Ataxia: Cerebellar Dz Flashcards
What may worsen sensory ataxia?
- loss of proprioception (slidy kennel)
- loss of vision (blindfold, dark room)
- reflection and darkenss not helpful
What are the 3 types of ataxia?
- sensory
- vestibular
- cerebellar
How is ataxia affected by gait?
EASIER TO RUN!!! cf. lameness which worsens with ^ gait
What aspects of the gait should you look for when assessing ataxia?
- limb movement
- head movement
- trunk movement
What is sensory ataxia also known as?
- spinal or proprioceptive
Define hypo and hypermetria
- shorter or longer protraction phase of gait
Define dysmetria
- ability to control distance, power and speed of an action (combination of hypo and hypermetria)
Give the 5 general proprioceptive pathways (-> sensory ataxia)
- peripheral nerves
- dorsal root
- spinal cord
- brainstem
- forebrain
What clinical signs are commonly seeen in combination with sensory ataxia?
- abnomal postural reactions
- limb paresis (looks like lameness)
What clinical sign may be seen with sciatica?
- arched back (relieves pressure on n. root)
- usually where pain is greatest
What is included in the vestibular apparatus?
- Vestibuular nuclei (central)
- Vestibular portion of VIII (vestibulocochlear n.)
- Vstibular receptors (peropheral)
Clinical signs of vestibular ataxia
- head tilt
- leaning, falling and rolling to one side
- abnormal nystagmus (slow phase TOWARDS lesion, fast run away from the lesion)
- positional strabismus
- normal (peripheral) or abnormal (central) postural reactions
Clinical signs of cerebellar ataxia
- wide based stance
- intention tremor (head)
- loss of balance and truncal sway
- delayed onset and hypermetric hopping
- ipsilateral menace deficits with normal vision
- no limb paresis or conscious proprioception deficits
- pendular nystagmus
What is the difference between concious and unconcious proprioception?
- conscious can be over ridden eg. foot placement
- unconcious cannot be overridden eg. hopping test
Where are movement impulses initiated?
Forebrain??? then modulated by cerebellum