lecture 15 - motor system 2

Question 1

What are some causes of hypotonia?

Answer 1

Motor neuron disease, polio, guillain-barre, cerebellar disease, muscle disease

Question 2

What are the 3 types/locations of UMN lesions?

Answer 2

cortical, brain stem, spinal cord

Question 3

What are the effects of a cortical UMN lesion?

Answer 3

UMN motor dysfunction, language/perceptual/cognitive dysfunction

Question 4

What are the effects of a brain stem UMN lesion?

Answer 4

UMN motor dysfunction, cranial nerve deficits

Question 5

What are the effects of a spinal cord UMN lesion?

Answer 5

UMN motor dysfunction, sensory pathway disruption

Question 6

What are the key components of the basal ganglia?

Answer 6

internal capsule, striatum (caudate + putamen), globus pallidus,

Question 7

What are the motor functions of the basal ganglia?

Answer 7

helps motor cortex select appropriate motor neurons for voluntary movement

Question 8

What structure in the brain stem inhibits the basal ganglia, and via what neurotransmitter?

Answer 8

The susbtantia nigra, via dopamine

Question 9

What are some examples of disorders of basal ganglia motor function?

Answer 9

Parkinson’s disease, Huntington’s disease

Question 10

What is the typical age of onset of Parkinson’s disease?

Answer 10

45-70

Question 11

What are the 5 key symptoms of Parkinson’s disease?

Answer 11

TRAPS:
Tremor (pill rolling)
Rigidity (lead pipe, cogwheel)
Akinesia/Bradykinesia (no/slow movement)
Postural Instability (forward leaning posture)
Shuffling Gait

Question 12

What is the difference between a tremor in Parkinson’s vs a tremor from cerebellar dysfunction?

Answer 12

Parkinson’s tremor is present at rest, while in cerebellar dysfunction there is an intention tremor (tremor while trying to execute a function)

Question 13

What is the rigidity symptom in Parkinson’s disease?

Answer 13

Sustained resistance to passive movements

Question 14

What is the pathophysiology of Parkinson’s disease?

Answer 14

Death of dopaminonergic neurons in the substantia nigra, which lowers normal feedback to the striatum of the basal ganglia which is needed to contol voluntary movements.

Question 15

What are the key drugs used in Parkinsons’ treatment?

Answer 15

Levo-dopa, Selegiline, Carbidopa

Question 16

What is the mechanism of action of L-dopa for Parkinson’s disease?

Answer 16

Is a precursor of dopamine, which crosses the BBB and becomes dopamine, replacing levels lost in Parkinsons

Question 17

What is Huntington’s Disease?

Answer 17

An autosomal dominant neurodegenerative condition causing progressive death of neurons in the basal ganglia (caudate/putamen)

Question 18

What is the pattern of inheritance of Huntington’s disease?

Answer 18

Autosomal dominant, worsening with increasing CAG triplets on the Huntingtin gene with successive generations

Question 19

What are the symptoms of Huntington’s disease?

Answer 19

Chorea (excessive, random movements), dementia, agitiation, mania, paranoia, eventually loss of all voluntary movement

Question 20

What are the 3 regions of the cerebellum?

Answer 20

Spinocerebellum, cerebrocerebellum, vestibulocerebellum

Question 21

What does the spinocerebellar tract connect, and what information does it carry?

Answer 21

connects spinal cord with ipsilateral cerebellum, carrying afferent proprioceptive information from the body to assist in movement and posture of the trunks and limbs

Question 22

What does the cerebro/cortico cerebellar tract connect, and what information does it carry?

Answer 22

connects the cerebral cortex with the cerebellum, carrying efferent information for planning and integrating motor commands

Question 23

What does the vestibulocerebellar tract connect, and what information does it carry?

Answer 23

Connects the vestibular nerve to the cerebellum. Carries information for balance and eye movement.

Question 24

What are some of the general signs of cerebellar dysfunction?

Answer 24

Ataxia, hypotonia, intention tremor, gait abnormalities (staggering/lurching), nystagmus/double vision, dysdiadokinesia (inability to perform rapid alternating movements), dysmetria

Question 25

What are the key functions of the cerebellum?

Answer 25

Planning movements, motor learning