Neuropathology of Ataxia

Question 1

4 areas of the brain involved in movement

Answer 1

Higher order neocortical areas
Basal ganglia
Cerebellum
Pyramidal system

Question 2

5 components of the basal ganglia

Answer 2

Caudate
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra

Question 3

PD effect on direct and indirect pathway

Answer 3

Net inhibition of the direct pathway

Net activation of the indirect pathway

Question 4

Alpha-synuclein

Answer 4

Abundantly expressed in the CNS
Localized in the presynaptic terminal and nucleus
Function not clearly defined
Involved in vesicular trafficking and release

Question 5

Huntington’s disease

Answer 5

Autosomal dominant hyperkinetic movement disorder
Progressive
Usually choreiform movement, dementia, and psychiatric disturbances
Initially affects the indirect pathway neurons more severely
From trinucleotide repeat expansion
Can get caudate atrophy and intranuclear occlusions

Question 6

Function of

1. Lateral hemispheres
2. Intermediate hemispheres
3. Vermis
4. Flocculonodular lobe

Answer 6

1. Motor planning for extremities
2. Distal limb coordination
3. Proximal limb and trunk coordination
4. Balance and vestibulo-ocular reflexes

Question 7

Cerebellar alcoholic degeneration

Answer 7

Frequent cause of chronic cerebellar degeneration
Affects predominantly the anterior vermis (superior) with relative sparing of cerebellar hemispheres
Clinically characterized by truncal ataxia and slurred speech

Question 8

Sensory ataxia

Answer 8

Due to loss of spinal cord inputs to the cerebellum and thalamus
Clinically associated with impaired position and vibration sense, lost deep tendon reflexes, positive Romberg test