Cerebellar damage

Question 1

what type of reflexes occur with spinocerebellar damage

Answer 1

hypermetric reflexes

Question 2

why do we see hypermetric reflexes with spinocerebellar damage

Answer 2

(spinocerebellar function is key for balance control)
damage to the spinocerebellum impairs balance control by disrupting the timing and increasing the amplitude of reflex responses

Question 3

what is the difference between a healthy patient and a patient with a spinocerebellar lesion

Answer 3

healthy
- reflex activity in agonist
- reflex inhibition of antagonist
lesion
- hypermetric reflexes occur during the higher levels of processing (LLR and VOL)
- osciallatory effect from not being able to effectively inhibit the antagonist muscle

Question 4

what are the 3 main things that can be caused by damage to the lateral or intermediate cerebellar hemispheres

Answer 4

• delayed / slow mvmts
• ataxia
• dysdiodochokinesia

Question 5

what causes delayed / slow mvmts

Answer 5

damage to the dentate or interposed nuclei
- delay the onset / reduce the speed of mvmt on the ipsilateral side of body
deficits arise due to improper timing and scaling of agonist and antagonist muscles

Question 6

what is dysmetria

Answer 6

difficulty initating and controlling the amount of force produced

Question 7

when subjects are instructed to produce matched, simultaneous force with left and right hands, what is the result in healthy vs patients with damage

Answer 7

healthy = smooth force profiles
damage = reduced rate of force production in ipsialateral hand relative to contralateral hand

Question 8

what causes ataxia

Answer 8

damage to the deep cerebellar nuclei
deficits arise due to improperly timed activation of hte agonist and antagonist muscles

Question 9

what is an intention tremor

Answer 9

hand oscillates irregularly around the target

Question 10

when reaching to a target, what is the difference in healthy vs patients with damage

Answer 10

healthy = smooth and roughly straight mvmts
damage = intention tremors when moving from target to target

Question 11

what causes dysdiodochokinesia

Answer 11

damage to the deep cerebellar nuclei
deficits arise due to improperly timed activation of agonist and antagonist muscles

Question 12

what is dysdiodochokinesia

Answer 12

inability to sustain regular, alternating rhythm of mvmt or force

Question 13

when asked to alternate supination and pronation, what is the difference between healthy vs patients with damage

Answer 13

healthy = regular alternating mvmts
damage = end up with smaller oscillations within the desired oscillatory mvmt and poor coordination