Movement Disorders

Question 1

What is the process of movement?

Answer 1

-Planning to initiating to executing movement
-Idea (goal setting)
-Cerebellum (skilled fine tuning) to cortical association areas to basal nuclei (procedural memory)
-Motor cortex
-Spinal cord
=Movement (cerebellum received spinal cord information)

Question 2

What is Apraxia?

Answer 2

Inability to perform purposeful movement despite motivation, and preserved overall neurological function (motor and sensory pathways)
Typically left hemisphere localisation (front and parietal lobes)

Question 3

What is ‘Executive’ apraxia?

Answer 3

Deficit in ‘sequencing’ complex movements SMA & PMA
(supplementary and pre motor areas)

Question 4

What is ‘Posterior’ apraxia?

Answer 4

Deficit in the spatial construction of complex movements PPC (posterior parietal cortex)

Question 5

What are the functional systems in human movement?

Answer 5

• Corticospinal tracts (motor regions of cerebral cortex. brainstem, spinal cord)
• Basal ganglia loop (motor regions of cerebral cortex, thalamus, basal ganglia)
• Cerebellar loop (motor regions of cerebral cortex, thalamus, cerebellum)

Question 6

How can we clinically think about the functional systems in movement?

Answer 6

1. Corticospinal= weakness, spasticity
2. Basal ganglia loop= movement disorders (tone, posture and patterned behaviour)
3. Coordination disorders= cerebellar loop

Question 7

What are the types of movement disorders?

Answer 7

• Hypokinetic= Parkinson’s

- Hyperkinetic= Chorea

Question 8

What are the hypokinetic features?

Answer 8

• Akinesia (lack of movement)
• Hypokinesia (reduced amplitude of movements)
• Bradykinesia (slow movement)
• Rigidity (change in tone)

Question 9

What are the three patterns of increased tone?

Answer 9

-Spasticity
=‘Clasp knife’ (attempting to open a pen knife, max stiffness at start and end), CST (corticospinal) pathology, ‘Pyramidal tract disorder’ (UMN) sign, deep tendon reflex primed to contract with no descending inhibition 
-Rigidity
=‘Lead pipe’ (throughout range of movement), BG pathology, ‘Extrapyramidal disorder’ sign
-Paratonia/ Gegenhalten
=Voluntary resistance
, Executive system pathology
Typically seen in delirium / dementia

Question 10

What are the UMN signs of increased tone?

Answer 10

spasticity, brisk reflexes, pyramidal pattern weakness (large muscles well preserved, stronger flexors in arms and vice versa in legs)

Question 11

What are the extra-pyramidal signs of increased signs?

Answer 11

rigidity, tremor (normal reflexes, no weakness)

Question 12

What is IDP?

Answer 12

Idiopathic Parkinson’s Disease

• Archetypal hypokinetic movement disorder
• A lack of dopamine supply to the basal ganglia
• Dopamine made in midbrain in substantia nigra projects to basal ganglia
• Accumulate alpha-synucleinopathy protein

Question 13

What are the core clinical features (motor) of IDP?

Answer 13

Bradykinesia
Rigidity
Tremor
Postural instability
\+ ‘non-motor’
F:M = 1:2
Peak incidence in 80s

Question 14

What is the role of dopamine in the basal ganglia??

Answer 14

BG structure receive signals from, and project to, the motor cortex
2 key pathways stimulated by dopamine
-Direct pathway
The “accelerator”: pro-movement
D2 receptors
-Indirect pathway
The “brake”: anti-movement
D1 receptors

Question 15

What occurs with dopamine pathways in Parkinson’s?

Answer 15

Reduction in supply of dopamine from the substantia nigra to striatum

• Normally a balance in pathways
• Parkinson’s= reduction in direct pathway, increase in indirect pathway: hypokinesia

Question 16

What are the core treatments for Parkinson’s Disease?

Answer 16

Replacement of dopamine

-Provision of Levo-DOPA plus DOPA decarboxylase inhibitor so converted into dopamine only in the CNS

Question 17

What are the hyperkinetic disorder features?

Answer 17

Jerky movements= tremor (rhythmic between agonist and antagonist muscle pairs), chorea (dance), tics (brief contractions partially suppressible with conscious control)
Non-jerky movements= dystonia (writer’s cramp), myoclonus (brief twitches), stereotypies (patterned behaviours)

Question 18

What are the different types of tremor and what do they indicate?

Answer 18

Moment of occurrence
-At rest= extra pyramidal, Parkinson’s
-With action
=Postural so extended upper limbs and tremor of hands (physiological and caffeine, essential)
=Simple kinetic so maximally throughout range of movement (essential tremor)
=Intention so worst towards end of movement (cerebellar ataxia, problems with fine tuning)
=Task specific (dystonic writing tremor)

Question 19

What are the cerebellar disorders?

Answer 19

Vertigo
Ataxia
Nystagmus
Intention tremor
Slurred (global)/ Staccato (patchy pathology, scarring in pathways from MS or strokes) speech
Hypotonia
Dysdiadochokinesis (problems with rapid alternating movement)

Question 20

What is limb-kinetic apraxia?

Answer 20

• Impairment of fine finger control
• Awkward hand and arm
• Pre-frontal cortex affecting supplementary motor areas

Question 21

What is speech apraxia?

Answer 21

Slow and incoordination of speech in presence of normal language

Question 22

What is ideational apraxia?

Answer 22

• Left parietal lobe injury

- Failure to know how to perform a complex movement

Question 23

What is ideomotor apraxia?

Answer 23

• Inability to conceptualize an action – the plan is intact, but the motor programs are defective
• Injury to left intraparietal sulcus