/L

Front 6

• How does the Cb actively compare the motor plan to the current execution of the plan?
  
• How does the Cb aid visual tracking? What would a loss of this function present as? Why?

Back 6

• It receives ongoing input from both the CNS and the periphery, altering its output to match the plan
  
• Coordinates movements to track objects; Object tracking is needed for judging spatial-temporal variability, so loss of tracking results in inability to perform tasks within spatial/temporal constraints (+ for dysmetria)

Front 7

What are 2 ways the Cb modulates scale of movement?

Back 7

• It alters the output of the descending tracts to match the desired scale of movement
  
• It alters brainstem and cord influences on posture and movement to stabilize during perturbations
  

Front 8

• What 3 deficits would be observed in a lesion within the central portion of the anterior or posterior lobe, or within the vermis?

Back 8

1. LE dyscoordination
2. Deficits in LE equilibrium responses
3. Abnormal head and trunk synergies
   

Front 9

• What 3 abnormalities would be observed with a lesion to the anterior lobe of the Cb?
• What would be normal?

Back 9

1. Amplitude/duration of postural response reactions 2-3x normal
2. Lack of habituation
3. 3-Hz postural sway

• Response latencies would be normal

Front 10

• How do pts adapt to loss of Cb-mediated balance? What is the characteristic gait result?
  

• What are the biological benefits of a closed-packed gait?

Back 10

• Intersegmental counterbalancing, which results in less falls, but a stiff-legged (closed-packed) gait
  
• Less control to remain stable; Increased proprioceptive feedback

Front 11

What are the 3 sub-systems within the cerebellum? What anatomical region coincides with each system?

Back 11

• Cerebrocerebellar system (lateral aspects of the hemispheres)
• Spinocerebellar system (vermis, intermediate hemispheres)
• Vestibulocerebellar system (flocculonodular lobe, adjacent vermis)

Front 12

• What are 6 functions that are controlled by the cerebrocerebellum?

Back 12

1. Complex multi-joint movement
2. Visual-guided movement
3. Motor planning and learning, anticipatory feed-forward mechanisms
4. Sensorimotor error assessment
5. Precision of quick movements, agonist/antagonist activation patterns
6. Judgment of spatio-temporal factors during movement
   

Front 13

• What functions are controlled by the spinocerebellum?
  
• How would a lesion affect the pt?

Back 13

• Postural tone, balance, locomotion, gaze and other eye movements, coordination of agonist-antagonist muscle pairs, limb movement
  
• Hypotonia (observed c/ pendular knee jerk), imbalance, gait ataxia, oculomotor deficit, dysmetria, DDK, lack of check, intention tremor

Front 14

• Where does the vestibulocerebellum receive input from?
• Where does its output go?
• What does its output control?
• What does local lesion cause?

Back 14

• CN8, vestibular nuclei, visual brain areas
• Medial and lateral vestibular nuclei
• VSR, VOR, gaze and eye movements, posture and balance
• Disequilibrium, nystagmus, N/V, vertigo

Front 15

What are 7 possible etiologies of Cb damage?

Back 15

1. TBI (most common)
2. Developmental abnormality (hydrocephalus, hypoxia)
3. Demyelinating disease
4. Hereditary disease
5. Metabolic disorders
6. Vascular insufficiency (stroke)
7. Drug/alcohol intoxication

Front 16

• What is Friedreich's Ataxia?
  

• How is it contracted?
  
• Lifespan?

Back 16

• Disease of nerve tissue deterioration, including Cb

• Hereditary
• 30-40 years

Front 17

• What are 3 classic symptoms of chronic alcoholism and Wernicke-Korsakoff syndrome?
  
• What is the nutrient-cause of Wernicke-Korsakoff syndrome?

Back 17

• Ataxia, confusion, coma
• Thiamine (B₁)