8. Motor Disorders

Question 1

What are the three motor tracts?

Answer 1

Pyramidal - corticospinal and corticobulbar tracts; and extrapyramidal.

Question 2

Where is the cerebellum located?

Answer 2

Posterior cranial fossa.

Question 3

How is the cerebellum separated from the occipital and parietal lobes?

Answer 3

By the tenorium cerebelli.

Question 4

How is the cerebellum separated from the pons?

Answer 4

By the 4th ventricle.

Question 5

What does the cerebellum consist of?

Answer 5

Vermis and two lateral hemispheres.

Question 6

What is the role of the vermis of the cerebellum?

Answer 6

Regulate trunk musculature.

Question 7

What is the role of the lateral cerebellar hemispheres?

Answer 7

Regulate distal structures.

Question 8

How does the cerebellum communicate with the brainstem?

Answer 8

Via cerebellar peduncles - superior cerebellar peduncle attaches to midbrain, middle to pons, and inferior to medulla.

Question 9

What presentation would a midline cerebellar lesion cause?

Answer 9

Truncal ataxia and abnormal gait.

Question 10

What presentation would extension of a midline cerebellar lesion cause?

Answer 10

Truncal ataxia and abnormal gait along with 4th cranial nerve lesions, ipsilateral arm tremors, compression of 4th ventricle - hydrocephalus.

Question 11

Which side do cerebellar hemisphere lesions cause symptoms on?

Answer 11

Ipsilateral.

Question 12

What are the symptoms of cerebellar lesions?

Answer 12

DANISH - dysdiadochokinesia, ataxia, nystagmus, intention tremor, scanning dysarthria, heel-shin test positive.

Question 13

What are the structures in the basal ganglia?

Answer 13

Caudate, lentiform nucleus (putamen, globus pallidus externa, globus pallidus interna), substantia nigra (pars compacta and pars reticularis).

Question 14

What is the role of the basal ganglia?

Answer 14

Stimulates motor activity in the cerebral cortex.

Question 15

Where are dopaminergic neurones found?

Answer 15

Substantia nigra pars compacta.

Question 16

What is the overall net effect of direct and indirect pathways in the basal ganglia?

Answer 16

Thalamic stimulation of the motor cortex.

Question 17

What are the effects of basal ganglia disorder?

Answer 17

Abnormal motor control, altered posture, affects muscle tone, dyskinesia.

Question 18

What is Parkinson’s disease?

Answer 18

Chronic, progressive movement disorder due to degeneration of substantia nigra causing a deficiency of dopamine.

Question 19

What are the triad of signs that characterise Parkinson’s?

Answer 19

Bradykinesia, tremor, and rigidity.

Question 20

What are the associated features of Parkinson;s?

Answer 20

Hypophonia, reduced facial expression, micrographia, dementia, depression.

Question 21

What is Huntington’s disease?

Answer 21

Autosomal-dominant, progressive neurodegenerative disorder.

Question 22

When does Huntington’s disease normally start presenting?

Answer 22

30-50 years.

Question 23

What are the symptoms of Huntington’s disease?

Answer 23

Chorea (abnormal movements), dystonia (abnormal tone in trunk), incoordination, cognitive decline, behavioural difficulties.

Question 24

What cell changes are associated with Huntington’s disease?

Answer 24

Cell loss in basal ganglia and cortex.