Lecture 19 - Cerebellum

Question 1

Signs of Cerebellar dysfunction can be remembered with the mnemonic DANISH. What do the letters stand for?

Answer 1

Dysdiadochokinesis (flappy hand when turning it over in lap)

Ataxia (wide and wobbly gait, but not rigid and with short strides like in Parkinson’s!)

Nystagmus

Intention tremor (tremor gets worse as they focus on fine movement, like when reaching to touch a pencil –> tremor is worse the closer they get to the pencil)

Scanning speech

Hypotonia

Question 2

Information comes into the Cerebellum through the ______ and ______ Peduncle, and it flows out through the ______ Peduncle.

Specifically, info (mostly proprioceptive) coming from the spinocerebellar track and the Inferior olive come into the Cerebellum via the _____ peduncle. Info coming from the Cortex first enters the _____, then moves through the _____ peduncle into the Cerebellum. Info moves OUT of the Cerebellum from the ______ nucleus, through the _______ peduncle and up to the ______ or _____ Nucleus.

Answer 2

Inferior

Middle

Superior

Inferior

Pons

Middle (largest cerebellar peduncle)

Dentate nucleus

Superior

Thalamus

Red nucleus

Question 3

Describe the control of the following regions of the Cerebellum:

Lateral Heispheres -

Intermediate Hemispheres -

Vermis and Flocculonodular lobe -

Answer 3

Later Hemispheres - Motor Planning for Extremities

Intermediate Hemishpheres - Distal limb coordination

Vermis and Floc - Proximal Limb and Trunk coordination as well as Balance and Vestibulo-ocular reflexes

Question 4

Lesions in the Cerebellum will affect _______ (ipsilateral or contralateral?) movements, while Lesions in the Basal Ganglia will affect _______ movements. Keep in mind the Cerebellum projects to the _____ (fine motor movememnt) aspect of the motor cortex via the Ventral Lateral Thalamus, while the Basal ganglia projects to the _____ (internally initiated movement) and _____ (sensory-input initiated movement) aspects of the motor cortex via the Ventral Anterior Thalamus.

Answer 4

Ipsilateral

Contralateral

M1

M2

PML

Question 5

Keep in mind the ____ ____ is the checkpoint of sorts for information coming into the Cerebellum –> it controls timing and processing.

Answer 5

Inferior Olive

Question 6

Stellate and Basket cells are both Inhibitory cells of the _____ layer of the Cerebellum.

Which one acts on the Dendrites of Purkinje cells and which acts on the Axons of Purkinje cells?

Answer 6

Molecular layer

Stellate –> dendrites

Basket –> axons

Question 7

Golgi cells of the Cerebellum receive Afferent input from _____ fibers (from all over, including the cerebral corticies) –> they act to _____ (inhibit or excite?) Granular cells of the Cerebellum –> What would this mean for action of the Purkinge cells?

Answer 7

Mossy fibers

Inhibit

This would Decrease the activity and thus Inhibitory effect of Purkinje cells –> increased activity of the deep cerebellar nuclei.

Also leep in mind Purkinje cells receive input from the Contralateral Olivary Nuclei, which increases Purkinje cell activity, and thus their inhibitory effect.