CA Flashcards
Define Cerebellar Ataxia (CA)
Abnormal coordination due to damaged neurons in the cerebellum. Affects:
- speed
- amplitude
- accuracy
- force of movement
Causes of CA (and 4 examples)?
Focal lesions (e.g. stroke, TBI, tumour and MS)
Name the 3 functional divisions of the cerebellum and describe their functions
1) Vestibular cerebellum ? (balance) balance, eye movement
2) Cerebrocerebellum ? (planning) preparation, initiation, precision, timing, sequencing, coordination of movement
3) Spinocerebellum ? (execution) execution of limb movements, smoothness of muscle movements
What roles does the cerebellum have?
- Motor control regulation
- Synergies
- Intensity of movement
- Movement to movement error correction
- Timing and sequencing
General function of the cerebellum
Dexterity and postural control
Define ataxia
Lack of voluntary coordination of muscle movements
Define
- Dysmetria
- Rebound phenomenon
Dysmetria ? lack of coordination typified by under/overshooting (not measuring distance correctly)
Rebound phenomenon ? slow antagonist action
Define
- Dysdiadochokinesia
- Dysarthria
- Nystagmus
Dysdiadochokinesia ? inability to perform rapid alternating movements
Dysarthria ? poor coordination of speech production muscles
Define
- Dyssynergia
- Nystagmus
Dyssynergia - poor coordination of timing onset and offset of ag/antagonists (loss of smoothness)
Nystagmus ? oscillating eye movement
What are the main impairments in CA? (2)
Loss of dexterity/coordination etc
Loss of balance
What are the main motor performance characteristics in CA?
Dysmetria Rebound phenomenon Dysdiadochokinesia Dyssinergia Tremors Dysarthria Nystagmus
How is CA assessed?
Dexterity tests
- Pronation/supination, postural sway, heel/shin, heel over foot, finger to nose/finger, rebound
- Functional assessment ? sitting, standing etc.
Is a strength assessment usually necessary in CA?
NO
- Strength is usually unaffected in CA
CA measures (6)
Measures (record accuracy)
- 10 m walk test (variable step lengths)
- TUG
- Step test
- Functional Reach
- 6 min walk
- 9 hole peg test
Typical motor behaviours in CA
- restrictions (2), increases (2) and excessive (2)
Restricted
- amplitude of movement
- ROM (i.e. stiffness)
Excessive
- pre shaping and use of support surfaces during reaching (use of adaptive strategies)
- BOS, stepping and use of arms in walking
Increased
- speed and difficulty slowing when walking
- variability of performance
Intervention considerations for CA
Considerations:
- Task specific, high reps
- May modify and add adaptive behaviours to make task easier with degenerative CA (e.g. multijoint training for recoverable, stabilize joints for degenerative)
- Train accuracy and speed
- Remember balance is a main impairment in CA (safety)
CA research say about reaching?
Reaching
- Abnormally curved wrist path
- Better with joints fixed
CA research say about gait?
Gait
- Less PF and knee yield
- More variable
Stepping over an obstacle
- more dysmetria than normal walking
CA research on timing?
Heel raise
- same sequence but poor timing
- poor build up of EMG
CA research on dual tasks?
Poor with addition of dual task
CA research on training accuracy and balance/coordination?
Improved accuracy
Improved function and independent walking ability
Degenerative CA training?
2hrs daily for 4ks PT/OT
= better (walking speed, less falls, ADLs)
= maintained at 12/24wks
