Cerebellar Lesions

Question 1

What does vermis control?

Answer 1

Midline of the body;

Lesion => truncal ataxia

Question 2

What do hemispheres control?

Answer 2

Distal musculature movement and planning;

Lesion => intention tremor

Question 3

Which pathways lay in cerebellar peduncles?

Answer 3

ICP and MCP - input to the cerebellum

SCP - output from the cerebellum

Question 4

How does cerebellum work?

Answer 4

Excitatory innervation (glutamate) -> Purkinje cells -> inhibitory innervation (GABA) -> deep nuclei inhibit UMN -> smooth muscle action

Question 5

Why do cerebellar diseases are ipsilateral?

Answer 5

Because of a double cross in the cerebellar pathway

Question 6

What are the symptoms of cerebellar hemispheres lesion?

Answer 6

• intention tremor
• dysmetria (past pointing) is the inability to stop a movement at the proper place. The patient has difficulty performing the finger-to-nose test
• dysdiadochokinesia (adiadochokinesia) is the reduced ability to perform alternating movements, such as pronation and supination of the forearm, at a moderately quick pace
• scanning dysarthria (asynergy of the muscles responsible for speech)
• Gaze dysfunction (+- nystagmus to the side of lesion)

Question 7

What are the symptoms of cerebellar vermis lesion?

Answer 7

difficulty maintaining posture, gait, or balance (an

ataxic gait

Question 8

How to distinguish cerebellar vermis lesion from the dorsal columns lesion?

Answer 8

Lesion to dorsal columns => + Romberg sign only with closed eyes (cerebellum can SEE, where the body is)
Lesion to cerebellar vermis => + Romberg sign wih closed and opened eyes