Ataxia Flashcards
Define Ataxia
Abnormal coordination that affects T.A.A.F (timing, amplitude, accuracy, and force of movements)
List ataxic motor impairments
Dysmetria Rebound phenomenon Dysdiadochokinesia Dyssynergia Tremor Hypotonia Dysarthria (red coordination of speech mm's) Nystagmus (oscillatory movements of the eyes; sign of vestibular dysfunction)
Define dysmetria
Reaching a target precisely and with speed; disorder of movement termination (where you overshoot or undershoot the target; hyper or hypometria)
Define Rebound phenomenon
Delayed antagonist response
Define dysdiadochokinesia
reduce coordination of RAPID ALTERNATING MOVEMENTS
Define dyssynergia
Loss of smoothness, joints moving independently of each other or at abnormal rates; reduced coordination of antagonists + agonists
Adaptive motor behaviours - UL
- excessive preshaping
- use of support surface to brake the reach
- restricted amplitude of movement
- restricted degrees of freedom of movement
- increased variability of performance from trial to trial
Adaptive motor behaviours - LL
- wide BOS
- excessive use of the arms
- excessive stepping when standing
- faster walking
- difficulty slowing down
- restricted amplitude of movement
- restricted degrees of freedom of movement
- increased variability of performance from trial to trial
Palliyath et al (1998) - this study charted the force production at the ankles, knees, and hips - what did they find?
Reduced amplitude of movement - especially noticeable at the ankles (and hips)
Bastian et al (1996) - had people point to a target in front of them so their hand had to take a path to the object. Pt is instructed to just be accurate or FAST + accurate. What did they find?
Regardless of speed, the control group path of movement was more direct and precise; not so with the cerebellar lesion group - and this group overshot the target when fast movement is instructed
CLINICAL IMPLICATION - whote task training where possible that stresses speed and accuracy; sometimes you’ll have to modify as necessary
Bastian et al (2000) - this study had pt’s move their hands to a target at 1 joint whilst the elbow was supported and unsupported. What did they find?
For controls - good accuracy regardless of support
For patients - much better accuracy with elbow supported
CLINICAL IMLPLICATION: fixing a joint improves accuracy but not great for learning; so if they have potential for relearning skills stopping them using the support will aid with coordination
Deiner & Dichgans (1992) - this study had people to a calf raise. What did they find?
In normal people - TA came on first, then quads, then plantar flexors; mm’s reached peak quickly
In cerebellar patients - although the same SEQUENCING was present, took a long time to reach peak force prod
CLINCAL IMPLICATION: whole task training; focus on power + timing
Lang & Bastian (2002) - this study had people do a figure 8 (25 x 8s) pattern with and without concurrent auditory vigilance task. What did they find?
The cerebellar group did get better with practice but as soon as the auditory task was introduced they fell apart.
IMPLICATIONS - cerebellar patients DO improve with practice but you cant assume that they will perform as well with added cognitive tasks/distractions as without
Klintsova et al (1998) - investigated the effect of rehab motor training on rats that had their cerebellum destroyed. Groups were divided into 1) Inactive, 2) Motor Control (rats walk on a flat surface with no challenges), 3) Rehab motor skill training (walking with challenges). What did they find?
The rehab motor skill group fared better and histologically there was more connections in the cerebellum
IMPLICATION - exercises need to be COMPLEX to stimulate improvement!
Langton Hewer et al (1972) - Added weights to upper limb to see how it affected the trace of a hand moving to a target. What did they find?
Addition of weights = reduced intention tremor in 58% of subjects
