Session 6 - Motor Disorders

Question 1

Where is the cerebellum located?

Answer 1

Posterior cranial fossa at the back of the brain.

Question 2

The cerebellum is important in what functions?

Answer 2

Motor control

Coordination

Question 3

What separates the cerebellum from the occipital and parietal lobes?

Answer 3

Tentorium cerebelli

Question 4

The cerebellum communicates with the brainstem via what?

Answer 4

The cerebellar peduncles.

Superior cerebellar peduncle attaches the cerebellum to the midbrain.
Middle cerebellar peduncle attaches the cerebellum to the pons.
Inferior cerebellar peduncle attaches the cerebellum to the medulla.

Question 5

The cerebellum communicates with the cortex via what?

Answer 5

The thalamus

Question 6

The cerebellum is separated from the pons by what?

Answer 6

The fourth ventricle

Question 7

What does the cerebellum consist of?

Answer 7

Vermis - regulates trunk musculature

Two lateral cerebellar hemispheres - regulate distal structures i.e. limbs

Question 8

Lesions in the midline (vermis) can result in what?

Answer 8

Truncal ataxia
Abnormal gait

Extension of midline lesions can also cause compression of the fourth ventricle leading to hydrocephalus.

Question 9

What are the symptoms of cerebellar disease?

Answer 9

Dysdiadochokinesis 
Ataxia
Nystagmus
Intention tremor
Slurred speech 
Hypotonia

Question 10

What is dysdiadochokinesis?

Answer 10

Inability to perform rapid, alternating movements

Question 11

What is the function of the basal ganglia?

Answer 11

Communicate with the cortex and cerebellum to aid with the initiation of movement.

Question 12

What are the important structures in the basal ganglia?

Answer 12

Caudate nucleus
Putamen
Globus pallidus externa
Globus pallidus interna
Substantia nigra (pars compacta and pars reticularis)
Subthalamic nucleus

Question 13

Which parts of the basal ganglia make up the lentiform nucleus?

Answer 13

Putamen
Globus pallidus externa
Globus pallidus interna

Question 14

Which parts of the basal ganglia make up the striatum?

Answer 14

Putamen and caudate nucleus

Question 15

Is dopamine excitatory or inhibitory?

Answer 15

Can be either excitatory or inhibitory depending on the receptors it acts on.

Question 16

What is the overall net effect of dopamine in the basal ganglia pathways?

Answer 16

Overall net effect of dopamine is motor cortex stimulation via the thalamus.

Question 17

Parkinson’s disease is characterised by a triad of what symptoms?

Answer 17

Bradykinesia
Tremor
Rigidity

Question 18

What is the cause of Parkinson’s disease?

Answer 18

Degeneration of the substantia nigra causes deficiency of dopamine

Question 19

What are the symptoms of Parkinson’s disease?

Answer 19

Cardinal features:
Resting tremor
Bradykinesia
Hypertonia - rigidity

Other associated features:
Shuffling gait
Hypophonia
Reduced facial expression 
Micrographia
Dementia
Depression

Question 20

What sort of disease is Huntington’s disease?

Answer 20

Autosomal-dominant, progressive neurodegenerative disorder

Question 21

What are the symptoms of Huntington’s disease?

Answer 21

Chorea
Dystonia
Incoordination
Cognitive decline
Behavioural difficulties

Question 22

What is the cause of Huntington’s disease?

Answer 22

Associated with cell loss within the striatum.

Question 23

What is chorea?

Answer 23

Jerky involuntary movements, especially affecting the shoulders, hip and face.

Question 24

What is hemiballismus?

Answer 24

Rare movement disorder resulting in unilateral abnormal movement contralateral to subthalamic nuclei damage. Often secondary to sub-cortical stroke.