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8 Cards in this Set
- Front
- Back
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What are the symptoms of cerebellar lesions? |
1. Disturbance in muscle tone 2. Slowness in contractions & relaxations 3. Ataxia - Decomposition of movement, dysmetria, tremor 4. Adiadochokinesis 5. Akinetics (Disturbances of stance, gait & eye movement) |
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What is Adiadochokinesis? |
A variation of ataxia. No longer able to carry out rapid alternating movements such as supination & pronation, flexion & extension. |
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How described symptoms of gunshot wounds and what were they? |
Holmes, 1917 1. Disturbance of muscle tone on ipsilesional side (hypotonia) 2. Slowness in contraction & relaxation (ability to generate & reduce force is still present but change in development of force is much slower) 3. Ataxia (decomposition of movement - no longer continuous, dysmetrias, tremor) 4. Adiadochokinesis |
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What does cooling of dentate and interposed nuclei cause? |
Ataxia 1. Disruption of agonist-antagonist coordination 2. Elimination of information flow as APs cease 3. Hand-arm movements are less reliable, less precise & not as fast 4. Disorganized & uncoordinated muscle activity (seen in EMG profile) 5. Not only affects hand-arm movements but also gait, running, walking and eye movements |
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What happens after a lesion in human posterior vermis? |
Saccadic dysmetria 1. Eye movements imprecise 2. Gait & stance also disturbed (drunk walk) 3. Hand movements are intact 4. Latency of eye movements much larger First pass eye movement is too small - 100-200ms needed for first correction - Normally, 30-40ms |
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Why are hand movements intact after a posterior vermis lesion? |
Because the area responsible for them is located more laterally |
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What is the cerebellum needed for generally? |
Translating sensory information into motor action execution |
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What did Jenkinson & Glickstein study? What was their interepretation of results? |
Rats jumping a gap 1. Whisker system and information derived from cortical representations of whisker system were manipulated 2. Rat's performance in jumping task (crossing a gap) decreased only when the right cerebellar peduncle was lesioned & ipsilateral whiskers shaved 3. Combination prevented any information reaching the cerebellum at all and animal could not cross the gap Conclusion: Lesions of the cerebellar peduncle (which projects to pontine nuclei) or disrupting sensory input at level of whiskers Disturbs a correct sensory motor integration (leading to reduced gap crossing) |
