L25: Ataxia assessment and therapy options Flashcards
_____ takes 10% of the brain’s volume but has 50% of total neurons in the brain
Cerebellum
What are 5 purposes of cerebellum?
- Maintenance of balance and posture
- Coordination of voluntary movements
- Motor learning
- Cognitive functions (language)
- Cerebellum is highly involved in central vestibular pathology
What are 4 functional areas of the cerebellum that influence locomotion?
- Vermis (medial zone)
- Intermediate zone
- Lateral zone
- Flocculonodular lobe
What are 4 afferents of the vermis (medial zone)?
- Vestibular afferents
- Vestibular nuclei
- Reticular & pontine nuclei
- Dorsal & ventral spinocerebellar tracts
- DSCT conveys information about the limbs
- VSCT conveys information about motor commands
What is an efferent of the vermis (medial zone)?
Projects out to vestibular nuclei & reticular nuclei
What are functions of the vermis (medial zone)?
Integration of spinal and vestibular inputs and influences motor pathways for walking
What 2 lesions of the vermis (medial zone)?
- Damage to the vermis affects gait and sitting balance, with relative sparing of eye movements and speech
- Dizzy, altered eye movements, tone issues, verticality issues
- Medial zone: Alternative the locomotor pattern from sensory feedback from the limbs
What are lesions of the cerebellum?
Damage to one cerebellar hemisphere usually causes ataxia in the ipsilateral limbs
What are 3 afferents of the intermediate zone?
- DSCT and VSCT
- Reticular nuclei
- Cerebral cortex
What are 2 efferents of the intermediate zone?
- Red nuclei
- Cerebral cortex
What are functions of the intermediate zone?
Integration of spinal and cortical imputes to influence walking through projections to motor cortical areas
What are 3 regulations of lesions of the intermediate zone?
Regulation of:
- Timing
- Amplitude
- Trajectory of elevation and descent
What are 5 afferents of the lateral zone?
Cerebral cortex (via pontine nuclei)
- Primary motor
- Pre-motor
- Primary somatosensory
- Posterior parietal cortices
- Pre-frontal and temporal lobes
What are 2 efferents (2) of the lateral zone?
- Red nucleus
- Cerebral cortex (via thalmus)
- Primary, pre-motor
- Parietal
- Prefrontal cortex
What are functions of the lateral zone?
What are 2 regulations of lesions of the lateral zone?
- Adjustments for novel contexts
- Adjustments when strong visual guidance is required.
What are 3 afferents of the flocculonodular lobe?
- Primary vestibular afferents
- Vestibular nuclei
- Reticular nuclei
- Visual inputs
What are 2 efferents of the flocculonodular lobe?
- Projects out to vestibular nuclei for control of eye
- Movements and balance
What are lesions of the flocculonodular lobe?
Control of balance and locomotion
- Control extensor tone modulation control over rhythmic flexor/extensor activation
What is the summary of the cerebellar?
- Inferior peduncle - vestib
- Superior & middle peduncle - motor
- Lateral nuclei get input from lateral hemisphere
- Medial nuclei get input from vermis & flocculonodular lobe
What are 3 functions of the cerebellum as an integrator - controller - adaptor?
- Evaluates sensory input
- Modulates learning and outcomes
- Modify motor activity
What are 2 functions of the cerebellum as influence?
- Functions in the somatomotor area
- Does not precipitate muscle activity
What are 2 functions of the cerebellum as control?
- Influences purposeful movement
- Lesions create general movement decomposition (not paralysis)
What are 7 cerebellum in tracking?
- Stabilise oscillating outputs
- Scaling of the amplitudes of the responses
- Improve speed and crispness of the response
- Proper distribution of the control commands across multiple inputs
- Reduction in systems output sensitivity to inward and outward influences.
- Predict explicitly the systems inputs and outputs
- Self-adaptation to adjust to changes in dynamics or environments.
What are 2 main blood supplies to the brain (cerebellum)?
- Anterior circulation arising from internal carotids
- Posterior (vertebrobasilar) circulation arising from subclavian artery
What are 3 things that the vertebrobasilar vascular system?
- Brain stem
- Cerebellum
- Inner ear
What are 6 main branches for posterior circulation?
- Vertebral arteries
- Basilar artery
- Posterior inferior cerebellar artery (PICA)
- Labyrinthine artery
- Anterior inferior cerebellar artery (AICA)
- Superior cerebellar arteries (SCAs)
~ 20% of all TIAs and strokes arise from posterior circulation. Most common symptoms is _____/_____
dizziness/vertigo
What are 4 blood supply of the cerebral cortex?
- Anterior cerebral artery (ACA)
- Middle cerebral artery (MCA)
- Posterior cerebral artery (PCA)
- Anterior circulation CVAs cause light-headedness rather than vertigo
What is the origin for PICA as posterior circulation stroke?
Largest branch of vertebral artery
What are 2 supplies for PICA as posterior circulation stroke?
- Lateral medulla, including vestibular nuclei
- Posteroinferior cerebellum: Inferior cerebellar peduncle, nodulus & uvula
What is the stroke for PICA as posterior circulation stroke?
PICA stroke gives dizziness.
What is the origin for AICA as posterior circulation stroke?
Largest circumferential branches, arising from basilar artery