Ataxia Flashcards
Where is the cerebellar located and what part of the brain is it a part of?
Means ‘little brain’. Sits dorsal to the pons and medulla and inferior to the cortex.
How many hemispheres and lobes does the cerebellum have?
It has 2 hemispheres and 3 lobes
How does the cerebellar attach to the brainsteam?
Three pairs of cerebellar peduncles- Tracts of axional fibres. Superior, middle and inferior.
Input fibres come in where in the cerebellum?
Afferent (Input) fibres come through mid and inferior.
Lesions to the cerebellum peduncle before and after the crossing results in
Ipisilateral deficients when before and contralateral when after.
What is the role of the cerebellum?
Recieves alot of information about voluntary movement
Coordination of movement and activities
Rate of force
Postural equillberium
Damage to the cerebellum will result in?
Can effect gait, speech and eye movement. Impact movement quality but don’t prevent it from happening
What are some features of cerebellar dysfunction?
Hyptonia- Decreased in general muscle tone
Ataxia- Uncoordinated movements
Dysarthria- Slurred speech
Tremor
Ocular motor dysfunction
The cerebellum is divided into three areas. Name them and their role
1) Vestibulocerebellum- Disturbances of equalibrium and nystagmus
2) Spinocerebellum- Centrally located. Focused on postural tone and spinal cord. Hypotonia (neck and head). Usually acute lesions.
3) Neocerebellum (cerebrocerebellum)- Outside lobe. Dysmetria, attention tremor, visual persuit.
Vestibulocerebellum lesions caused what?
Nystagmus and they drift away from objects and return. Tend to move fast towards side of the cerebellar lesion.
- Unable to sit or stand unsupported. Fades when lying down.
Spinocerebellum lesions can cause
Loss of programmed deceleration
Hypermetra- Reaching beyond an item
Rebound phenonmenon
Doesn’t fade when lying down.
Intention tremor- As it approaches target, it goes into oscillations (Finger to nose)
Neocerebellum lesions can cause
Movement decomposition. No smooth movement. Asthenia (weakness and heaviness).
Dysmetria- Arc is wavey and jerking.
Dysdiadochokineasia- Quick movements uncordinated- Tpaping toes, flipping hands over.
What is the classic, cardinal feature of cerebellum disease?
Ataxia.
What are the four main types of Ataxia?
1) Sensory
2) Vestibular
3) Cerebellar
4) Frontal
What is frontal Ataxia?
Also known as gait ataxia. Tumours, strokes, absenses. Front dementia. Scissoring gait- Legs crossing.
What is sensory Ataxia?
Caused by damage to the sensory pathways responsible for transferring proprioceptive information back to cerebellum.
- Loss of proprioception and vibration sense
- Worse with eyes closed
-
What is vestibular Ataxia?
Damage to VIII or general Cerebellar damage
- Vertigo, nystagmus.
- What causes cerebellar Ataxia?
- Explain some of the common symptoms
Damage to cerebellum
- Closing eyes doesn’t make it much worse
- Intact sensory receptors and afferent pathways
- Integration of propriception is faulty
- Wrose with speed
- Gait is wide based and irregular.
Differentiatying cerebellar ataxia- What does light headedness and sensation of movement when stationary mean is being affected?
Vestibular system
Differentiatying cerebellar ataxia- What does a positive Rhomberg sign mean? (Loss of balance with eyes closed)
Sensory system
Differentiatying cerebellar ataxia- What does progressive increase in ataxia, bilaterally and symetric?
Metabolic, toxic or an immune process?
Ataxias can be differientated into two different types
Acquired and inherited
Acquired ataxias can be differentiated into two different ways
Symmetrical and Asymmetrical
List the difference ataxias in the acquired category
Symmetrical and Asymmetrical
Symmetrical is intoxications, infections, hydrocephalus
Asymmetrical is stroke/TBI, demyelination, tumours
Name an inherited Ataxia
Fredereichs ataxia.
- Affects 1/50,000
What are the symptoms of Fredereichs ataxia?
Ataxia first symptom
Progressive weakness and fatigue
Decreased sensation to vibration, proprioception
Cardiac anomalities- Hypertrophic cardiomyopathy
