Basal Ganglia - Shorer

Question 1

What is hypokinesis and what are the different types?

Answer 1

Unable to begin movement at will, or terminate movement, or move precisely
Ex: Parkinsons
Difficulty starting and stopping, difficulty in precision
There is unconscious immediate input to movement
Dystonia
Slow, prolonged, abnormal, purposeless movement is not controlled
Ex: dystonia musculorum deformans
Antiemetic and antipsychotic medication (esp in children) can cause hypokinesis as a side effect.
Wilson’s disease- distal movements

Question 2

What is hyperkinesis and what are the different types?

Answer 2

Chorea- proximal abnormal movement (distal is fine)
Involuntary, purposeless movement from proximal side (shoulders, etc., not fingers), can also be violent, continuous
Expends energy by interfering with movement making imprecise
Different intensity of abnormal movement
Can be genetic (Huntington corea- also dimentia)
What is relatinoship between basal ganglia (movement) and dimentia? There is connection because system interferes with cognition.
In MRI or CT see shrinkage of caudate nucleus.
Due to distruction of caudate nucleus
Post-streptococcal: Sydenham Chorea
In MRI or CT no abnormality seen
Problem is immune system working, crossacting, recognizing basal ganglia cells as abnormal immune and acting against it immunologically-changing dopamine and acetylcholine.
Can treat with antidopaminergic
Hemibalismus
Damage of subthalamic nucleus: severe movement of arm and hand
Violent, rapid, purposeless, in circle

Question 3

What are the components of the pyramidal system?

Answer 3

Corticospinal: Into tract
Corticonuclear: When coming into nucleus in brainstem

Corticobulbar: lower brainstem

Question 4

What is the extrapyramidal system and what are its components? What do they do?

Answer 4

Not part of direct system
Tracts continue to spinal cord but also nerves continue to 2 places:
1. Reticular formation
Tiny bundles of fibers come from reticular formation going down to cerviculate region, important for movements

2. Red nucleus
   -Reticulospinal
   -Rubrospinal tract
   Terminate mainly on cervical part of spinal cord, relay station
   Indirect influence of basal ganglia on SC (in contrast to corticospinal with direct contact)