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15 Cards in this Set
- Front
- Back
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What are signs of a cerebellar lesion?
What are NOT signs of a cerebellar lesion? |
Signs:
ATAXIA (poor coordination, disruption of timing/spatial accuracy; IPSIlateral to lsn) -dysmetria (overshooting/past-pointing) -Slowness initiating/terminating movement DYSDIADOKOKINESIS-can't flip hands back and forth rhythmically -drunken gait -explosive, staccato, "scanning" speech -Megalographia (really big handwriting) NOT signs: Paralysis Rigidity Obvious dyskinesia -Deficit in conscious sensation -Reduction in muscle strength |
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What is dysdiadokokinesis?
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Can't flip hands back and forth rhythmically
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Possible effects of a cerebellar hemorrhage?
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Compression of brainstem and fourth ventricle
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PICA branches from?
AICA? |
PICA: vertebral aa
AICA: basilar a |
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What structures can a cerebellar pontine angle tumor involve?
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CN V, VII, VIII
VI if it's big enough Cerebellum Pons |
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Input and output of dentate nucleus.
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cerebrocerebellum-->dentate nuc-->primary motor cortex, VL nuc of thalamus (coordination of fine movement)
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Input and output of interpositus nucleus.
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Intermed zone-->interpositus nuc-->red nuc and lateral BS
(flexure of upper extremitites) |
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Input and output of fastigial nucleus.
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Vermis-->fastigial-->ventro-medial BS PW
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Input and output of vestibular nucleus.
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Vestibulo-cerebellum-->vestibular nuc-->ventro-medial BS PW
(oldest) |
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If the cerebellum has ipsilateral motor output, and the cortex has contralateral motor output, how are the two reconciled?
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Cortical fibers decussate within pons before entering cerebellum and synapsing on dentate nuc.
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What is the effect of increased cortical output on the cerebellum? On the Deep cerebellar nuclei?
How does the cerebellum respond? |
Cortical output-->excited cerebellum and deep nuc
Deep nuc excites cortex Cerebellum (via Purkinje fibers) inhibits deep nuc (thus decreased activation of cortex) This allows for moderation of motor signals (fine tuning!) |
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What is the effect of reduced cerebellar output?
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Reduced motor neuron excitability-->HYPOTONIA
can also get errors of timing/space/coordination (dysmetria, ataxia) |
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Most cerebellar neurons are ____________
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GABAergic (inhibitory)
Purkinje cells are output and inhibitory |
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What class is neuron is most prevalent in the cerebellum?
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Granule Cells
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Which cerebellar neurons play a role in plasticity and learning?
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Mossy and Climbing fibers (input!)
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