11 - Motor Control and Disorders of Action Flashcards
what are the 3 basal ganglia disorders
– Parkinson’s disease
– Huntington’s disease
– Tourette syndrome
whats in the basal ganglia
putamen caudate nucleus thalamus subthalamic nucleus substantia nigra global pallidus
what is the direct pathway in the basal ganglia
allows desired movements to occur
what is the indirect pathway
prevents undesired movement occurring
MUST LOOK AT POWERPOINT
LOOK AT POWERPOINT
parkinsons
underactive direct pathway
overactive indirect pathway
both lead to increased inhibiion of the thalamus and reduced excitation of the cortex
slower and shorter movements
treatment for parkinsons
L-dopa
lesions and deep brain simulation - surgery
whats the problem with L-dopa
drug induced dyskinesias
extra undesired movements
what is deep brain stimulation
pacemaker in chest - position an electrode targetting basal ganglia switch of targetted cells
Battery-operated stimulator delivers electrical stimulation to targeted areas
• Targets - thalamus, subthalamic nucleus, and globuspallidus
what does deep brain stimulation do
reduces effect of indirect pathway
reduced activity in the sub thalamic nucleus
greater excitation of motor cortex
is there treatment for huntingtons
no
is there treatment for huntingtons
no
huntingtons
inherited, autosomal dominant condition • Onset in 30’s or 40’s
• Chorea – uncontrolled movements
• Degeneration of putamen and caudate
huntingtons brain
enlarged lateral ventricles
cortical degeneration
HD and basal ganglia
underactivity of indirect pathway
too much movement
cognitive impairments of HD
- Attention
- Executive function
- Speed of processing
- Prospective memory
- Emotion recognition
Tourette
- Simple tics e.g. eye blinking, nose twitching
- Complex tics e.g. scratching, gestures, utterances
- May increase during times of stress and decrease when concentrating
Tourette syndrome
Tourette Syndrome
• >1000 per 100,000 children (greater than 1 in 1000)
• Hereditary
• Links to obsessive-compulsive behaviours
• Developmental
TS and basal ganglia
increased dopamine from substantia nigra
overactivity of direct pathway - disinhibition of an unwanted movement
opposite of Parkinson’s
TS - aberrant selection
aberrant focus of activity in striatum leads to activity in direct pathway
disinhibition of undesired movement
may also explain obsessive compulsive behaviours
dopamine overactivity
basal ganglua - direct pathway - excitatory
underactive
basal ganglua - indirect pathway - inhibitory
overactive - slow movement
huntingtons disease - indirect pathway
underactive
tourette - direct
overactive - allowing tics
Moving and the Environment in PD • Detrimental - ‘Freezing’ – edges of doorway • Beneficial - Paradoxical movement • Internal v. external movements • Cueing of movement usedtherapeutically
Could observing actions be more effective at driving movement?
- Viewing a reaching movement facilitates own reach (Castiello et al., 2009)
- Action observation and physiotherapy helpful for freezing (Pelosin et al., 2010)
Action Observation plus Motor Imagery (AO+MI)
Action Observation plus Motor Imagery (AO+MI)
• MI or attention instructions produced greater vertical amplitude (height) in healthy young participants
Also boosted imitation of amplitude in people with Parkinson’s
Focus Group: potential intervention
Focus Group: potential intervention
• Examples of observation/imitation in daily life: – Gym/yoga/exercise class, when walking
• Examples of movement imagery: getting out of bed
• Range of actions to train: using mouse, brushing teeth, folding laundry, turning pages
• Importance of choice/personalisation
• Motivation
